fix command ptr alignment

Reviewed-on: #15

.gitignore

@@ -1 +1,5 @@
 zig-cache/
+zig-out/
+*.mp3
+*.wav
+build_runner.zig

README.md

@@ -9,20 +9,24 @@ glitch art "framework", ???????? language??? something?
 
 # how do?
 
-## build depedencies:
+## build depedencies (headers included):
  - zig at https://ziglang.org
  - libc, lilv and libsndfile
- - an appreciation for glitched anime girls on your hard drive
  - graphicsmagick for the `rotate` command
+ - readline (for repl)
 
-## plugin depedencies:
- - lv2 default plugins (most specifically the eg-amp plugin)
+## plugin depedencies (only required at runtime):
+ - lv2 default plugins (most specifically the eg-amp plugin,
+    will likely be there by default)
  - the SWH plugins ( https://github.com/swh/lv2 )
  - the Invada Studio plugins ( https://launchpad.net/invada-studio/ )
+ - abGate plugin
+ - MDA plugins
+ - Calf plugins
 
 ```bash
 # build and install
-# assumes lilv headers are at /usr/include/lilv-0, check build.zig if different
+# assumes lilv headers are at /usr/include/lilv-0, edit build.zig if different
 git clone https://gitdab.com/luna/scritcher.git
 cd scritcher
 
@@ -31,9 +35,33 @@ zig build install --prefix ~/.local/
 # on your input image file
 convert blah.jpg blah.bmp
 
+# if you got the lv2 default amp plugin, this is runnable
 scritcher examples/middle_amp.scri blah.bmp
 
+# if not, the noise plugin does not depend on any lv2 plugin.
+scritcher examples/noise.scri blah.bmp
+
 // scritcher saves it on an incremental basis, so the first run will save to
 // blah_g1.bmp, the second saves to blah_g2.bmp, etc.
 $your_image_viewer blah_g1.bmp
 ```
+
+# using the repl
+
+using repl works via `scritcher repl scri_file.scri input_image.bmp`
+
+you type commands as you'd write the specific scritcher commands
+(`doc/README.md`), with four repl-specific ones (semicolons do not apply):
+ - `push`, to push the last written command to the queue
+ - `save`, to write the queue to the given `scri_file.scri` file
+ - `list`, to print the current contents of the queue
+ - `quit`, to exit
+
+After a non-REPL command, such as an effect, the program pointed by
+`SCRITCHER_RUNNER` will run as argument to the `runqs` command. By default,
+the program run will be `ristretto` (as it is my preffered image viewer,
+considering it was able to handle when some images went broke)
+
+this allows for quicker iteration of commands, as you can type a command, see
+the image changes as fast as possible, tweak its arguments,
+and when satisfied, `push` it, and work on the next command, etc.

build.zig

@@ -1,24 +1,73 @@
-const Builder = @import("std").build.Builder;
+const std = @import("std");
 
-pub fn build(b: *Builder) void {
-    const mode = b.standardReleaseOptions();
-    const exe = b.addExecutable("scritcher", "src/main.zig");
-    exe.setBuildMode(mode);
-    exe.install();
+fn setupLinks(step: *std.Build.Step.Compile) void {
+    step.linkSystemLibrary("c");
 
-    exe.linkSystemLibrary("lilv-0");
-    exe.linkSystemLibrary("sndfile");
-    exe.linkSystemLibrary("c");
+    step.linkSystemLibrary("lilv-0");
+    step.linkSystemLibrary("sndfile");
+    step.linkSystemLibrary("readline");
 
-    exe.linkSystemLibrary("GraphicsMagickWand");
-    exe.linkSystemLibrary("GraphicsMagick");
+    step.linkSystemLibrary("GraphicsMagickWand");
+    step.linkSystemLibrary("GraphicsMagick");
 
-    exe.addIncludeDir("/usr/include/lilv-0");
-    exe.addIncludeDir("/usr/include/GraphicsMagick");
+    step.addIncludePath(.{ .path = "/usr/include/GraphicsMagick" });
+    step.addIncludePath(.{ .path = "/usr/include" });
 
-    const run_cmd = exe.run();
-    run_cmd.step.dependOn(b.getInstallStep());
+    const possible_lilv_include_dirs = [_][]const u8{
+        "/usr/include/lilv-0/lilv",
+        "/usr/include/lilv-0",
+    };
+
+    var found_any_lilv = false;
+
+    for (possible_lilv_include_dirs) |possible_lilv_dir| {
+        var possible_dir = std.fs.cwd().openDir(possible_lilv_dir, .{}) catch |err| {
+            std.debug.print("possible lilv {s} fail: {s}\n", .{ possible_lilv_dir, @errorName(err) });
+            continue;
+        };
+
+        possible_dir.close();
+        found_any_lilv = true;
+
+        std.debug.print("found lilv at '{s}'\n", .{possible_lilv_dir});
+        step.addIncludePath(.{ .path = possible_lilv_dir });
+    }
+
+    if (!found_any_lilv) {
+        std.debug.print("No LILV library was found :(\n", .{});
+        @panic("no lilv found");
+    }
+}
+
+pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const exe = b.addExecutable(.{
+        .name = "scritcher",
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+    setupLinks(exe);
+    b.installArtifact(exe);
+
+    const run_cmd = b.addRunArtifact(exe);
+
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
 
     const run_step = b.step("run", "Run the app");
     run_step.dependOn(&run_cmd.step);
+
+    const test_step = b.addTest(.{
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+    setupLinks(test_step);
+    const run_unit_tests = b.addRunArtifact(test_step);
+    const test_cmd = b.step("test", "run unit tests");
+    test_cmd.dependOn(&run_unit_tests.step);
 }

doc/README.md

@@ -23,7 +23,8 @@ where in the file you want the plugin to be ran.
 so, if you did `plugin 3 1...`, it would split the file in 3, then get the
 part that is of index 1 (starting at 0).
 
-**Keep in mind parts start from the bottom of the file.**
+**Keep in mind parts can start from either top or bottom of the image,
+it depends of the file format**
 
 ## `load path_or_arg`
 
@@ -38,8 +39,9 @@ Run the eg-amp plugin over the given slice of the file.
 
 Run the Retro Flanger script from the SWH plugins.
 
- - `delay_depth_avg` is for the `Average stall (ms)` parameter of the plugin.
- - `law_freq` is for the `Flange frequency` parameter of the plugin.
+Parameters:
+ - `delay_depth_avg`: Average stall (ms), 0..10, default 2.5
+ - `law_freq`: Flange frequency (Hz), 0.5..8, default 1
 
 ## `eq split index lo mid hi`
 
@@ -165,6 +167,11 @@ Rotate the image by `deg` degrees, filling the resulting triangles with `bgfill`
 
 `bgfill` is a hex string, e.g `#000000`.
 
+## `embed split index path_to_file`
+
+embed an audio file in the given image. the file is opened with libsndfile,
+which means some formats, like mp3, will not be opened.
+
 ## `quicksave`
 
 Save the file on the same directory of the file specified by `load`, but
@@ -172,3 +179,201 @@ with a suffix on the filename (before extension).
 
 Doing consecutive `quicksave`s will not overwrite any files, the suffixes will
 just be different.
+
+## `gate split index switch threshold attack hold decay gaterange` 
+
+**TODO:** find good parameters
+
+ - switch (bool): 0..1, default 0
+ - threshold (dB): -70..12, default -70
+ - attack (ms): 0.1..500, default 30
+ - hold (ms): 5..3000, default 500
+ - decay (ms): 5..4000, default 1000
+ - gaterange (dB): -90..-20, default -90
+
+## `detune split index detune mix output latency`
+
+> A low-quality stereo pitch shifter for the sort of chorus and detune effects found on multi-effects hardware.
+
+ - detune (cents, left channel is lowered in pitch, right channel is raised): 0..1, default 0.2
+ - mix (wet/dry mix): 0..1, default 0.9
+ - output (level trim): 0..1, default 0.5
+ - latency (trade-off between latency and low-freq response): 0..1, default 0.5
+
+other presets:
+ - stereo detune: 0.2 0.9 0.5 0.5
+ - out of tune: 0.8 0.7 0.5 0.5
+
+
+## `overdrive split index drive muffle output`
+
+> Possible uses include adding body to drum loops, fuzz guitar, and that 'standing outside a nightclub' sound. This plug does not simulate valve distortion, and any attempt to process organ sounds through it will be extremely unrewarding!
+
+ - drive (amount of distortion): 0..1, default 0
+ - muffle (gentle low-pass filter): 0..1, default 0
+ - output (level trim): 0..1, default 0.5
+
+## `degrade split index headroom quant rate post_filt non_lin output`
+
+> Sample quality reduction
+
+**NOTE:** finding the right parameters is HARD for this plugin.
+
+ - headroom (peak clipping threshold): 0..1, default 0.8
+ - quant (bit depth, typically 8 or below for "telephone" quality): 0..1, default 0.5
+ - rate (sample rate): 0..1, default 0.65
+ - post_filt (low-pass filter to muffle the distortion): 0..1, default 0.9
+ - non_lin (additional harmonic distortion "thickening"): 0..1, default 0.58
+ - output: 0..1, default 0.5
+
+## `repsycho split index tune fine decay thresh hold mix quality`
+
+**NOTE:** HARD to find good parameters
+
+ - tune (coarse tune, semitones): 0..1, default 1
+ - fine (fine tune, cents): 0..1, default 1
+ - decay (adjust envelope of each trunk, a fast decay can be useful while setting up): 0..1, default 0.5
+ - thresh (trigger level to divide the input into chunks): 0..1, default 0.6
+ - hold (minimum chunk length): 0..1, default 0.45
+ - mix (mix original signal with output): 0..1, default 1
+ - quality (quality, bool. the high=1 setting uses smoother pitch-shifting and allows stereo): 0..1, default 0
+
+## `talkbox split index wet dry carrier quality`
+
+> High resolution vocoder
+
+ - wet: 0..1, default 0.5
+ - dry: 0..1, default 0
+ - carrier: 0..1, default 0
+ - quality: 0..1, default 1
+
+## `dyncomp split index enable hold inputgain threshold ratio attack release gain_min gain_max rms`
+
+ - enable (bool): 0..1, default 1
+ - hold (bool): 0..1, default 0
+ - inputgain (dB): -10..30, default 0
+ - threshold (dB): -50..-10, default -30
+ - ratio (???): 0..1, default 0
+ - attack (seconds): 0.001..0.1, default 0.01
+ - release (seconds): 0.03..3.0, default 0.3
+ - gain\_min (dB): -20..40
+ - gain\_max (dB): -20..40
+ - rms (signal level, dB): -80..10
+ 
+## `thruzero split index rate mix feedback depth_mod`
+
+> Tape flanger and ADT
+
+> This plug simulates tape-flanging, where two copies of a signal cancel out completely as the tapes pass each other. It can also be used for other "modulated delay" effects such as phasing and simple chorusing.
+
+ - rate (modulation rate, set to minimum for static comb filtering): 0..1, default 0.3
+ - mix (wet/dry mix, set to 50% for complete cancelling): 0..1, default 0.47
+ - feedback (add positive or negative feedback for harsher or "ringing" sound): 0..1, default 0.3
+ - depth_mod (modulation depth, set to less than 100% to limit build up of low frequencies with feedback): 0..1, default 1
+
+## `foverdrive split index drive`
+
+Fast Overdrive from SWH plugins.
+
+ - drive: 1..3, default 1
+
+## `gverb split index roomsize revtime damping drylevel earlylevel taillevel`
+
+GVerb algorithm from SWH plugins.
+
+ - roomsize (meters): 1..300, default 75.75
+ - revtime (reverb time, seconds): 0.1..30, default 7.575
+ - damping: 0..1, default 0.5
+ - inputbandwidth: 0..1, default 0.75
+ - drylevel (dB): -70..0, default 0
+ - earlylevel (dB): -70..0, default 0
+ - taillevel (dB): -70..0, default -17.5
+
+## `invert split index`
+
+> A utility plugin that inverts the signal, also (wrongly) known as a 180 degree phase shift.
+
+## `tapedelay split index speed da_db t1d t1a_db...`
+
+**TODO:** gives 0 output
+
+> Correctly models the tape motion and some of the smear effect, there is no simulation fo the head saturation yet, as I don't have a good model of it. When I get one I will add it.
+
+> The way the tape accelerates and decelerates gives a nicer delay effect for many purposes.
+
+ - speed (inches/sec, 1=normal): 0..10, default 1
+ - da\_db (dry level, dB): -90..0, default -90
+ - t1d (tap 1 distance, inches): 0..4, default 0
+ - t1a\_db (tap 1 level, dB): -90..0, default 0
+ - t2d (tap 2 distance, inches): 0..4, default 1
+ - t2a\_db (tap 2 level, dB): -90..0, default -90
+ - t3d (tap 3 distance, inches): 0..4, default 2
+ - t3a\_db (tap 3 level, dB): -90..0, default -90
+ - t4d (tap 4 distance, inches): 0..4, default 3
+ - t4a\_db (tap 4 level, dB): -90..0, default -90
+
+## `moddelay split index base`
+
+> A delay whose tap can be modulated at audio rate.
+
+ - base (base delay, seconds): 0..1, default 1
+
+## `multichorus split index min_delay mod_depth mod_rate stereo voices vphase amount dry freq freq2 q overlap level_in level_out lfo`
+
+Calf Multi Chorus
+
+ - `min_delay` (ms): 0.1..10, default 5
+ - `mod_depth` (ms): 0.1..10, default 6
+ - `mod_rate` (hz): 0.1..20, default 0.1
+ - `stereo` (degrees): 0..360, default 180
+ - `voices`: 1..8, default 4
+ - `vphase` (inter-voice phase, degrees): 0..360, default 64
+ - `amount`: 0..4, default 0.5
+ - `dry`: 0..4, default 0.5
+ - `freq` (center frq 1, hz): 10..20000, default 100
+ - `freq2` (center frq 2, hz): 10..20000, default 5000
+ - `q` (???): 0.125..8, default 0.125
+ - `overlap`: 0..1, default 0.75
+ - `level_in` (Input Gain): 0.0156250..64, default 1
+ - `level_out` (Output Gain): 0.0156250..64, default 1
+ - `lfo` (toggle): 0..1, default 1
+
+## `saturator split index bypass level_in level_out mix drive blend lp_pre_freq hp_pre_fre lp_post_freq hp_post_freq p_freq p_level p_q pre post`
+
+ - `bypass` (toggle): 0..1, default 0
+ - `level_in` (Input Gain): 0.0156250..64, default 1
+ - `level_out` (Output Gain): 0.0156250..64, default 1
+ - `mix`: 0..1, default 1
+ - `drive` (saturation, coef): 0.1..10, default 5
+ - `blend` (coef): -10..10, default 10
+ - `lp_pre_freq` (lowpass, hz): 10..20000, default 20000
+ - `hp_pre_freq` (highpass, hz): 10..20000, default 10
+ - `lp_post_freq` (lowpass, hz): 10..20000, default 20000
+ - `hp_post_freq` (highpass, hz): 10..20000, default 10
+ - `p_freq` (Tone, hz): 80..8000, default 2000
+ - `p_level` (Amount): 0.0625..16, default 1
+ - `p_q` (???, coef): 0.1..10, default 1
+ - `pre` (Activate Pre, toggle): 0..1, default 0
+ - `post` (Activate Post, toggle): 0..1, default 0
+
+## `vintagedelay split index ...`
+
+ - `level_in` (Input Gain): 0.0156250..64, default 1
+ - `level_out` (Output Gain): 0.0156250..64, default 1
+ - `subdiv` (int): 1..16, default 4
+ - `time_l` (int): 1..16, default 3
+ - `time_r` (int): 1..16, default 5
+ - `feedback`: 0..1, default 0.5
+ - `amount` (Wet): 0..4, default 0.25
+ - `mix_mode` (enum): Stereo=0, Ping-Pong=1, L then R=2, R then L=3, default 1
+ - `medium` (enum): Plain=0, Tape=1, Old Tape=2, default 1
+ - `dry` (dry): 0..4, default 1
+ - `width` (stereo width, strict): -1..1, default 1
+ - `fragmentation` (enum): Repeating=0, Pattern=1, default 0
+ - `pbeats` (Pattern Beats, int): 1..8, default 4
+ - `pfrag` (Pattern Fragmentation, int): 1..8, default 4
+ - `timing` (enum): BPM=0, ms=1, Hz=2, Sync=3, default 0
+ - `bpm`: 30..300, default 120
+ - `ms` (int): 10..2000, default 500
+ - `hz`: 0.01..100, default 2
+ - `bpm_host` (strict): 1..300, default 120

examples/degrade.scri

@@ -0,0 +1,8 @@
+load :0;
+degrade 8 1 0.8 0.5 0.65 0.9 0.58 0.5;
+degrade 8 2 0.1 1 0.65 0.5 0.5 0.4;
+degrade 8 3 0.1 1 0.65 0.9 0.58 0.5;
+degrade 8 4 0 1 1 0 0 1;
+degrade 8 5 0 1 1 0 0 0;
+degrade 8 6 0 0 0 0 0 0;
+quicksave;

