enhance embed custom plugin

- seek to 0 on setup
 - ignore and copy original bytes if we reached end of audio file

.gitignore

@@ -1 +1,3 @@
 zig-cache/
+*.mp3
+*.wav

examples/embed.scri

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

src/custom.zig

@@ -2,6 +2,7 @@
 const std = @import("std");
 const lv2 = @import("lv2_helpers.zig");
 const plugins = @import("plugin.zig");
+const image = @import("image.zig");
 
 const c = lv2.c;
 
@@ -131,3 +132,63 @@ pub const Write = struct {
         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, filepath: []const u8) @This() {
+        return Embed{
+            .allocator = allocator,
+            .filepath = filepath,
+        };
+    }
+
+    pub fn setup(self: *@This()) !void {
+        var in_fmt = c.SF_INFO{
+            .frames = c_int(0),
+            .samplerate = c_int(0),
+            .channels = c_int(0),
+            .format = c_int(0),
+            .sections = c_int(0),
+            .seekable = 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, @intCast(usize, in_fmt.channels));
+    }
+
+    pub fn deinit(self: *@This()) void {}
+
+    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);
+            std.debug.warn(
+                "Failed to read {} ({})\n",
+                self.filepath,
+                c.sf_error_number(st),
+            );
+            return;
+        }
+
+        bufs.out[0] = bufs.in[0] + self.buf[0];
+    }
+};

src/image.zig

@@ -1,7 +1,6 @@
 const std = @import("std");
 const lv2 = @import("lv2_helpers.zig");
 const c = lv2.c;
-const custom = @import("custom.zig");
 const bmp = @import("bmp_valid.zig");
 
 const plugins = @import("plugin.zig");
@@ -23,7 +22,7 @@ pub const ImageError = error{
 };
 
 /// Low level integration function with libsndfile.
-fn sopen(
+pub fn sopen(
     allocator: *std.mem.Allocator,
     path: []const u8,
     mode: i32,
@@ -57,7 +56,7 @@ fn sopen(
     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) {
@@ -66,7 +65,7 @@ fn swrite(file: *c.SNDFILE, buf: [*]f32, frames: i64) !void {
     }
 }
 
-fn sseek(file: *c.SNDFILE, offset: usize) void {
+pub fn sseek(file: *c.SNDFILE, offset: usize) void {
     const offset_i64 = @intCast(i64, offset);
     const frames = c.sf_seek(file, offset_i64, c.SEEK_SET);
     const frames_current = c.sf_seek(file, 0, c.SEEK_CUR);
@@ -109,7 +108,7 @@ pub fn temporaryName(allocator: *std.mem.Allocator) ![]u8 {
     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),
@@