examples/detune.scri

@@ -0,0 +1,3 @@
+load :0;
+detune 3 1 0.2 0.9 0.5 0.5;
+quicksave;

examples/dyncomp.scri

@@ -0,0 +1,3 @@
+load :0;
+dyncomp 3 1 1 0 0 -30 0 0.01 0.3 0 0 0;
+quicksave;

examples/embed.scri

@@ -0,0 +1,3 @@
+load :0;
+embed 3 1 ./file.wav;
+quicksave;

examples/foverdrive.scri

@@ -0,0 +1,3 @@
+load :0;
+foverdrive 3 1 100;
+quicksave;

examples/gate.scri

@@ -0,0 +1,3 @@
+load :0;
+gate 3 1 0 -70 30 500 1000 -90;
+quicksave;

examples/gverb.scri

@@ -0,0 +1,3 @@
+load :0;
+gverb 3 1 75.75 7.575 0.5 0.75 0 0 -17.5;
+quicksave;

examples/invert.scri

@@ -0,0 +1,3 @@
+load :0;
+invert 3 1;
+quicksave;

examples/mbeq.scri

@@ -1,3 +1,3 @@
 load :0;
-mbeq 3 1 1 4 0.2 2.1;
+mbeq 3 1 0 0 0 0.3 0 0 7 0 0 0 0 0 0.1 0 0;
 quicksave;

examples/moddelay.scri

@@ -0,0 +1,3 @@
+load :0;
+moddelay 3 1 1;
+quicksave;

examples/multichorus.scri

@@ -0,0 +1,3 @@
+load :0;
+multichorus 3 1 5 6 0.1 180 4 64 0.5 0.5 100 5000 0.125 0.75 1 1 1;
+quicksave;

examples/overdrive.scri

@@ -0,0 +1,5 @@
+load :0;
+overdrive 5 1 0.5 0 0.4;
+overdrive 5 2 0.6 0.2 0.3;
+overdrive 5 3 0.7 0.3 0.2;
+quicksave;

examples/repsycho.scri

@@ -0,0 +1,8 @@
+load :0;
+repsycho 8 1 1 1 0.5 0.6 0.45 1 0;
+repsycho 8 2 1 1 1 0.6 0.45 1 0;
+repsycho 8 3 1 1 0.5 0.8 0.45 1 0;
+repsycho 8 4 1 1 0.5 0.6 0.1 1 0;
+repsycho 8 5 1 1 0.5 0.6 0.45 0.5 0;
+repsycho 8 6 1 1 0.5 0.6 0.45 1 1;
+quicksave;

examples/rflanger.scri

@@ -0,0 +1,3 @@
+load :0;
+rflanger 3 1 2.5 1;
+quicksave;

examples/saturator.scri

@@ -0,0 +1,3 @@
+load :0;
+saturator 3 1 0 1 1 1 5 10 20000 10 20000 10 2000 1 1 0 0;
+quicksave;

examples/talkbox.scri

@@ -0,0 +1,3 @@
+load :0;
+talkbox 3 1 0.5 0 0 1;
+quicksave;

examples/tapedelay.scri

@@ -0,0 +1,3 @@
+load :0;
+tapedelay 3 1 1 -90 0 0 1 -90 2 -90 3 -90;
+quicksave;

examples/thruzero.scri

@@ -0,0 +1,3 @@
+load :0;
+thruzero 3 1 0.3 0.47 0.3 1;
+quicksave;

examples/vintagedelay.scri

@@ -0,0 +1,3 @@
+load :0;
+vintagedelay 3 1 1 1 4 3 5 0.5 0.25 1 1 1 1 0 4 4 0 120 500 2 120;
+quicksave;

examples/write.scri

@@ -0,0 +1,3 @@
+load :0;
+write 3 1 1;
+quicksave;

src/bmp_valid.zig

@@ -0,0 +1,25 @@
+const std = @import("std");
+const log = std.log.scoped(.scritcher_bmp);
+pub const BMPValidError = error{InvalidMagic};
+
+const VALID_MAGICS = [_][]const u8{
+    "BM",
+    "BA",
+    "CI",
+    "CP",
+    "IC",
+    "PT",
+};
+
+pub fn magicValid(magic: []const u8) !void {
+    var valid = false;
+
+    for (VALID_MAGICS) |valid_magic| {
+        if (std.mem.eql(u8, magic, valid_magic)) valid = true;
+    }
+
+    if (!valid) {
+        log.debug("\tINVALID HEADER: '{s}'", .{magic});
+        return BMPValidError.InvalidMagic;
+    }
+}

src/custom.zig

@@ -2,74 +2,78 @@
 const std = @import("std");
 const lv2 = @import("lv2_helpers.zig");
 const plugins = @import("plugin.zig");
+const image = @import("image.zig");
 
+const log = std.log.scoped(.scritcher_custom);
 const c = lv2.c;
 
 const RunBuffers = plugins.RunBuffers;
 
 pub const RandomNoise = struct {
     r: std.rand.DefaultPrng,
-    rand_buf: ?[]f32,
+    rand_buf: ?[]f32 = null,
+    allocator: ?std.mem.Allocator = null,
     cnt: usize = 0,
 
     pub fn init(
-        allocator: *std.mem.Allocator,
-        params: *plugins.ParamMap,
-    ) !RandomNoise {
-        const seed = @floatToInt(u64, params.get("seed").?.value);
-        const fillbytes = @floatToInt(usize, params.get("fill_bytes").?.value);
+        allocator: std.mem.Allocator,
+        params: anytype,
+    ) ?RandomNoise {
+        var r = std.rand.DefaultPrng.init(params.seed);
 
-        var r = std.rand.DefaultPrng.init(seed);
+        if (params.fill_bytes > 0) {
+            var rand_buf = allocator.alloc(f32, params.fill_bytes) catch return null;
 
-        if (fillbytes > 0) {
-            var rand_buf = try allocator.alloc(f32, fillbytes);
-
-            for (rand_buf) |_, idx| {
-                rand_buf[idx] = r.random.float(f32);
+            for (rand_buf, 0..) |_, idx| {
+                rand_buf[idx] = r.random().float(f32);
             }
 
             return RandomNoise{
                 .r = r,
+                .allocator = allocator,
                 .rand_buf = rand_buf,
             };
         } else {
             return RandomNoise{
                 .r = r,
-                .rand_buf = null,
             };
         }
     }
 
+    pub fn deinit(self: *RandomNoise) void {
+        if (self.allocator == null) return;
+        if (self.rand_buf == null) return;
+        self.allocator.?.free(self.rand_buf.?);
+    }
+
     pub fn run(self: *RandomNoise, bufs: *RunBuffers) void {
         if (self.rand_buf) |rand_buf| {
             if (self.cnt >= rand_buf.len) self.cnt = 0;
             bufs.out[0] = rand_buf[self.cnt];
             self.cnt += 1;
         } else {
-            bufs.out[0] = self.r.random.float(f32);
+            bufs.out[0] = self.r.random().float(f32);
         }
     }
 };
 
 pub const WildNoise = struct {
     r: std.rand.DefaultPrng,
-    rand_buf: ?[]f32,
+    rand_buf: ?[]f32 = null,
+    allocator: ?std.mem.Allocator = null,
     cnt: usize = 0,
 
     pub fn init(
-        allocator: *std.mem.Allocator,
-        params: *plugins.ParamMap,
-    ) !WildNoise {
-        const seed = @floatToInt(u64, params.get("seed").?.value);
-        const fillbytes = @floatToInt(usize, params.get("fill_bytes").?.value);
+        allocator: std.mem.Allocator,
+        params: anytype,
+    ) ?WildNoise {
+        var r = std.rand.DefaultPrng.init(params.seed);
 
-        var r = std.rand.DefaultPrng.init(seed);
+        if (params.fill_bytes > 0) {
+            var rand_buf = allocator.alloc(f32, params.fill_bytes) catch return null;
 
-        if (fillbytes > 0) {
-            var rand_buf = try allocator.alloc(f32, fillbytes);
-
-            for (rand_buf) |_, idx| {
-                rand_buf[idx] = @intToFloat(f32, r.random.int(u1));
+            for (rand_buf, 0..) |_, idx| {
+                rand_buf[idx] = @as(f32, @floatFromInt(r.random().int(u1)));
             }
 
             return WildNoise{
@@ -79,18 +83,110 @@ pub const WildNoise = struct {
         } else {
             return WildNoise{
                 .r = r,
-                .rand_buf = null,
             };
         }
     }
 
+    pub fn deinit(self: *WildNoise) void {
+        if (self.allocator == null) return;
+        if (self.rand_buf == null) return;
+        self.allocator.?.free(self.rand_buf.?);
+    }
+
     pub fn run(self: *WildNoise, bufs: *RunBuffers) void {
         if (self.rand_buf) |rand_buf| {
             if (self.cnt >= rand_buf.len) self.cnt = 0;
             bufs.out[0] = rand_buf[self.cnt];
             self.cnt += 1;
         } else {
-            bufs.out[0] = @intToFloat(f32, self.r.random.int(u1));
+            bufs.out[0] = @as(f32, @floatFromInt(self.r.random().int(u1)));
         }
     }
 };
+
+/// Write any float to the image.
+/// Keep in mind that the bit representation of the float will clash with
+/// the format of BMP pixel data, which means writing 0 everywhere won't give
+/// you the black color.
+pub const Write = struct {
+    data: f32,
+
+    pub fn init(
+        allocator: std.mem.Allocator,
+        params: anytype,
+    ) Write {
+        _ = allocator;
+        return Write{
+            .data = params.data,
+        };
+    }
+
+    pub fn deinit(self: *Write) void {
+        _ = self;
+    }
+
+    pub fn run(self: *Write, bufs: *RunBuffers) void {
+        bufs.out[0] = self.data;
+    }
+};
+
+pub const Embed = struct {
+    allocator: std.mem.Allocator,
+    filepath: []const u8,
+
+    sndfile: *c.SNDFILE = undefined,
+    buf: []f32 = undefined,
+
+    pub fn init(allocator: std.mem.Allocator, params: anytype) @This() {
+        return Embed{
+            .allocator = allocator,
+            .filepath = params.path,
+        };
+    }
+
+    pub fn setup(self: *@This()) !void {
+        var in_fmt = c.SF_INFO{
+            .frames = @as(c_int, 0),
+            .samplerate = @as(c_int, 0),
+            .channels = @as(c_int, 0),
+            .format = @as(c_int, 0),
+            .sections = @as(c_int, 0),
+            .seekable = @as(c_int, 0),
+        };
+
+        self.sndfile = try image.sopen(
+            self.allocator,
+            self.filepath,
+            c.SFM_READ,
+            &in_fmt,
+        );
+
+        image.sseek(self.sndfile, 0);
+
+        self.buf = try self.allocator.alloc(f32, @as(usize, @intCast(in_fmt.channels)));
+    }
+
+    pub fn deinit(self: *@This()) void {
+        _ = self;
+    }
+
+    pub fn run(self: *@This(), bufs: *RunBuffers) void {
+        const read_bytes = c.sf_readf_float(self.sndfile, self.buf.ptr, 1);
+
+        if (read_bytes == 0) {
+            bufs.out[0] = bufs.in[0];
+            return;
+        }
+
+        if (read_bytes < 0) {
+            const st: i32 = c.sf_error(self.sndfile);
+            log.debug("Failed to read {s} ({s})", .{
+                self.filepath,
+                c.sf_error_number(st),
+            });
+            return;
+        }
+
+        bufs.out[0] = bufs.in[0] + self.buf[0];
+    }
+};

src/image.zig

@@ -1,14 +1,13 @@
 const std = @import("std");
 const lv2 = @import("lv2_helpers.zig");
 const c = lv2.c;
+const bmp = @import("bmp_valid.zig");
 
+const log = std.log.scoped(.scritcher_image);
 const plugins = @import("plugin.zig");
 
-/// Approximate size of the BMP header.
-pub const BMPHeaderSize: usize = 82000;
-
-/// Buffer size for main copying
-pub const BufferSize: usize = 60000;
+/// Buffer size for main image copying.
+pub const BufferSize: usize = 300000;
 
 pub const ImageError = error{
     OpenFail,
@@ -17,100 +16,113 @@ pub const ImageError = error{
     InvalidSymbol,
     InstantiateFail,
     WriteFail,
+    PluginLoadFail,
 };
 
 /// Low level integration function with libsndfile.
-fn sopen(
-    allocator: *std.mem.Allocator,
+pub fn sopen(
+    allocator: std.mem.Allocator,
     path: []const u8,
     mode: i32,
     fmt: *c.SF_INFO,
 ) !*c.SNDFILE {
-    var cstr_path = try std.cstr.addNullByte(allocator, path);
+    const cstr_path = try allocator.dupeZ(u8, path);
     defer allocator.free(cstr_path);
 
-    var file = c.sf_open(cstr_path.ptr, mode, fmt);
+    const file = c.sf_open(cstr_path.ptr, mode, fmt);
     const st: i32 = c.sf_error(file);
 
     if (st != 0) {
-        std.debug.warn(
-            "Failed to open {} ({})\n",
+        log.debug("Failed to open {s} ({s})", .{
             path,
             c.sf_error_number(st),
-        );
+        });
 
         return ImageError.OpenFail;
     }
 
+    const frames_on_end = c.sf_seek(file, 0, c.SEEK_END);
+    _ = c.sf_seek(file, 0, c.SEEK_SET);
+    try std.testing.expectEqual(fmt.frames, frames_on_end);
+
+    const frames_on_end_by_end = c.sf_seek(file, frames_on_end, c.SEEK_SET);
+    try std.testing.expectEqual(frames_on_end, frames_on_end_by_end);
+
+    log.debug("frames on end: {}, frame on end (2): {}", .{ frames_on_end, frames_on_end_by_end });
+
     return file.?;
 }
 
-fn swrite(file: *c.SNDFILE, buf: [*]f32, frames: i64) !void {
+pub fn swrite(file: *c.SNDFILE, buf: [*]f32, frames: i64) !void {
     const count = c.sf_writef_float(file, buf, frames);
 
     if (count != frames) {
-        std.debug.warn("Wanted to read {}, got {}\n", frames, count);
+        log.debug("Wanted to write {}, got {}", .{ frames, count });
         return ImageError.WriteFail;
     }
 }
 
-fn sseek(file: *c.SNDFILE, offset: usize) void {
-    const frames = c.sf_seek(file, @intCast(i64, offset), c.SEEK_SET);
-    if (frames != @intCast(i64, offset)) {
-        std.debug.warn("failed to seek to {}\n", offset);
+pub fn sseek(file: *c.SNDFILE, offset: usize) void {
+    const offset_i64 = @as(i64, @intCast(offset));
+    const frames = c.sf_seek(file, offset_i64, c.SEEK_SET);
+    const frames_current = c.sf_seek(file, 0, c.SEEK_CUR);
+    std.debug.assert(frames == frames_current);
+
+    if (frames != offset_i64) {
+        log.debug("failed to seek to {} (seeked {} frames, offset_i64={})", .{ offset, frames, offset_i64 });
     }
 }
 
-fn sf_tell(file: *c.SNDFILE) i64 {
-    var frames = c.sf_seek(file, 0, c.SEEK_CUR);
-    std.debug.warn("\t\t{} frames\n", frames);
-    return -frames;
-}
-
-pub fn temporaryName(allocator: *std.mem.Allocator) ![]u8 {
+/// Caller owns the returned memory.
+pub fn temporaryName(allocator: std.mem.Allocator) ![]u8 {
     const template_start = "/temp/temp_";
-    const template = "/tmp/temp_XXXXXXXX";
+    const template = "/tmp/temp_XXXXXXXXXXXXXXXXXXXXX";
     var nam = try allocator.alloc(u8, template.len);
-    std.mem.copy(u8, nam, template);
+    std.mem.copyForwards(u8, nam, template);
 
-    var r = std.rand.DefaultPrng.init(std.time.timestamp());
+    const seed = @as(u64, @truncate(@as(u128, @bitCast(std.time.nanoTimestamp()))));
+    var r = std.rand.DefaultPrng.init(seed);
 
     var fill = nam[template_start.len..nam.len];
 
     var i: usize = 0;
     while (i < 100) : (i += 1) {
-
         // generate a random uppercase letter, that is, 65 + random number.
-        for (fill) |_, f_idx| {
-            var idx = @intCast(u8, r.random.uintLessThan(u5, 24));
-            var letter = u8(65) + idx;
+        for (fill, 0..) |_, f_idx| {
+            const idx = @as(u8, @intCast(r.random().uintLessThan(u5, 24)));
+            const letter = @as(u8, 65) + idx;
             fill[f_idx] = letter;
         }
 
         // if we fail to access it, we assume it doesn't exist and return it.
-        std.fs.File.access(nam) catch |err| {
-            if (err == error.FileNotFound) {
-                return nam;
-            }
+        var tmp_file: std.fs.File = std.fs.cwd().openFile(
+            nam,
+            .{ .mode = .read_only },
+        ) catch |err| {
+            if (err == error.FileNotFound) return nam else continue;
         };
+
+        // if we actually found someone, close the handle so that we don't
+        // get EMFILE later on.
+        tmp_file.close();
     }
 
     return error.TempGenFail;
 }
 
-fn mkSfInfo() c.SF_INFO {
+pub fn mkSfInfo() c.SF_INFO {
     return c.SF_INFO{
-        .frames = c_int(0),
-        .samplerate = c_int(44100),
-        .channels = c_int(1),
+        .frames = @as(c_int, 0),
+        .samplerate = @as(c_int, 44100),
+        .channels = @as(c_int, 1),
         .format = c.SF_FORMAT_ULAW | c.SF_FORMAT_RAW | c.SF_ENDIAN_BIG,
-        .sections = c_int(0),
-        .seekable = c_int(0),
+        .sections = @as(c_int, 0),
+        .seekable = @as(c_int, 0),
     };
 }
 
 pub const Image = struct {
-    allocator: *std.mem.Allocator,
+    allocator: std.mem.Allocator,
 
     /// Pointer to the underlying libsndfile's SNDFILE struct.
     sndfile: *c.SNDFILE,
@@ -125,55 +137,79 @@ pub const Image = struct {
     curpath: []const u8,
 
     /// Open a BMP image for later.
-    pub fn open(allocator: *std.mem.Allocator, path: []const u8) !*Image {
+    pub fn open(allocator: std.mem.Allocator, path: []const u8) !*Image {
         var in_fmt = mkSfInfo();
+        const sndfile = try sopen(allocator, path, c.SFM_READ, &in_fmt);
 
-        var sndfile = try sopen(allocator, path, c.SFM_READ, &in_fmt);
-        var image = try allocator.create(Image);
+        const image = try allocator.create(Image);
 
-        std.debug.assert(in_fmt.frames > i64(0));
-        std.debug.assert(in_fmt.seekable == i32(1));
+        std.debug.assert(in_fmt.frames > @as(i64, 0));
+        std.debug.assert(in_fmt.seekable == @as(i32, 1));
 
         image.* = Image{
             .allocator = allocator,
             .sndfile = sndfile,
             .path = path,
             .curpath = path,
-            .frames = @intCast(usize, in_fmt.frames),
+            .frames = @as(usize, @intCast(in_fmt.frames)),
+        };
+
+        return image;
+    }
+
+    pub fn clone(self: *Image) !*Image {
+        var in_fmt = mkSfInfo();
+        // clone sndfile
+        const sndfile = try sopen(self.allocator, self.curpath, c.SFM_READ, &in_fmt);
+        std.debug.assert(self.frames == @as(usize, @intCast(in_fmt.frames)));
+
+        const image = try self.allocator.create(Image);
+
+        std.debug.assert(in_fmt.frames > @as(i64, 0));
+        std.debug.assert(in_fmt.seekable == @as(i32, 1));
+
+        image.* = Image{
+            .allocator = self.allocator,
+            .sndfile = sndfile,
+            .path = self.path,
+            .curpath = self.curpath,
+            .frames = @as(usize, @intCast(in_fmt.frames)),
         };
 
         return image;
     }
 
     pub fn close(self: *Image) void {
-        //self.allocator.free(self.path);
-        //self.allocator.free(self.curpath);
-        var st: i32 = c.sf_close(self.sndfile);
-
+        const st: i32 = c.sf_close(self.sndfile);
         if (st != 0) {
-            std.debug.warn(
-                "Failed to close {} ({})\n",
+            log.debug("Failed to close {s} ({s})", .{
                 self.path,
                 c.sf_error_number(st),
-            );
+            });
         }
+
+        self.allocator.free(self.path);
+        self.allocator.free(self.curpath);
+
+        var allocator = self.allocator;
+        self.* = undefined;
+        allocator.destroy(self);
     }
 
     pub fn read(self: *Image, file_chans: c_int, buf: []f32) bool {
-        var file = file_opt.?;
-
-        const n_read: c.sf_count_t = c.sf_readf_float(file, buf.ptr, 1);
-        const buf_chans = @intCast(c_int, buf.len);
+        const n_read: c.sf_count_t = c.sf_readf_float(self.sndfile, buf.ptr, 1);
+        const buf_chans = @as(c_int, @intCast(buf.len));
 
         var i = file_chans - 1;
         while (i < buf_chans) : (i += 1) {
             //buf[@intCast(usize, i)] = buf[i % file_chans];
-            buf[@intCast(usize, i)] = buf[@intCast(usize, @mod(i, file_chans))];
+            buf[@as(usize, @intCast(i))] = buf[@as(usize, @intCast(@mod(i, file_chans)))];
         }
 
         return n_read == 1;
     }
 
+    /// Copy bytes from the current file to out_file.
     fn copyBytes(
         self: *Image,
         out_file: *c.SNDFILE,
@@ -191,7 +227,7 @@ pub const Image = struct {
         sseek(out_file, start);
 
         while (i <= end) : (i += buf.len) {
-            std.debug.warn("i={}, buf.len={}, end={}\n", i, buf.len, end);
+            log.debug("\t\ti={d}, buf.len={d}, end={d}", .{ i, buf.len, end });
             sseek(self.sndfile, i);
             sseek(out_file, i);
 
@@ -201,13 +237,13 @@ pub const Image = struct {
             var view: []f32 = buf[0..buf.len];
 
             if (bytes_until_end < buf.len) {
-                read_bytes = c.sf_readf_float(self.sndfile, buf.ptr, @intCast(i64, bytes_until_end));
+                read_bytes = c.sf_readf_float(self.sndfile, buf.ptr, @as(i64, @intCast(bytes_until_end)));
                 view = buf[0..bytes_until_end];
             } else {
-                read_bytes = c.sf_readf_float(self.sndfile, buf.ptr, @intCast(i64, buf.len));
+                read_bytes = c.sf_readf_float(self.sndfile, buf.ptr, @as(i64, @intCast(buf.len)));
             }
 
-            try swrite(out_file, view.ptr, @intCast(i64, view.len));
+            try swrite(out_file, view.ptr, @as(i64, @intCast(view.len)));
         }
 
         sseek(self.sndfile, end);
@@ -216,11 +252,44 @@ pub const Image = struct {
 
     fn getSeekPos(self: *Image, position: plugins.Position) plugins.SeekPos {
         const file_end = self.frames;
-        var seek_pos = position.seekPos(file_end);
-        std.debug.warn("\tstart {} end {}\n", seek_pos.start, seek_pos.end);
+        const seek_pos = position.seekPos(file_end);
+        log.debug("\tstart {d} end {d}", .{ seek_pos.start, seek_pos.end });
         return seek_pos;
     }
 
+    pub fn reopen(self: *Image, path: []const u8) !void {
+        var in_fmt = mkSfInfo();
+
+        self.sndfile = try sopen(self.allocator, path, c.SFM_READ, &in_fmt);
+        // std.testing.expectEqual(self.frames, @intCast(usize, in_fmt.frames));
+
+        self.curpath = path;
+        self.frames = @as(usize, @intCast(in_fmt.frames));
+
+        log.debug("\timage: reopened on '{s}' (frames={d}, fmt.frames={d})", .{
+            self.curpath,
+            self.frames,
+            in_fmt.frames,
+        });
+    }
+
+    pub fn checkValid(self: *Image) !void {
+        var file = try std.fs.cwd().openFile(self.path, .{ .mode = .read_only });
+        defer file.close();
+
+        // main bmp header:
+        //  2 bytes for magic header
+        //  4 bytes for size in bytes
+        //  2 bytes ?
+        //  2 bytes ?
+        //  4 bytes for pixel array offset
+        var magic = [2]u8{ 0, 0 };
+        _ = try file.read(&magic);
+
+        if (std.mem.endsWith(u8, self.path, ".bmp"))
+            try bmp.magicValid(&magic);
+    }
+
     /// Run a plugin over the image.
     /// This setups a new lilv world/plugin among other things.
     /// The internal SNDFILE pointer is modified to point to the output of the
@@ -231,51 +300,54 @@ pub const Image = struct {
         position: plugins.Position,
         params: plugins.ParamList,
     ) !void {
+        var timer = try std.time.Timer.start();
+
         var ctx = try plugins.makeContext(self.allocator, plugin_uri);
         defer ctx.deinit();
 
         var ports = try lv2.setupPorts(&ctx);
+        defer ctx.allocator.free(ports);
 
         if (ctx.n_audio_in > 2) {
-            std.debug.warn("plugin <{}> accepts more than two channels.\n", plugin_uri);
+            log.debug("plugin <{s}> has more than two inputs.", .{plugin_uri});
             return ImageError.InvalidPlugin;
         }
 
-        // TODO check n_audio_out > 2
+        if (ctx.n_audio_out > 2) {
+            log.debug("plugin <{s}> has more than two outputs.", .{plugin_uri});
+            return ImageError.InvalidPlugin;
+        }
 
         // now, for each param for the plugin, we find its port, and set
         // the value for the port there.
-        var it = params.iterator();
-
-        while (it.next()) |param| {
-            var sym_cstr = try std.cstr.addNullByte(self.allocator, param.sym);
+        for (params.items) |param| {
+            const sym_cstr = try self.allocator.dupeZ(u8, param.sym);
             defer self.allocator.free(sym_cstr);
 
-            var sym = c.lilv_new_string(ctx.world, sym_cstr.ptr);
-            const port = c.lilv_plugin_get_port_by_symbol(ctx.plugin, sym) orelse blk: {
-                std.debug.warn("assert fail: symbol {} not found on port\n", param.sym);
+            const sym = c.lilv_new_string(ctx.world, sym_cstr.ptr);
+            const port = c.lilv_plugin_get_port_by_symbol(ctx.plugin, sym) orelse {
+                log.debug("assert fail: symbol {s} not found on port", .{param.sym});
                 return ImageError.InvalidSymbol;
             };
 
             c.lilv_node_free(sym);
 
-            var idx = c.lilv_port_get_index(ctx.plugin, port);
-            std.debug.warn(
-                "\tset sym={}, idx={} to val={}\n",
+            const idx = c.lilv_port_get_index(ctx.plugin, port);
+            log.debug("\tset sym={s}, idx={d} to val={}", .{
                 param.sym,
                 idx,
                 param.value,
-            );
-            ports[idx].value = param.value;
+            });
+            (&ports[idx]).value = param.value;
         }
 
         // now we need to generate a temporary file and put the output of
         // running the plugin on that file
-        var tmpnam = try temporaryName(self.allocator);
-        std.debug.warn("\trunning plugin from '{}' to '{}'\n", self.curpath, tmpnam);
+        const tmpnam = try temporaryName(self.allocator);
+        log.debug("\trunning plugin from '{s}' to '{s}'", .{ self.curpath, tmpnam });
 
         var out_fmt = mkSfInfo();
-        var out_file = try sopen(self.allocator, tmpnam, c.SFM_WRITE, &out_fmt);
+        const out_file = try sopen(self.allocator, tmpnam, c.SFM_WRITE, &out_fmt);
 
         var rctx = try plugins.RunContext.init(self.allocator, ctx.plugin);
         defer rctx.deinit();
@@ -298,27 +370,34 @@ pub const Image = struct {
         // pre-plugin copy, merged with bmp header copy
         try self.copyBytes(
             out_file,
-            usize(0),
+            @as(usize, 0),
             seek_pos.start,
         );
 
         sseek(self.sndfile, seek_pos.start);
 
         var i: usize = seek_pos.start;
-        std.debug.warn("\tseek pos start: {} end: {}\n", seek_pos.start, seek_pos.end);
+        log.debug("\tseek pos start: {d} end: {d}", .{ seek_pos.start, seek_pos.end });
 
-        var inbuf = rctx.buffers.in;
-        var outbuf = rctx.buffers.out;
+        var inbuf = &rctx.buffers.in;
+        const outbuf = &rctx.buffers.out;
 
         while (i <= seek_pos.end) : (i += 1) {
-            const read_bytes = c.sf_readf_float(self.sndfile, inbuf.ptr, 1);
+            inbuf[0] = 0;
+            inbuf[1] = 0;
+
+            const read_bytes = c.sf_readf_float(self.sndfile, inbuf, 1);
             if (read_bytes == 0) {
-                std.debug.warn("WARN! reached EOF at idx={}\n", i);
+                log.debug("WARN! reached EOF at idx={d}", .{i});
                 break;
             }
 
+            // trick plugins into having correct stereo signal from
+            // my mono input
+            inbuf[1] = inbuf[0];
+
             lv2.lilv_instance_run(rctx.instance, 1);
-            try swrite(out_file, outbuf.ptr, 1);
+            try swrite(out_file, outbuf, 1);
         }
 
         sseek(self.sndfile, seek_pos.end);
@@ -334,35 +413,48 @@ pub const Image = struct {
         _ = c.sf_close(out_file);
         _ = c.sf_close(self.sndfile);
 
-        // reopen the file as SFM_READ so we can run plugin chains etc
-        self.sndfile = try sopen(self.allocator, tmpnam, c.SFM_READ, &out_fmt);
-        self.curpath = tmpnam;
+        try self.reopen(tmpnam);
+        try self.checkValid();
+
+        const time_taken = timer.read();
+        log.debug("\ttook {d:.2}ms running plugin", .{time_taken / std.time.us_per_ms});
     }
 
     pub fn saveTo(self: *Image, out_path: []const u8) !void {
-        std.debug.warn("\timg: copy from '{}' to '{}'\n", self.curpath, out_path);
-        try std.fs.copyFile(self.curpath, out_path);
+        log.debug("\timg: copy from '{s}' to '{s}'", .{ self.curpath, out_path });
+        try std.fs.copyFileAbsolute(self.curpath, out_path, .{});
     }
 
     pub fn runCustomPlugin(
         self: *Image,
         comptime Plugin: type,
         position: plugins.Position,
-        params: *plugins.ParamMap,
+        extra: anytype,
     ) !void {
-        var plugin = try Plugin.init(self.allocator, params);
+        const plugin_opt: ?Plugin = Plugin.init(self.allocator, extra);
+        if (plugin_opt == null) {
+            return ImageError.PluginLoadFail;
+        }
+
+        var plugin = plugin_opt.?;
+        defer plugin.deinit();
+
+        const decls = comptime std.meta.declarations(Plugin);
+        inline for (decls) |decl| {
+            if (comptime std.mem.eql(u8, decl.name, "setup")) {
+                try plugin.setup();
+            }
+        }
 
         // the code here is a copypaste of runPlugin() without the specific
         // lilv things.
-        var tmpnam = try temporaryName(self.allocator);
-        std.debug.warn("\trunning CUSTOM plugin from '{}' to '{}'\n", self.curpath, tmpnam);
+        const tmpnam = try temporaryName(self.allocator);
+        log.debug("\trunning CUSTOM plugin from '{s}' to '{s}'", .{ self.curpath, tmpnam });
 
         var out_fmt = mkSfInfo();
-        var out_file = try sopen(self.allocator, tmpnam, c.SFM_WRITE, &out_fmt);
-
-        var bufs = try plugins.RunBuffers.init(self.allocator);
-        defer bufs.deinit();
+        const out_file = try sopen(self.allocator, tmpnam, c.SFM_WRITE, &out_fmt);
 
+        var bufs = plugins.RunBuffers{};
         const seek_pos = self.getSeekPos(position);
 
         // make sure we start from 0
@@ -377,27 +469,27 @@ pub const Image = struct {
         // pre-plugin copy, merged with bmp header copy
         try self.copyBytes(
             out_file,
-            usize(0),
+            @as(usize, 0),
             seek_pos.start,
         );
 
         sseek(self.sndfile, seek_pos.start);
 
         var i: usize = seek_pos.start;
-        std.debug.warn("\tseek pos start: {} end: {}\n", seek_pos.start, seek_pos.end);
+        log.debug("\tseek pos start: {d} end: {d}", .{ seek_pos.start, seek_pos.end });
 
-        var inbuf = bufs.in;
-        var outbuf = bufs.out;
+        const inbuf = &bufs.in;
+        const outbuf = &bufs.out;
 
         while (i <= seek_pos.end) : (i += 1) {
-            const read_bytes = c.sf_readf_float(self.sndfile, bufs.in.ptr, 1);
+            const read_bytes = c.sf_readf_float(self.sndfile, inbuf, 1);
             if (read_bytes == 0) {
-                std.debug.warn("WARN! reached EOF at idx={}\n", i);
+                log.debug("WARN! reached EOF at idx={d}", .{i});
                 break;
             }
 
             plugin.run(&bufs);
-            try swrite(out_file, bufs.out.ptr, 1);
+            try swrite(out_file, outbuf, 1);
         }
 
         sseek(self.sndfile, seek_pos.end);
@@ -414,7 +506,7 @@ pub const Image = struct {
         _ = c.sf_close(self.sndfile);
 
         // reopen the file as SFM_READ so we can run plugin chains etc
-        self.sndfile = try sopen(self.allocator, tmpnam, c.SFM_READ, &out_fmt);
-        self.curpath = tmpnam;
+        try self.reopen(tmpnam);
+        try self.checkValid();
     }
 };

src/lang.zig

@@ -1,213 +1,762 @@
 const std = @import("std");
 
 const plugin = @import("plugin.zig");
+const custom = @import("custom.zig");
 
-pub const ParseError = error{
-    NoCommandGiven,
-    UnknownCommand,
-    ArgRequired,
-};
+const log = std.log.scoped(.scritcher_lang);
+pub const ParseError = error{ParseFail};
 
 pub const CommandType = enum {
-    Noop,
-    Load,
-    Quicksave,
-    RunQS,
+    /// "LV2 Commands" are commands that receive split, index, and then receive
+    /// any f64 arguments.
+    lv2_command,
 
-    Amp,
-    RFlanger,
-    Eq,
-    Phaser,
-    Mbeq,
-    Chorus,
-    PitchScaler,
-    Reverb,
-    Highpass,
-    Delay,
-    Vinyl,
-    RevDelay,
-    Noise,
-    WildNoise,
-
-    Rotate,
+    custom_command,
 };
 
+fn LV2Command(
+    comptime tag: Command.Tag,
+    comptime plugin_url: []const u8,
+    comptime LV2Parameters: type,
+) type {
+    return struct {
+        pub const base_tag = tag;
+        pub const command_type = CommandType.lv2_command;
+        pub const lv2_url = plugin_url;
+
+        base: Command,
+        split: usize,
+        index: usize,
+        parameters: LV2Parameters,
+    };
+}
+
+fn CustomCommand(
+    comptime tag: Command.Tag,
+    comptime Plugin: type,
+    comptime PluginParameters: type,
+) type {
+    return struct {
+        pub const base_tag = tag;
+        pub const command_type = CommandType.custom_command;
+        pub const plugin_type = Plugin;
+
+        base: Command,
+        split: usize,
+        index: usize,
+        parameters: PluginParameters,
+    };
+}
+
 pub const Command = struct {
-    command: CommandType,
-    args: ArgList,
-    cur_idx: usize = 0,
+    tag: Tag,
 
-    pub fn print(self: *const Command) void {
-        std.debug.warn("cmd:{}\n", self.command);
-    }
+    pub const Tag = enum {
+        noop,
+        load,
+        quicksave,
+        runqs,
 
-    pub fn argAt(self: *const Command, idx: usize) ![]const u8 {
-        const args = self.args.toSliceConst();
+        amp,
+        rflanger,
+        eq,
+        phaser,
+        mbeq,
+        chorus,
+        pitchscaler,
+        reverb,
+        highpass,
+        delay,
+        vinyl,
+        revdelay,
+        gate,
+        detune,
+        overdrive,
+        degrade,
+        repsycho,
+        talkbox,
+        dyncomp,
+        thruzero,
+        foverdrive,
+        gverb,
+        invert,
+        tapedelay,
+        moddelay,
+        multichorus,
+        saturator,
+        vintagedelay,
 
-        if (idx > (args.len - 1)) {
-            std.debug.warn("Expected argument at index {}\n", idx);
-            return ParseError.ArgRequired;
-        }
+        noise,
+        wildnoise,
+        write,
+        embed,
 
-        return args[idx];
-    }
+        rotate,
+    };
 
-    pub fn usizeArgAt(self: *const Command, idx: usize) !usize {
-        var arg = try self.argAt(idx);
-        return try std.fmt.parseInt(usize, arg, 10);
-    }
+    pub fn tagToType(comptime tag: Tag) type {
+        return switch (tag) {
+            .noop => Noop,
+            .load => Load,
+            .quicksave => Quicksave,
+            .runqs => RunQS,
 
-    pub fn consumePosition(self: *Command) !plugin.Position {
-        self.cur_idx = 2;
-        return plugin.Position{
-            .split = try self.usizeArgAt(0),
-            .index = try self.usizeArgAt(1),
+            .amp => Amp,
+            .rflanger => RFlanger,
+            .eq => Eq,
+            .phaser => Phaser,
+            .mbeq => Mbeq,
+            .chorus => Chorus,
+            .pitchscaler => Pitchscaler,
+            .reverb => Reverb,
+            .highpass => Highpass,
+            .delay => Delay,
+            .vinyl => Vinyl,
+            .revdelay => Revdelay,
+            .gate => Gate,
+            .detune => Detune,
+            .overdrive => Overdrive,
+            .degrade => Degrade,
+            .repsycho => Repsycho,
+            .talkbox => Talkbox,
+            .dyncomp => Dyncomp,
+            .thruzero => Thruzero,
+            .foverdrive => Foverdrive,
+            .gverb => Gverb,
+            .invert => Invert,
+            .tapedelay => Tapedelay,
+            .moddelay => Moddelay,
+            .multichorus => Multichorus,
+            .saturator => Saturator,
+            .vintagedelay => Vintagedelay,
+
+            .noise => Noise,
+            .wildnoise => Wildnoise,
+            .write => Write,
+            .embed => Embed,
+
+            .rotate => Rotate,
         };
     }
 
-    pub fn intArgAt(self: *const Command, idx: usize) !i32 {
-        var arg = try self.argAt(idx);
-        return try std.fmt.parseInt(i32, arg, 10);
+    pub fn cast(base: *const @This(), comptime T: type) ?*const T {
+        if (base.tag != T.base_tag)
+            return null;
+
+        //const baseInt = @intFromPtr(base);
+
+        //log.debug("casting from {d}", .{baseInt});
+        //log.debug("aligns from 8? {d}", .{baseInt % 8});
+        //log.debug("align T: {d} {s}", .{ @alignOf(*T), @typeName(T) });
+        //log.debug("align base: {d} {s}", .{ @alignOf(*const @This()), @typeName(@This()) });
+        const base_aligned: *const @This() = @alignCast(base);
+
+        const parented = @as(*const T, @alignCast(@fieldParentPtr("base", base_aligned)));
+
+        const ptr: *const T = @alignCast(parented);
+        //log.debug("align: {d}\n", .{@alignOf(@TypeOf(ptr))});
+        return ptr;
     }
 
-    pub fn floatArgAt(self: *const Command, idx: usize) !f32 {
-        var arg = try self.argAt(idx);
-        return try std.fmt.parseFloat(f32, arg);
+    pub fn print(base: *const @This()) void {
+        log.debug("tag: {}", .{base.tag});
     }
 
-    pub fn floatArgMany(
-        self: *const Command,
-        allocator: *std.mem.Allocator,
-        start_index: usize,
-        elements: usize,
-        default: f32,
-    ) ![]const f32 {
-        var i: usize = start_index;
-        var arr = std.ArrayList(f32).init(allocator);
+    pub const Noop = struct {
+        pub const base_tag = Tag.noop;
+        base: Command,
+    };
 
-        while (i < elements) : (i += 1) {
-            var value: f32 = self.floatArgAt(i) catch |err| blk: {
-                std.debug.warn("\tdoing default on arg {}\n", i);
-                break :blk default;
-            };
+    pub const Load = struct {
+        pub const base_tag = Tag.load;
+        base: Command,
+        path: []const u8,
+    };
 
-            try arr.append(value);
+    pub const Quicksave = struct {
+        pub const base_tag = Tag.quicksave;
+        base: Command,
+    };
+
+    pub const RunQS = struct {
+        pub const base_tag = Tag.runqs;
+        base: Command,
+        program: []const u8,
+    };
+
+    pub const Noise = CustomCommand(Tag.noise, custom.RandomNoise, struct {
+        seed: u64,
+        fill_bytes: usize,
+    });
+
+    pub const Wildnoise = CustomCommand(Tag.wildnoise, custom.WildNoise, struct {
+        seed: u64,
+        fill_bytes: usize,
+    });
+
+    pub const Write = CustomCommand(Tag.write, custom.Write, struct {
+        data: f32,
+    });
+
+    pub const Embed = CustomCommand(Tag.write, custom.Embed, struct {
+        path: []const u8,
+    });
+
+    pub const Rotate = struct {
+        pub const base_tag = Tag.rotate;
+        base: Command,
+        deg: f32,
+        bgfill: []const u8,
+    };
+
+    pub const Amp = LV2Command(
+        .amp,
+        "http://lv2plug.in/plugins/eg-amp",
+        struct { gain: f32 },
+    );
+
+    pub const RFlanger = LV2Command(
+        .rflanger,
+        "http://plugin.org.uk/swh-plugins/retroFlange",
+        struct { delay_depth_avg: f32, law_freq: f32 },
+    );
+
+    pub const Eq = LV2Command(
+        .rflanger,
+        "http://plugin.org.uk/swh-plugins/dj_eq_mono",
+        struct { lo: f32, mid: f32, hi: f32 },
+    );
+
+    pub const Phaser = LV2Command(
+        .phaser,
+        "http://plugin.org.uk/swh-plugins/lfoPhaser",
+        struct { lfo_rate: f32, lfo_depth: f32, fb: f32, spread: f32 },
+    );
+
+    pub const Mbeq = LV2Command(
+        .mbeq,
+        "http://plugin.org.uk/swh-plugins/mbeq",
+        struct {
+            band_1: f32,
+            band_2: f32,
+            band_3: f32,
+            band_4: f32,
+            band_5: f32,
+            band_6: f32,
+            band_7: f32,
+            band_8: f32,
+            band_9: f32,
+            band_10: f32,
+            band_11: f32,
+            band_12: f32,
+            band_13: f32,
+            band_14: f32,
+            band_15: f32,
+        },
+    );
+
+    pub const Chorus = LV2Command(
+        .chorus,
+        "http://plugin.org.uk/swh-plugins/multivoiceChorus",
+        struct {
+            voices: f32,
+            delay_base: f32,
+            voice_spread: f32,
+            detune: f32,
+            law_freq: f32,
+            attendb: f32,
+        },
+    );
+
+    pub const Pitchscaler = LV2Command(
+        .pitchscaler,
+        "http://plugin.org.uk/swh-plugins/pitchScaleHQ",
+        struct { mult: f32 },
+    );
+
+    pub const Reverb = LV2Command(
+        .reverb,
+        "http://invadarecords.com/plugins/lv2/erreverb/mono",
+        struct {
+            roomLength: f32,
+            roomWidth: f32,
+            roomHeight: f32,
+            sourceLR: f32,
+            sourceFB: f32,
+            listLR: f32,
+            listFB: f32,
+            hpf: f32,
+            warmth: f32,
+            diffusion: f32,
+        },
+    );
+
+    pub const Highpass = LV2Command(.highpass, "http://invadarecords.com/plugins/lv2/filter/hpf/mono", struct {
+        freq: f32,
+        gain: f32,
+        noClip: f32,
+    });
+
+    pub const Delay = LV2Command(.delay, "http://plugin.org.uk/swh-plugins/delayorama", struct {
+        seed: f32,
+        gain: f32,
+        feedback_pc: f32,
+        tap_count: f32,
+        first_delay: f32,
+        delay_range: f32,
+        delay_scale: f32,
+        delay_rand_pc: f32,
+        gain_scale: f32,
+        wet: f32,
+    });
+
+    pub const Vinyl = LV2Command(.vinyl, "http://plugin.org.uk/swh-plugins/vynil", struct {
+        year: f32,
+        rpm: f32,
+        warp: f32,
+        click: f32,
+        wear: f32,
+    });
+
+    pub const Revdelay = LV2Command(.revdelay, "http://plugin.org.uk/swh-plugins/revdelay", struct {
+        delay_time: f32,
+        dry_level: f32,
+        wet_level: f32,
+        feedback: f32,
+        xfade_samp: f32,
+    });
+    // pub const  Noise= LV2Command(.,,struct{});
+    pub const Gate = LV2Command(.gate, "http://hippie.lt/lv2/gate", struct {
+        @"switch": f32,
+        threshold: f32,
+        attack: f32,
+        hold: f32,
+        decay: f32,
+        gaterange: f32,
+    });
+    pub const Detune = LV2Command(.detune, "http://drobilla.net/plugins/mda/Detune", struct {
+        detune: f32,
+        mix: f32,
+        output: f32,
+        latency: f32,
+    });
+    pub const Overdrive = LV2Command(.overdrive, "http://drobilla.net/plugins/mda/Overdrive", struct {
+        drive: f32,
+        muffle: f32,
+        output: f32,
+    });
+    pub const Degrade = LV2Command(.degrade, "http://drobilla.net/plugins/mda/Degrade", struct {
+        headroom: f32,
+        quant: f32,
+        rate: f32,
+        post_filt: f32,
+        non_lin: f32,
+        output: f32,
+    });
+    pub const Repsycho = LV2Command(.repsycho, "http://drobilla.net/plugins/mda/RePsycho", struct {
+        tune: f32,
+        fine: f32,
+        decay: f32,
+        thresh: f32,
+        hold: f32,
+        mix: f32,
+        quality: f32,
+    });
+    pub const Talkbox = LV2Command(.talkbox, "http://drobilla.net/plugins/mda/TalkBox", struct {
+        wet: f32,
+        dry: f32,
+        carrier: f32,
+        quality: f32,
+    });
+    pub const Dyncomp = LV2Command(.dyncomp, "http://gareus.org/oss/lv2/darc#mono", struct {
+        enable: f32,
+        hold: f32,
+        inputgain: f32,
+        threshold: f32,
+        Ratio: f32,
+        attack: f32,
+        release: f32,
+        gain_min: f32,
+        gain_max: f32,
+        rms: f32,
+    });
+    pub const Foverdrive = LV2Command(.foverdrive, "http://plugin.org.uk/swh-plugins/foverdrive", struct {
+        drive: f32,
+    });
+    pub const Thruzero = LV2Command(.thruzero, "http://drobilla.net/plugins/mda/ThruZero", struct { rate: f32, mix: f32, feedback: f32, depth_mod: f32 });
+
+    pub const Gverb = LV2Command(.gverb, "http://plugin.org.uk/swh-plugins/gverb", struct {
+        roomsize: f32,
+        revtime: f32,
+        damping: f32,
+        inputbandwidth: f32,
+        drylevel: f32,
+        earlylevel: f32,
+        taillevel: f32,
+    });
+    pub const Invert = LV2Command(.invert, "http://plugin.org.uk/swh-plugins/inv", struct {});
+    pub const Tapedelay = LV2Command(.tapedelay, "http://plugin.org.uk/swh-plugins/tapeDelay", struct {
+        speed: f32,
+        da_db: f32,
+
+        t1d: f32,
+        t1a_db: f32,
+
+        t2d: f32,
+        t2a_db: f32,
+
+        t3d: f32,
+        t3a_db: f32,
+
+        t4d: f32,
+        t4a_db: f32,
+    });
+
+    pub const Moddelay = LV2Command(
+        .moddelay,
+        "http://plugin.org.uk/swh-plugins/modDelay",
+        struct {
+            base: f32,
+        },
+    );
+
+    pub const Multichorus = LV2Command(.multichorus, "http://calf.sourceforge.net/plugins/MultiChorus", struct {
+        min_delay: f32,
+        mod_depth: f32,
+        mod_rate: f32,
+        stereo: f32,
+        voices: f32,
+        vphase: f32,
+        amount: f32,
+        dry: f32,
+        freq: f32,
+        freq2: f32,
+        q: f32,
+        overlap: f32,
+        level_in: f32,
+        level_out: f32,
+        lfo: f32,
+    });
+    pub const Saturator = LV2Command(.saturator, "http://calf.sourceforge.net/plugins/Saturator", struct {
+        bypass: f32,
+        level_in: f32,
+        level_out: f32,
+        mix: f32,
+        drive: f32,
+        blend: f32,
+        lp_pre_freq: f32,
+        hp_pre_freq: f32,
+        lp_post_freq: f32,
+        hp_post_freq: f32,
+        p_freq: f32,
+        p_level: f32,
+        p_q: f32,
+        pre: f32,
+        post: f32,
+    });
+    pub const Vintagedelay = LV2Command(.vintagedelay, "http://calf.sourceforge.net/plugins/VintageDelay", struct {
+        level_in: f32,
+        level_out: f32,
+        subdiv: f32,
+        time_l: f32,
+        time_r: f32,
+        feedback: f32,
+        amount: f32,
+        mix_mode: f32,
+        medium: f32,
+        dry: f32,
+        width: f32,
+        fragmentation: f32,
+        pbeats: f32,
+        pfrag: f32,
+        timing: f32,
+        bpm: f32,
+        ms: f32,
+        hz: f32,
+        bpm_host: f32,
+    });
+};
+
+const CmdArrayList = std.ArrayList(*Command);
+
+pub const CommandList = struct {
+    list: CmdArrayList,
+    const Self = @This();
+
+    pub fn init(allocator: std.mem.Allocator) Self {
+        return .{
+            .list = CmdArrayList.init(allocator),
+        };
+    }
+
+    pub fn deinit(self: *Self) void {
+        for (self.list.items) |cmd_ptr| {
+            inline for (@typeInfo(Command.Tag).Enum.fields) |field| {
+                if (cmd_ptr.tag == @field(Command.Tag, field.name)) {
+                    const actual_tag =
+                        @field(Command.Tag, field.name);
+                    // if we find a match on the tag, we can get the type
+                    const typ = Command.tagToType(actual_tag);
+
+                    const inner_command = cmd_ptr.cast(typ).?;
+                    inline for (@typeInfo(typ).Struct.fields) |cmd_field| {
+                        switch (cmd_field.type) {
+                            []u8, []const u8 => self.list.allocator.free(@field(inner_command, cmd_field.name)),
+                            else => {},
+                        }
+                    }
+                }
+            }
+
+            //TODO this is ian invalid free
+            //self.list.allocator.destroy(cmd_ptr);
         }
-
-        return arr.toSliceConst();
+        self.list.deinit();
     }
 
-    pub fn appendParam(
-        self: *Command,
-        params: *plugin.ParamList,
-        symbol: []const u8,
-    ) !void {
-        var val = try self.floatArgAt(self.cur_idx);
-        self.cur_idx += 1;
-
-        try params.append(plugin.Param{
-            .sym = symbol,
-            .value = val,
-        });
-    }
-
-    pub fn appendParamMap(
-        self: *Command,
-        map: *plugin.ParamMap,
-        symbol: []const u8,
-    ) !void {
-        var val = try self.floatArgAt(self.cur_idx);
-        self.cur_idx += 1;
-        _ = try map.put(symbol, val);
+    pub fn append(self: *Self, cmd: *Command) !void {
+        return try self.list.append(cmd);
     }
 };
 
-pub const CommandList = std.ArrayList(*Command);
-pub const ArgList = std.ArrayList([]const u8);
-
-pub const PluginKeywords = [_]CommandType{ .Amp, .RFlanger };
-pub const KeywordMap = std.AutoHashMap([]const u8, CommandType);
-
+/// A parser.
 pub const Lang = struct {
-    allocator: *std.mem.Allocator,
-    keywords: KeywordMap,
+    allocator: std.mem.Allocator,
 
-    pub fn init(allocator: *std.mem.Allocator) Lang {
+    has_error: bool = false,
+    line: usize = 0,
+
+    pub fn init(allocator: std.mem.Allocator) Lang {
         return Lang{
             .allocator = allocator,
-            .keywords = KeywordMap.init(allocator),
         };
     }
 
-    fn fillKeywords(self: *Lang) !void {
-        _ = try self.keywords.put("noop", .Noop);
-        _ = try self.keywords.put("load", .Load);
-        _ = try self.keywords.put("quicksave", .Quicksave);
-        _ = try self.keywords.put("runqs", .RunQS);
+    pub fn deinit(self: *Lang) void {
+        _ = self;
+    }
 
-        _ = try self.keywords.put("amp", .Amp);
-        _ = try self.keywords.put("rflanger", .RFlanger);
-        _ = try self.keywords.put("eq", .Eq);
-        _ = try self.keywords.put("mbeq", .Mbeq);
-        _ = try self.keywords.put("phaser", .Phaser);
-        _ = try self.keywords.put("chorus", .Chorus);
-        _ = try self.keywords.put("pitchscaler", .PitchScaler);
-        _ = try self.keywords.put("reverb", .Reverb);
-        _ = try self.keywords.put("highpass", .Highpass);
-        _ = try self.keywords.put("delay", .Delay);
-        _ = try self.keywords.put("vinyl", .Vinyl);
-        _ = try self.keywords.put("revdelay", .RevDelay);
+    pub fn reset(self: *Lang) void {
+        self.has_error = false;
+        self.line = 0;
+    }
 
-        // custom implementations (not lv2)
-        _ = try self.keywords.put("noise", .Noise);
-        _ = try self.keywords.put("wildnoise", .WildNoise);
+    fn doError(self: *Lang, comptime fmt: []const u8, args: anytype) void {
+        log.warn("ERROR! at line {}: ", .{self.line});
+        log.warn(fmt, args);
+        self.has_error = true;
+    }
 
-        // even more custom
-        _ = try self.keywords.put("rotate", .Rotate);
+    fn parseCommandArguments(
+        self: *@This(),
+        comptime command_struct: type,
+        tok_it: *std.mem.SplitIterator(u8, .sequence),
+        commands: *CommandList,
+    ) !void {
+        // Based on the command struct fields, we can parse the arguments.
+        var cmd = try self.allocator.create(command_struct);
+
+        // we already add the command to the list to prevent memory leaks
+        // by commands that error out
+        try commands.append(&cmd.base);
+
+        const is_lv2_command = switch (command_struct.base_tag) {
+            .noop, .load, .quicksave, .runqs, .rotate => false,
+            else => true,
+        };
+
+        if (is_lv2_command) {
+            const split = tok_it.next();
+            if (split == null) {
+                self.doError("Expected split parameter, got EOL", .{});
+                return;
+            }
+
+            const index = tok_it.next();
+            if (index == null) {
+                self.doError("Expected index parameter, got EOL", .{});
+                return;
+            }
+
+            cmd.split = try std.fmt.parseInt(usize, split.?, 10);
+            cmd.index = try std.fmt.parseInt(usize, index.?, 10);
+
+            inline for (@typeInfo(@TypeOf(cmd.parameters)).Struct.fields) |cmd_field| {
+                const maybe_arg = tok_it.next();
+                if (maybe_arg == null) {
+                    self.doError("Expected parameter for {s}, got nothing", .{cmd_field.name});
+                    return;
+                }
+
+                const arg = maybe_arg.?;
+                const arg_value = switch (cmd_field.type) {
+                    f32 => try std.fmt.parseFloat(f32, arg),
+                    u64 => try std.fmt.parseInt(u64, arg, 10),
+                    usize => try std.fmt.parseInt(usize, arg, 10),
+                    []const u8 => @as([]const u8, try self.allocator.dupe(u8, arg)),
+                    else => @compileError("parameter struct has unsupported type " ++ @typeName(cmd_field.field_type)),
+                };
+
+                @field(cmd.parameters, cmd_field.name) = arg_value;
+            }
+        } else {
+            inline for (@typeInfo(command_struct).Struct.fields) |cmd_field| {
+                comptime {
+                    if (std.mem.eql(u8, cmd_field.name, "base")) {
+                        continue;
+                    }
+                }
+
+                const arg_opt = tok_it.next();
+                if (arg_opt == null) {
+                    self.doError("Expected parameter for {s}, got nothing", .{cmd_field.name});
+                    return;
+                }
+                const arg = arg_opt.?;
+
+                const argument_value = switch (cmd_field.type) {
+                    usize => try std.fmt.parseInt(usize, arg, 10),
+                    i32 => try std.fmt.parseInt(i32, arg, 10),
+                    f32 => try std.fmt.parseFloat(f32, arg),
+                    []const u8 => @as([]const u8, try self.allocator.dupe(u8, arg)),
+                    else => @compileError("Invalid parameter type (" ++ @typeName(cmd_field.field_type) ++ ") left on command struct " ++ @typeName(command_struct) ++ "."),
+                };
+
+                log.debug("parsing {s}, arg of type {s} => {any}", .{
+                    @typeName(command_struct),
+                    @typeName(@TypeOf(argument_value)),
+                    argument_value,
+                });
+
+                @field(cmd, cmd_field.name) = argument_value;
+            }
+        }
+
+        cmd.base.tag = command_struct.base_tag;
+        const command = cmd.base.cast(command_struct).?;
+        log.debug("cmd: {}", .{command});
     }
 
     pub fn parse(self: *Lang, data: []const u8) !CommandList {
-        var splitted_it = std.mem.separate(data, ";");
-        try self.fillKeywords();
+        var splitted_it = std.mem.split(u8, data, ";");
         var cmds = CommandList.init(self.allocator);
+        errdefer cmds.deinit();
 
         while (splitted_it.next()) |stmt_orig| {
+            self.line += 1;
             var stmt = std.mem.trimRight(u8, stmt_orig, "\n");
             stmt = std.mem.trimLeft(u8, stmt, "\n");
 
             if (stmt.len == 0) continue;
-            if (stmt[0] == '#') continue;
+            if (std.mem.startsWith(u8, stmt, "#")) continue;
 
-            // TODO better tokenizer instead of just tokenize(" ");
-            var tok_it = std.mem.tokenize(stmt, " ");
+            // TODO better tokenizer instead of just tokenize(" ")...maybe????
+            var tok_it = std.mem.splitSequence(u8, stmt, " ");
 
-            var cmd_opt = tok_it.next();
-            if (cmd_opt == null) return ParseError.NoCommandGiven;
-            var command = cmd_opt.?;
+            const cmd_opt = tok_it.next();
+            if (cmd_opt == null) {
+                self.doError("No command given", .{});
+                continue;
+            }
+            const command_string = cmd_opt.?;
 
-            var kv_opt = self.keywords.get(command);
-            var ctype: CommandType = undefined;
-            if (kv_opt) |kv| {
-                ctype = kv.value;
-            } else {
-                std.debug.warn("Unknown command: '{}'\n", command);
-                return ParseError.UnknownCommand;
+            var found: bool = false;
+
+            inline for (@typeInfo(Command).Struct.decls) |cmd_struct_decl| {
+                const struct_name = cmd_struct_decl.name;
+                const cmd_struct_type = @field(Command, struct_name);
+
+                const info_of_info = @typeInfo(@TypeOf(cmd_struct_type));
+
+                switch (info_of_info) {
+                    .Type => {},
+                    else => continue,
+                }
+
+                const info = @typeInfo(cmd_struct_type);
+
+                switch (info) {
+                    .Struct => {},
+                    else => continue,
+                }
+
+                comptime var lowered_command_name = [_]u8{0} ** struct_name.len;
+                var runtime_lowered_command_name = [_]u8{0} ** struct_name.len;
+                comptime {
+                    for (struct_name, 0..) |c, i| {
+                        lowered_command_name[i] = std.ascii.toLower(c);
+                    }
+                }
+                const c_l = lowered_command_name;
+                std.mem.copyForwards(u8, &runtime_lowered_command_name, &c_l);
+
+                // if we have a match, we know the proper struct type
+                // to use. this actually works compared to storing command_struct
+                // in a variable because then that variable must be comptime.
+
+                // the drawback of this approach is that our emitted code is basically linear
+                // because we don't use the hashmap anymore.
+                //
+                // Attempting to use ComptimeHashMap hits compiler bugs and I'm
+                // not sure if we can map strings to *types* in it.
+
+                if ((!found) and std.mem.eql(u8, &runtime_lowered_command_name, command_string)) {
+                    found = true;
+                    try self.parseCommandArguments(cmd_struct_type, &tok_it, &cmds);
+                }
             }
 
-            var args = ArgList.init(self.allocator);
-
-            while (tok_it.next()) |arg| {
-                try args.append(arg);
+            if (!found) {
+                self.doError("Unknown command '{s}' ({d} bytes)", .{ command_string, command_string.len });
+                continue;
             }
-
-            // construct final Command based on command
-            var cmd_ptr = try self.allocator.create(Command);
-            cmd_ptr.* = Command{ .command = ctype, .args = args };
-            try cmds.append(cmd_ptr);
         }
 
+        if (self.has_error) return ParseError.ParseFail;
+
         return cmds;
     }
 };
 
-// TODO tests
+test "noop" {
+    var lang = Lang.init(std.testing.allocator);
+    defer lang.deinit();
+
+    var cmds = try lang.parse("noop;");
+    defer cmds.deinit();
+
+    try std.testing.expectEqual(cmds.list.items.len, 1);
+    try std.testing.expectEqual(cmds.list.items[0].tag, .noop);
+}
+
+test "load, phaser, quicksave" {
+    var lang = Lang.init(std.testing.allocator);
+    defer lang.deinit();
+
+    const prog =
+        \\load :0;
+        \\phaser 3 1 25 0.25 0 1;
+        \\quicksave;
+    ;
+
+    var cmds = try lang.parse(prog);
+    defer cmds.deinit();
+
+    try std.testing.expectEqual(cmds.list.items.len, 3);
+    try std.testing.expectEqual(cmds.list.items[0].tag, .load);
+    try std.testing.expectEqual(cmds.list.items[1].tag, .phaser);
+    try std.testing.expectEqual(cmds.list.items[2].tag, .quicksave);
+}
+
+test "load, phaser with errors, quicksave" {
+    var lang = Lang.init(std.testing.allocator);
+    defer lang.deinit();
+
+    const prog =
+        \\load :0;
+        \\phaser 3 1 25;
+        \\quicksave;
+    ;
+
+    try std.testing.expectError(error.ParseFail, lang.parse(prog));
+}

src/lv2_helpers.zig

@@ -1,27 +1,29 @@
 const std = @import("std");
 const plugin = @import("plugin.zig");
 
+const log = std.log.scoped(.scritcher_lv2);
+
 pub const c = @cImport({
     @cInclude("sndfile.h");
     @cInclude("lilv/lilv.h");
-    @cInclude("lv2/core/lv2.h");
+    @cInclude("lv2.h");
 });
 
-const LV2_CORE_URI = "http://lv2plug.in/ns/lv2core";
-
-pub fn Lv2Core(ns: []const u8) ![]const u8 {
-    var allocator = std.heap.direct_allocator;
-
-    return try std.cstr.addNullByte(
-        allocator,
-        try std.fmt.allocPrint(allocator, "{}{}", LV2_CORE_URI, ns),
-    );
+pub fn Lv2Core(comptime ns: []const u8) []const u8 {
+    const LV2_CORE_URI = "http://lv2plug.in/ns/lv2core";
+    return LV2_CORE_URI ++ ns ++ [_]u8{0};
 }
 
+const LV2_CORE__InputPort = Lv2Core("#InputPort");
+const LV2_CORE__OutputPort = Lv2Core("#OutputPort");
+const LV2_CORE__AudioPort = Lv2Core("#AudioPort");
+const LV2_CORE__ControlPort = Lv2Core("#ControlPort");
+const LV2_CORE__connectionOptional = Lv2Core("#connectionOptional");
+
 pub fn lilv_instance_connect_port(
     instance: [*c]c.LilvInstance,
     port_index: u32,
-    data_location: ?*c_void,
+    data_location: ?*anyopaque,
 ) void {
     instance.?.*.lv2_descriptor.?.*.connect_port.?(instance.?.*.lv2_handle, port_index, data_location);
 }
@@ -59,56 +61,48 @@ pub const Port = struct {
 /// Setup ports for a given plugin. Gives an array to pointers of Port structs.
 /// This setup is required so we link the plugin to the ports later on, and
 /// also link our buffers, and control values.
-pub fn setupPorts(ctx: *plugin.Context) ![]*Port {
-    var world = ctx.world;
+///
+/// Caller owns returned memory.
+pub fn setupPorts(ctx: *plugin.Context) ![]Port {
+    const world = ctx.world;
     const n_ports: u32 = c.lilv_plugin_get_num_ports(ctx.plugin);
 
-    var ports = try ctx.allocator.alloc(*Port, n_ports);
+    var ports = try ctx.allocator.alloc(Port, n_ports);
 
-    for (ports) |port_ptr, idx| {
-        var port = try ctx.allocator.create(Port);
+    for (ports, 0..) |_, idx| {
+        const port: *Port = &ports[idx];
         port.* = Port{
             .lilv_port = null,
             .ptype = .Control,
-            .index = f32(0),
-            .value = f32(0),
+            .index = @as(f32, 0),
+            .value = @as(f32, 0),
             .is_input = false,
             .optional = false,
         };
-
-        ports[idx] = port;
     }
 
-    var values: []f32 = try ctx.allocator.alloc(f32, n_ports);
+    const values: []f32 = try ctx.allocator.alloc(f32, n_ports);
     defer ctx.allocator.free(values);
 
     c.lilv_plugin_get_port_ranges_float(ctx.plugin, null, null, values.ptr);
+    const lv2_InputPort = c.lilv_new_uri(world, LV2_CORE__InputPort.ptr).?;
+    //defer std.heap.c_allocator.destroy(lv2_InputPort);
 
-    // bad solution, but it really do be like that
-    const LV2_CORE__InputPort = try Lv2Core("#InputPort");
-    const LV2_CORE__OutputPort = try Lv2Core("#OutputPort");
-    const LV2_CORE__AudioPort = try Lv2Core("#AudioPort");
-    const LV2_CORE__ControlPort = try Lv2Core("#ControlPort");
-    const LV2_CORE__connectionOptional = try Lv2Core("#connectionOptional");
+    const lv2_OutputPort = c.lilv_new_uri(world, LV2_CORE__OutputPort.ptr).?;
+    //defer std.heap.c_allocator.destroy(lv2_OutputPort);
 
-    var lv2_InputPort = c.lilv_new_uri(world, LV2_CORE__InputPort.ptr);
-    defer std.heap.c_allocator.destroy(lv2_InputPort);
+    const lv2_AudioPort = c.lilv_new_uri(world, LV2_CORE__AudioPort.ptr).?;
+    //defer std.heap.c_allocator.destroy(lv2_AudioPort);
 
-    var lv2_OutputPort = c.lilv_new_uri(world, LV2_CORE__OutputPort.ptr);
-    defer std.heap.c_allocator.destroy(lv2_OutputPort);
+    const lv2_ControlPort = c.lilv_new_uri(world, LV2_CORE__ControlPort.ptr).?;
+    //defer std.heap.c_allocator.destroy(lv2_ControlPort);
 
-    var lv2_AudioPort = c.lilv_new_uri(world, LV2_CORE__AudioPort.ptr);
-    defer std.heap.c_allocator.destroy(lv2_AudioPort);
-
-    var lv2_ControlPort = c.lilv_new_uri(world, LV2_CORE__ControlPort.ptr);
-    defer std.heap.c_allocator.destroy(lv2_ControlPort);
-
-    var lv2_connectionOptional = c.lilv_new_uri(world, LV2_CORE__connectionOptional.ptr);
-    defer std.heap.c_allocator.destroy(lv2_connectionOptional);
+    const lv2_connection_string = c.lilv_new_uri(world, LV2_CORE__connectionOptional.ptr).?;
+    //defer std.heap.c_allocator.destroy(lv2_connection_string);
 
     var i: u32 = 0;
     while (i < n_ports) : (i += 1) {
-        var port: *Port = ports[i];
+        var port: *Port = &ports[i];
 
         const lport = c.lilv_plugin_get_port_by_index(ctx.plugin, i).?;
 
@@ -116,17 +110,17 @@ pub fn setupPorts(ctx: *plugin.Context) ![]*Port {
         port.index = i;
 
         if (std.math.isNan(values[i])) {
-            port.value = f32(0);
+            port.value = @as(f32, 0);
         } else {
             port.value = values[i];
         }
 
-        port.optional = c.lilv_port_has_property(ctx.plugin, lport, lv2_connectionOptional);
+        port.optional = c.lilv_port_has_property(ctx.plugin, lport, lv2_connection_string);
 
         if (c.lilv_port_is_a(ctx.plugin, lport, lv2_InputPort)) {
             port.is_input = true;
         } else if (!c.lilv_port_is_a(ctx.plugin, lport, lv2_OutputPort) and !port.optional) {
-            std.debug.warn("Port {} is neither input or output\n", i);
+            log.debug("Port {d} is neither input or output", .{i});
             return error.UnassignedIOPort;
         }
 
@@ -142,7 +136,7 @@ pub fn setupPorts(ctx: *plugin.Context) ![]*Port {
                 ctx.n_audio_out += 1;
             }
         } else if (!port.optional) {
-            std.debug.warn("Port {} has unsupported type\n", i);
+            log.debug("Port {d} has unsupported type", .{i});
             return error.UnsupportedPortType;
         }
     }

src/magick.zig

@@ -2,9 +2,12 @@
 const std = @import("std");
 const images = @import("image.zig");
 
+const log = std.log.scoped(.scritcher_magick);
 const Image = images.Image;
 
-const mc = @import("magick_wand.zig");
+const mc = @cImport({
+    @cInclude("wand/magick_wand.h");
+});
 
 pub const MagickContext = struct {
     wand: *mc.MagickWand,
@@ -12,7 +15,7 @@ pub const MagickContext = struct {
     pub fn init() !MagickContext {
         mc.InitializeMagick(null);
 
-        var wand = mc.NewMagickWand();
+        const wand = mc.NewMagickWand();
         if (wand == null) return error.WandCreateFail;
 
         return MagickContext{
@@ -26,6 +29,7 @@ pub const MagickContext = struct {
     }
 
     pub fn doErr(self: *MagickContext) !void {
+        _ = self;
         return error.WandError;
     }
 };
@@ -34,10 +38,10 @@ fn magickLoad(image: *Image) !MagickContext {
     var mctx = try MagickContext.init();
     errdefer mctx.deinit();
 
-    var curpath = try std.cstr.addNullByte(image.allocator, image.curpath);
+    const curpath = try image.allocator.dupeZ(u8, image.curpath);
     defer image.allocator.free(curpath);
 
-    std.debug.warn("loading '{}'\n", curpath);
+    log.debug("loading '{s}'", .{curpath});
 
     if (mc.MagickReadImage(mctx.wand, curpath.ptr) != 1)
         return error.MagickReadFail;
@@ -48,17 +52,18 @@ fn magickLoad(image: *Image) !MagickContext {
 fn magickSave(image: *Image, wand: *mc.MagickWand) !void {
     const allocator = image.allocator;
 
-    var tmpnam = try images.temporaryName(allocator);
-    var c_tmpnam = try std.cstr.addNullByte(allocator, tmpnam);
+    const tmpnam = try images.temporaryName(allocator);
+    const c_tmpnam = try allocator.dupeZ(u8, tmpnam);
     defer allocator.free(c_tmpnam);
 
-    std.debug.warn("\tmagick: saving to '{}'..", c_tmpnam);
+    log.debug("\tmagick: saving to '{s}'..", .{c_tmpnam});
 
     if (mc.MagickWriteImage(wand, c_tmpnam.ptr) != 1)
         return error.MagickWriteFail;
 
-    image.curpath = tmpnam;
-    std.debug.warn("OK\n");
+    log.debug("OK", .{});
+
+    try image.reopen(tmpnam);
 }
 
 /// Rotate the given image.
@@ -67,7 +72,7 @@ pub fn runRotate(image: *Image, deg: f32, bgfill: []const u8) !void {
     var mctx = try magickLoad(image);
     defer mctx.deinit();
 
-    var bg = mc.NewPixelWand();
+    const bg = mc.NewPixelWand();
     defer mc.DestroyPixelWand(bg);
 
     if (mc.PixelSetColor(bg, bgfill.ptr) != 1)

src/main.zig

@@ -1,33 +1,258 @@
 const std = @import("std");
 const langs = @import("lang.zig");
 const runners = @import("runner.zig");
+const printer = @import("printer.zig");
 
-pub fn main() !void {
-    var arena = std.heap.ArenaAllocator.init(std.heap.c_allocator);
-    defer arena.deinit();
+const log = std.log.scoped(.scritcher);
 
-    const allocator = &arena.allocator;
+test "scritcher" {
+    _ = @import("lang.zig");
+    _ = @import("runner.zig");
+}
+
+const readline = @cImport({
+    @cInclude("stdio.h");
+    @cInclude("stdlib.h");
+
+    @cInclude("readline/readline.h");
+    @cInclude("readline/history.h");
+});
+
+fn wrapInCmdList(allocator: std.mem.Allocator, cmd: *langs.Command) !langs.CommandList {
+    var cmds = langs.CommandList.init(allocator);
+    try cmds.append(cmd);
+    return cmds;
+}
+
+fn copyCommandToHeap(allocator: std.mem.Allocator, command: langs.Command, comptime tag: langs.Command.Tag) !*langs.Command {
+    const CommandStruct = langs.Command.tagToType(tag);
+    const casted = command.cast(CommandStruct).?;
+    var heap_cmd = try allocator.create(CommandStruct);
+
+    heap_cmd.* = casted.*;
+    log.debug("casted: {}", .{casted});
+    log.debug("heap_cmd: {}", .{heap_cmd});
+
+    return &heap_cmd.base;
+}
+
+pub fn doRepl(allocator: std.mem.Allocator, args_it: anytype) !void {
+    var stdout_file = std.io.getStdOut();
+    const stdout = &stdout_file.writer();
+    const scri_path = (args_it.next() orelse @panic("expected scri path"));
+    errdefer allocator.free(scri_path);
+    defer allocator.free(scri_path);
+
+    var file_read_opt: ?std.fs.File = std.fs.cwd().openFile(scri_path, .{}) catch |err| blk: {
+        if (err == error.FileNotFound) break :blk null;
+        return err;
+    };
+    const total_bytes = if (file_read_opt) |file_read| try file_read.getEndPos() else 0;
+
+    var cmds = langs.CommandList.init(allocator);
+    defer cmds.deinit();
 
     var lang = langs.Lang.init(allocator);
-    //defer lang.deinit();
+    defer lang.deinit();
 
-    var runner = runners.Runner.init(allocator);
+    if (total_bytes > 0) {
+        const scri_existing = try allocator.alloc(u8, total_bytes);
+        _ = try file_read_opt.?.read(scri_existing);
+        defer allocator.free(scri_existing);
+
+        // we can't defer this directly because we copy the
+        // Command pointers to the cmds list. running deinit() directly
+        // would cause those pointers to be freed.
+        var existing_cmds = try lang.parse(scri_existing);
+        defer existing_cmds.list.deinit();
+
+        // copy the existing command list into the repl's command list
+        for (existing_cmds.list.items) |existing_cmd| {
+            try cmds.append(existing_cmd);
+        }
+    } else {
+        // if there isn't any commands on the file, we load our default
+        // 'load :0' command
+
+        // TODO: deliberate memleak here. we only allocate this
+        // command once, for the start of the file, so.
+        var load_cmd = try allocator.create(langs.Command.Load);
+        load_cmd.path = ":0";
+        load_cmd.base.tag = langs.Command.Tag.load;
+
+        // taking address is fine, because load_cmd lives in the lifetime
+        // of the allocator.
+        try cmds.append(&load_cmd.base);
+    }
+
+    if (file_read_opt) |file_read| {
+        file_read.close();
+    }
+
+    var file = try std.fs.cwd().createFile(scri_path, .{
+        .read = false,
+        .truncate = true,
+    });
+    defer file.close();
+
+    var out = file.writer();
+    const stream = &out;
+
+    // since we opened the file for writing, it becomes empty, so, to ensure
+    // we don't fuck up later on, we print cmds before starting the repl
+    try printer.printList(cmds, stdout);
+    try printer.printList(cmds, stream);
+
+    // we keep
+    //  - a CommandList with the full commands we have right now
+    //  - a Command with the current last typed successful command
+
+    //  - one runner that contains the current full state of the image
+    //     as if the current cmds was ran over it (TODO better wording)
+    //  - one runner that gets copied from the original on every new
+    //    command the user issues
+
+    var current: langs.Command = undefined;
+
+    var runner = runners.Runner.init(allocator, true);
     defer runner.deinit();
 
-    var args_it = std.process.args();
+    // run the load command
+    try runner.runCommands(cmds, true);
 
-    const exe_name = try (args_it.next(allocator) orelse @panic("expected exe name"));
+    const wanted_runner: []const u8 = std.posix.getenv("SCRITCHER_RUNNER") orelse "ristretto";
 
-    // args[1] is the path to scri file
-    const scri_path = try (args_it.next(allocator) orelse @panic("expected scri path"));
+    var runqs_cmd = langs.Command.RunQS{
+        .base = langs.Command{ .tag = langs.Command.Tag.runqs },
+        .program = wanted_runner,
+    };
 
-    var file = try std.fs.File.openRead(scri_path);
+    while (true) {
+        lang.reset();
+
+        var rd_line = readline.readline("> ");
+        if (rd_line == null) {
+            log.debug("leaving from eof", .{});
+            break;
+        }
+        readline.add_history(rd_line);
+        //defer std.heap.c_allocator.destroy(rd_line);
+
+        const line = rd_line[0..std.mem.len(rd_line)];
+
+        if (std.mem.eql(u8, line, "push")) {
+            const heap_cmd = switch (current.tag) {
+                .noop => try copyCommandToHeap(allocator, current, .noop),
+                .load => try copyCommandToHeap(allocator, current, .load),
+                .quicksave => try copyCommandToHeap(allocator, current, .quicksave),
+                .runqs => try copyCommandToHeap(allocator, current, .runqs),
+                .amp => try copyCommandToHeap(allocator, current, .amp),
+                .rflanger => try copyCommandToHeap(allocator, current, .rflanger),
+                .eq => try copyCommandToHeap(allocator, current, .eq),
+                .phaser => try copyCommandToHeap(allocator, current, .phaser),
+                .mbeq => try copyCommandToHeap(allocator, current, .mbeq),
+                .chorus => try copyCommandToHeap(allocator, current, .chorus),
+                .pitchscaler => try copyCommandToHeap(allocator, current, .pitchscaler),
+                .reverb => try copyCommandToHeap(allocator, current, .reverb),
+                .highpass => try copyCommandToHeap(allocator, current, .highpass),
+                .delay => try copyCommandToHeap(allocator, current, .delay),
+                .vinyl => try copyCommandToHeap(allocator, current, .vinyl),
+                .revdelay => try copyCommandToHeap(allocator, current, .revdelay),
+                .gate => try copyCommandToHeap(allocator, current, .gate),
+                .detune => try copyCommandToHeap(allocator, current, .detune),
+                .overdrive => try copyCommandToHeap(allocator, current, .overdrive),
+                .degrade => try copyCommandToHeap(allocator, current, .degrade),
+                .repsycho => try copyCommandToHeap(allocator, current, .repsycho),
+                .talkbox => try copyCommandToHeap(allocator, current, .talkbox),
+                .dyncomp => try copyCommandToHeap(allocator, current, .dyncomp),
+                .thruzero => try copyCommandToHeap(allocator, current, .thruzero),
+                .foverdrive => try copyCommandToHeap(allocator, current, .foverdrive),
+                .gverb => try copyCommandToHeap(allocator, current, .gverb),
+                .invert => try copyCommandToHeap(allocator, current, .invert),
+                .tapedelay => try copyCommandToHeap(allocator, current, .tapedelay),
+                .moddelay => try copyCommandToHeap(allocator, current, .moddelay),
+                .multichorus => try copyCommandToHeap(allocator, current, .multichorus),
+                .saturator => try copyCommandToHeap(allocator, current, .saturator),
+                .vintagedelay => try copyCommandToHeap(allocator, current, .vintagedelay),
+                .noise => try copyCommandToHeap(allocator, current, .noise),
+                .wildnoise => try copyCommandToHeap(allocator, current, .wildnoise),
+                .write => try copyCommandToHeap(allocator, current, .write),
+                .embed => try copyCommandToHeap(allocator, current, .embed),
+                .rotate => try copyCommandToHeap(allocator, current, .rotate),
+            };
+
+            try cmds.append(heap_cmd);
+
+            // run the current added command to main cmds list
+            // with the main parent runner
+            var cmds_wrapped = try wrapInCmdList(allocator, heap_cmd);
+            defer cmds_wrapped.deinit();
+            try runner.runCommands(cmds_wrapped, true);
+
+            continue;
+        } else if (std.mem.eql(u8, line, "list")) {
+            try printer.printList(cmds, stdout);
+            continue;
+        } else if (std.mem.eql(u8, line, "save")) {
+            // seek to 0 instead of appending the new command
+            // NOTE appending single command might be faster
+            try file.seekTo(0);
+            try printer.printList(cmds, stream);
+            continue;
+        } else if (std.mem.eql(u8, line, "quit") or std.mem.eql(u8, line, "q")) {
+            log.debug("leaving", .{});
+            break;
+        } else if (std.mem.startsWith(u8, line, "#")) {
+            continue;
+        }
+
+        var cmds_parsed = lang.parse(line) catch |err| {
+            log.debug("repl: error while parsing: {}", .{err});
+            continue;
+        };
+
+        // no command? ignore!
+        if (cmds_parsed.list.items.len == 0) continue;
+        current = cmds_parsed.list.items[0].*;
+
+        // by cloning the parent runner, we can iteratively write
+        // whatever command we want and only commit the good results
+        // back to the parent runner
+        var runner_clone = try runner.clone();
+        defer runner_clone.deinit();
+
+        // taking address is fine, because runqs_cmd lives in the lifetime
+        // of this function.
+        try cmds_parsed.append(&runqs_cmd.base);
+
+        try runner_clone.runCommands(cmds_parsed, true);
+        _ = try stdout.write("\n");
+    }
+}
+
+fn doHelp() void {
+    log.debug("scritcher!", .{});
+    log.debug("usage: scritcher [run|help|repl]", .{});
+    log.debug("\tscritcher run path_to_script.scri path_to_input_file.bmp", .{});
+    log.debug("\tscritcher repl path_to_script.scri path_to_input_file.bmp", .{});
+}
+
+fn doRun(allocator: std.mem.Allocator, args_it: anytype) !void {
+    var lang = langs.Lang.init(allocator);
+    defer lang.deinit();
+
+    var runner = runners.Runner.init(allocator, false);
+    defer runner.deinit();
+
+    const scri_path = (args_it.next() orelse @panic("run: expected scri path"));
+
+    var file = try std.fs.cwd().openFile(scri_path, .{});
     defer file.close();
 
     // sadly, we read it all into memory. such is life
     const total_bytes = try file.getEndPos();
 
-    var data = try allocator.alloc(u8, total_bytes);
+    const data = try allocator.alloc(u8, total_bytes);
     defer allocator.free(data);
     _ = try file.read(data);
 
@@ -36,3 +261,33 @@ pub fn main() !void {
 
     try runner.runCommands(cmds, true);
 }
+
+pub fn main() !void {
+    var allocator_instance = std.heap.GeneralPurposeAllocator(.{}){};
+    defer {
+        _ = allocator_instance.deinit();
+    }
+    const allocator = allocator_instance.allocator();
+
+    var args_it = try std.process.argsWithAllocator(allocator);
+    defer args_it.deinit();
+
+    _ = args_it.skip();
+    const cli_command_opt = args_it.next();
+    if (cli_command_opt == null) {
+        return doHelp();
+    }
+
+    const cli_command = cli_command_opt.?;
+
+    if (std.mem.eql(u8, cli_command, "help")) {
+        return doHelp();
+    } else if (std.mem.eql(u8, cli_command, "repl")) {
+        return try doRepl(allocator, &args_it);
+    } else if (std.mem.eql(u8, cli_command, "run")) {
+        return try doRun(allocator, &args_it);
+    } else {
+        log.debug("unknown command: '{s}'", .{cli_command});
+        return error.UnknownCommand;
+    }
+}

src/plugin.zig

@@ -3,6 +3,7 @@ const std = @import("std");
 const lv2 = @import("lv2_helpers.zig");
 const c = lv2.c;
 
+const log = std.log.scoped(.scritcher_plugin);
 const ImageError = @import("image.zig").ImageError;
 
 /// Control port
@@ -16,7 +17,7 @@ pub const Param = struct {
 
 /// List of parameters to be set to control ports.
 pub const ParamList = std.ArrayList(Param);
-pub const ParamMap = std.AutoHashMap([]const u8, f32);
+pub const ParamMap = std.StringHashMap(f32);
 
 /// Represents an absolute position in the image.
 pub const SeekPos = struct {
@@ -34,7 +35,8 @@ pub const Position = struct {
     index: usize,
 
     pub fn seekPos(self: Position, total_size: usize) SeekPos {
-        var tot = total_size / self.split;
+        std.debug.assert(self.index <= self.split);
+        const tot = total_size / self.split;
 
         return SeekPos{
             .start = self.index * tot,
@@ -45,7 +47,7 @@ pub const Position = struct {
 
 /// Represents the starting context for a single plugin run.
 pub const Context = struct {
-    allocator: *std.mem.Allocator,
+    allocator: std.mem.Allocator,
     world: *c.LilvWorld,
     plugin: *const c.LilvPlugin,
 
@@ -60,29 +62,11 @@ pub const Context = struct {
 
 /// Specific run context for non-plugins.
 pub const RunBuffers = struct {
-    allocator: *std.mem.Allocator,
-
-    in: []f32,
-    out: []f32,
-
-    pub fn init(allocator: *std.mem.Allocator) !RunBuffers {
-        // we allocate []f32 with size 2 to account for stereo plugins, however
-        // we only use &in_buf[0] and &out_buf[0], and don't use the
-        // (supposedly) right side of neither input or output.
-        var in_buf = try allocator.alloc(f32, 2);
-        std.mem.secureZero(f32, in_buf);
-
-        return RunBuffers{
-            .allocator = allocator,
-            .in = in_buf,
-            .out = try allocator.alloc(f32, 2),
-        };
-    }
-
-    pub fn deinit(self: *RunBuffers) void {
-        self.allocator.free(self.in);
-        self.allocator.free(self.out);
-    }
+    // we use [2]f32 to account for stereo plugins, however
+    // we only use in_buf[0] and out_buf[0], and don't use the
+    // (supposedly) right side of neither input or output.
+    in: [2]f32 = [_]f32{0} ** 2,
+    out: [2]f32 = [_]f32{0} ** 2,
 };
 
 /// Represents the specific run context of plugin instantation.
@@ -91,76 +75,86 @@ pub const RunContext = struct {
     instance: *c.LilvInstance,
 
     pub fn init(
-        allocator: *std.mem.Allocator,
+        allocator: std.mem.Allocator,
         plugin: *const c.LilvPlugin,
     ) !RunContext {
-        var instance = c.lilv_plugin_instantiate(plugin, f64(44100), null);
+        _ = allocator; // TODO batch RunBuffers?
+
+        const instance = c.lilv_plugin_instantiate(plugin, @as(f64, 44100), null);
+        errdefer c.lilv_instance_free(instance);
+
         if (instance == null) {
             return ImageError.InstantiateFail;
         }
 
-        // we allocate []f32 with size 2 to account for stereo plugins, however
-        // we only use &in_buf[0] and &out_buf[0], and don't use the
-        // (supposedly) right side of neither input or output.
-        var in_buf = try allocator.alloc(f32, 2);
-        std.mem.secureZero(f32, in_buf);
-
         return RunContext{
-            .buffers = try RunBuffers.init(allocator),
+            .buffers = RunBuffers{},
             .instance = instance.?,
         };
     }
 
     pub fn deinit(self: *RunContext) void {
         c.lilv_instance_free(self.instance);
-        self.buffers.deinit();
     }
 
-    pub fn connectPorts(self: *RunContext, ports: []*lv2.Port) void {
+    pub fn connectPorts(self: *RunContext, ports: []lv2.Port) void {
         var i: usize = 0;
         var o: usize = 0;
 
-        var in_buf = self.buffers.in;
-        var out_buf = self.buffers.out;
-
-        for (ports) |port, p_idx| {
-            var p = @intCast(u32, p_idx);
+        for (ports, 0..) |_, p_idx| {
+            const p = @as(u32, @intCast(p_idx));
+            var port: *lv2.Port = &ports[p_idx];
 
             switch (port.ptype) {
                 .Control => lv2.lilv_instance_connect_port(self.instance, p, &port.value),
-                .Audio => blk: {
+                .Audio => {
                     if (port.is_input) {
-                        lv2.lilv_instance_connect_port(self.instance, p, &in_buf[i]);
+                        lv2.lilv_instance_connect_port(
+                            self.instance,
+                            p,
+                            &self.buffers.in[i],
+                        );
                         i += 1;
                     } else {
-                        lv2.lilv_instance_connect_port(self.instance, p, &out_buf[o]);
+                        lv2.lilv_instance_connect_port(
+                            self.instance,
+                            p,
+                            &self.buffers.out[o],
+                        );
                         o += 1;
                     }
                 },
-                else => lv2.lilv_instance_connect_port(self.instance, p, null),
+                // else => lv2.lilv_instance_connect_port(self.instance, p, null),
             }
         }
     }
 };
 
-pub fn makeContext(allocator: *std.mem.Allocator, plugin_uri: []const u8) !Context {
-    const cstr_plugin_uri = try std.cstr.addNullByte(allocator, plugin_uri);
-    var world = c.lilv_world_new().?;
+pub fn makeContext(allocator: std.mem.Allocator, plugin_uri: []const u8) !Context {
+    const cstr_plugin_uri = try allocator.dupeZ(u8, plugin_uri);
+    defer allocator.free(cstr_plugin_uri);
+
+    const world: *c.LilvWorld = c.lilv_world_new().?;
+    errdefer c.lilv_world_free(world);
 
     c.lilv_world_load_all(world);
-    var uri: *c.LilvNode = c.lilv_new_uri(world, cstr_plugin_uri.ptr) orelse blk: {
-        std.debug.warn("Invalid plugin URI <{}>\n", plugin_uri);
+
+    const uri: *c.LilvNode = c.lilv_new_uri(world, cstr_plugin_uri.ptr) orelse {
+        log.debug("Invalid plugin URI <{s}>", .{plugin_uri});
         return ImageError.InvalidPlugin;
     };
+    defer c.lilv_node_free(uri);
 
-    const plugins: *const c.LilvPlugins = c.lilv_world_get_all_plugins(world);
+    const plugins: *const c.LilvPlugins = c.lilv_world_get_all_plugins(world).?;
 
-    var plugin: *const c.LilvPlugin = c.lilv_plugins_get_by_uri(plugins, uri) orelse blk: {
-        std.debug.warn("Plugin <{}> not found\n", plugin_uri);
+    const plugin: *const c.LilvPlugin = c.lilv_plugins_get_by_uri(plugins, uri) orelse {
+        log.debug("Plugin <{s}> not found", .{plugin_uri});
         return ImageError.UnknownPlugin;
     };
 
-    c.lilv_node_free(uri);
-
-    return Context{ .allocator = allocator, .world = world, .plugin = plugin };
+    return Context{
+        .allocator = allocator,
+        .world = world,
+        .plugin = plugin,
+    };
 }

src/printer.zig

@@ -0,0 +1,88 @@
+const std = @import("std");
+const langs = @import("lang.zig");
+
+const log = std.log.scoped(.scritcher_printer);
+
+fn printCommandWithParams(stream: anytype, command: anytype) !void {
+    const Parameters = @TypeOf(command.parameters);
+    try stream.print(" {d} {d}", .{ command.split, command.index });
+    inline for (@typeInfo(Parameters).Struct.fields) |field| {
+        if (field.type == f32 or field.type == f64) {
+            try stream.print(" {}", .{@field(command.parameters, field.name)});
+        } else if (field.type == usize or field.type == u64) {
+            try stream.print(" {d}", .{@field(command.parameters, field.name)});
+        } else {
+            try stream.print(" {s}", .{@field(command.parameters, field.name)});
+        }
+    }
+}
+
+fn printCommand(stream: anytype, cmd: *langs.Command, comptime tag: langs.Command.Tag) !void {
+    const CommandStruct = langs.Command.tagToType(tag);
+    const casted = cmd.cast(CommandStruct).?;
+
+    const ctype = CommandStruct.command_type;
+    switch (ctype) {
+        .lv2_command => try printCommandWithParams(stream, casted),
+        .custom_command => try printCommandWithParams(stream, casted),
+    }
+}
+
+pub fn printList(list: langs.CommandList, stream: anytype) !void {
+    for (list.list.items) |cmd| {
+        const command = @tagName(cmd.tag);
+        try stream.print("{s}", .{command});
+
+        switch (cmd.tag) {
+            .load => {
+                const load = cmd.cast(langs.Command.Load).?;
+                try stream.print(" {s}", .{load.path});
+            },
+            .runqs => {
+                const runqs = cmd.cast(langs.Command.RunQS).?;
+                try stream.print(" {s}", .{runqs.program});
+            },
+            .noop, .quicksave => {},
+            .rotate => {
+                const rotate = cmd.cast(langs.Command.Rotate).?;
+                try stream.print(" {d} {s}", .{ rotate.deg, rotate.bgfill });
+            },
+
+            .amp => try printCommand(stream, cmd, .amp),
+            .rflanger => try printCommand(stream, cmd, .rflanger),
+            .eq => try printCommand(stream, cmd, .eq),
+            .phaser => try printCommand(stream, cmd, .phaser),
+            .mbeq => try printCommand(stream, cmd, .mbeq),
+            .chorus => try printCommand(stream, cmd, .chorus),
+            .pitchscaler => try printCommand(stream, cmd, .pitchscaler),
+            .reverb => try printCommand(stream, cmd, .reverb),
+            .highpass => try printCommand(stream, cmd, .highpass),
+            .delay => try printCommand(stream, cmd, .delay),
+            .vinyl => try printCommand(stream, cmd, .vinyl),
+            .revdelay => try printCommand(stream, cmd, .revdelay),
+            .gate => try printCommand(stream, cmd, .gate),
+            .detune => try printCommand(stream, cmd, .detune),
+            .overdrive => try printCommand(stream, cmd, .overdrive),
+            .degrade => try printCommand(stream, cmd, .degrade),
+            .repsycho => try printCommand(stream, cmd, .repsycho),
+            .talkbox => try printCommand(stream, cmd, .talkbox),
+            .dyncomp => try printCommand(stream, cmd, .dyncomp),
+            .thruzero => try printCommand(stream, cmd, .thruzero),
+            .foverdrive => try printCommand(stream, cmd, .foverdrive),
+            .gverb => try printCommand(stream, cmd, .gverb),
+            .invert => try printCommand(stream, cmd, .invert),
+            .tapedelay => try printCommand(stream, cmd, .tapedelay),
+            .moddelay => try printCommand(stream, cmd, .moddelay),
+            .multichorus => try printCommand(stream, cmd, .multichorus),
+            .saturator => try printCommand(stream, cmd, .saturator),
+            .vintagedelay => try printCommand(stream, cmd, .vintagedelay),
+
+            .noise => try printCommand(stream, cmd, .noise),
+            .wildnoise => try printCommand(stream, cmd, .wildnoise),
+            .write => try printCommand(stream, cmd, .write),
+            .embed => try printCommand(stream, cmd, .embed),
+        }
+
+        _ = try stream.write(";\n");
+    }
+}

src/runner.zig

@@ -5,6 +5,8 @@ const plugin = @import("plugin.zig");
 const custom = @import("custom.zig");
 const magick = @import("magick.zig");
 
+const log = std.log.scoped(.scritcher_runner);
+
 const Position = plugin.Position;
 const ParamList = plugin.ParamList;
 const ParamMap = plugin.ParamMap;
@@ -18,12 +20,21 @@ pub const RunError = error{
 };
 
 pub const Runner = struct {
-    allocator: *std.mem.Allocator,
+    allocator: std.mem.Allocator,
+
+    /// The currently opened image in the runner
     image: ?*Image = null,
 
-    pub fn init(allocator: *std.mem.Allocator) Runner {
+    /// If the runner is in REPL mode
+    repl: bool,
+
+    args: []const [:0]u8,
+
+    pub fn init(allocator: std.mem.Allocator, repl: bool) Runner {
         return Runner{
             .allocator = allocator,
+            .repl = repl,
+            .args = std.process.argsAlloc(allocator) catch unreachable,
         };
     }
 
@@ -31,41 +42,59 @@ pub const Runner = struct {
         if (self.image) |image| {
             image.close();
         }
+
+        std.process.argsFree(self.allocator, self.args);
+    }
+
+    pub fn clone(self: *Runner) !Runner {
+        const cloned_image = if (self.image) |image| try image.clone() else null;
+        return Runner{
+            .allocator = self.allocator,
+            .image = cloned_image,
+            .repl = self.repl,
+            .args = self.args,
+        };
     }
 
     fn resolveArg(self: *Runner, load_path: []const u8) ![]const u8 {
+        std.debug.assert(load_path.len > 0);
         if (load_path[0] == ':') {
             // parse the index from 1 to end
-            const index = try std.fmt.parseInt(usize, load_path[1..], 10);
-            var args_it = std.process.args();
-            _ = args_it.skip();
+            var index = try std.fmt.parseInt(usize, load_path[1..], 10);
 
-            var i: usize = 0;
-            while (i <= index) : (i += 1) {
-                _ = args_it.skip();
+            // if it isn't in the repl, args look like this:
+            // 'scritcher ./script ./image'
+            // if it is, it looks like this
+            // 'scritcher repl ./script ./image'
+
+            // ':0' should ALWAYS point to the image.
+            if (self.repl) index += 3 else index += 3;
+
+            for (self.args, 0..) |arg, idx| {
+                log.debug("arg{d} = {s}", .{ idx, arg });
             }
-
-            const arg = try (args_it.next(self.allocator) orelse @panic("expected argument"));
-
-            return arg;
+            log.debug("fetch arg idx={d}", .{index});
+            log.debug("fetch arg val={s}", .{self.args[index]});
+            return self.args[index];
         } else {
             return load_path;
         }
     }
 
+    // Caller owns returned memory.
     fn resolveArgPath(self: *Runner, path_or_argidx: []const u8) ![]const u8 {
         const path = try self.resolveArg(path_or_argidx);
         const resolved_path = try std.fs.path.resolve(
             self.allocator,
-            [_][]const u8{path},
+            &[_][]const u8{path},
         );
 
         return resolved_path;
     }
 
     fn loadCmd(self: *Runner, path_or_argidx: []const u8) !void {
-        var load_path = try self.resolveArgPath(path_or_argidx);
-        std.debug.warn("load path: {}\n", load_path);
+        const load_path = try self.resolveArgPath(path_or_argidx);
+        log.debug("\tload path: {s}", .{load_path});
 
         // we could use ImageMagick to convert from X to BMP
         // but i can't find an easy way to do things in memory.
@@ -74,14 +103,15 @@ pub const Runner = struct {
         // before loading the file into scritcher. for example, you can start
         // krita/gimp and make it export a bmp and while in the program you can
         // apply filters, etc.
-        if (!std.mem.endsWith(u8, load_path, ".bmp")) {
-            std.debug.warn("Only BMP files are allowed to be loaded.\n");
+        if (!std.mem.endsWith(u8, load_path, ".bmp") and !std.mem.endsWith(u8, load_path, ".ppm")) {
+            log.debug("Only BMP files are allowed to be loaded. Got path '{s}'", .{load_path});
             return RunError.NoBMP;
         }
 
         // we don't copy load_path into a temporary file because we're already
         // loading it under the SFM_READ mode, which won't cause any destructive
         // operations on the file.
+        if (self.image) |image| image.close();
         self.image = try Image.open(self.allocator, load_path);
     }
 
@@ -89,20 +119,21 @@ pub const Runner = struct {
         if (self.image) |image| {
             return image;
         } else {
-            std.debug.warn("image is required!\n");
+            log.debug("image is required!", .{});
             return RunError.ImageRequired;
         }
     }
 
+    /// Caller owns returned memory.
     fn makeGlitchedPath(self: *Runner) ![]const u8 {
         // we want to transform basename, if it is "x.bmp" to "x_gN.bmp", where
         // N is the maximum non-used integer.
-        var image = try self.getImage();
+        const image = try self.getImage();
 
         const basename = std.fs.path.basename(image.path);
         const dirname = std.fs.path.dirname(image.path).?;
 
-        var dir = try std.fs.Dir.open(self.allocator, dirname);
+        var dir = try std.fs.cwd().openDir(dirname, .{ .iterate = true });
         defer dir.close();
 
         const period_idx = std.mem.lastIndexOf(u8, basename, ".").?;
@@ -110,17 +141,18 @@ pub const Runner = struct {
 
         // starts_with would be "x_g", we want to find all files in the directory
         // that start with that name.
-        const starts_with = try std.fmt.allocPrint(
-            self.allocator,
-            "{}_g",
+        const starts_with = try std.fmt.allocPrint(self.allocator, "{s}_g", .{
             basename[0..period_idx],
-        );
+        });
+        defer self.allocator.free(starts_with);
 
         var max: usize = 0;
 
-        while (try dir.next()) |entry| {
+        var it = dir.iterate();
+
+        while (try it.next()) |entry| {
             switch (entry.kind) {
-                .File => blk: {
+                .file => blk: {
                     if (!std.mem.startsWith(u8, entry.name, starts_with)) break :blk {};
 
                     // we want to get the N in x_gN.ext
@@ -134,6 +166,8 @@ pub const Runner = struct {
                     // if N isn't a number, we just ignore that file
                     const idx_str = entry.name[entry_gidx + 2 .. entry_pidx];
                     const idx = std.fmt.parseInt(usize, idx_str, 10) catch |err| {
+                        log.debug("ignoring file {s}", .{@errorName(err)});
+
                         break :blk {};
                     };
 
@@ -143,14 +177,12 @@ pub const Runner = struct {
             }
         }
 
-        const out_path = try std.fmt.allocPrint(
-            self.allocator,
-            "{}/{}{}{}",
+        const out_path = try std.fmt.allocPrint(self.allocator, "{s}/{s}{d}{s}", .{
             dirname,
             starts_with,
             max + 1,
             extension,
-        );
+        });
 
         return out_path;
     }
@@ -158,303 +190,156 @@ pub const Runner = struct {
     fn quicksaveCmd(self: *Runner) !void {
         var image = try self.getImage();
         const out_path = try self.makeGlitchedPath();
+        defer self.allocator.free(out_path);
         try image.saveTo(out_path);
     }
 
-    fn runQSCmd(self: *Runner, program: []const u8) !void {
+    fn runQSCmd(self: *Runner, cmd: *lang.Command) !void {
+        const runqs = cmd.cast(lang.Command.RunQS).?;
         var image = try self.getImage();
         const out_path = try self.makeGlitchedPath();
+        defer self.allocator.free(out_path);
         try image.saveTo(out_path);
 
-        var proc = try std.ChildProcess.init(
-            [_][]const u8{ program, out_path },
+        var proc = std.ChildProcess.init(
+            &[_][]const u8{ runqs.program, out_path },
             self.allocator,
         );
-        defer proc.deinit();
+        //defer proc.deinit();
 
-        std.debug.warn("running '{} {}'", program, out_path);
+        log.debug("running '{s} {s}'", .{ runqs.program, out_path });
         _ = try proc.spawnAndWait();
     }
 
-    /// Run the http://lv2plug.in/plugins/eg-amp plugin over the file.
-    fn ampCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://lv2plug.in/plugins/eg-amp", pos, params);
+    fn rotateCmd(self: *Runner, cmd: *lang.Command) !void {
+        const rotate_cmd = cmd.cast(lang.Command.Rotate).?;
+
+        const image = try self.getImage();
+        const c_bgfill = try self.allocator.dupeZ(u8, rotate_cmd.bgfill);
+        defer self.allocator.free(c_bgfill);
+
+        try magick.runRotate(image, rotate_cmd.deg, c_bgfill);
     }
 
-    fn rFlangerCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/retroFlange", pos, params);
-    }
+    fn executeLV2Command(self: *@This(), command: anytype) !void {
+        const pos = plugin.Position{
+            .split = command.split,
+            .index = command.index,
+        };
 
-    fn eqCmd(self: *Runner, position: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/dj_eq_mono", position, params);
-    }
-
-    fn phaserCmd(self: *Runner, position: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/lfoPhaser", position, params);
-    }
-
-    fn mbeqCmd(self: *Runner, position: Position, bands: []const f32) !void {
-        var image = try self.getImage();
         var params = ParamList.init(self.allocator);
         defer params.deinit();
 
-        for (bands) |band_value, idx| {
-            var sym = try std.fmt.allocPrint(self.allocator, "band_{}", idx + 1);
+        const typ = @TypeOf(command);
+
+        inline for (@typeInfo(@TypeOf(command.parameters)).Struct.fields) |cmd_field| {
             try params.append(plugin.Param{
-                .sym = sym,
-                .value = band_value,
+                .sym = cmd_field.name,
+                .value = @field(command.parameters, cmd_field.name),
             });
         }
 
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/mbeq", position, params);
-    }
-
-    fn chorusCmd(self: *Runner, pos: Position, params: ParamList) !void {
         var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/multivoiceChorus", pos, params);
+        try image.runPlugin(typ.lv2_url, pos, params);
     }
 
-    fn pitchScalerCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/pitchScaleHQ", pos, params);
-    }
-
-    fn reverbCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://invadarecords.com/plugins/lv2/erreverb/mono", pos, params);
-    }
-
-    fn highpassCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://invadarecords.com/plugins/lv2/filter/hpf/mono", pos, params);
-    }
-
-    fn delayCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/delayorama", pos, params);
-    }
-
-    fn vinylCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/vynil", pos, params);
-    }
-
-    fn revDelayCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/revdelay", pos, params);
-    }
-
-    fn noiseCmd(self: *Runner, pos: Position, map: *ParamMap) !void {
-        var image = try self.getImage();
-        try image.runCustomPlugin(custom.RandomNoise, pos, map);
-    }
-
-    fn wildNoiseCmd(self: *Runner, pos: Position, map: *ParamMap) !void {
-        var image = try self.getImage();
-        try image.runCustomPlugin(custom.WildNoise, pos, map);
-    }
-
-    fn rotateCmd(
-        self: *Runner,
-        deg: f32,
-        bgfill: []const u8,
-    ) !void {
-        var image = try self.getImage();
-        var c_bgfill = try std.cstr.addNullByte(self.allocator, bgfill);
-        defer self.allocator.free(c_bgfill);
-
-        try magick.runRotate(image, deg, c_bgfill);
-    }
-
-    fn runCommand(self: *Runner, cmd: *lang.Command) !void {
-        var params = ParamList.init(self.allocator);
-        defer params.deinit();
-
-        var map = ParamMap.init(self.allocator);
-        defer map.deinit();
-
-        return switch (cmd.command) {
-            .Noop => {},
-            .Load => blk: {
-                var path = cmd.args.at(0);
-                try self.loadCmd(path);
-                break :blk;
-            },
-            .Quicksave => try self.quicksaveCmd(),
-            .RunQS => try self.runQSCmd(cmd.args.at(0)),
-
-            .Amp => blk: {
-                const pos = try cmd.consumePosition();
-                try cmd.appendParam(&params, "gain");
-                try self.ampCmd(pos, params);
-            },
-
-            .RFlanger => blk: {
-                const pos = try cmd.consumePosition();
-                try cmd.appendParam(&params, "delay_depth_avg");
-                try cmd.appendParam(&params, "law_freq");
-                try self.rFlangerCmd(pos, params);
-            },
-
-            .Eq => blk: {
-                const pos = try cmd.consumePosition();
-                try cmd.appendParam(&params, "lo");
-                try cmd.appendParam(&params, "mid");
-                try cmd.appendParam(&params, "hi");
-
-                try self.eqCmd(pos, params);
-            },
-
-            .Phaser => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParam(&params, "lfo_rate");
-                try cmd.appendParam(&params, "lfo_depth");
-                try cmd.appendParam(&params, "fb");
-                try cmd.appendParam(&params, "spread");
-
-                try self.phaserCmd(pos, params);
-            },
-
-            .Mbeq => blk: {
-                const pos = try cmd.consumePosition();
-                const bands = try cmd.floatArgMany(self.allocator, 2, 15, f32(0));
-                try self.mbeqCmd(pos, bands);
-            },
-
-            .Chorus => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParam(&params, "voices");
-                try cmd.appendParam(&params, "delay_base");
-                try cmd.appendParam(&params, "voice_spread");
-                try cmd.appendParam(&params, "detune");
-                try cmd.appendParam(&params, "law_freq");
-                try cmd.appendParam(&params, "attendb");
-
-                try self.chorusCmd(pos, params);
-            },
-
-            .PitchScaler => blk: {
-                const pos = try cmd.consumePosition();
-                try cmd.appendParam(&params, "mult");
-                try self.pitchScalerCmd(pos, params);
-            },
-
-            .Reverb => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParam(&params, "roomLength");
-                try cmd.appendParam(&params, "roomWidth");
-                try cmd.appendParam(&params, "roomHeight");
-                try cmd.appendParam(&params, "sourceLR");
-                try cmd.appendParam(&params, "sourceFB");
-                try cmd.appendParam(&params, "listLR");
-                try cmd.appendParam(&params, "listFB");
-                try cmd.appendParam(&params, "hpf");
-                try cmd.appendParam(&params, "warmth");
-                try cmd.appendParam(&params, "diffusion");
-
-                try self.reverbCmd(pos, params);
-            },
-
-            .Highpass => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParam(&params, "freq");
-                try cmd.appendParam(&params, "gain");
-                try cmd.appendParam(&params, "noClip");
-
-                try self.highpassCmd(pos, params);
-            },
-
-            .Delay => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParam(&params, "seed");
-                try cmd.appendParam(&params, "gain");
-                try cmd.appendParam(&params, "feedback_pc");
-                try cmd.appendParam(&params, "tap_count");
-                try cmd.appendParam(&params, "first_delay");
-                try cmd.appendParam(&params, "delay_range");
-                try cmd.appendParam(&params, "delay_scale");
-                try cmd.appendParam(&params, "delay_rand_pc");
-                try cmd.appendParam(&params, "gain_scale");
-                try cmd.appendParam(&params, "wet");
-
-                try self.delayCmd(pos, params);
-            },
-
-            .Vinyl => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParam(&params, "year");
-                try cmd.appendParam(&params, "rpm");
-                try cmd.appendParam(&params, "warp");
-                try cmd.appendParam(&params, "click");
-                try cmd.appendParam(&params, "wear");
-
-                try self.vinylCmd(pos, params);
-            },
-
-            .RevDelay => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParam(&params, "delay_time");
-                try cmd.appendParam(&params, "dry_level");
-                try cmd.appendParam(&params, "wet_level");
-                try cmd.appendParam(&params, "feedback");
-                try cmd.appendParam(&params, "xfade_samp");
-
-                try self.revDelayCmd(pos, params);
-            },
-
-            .Noise => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParamMap(&map, "seed");
-                try cmd.appendParamMap(&map, "fill_bytes");
-
-                try self.noiseCmd(pos, &map);
-            },
-
-            .WildNoise => blk: {
-                const pos = try cmd.consumePosition();
-
-                try cmd.appendParamMap(&map, "seed");
-                try cmd.appendParamMap(&map, "fill_bytes");
-
-                try self.wildNoiseCmd(pos, &map);
-            },
-
-            .Rotate => blk: {
-                const deg = try cmd.floatArgAt(0);
-                const bgfill = try cmd.argAt(1);
-                try self.rotateCmd(deg, bgfill);
-            },
-
-            else => blk: {
-                std.debug.warn("Unsupported command: {}\n", cmd.command);
-                break :blk RunError.UnknownCommand;
-            },
+    fn executeCustomCommand(self: *@This(), command: anytype) !void {
+        const pos = plugin.Position{
+            .split = command.split,
+            .index = command.index,
         };
+
+        var image = try self.getImage();
+        try image.runCustomPlugin(@TypeOf(command).plugin_type, pos, command.parameters);
     }
 
+    fn runSingleCommand(
+        self: *@This(),
+        cmd: *lang.Command,
+        comptime tag: lang.Command.Tag,
+    ) !void {
+        const typ = lang.Command.tagToType(tag);
+        const command = cmd.cast(typ).?;
+        const ctype = typ.command_type;
+        switch (ctype) {
+            .lv2_command => try self.executeLV2Command(command.*),
+            .custom_command => try self.executeCustomCommand(command.*),
+        }
+    }
+
+    fn runCommand(self: *@This(), cmd: *lang.Command) !void {
+        switch (cmd.tag) {
+            .noop => {},
+            .load => {
+                const command = cmd.cast(lang.Command.Load).?;
+                try self.loadCmd(command.path);
+            },
+            .quicksave => try self.quicksaveCmd(),
+            .rotate => try self.rotateCmd(cmd),
+            .runqs => try self.runQSCmd(cmd),
+
+            .amp => try self.runSingleCommand(cmd, .amp),
+            .rflanger => try self.runSingleCommand(cmd, .rflanger),
+            .eq => try self.runSingleCommand(cmd, .eq),
+            .phaser => try self.runSingleCommand(cmd, .phaser),
+            .mbeq => try self.runSingleCommand(cmd, .mbeq),
+            .chorus => try self.runSingleCommand(cmd, .chorus),
+            .pitchscaler => try self.runSingleCommand(cmd, .pitchscaler),
+            .reverb => try self.runSingleCommand(cmd, .reverb),
+            .highpass => try self.runSingleCommand(cmd, .highpass),
+            .delay => try self.runSingleCommand(cmd, .delay),
+            .vinyl => try self.runSingleCommand(cmd, .vinyl),
+            .revdelay => try self.runSingleCommand(cmd, .revdelay),
+            .gate => try self.runSingleCommand(cmd, .gate),
+            .detune => try self.runSingleCommand(cmd, .detune),
+            .overdrive => try self.runSingleCommand(cmd, .overdrive),
+            .degrade => try self.runSingleCommand(cmd, .degrade),
+            .repsycho => try self.runSingleCommand(cmd, .repsycho),
+            .talkbox => try self.runSingleCommand(cmd, .talkbox),
+            .dyncomp => try self.runSingleCommand(cmd, .dyncomp),
+            .thruzero => try self.runSingleCommand(cmd, .thruzero),
+            .foverdrive => try self.runSingleCommand(cmd, .foverdrive),
+            .gverb => try self.runSingleCommand(cmd, .gverb),
+            .invert => try self.runSingleCommand(cmd, .invert),
+            .tapedelay => try self.runSingleCommand(cmd, .tapedelay),
+            .moddelay => try self.runSingleCommand(cmd, .moddelay),
+            .multichorus => try self.runSingleCommand(cmd, .multichorus),
+            .saturator => try self.runSingleCommand(cmd, .saturator),
+            .vintagedelay => try self.runSingleCommand(cmd, .vintagedelay),
+
+            .noise => try self.runSingleCommand(cmd, .noise),
+            .wildnoise => try self.runSingleCommand(cmd, .wildnoise),
+            .write => try self.runSingleCommand(cmd, .write),
+            .embed => try self.runSingleCommand(cmd, .embed),
+        }
+    }
     /// Run a list of commands.
     pub fn runCommands(
         self: *Runner,
         cmds: lang.CommandList,
         debug_flag: bool,
     ) !void {
-        var it = cmds.iterator();
-
-        while (it.next()) |cmd| {
-            if (debug_flag) cmd.print();
+        _ = debug_flag;
+        for (cmds.list.items) |cmd| {
+            cmd.print();
             try self.runCommand(cmd);
         }
     }
 };
+
+test "running noop" {
+    const allocator = std.testing.allocator;
+    var cmds = lang.CommandList.init(allocator);
+    defer cmds.deinit();
+
+    const command = lang.Command{ .tag = .noop };
+
+    var noop = try allocator.create(lang.Command.Noop);
+    noop.* = lang.Command.Noop{ .base = command };
+    try cmds.append(&noop.base);
+
+    var runner = Runner.init(allocator, false);
+    defer runner.deinit();
+
+    try runner.runCommands(cmds, false);
+}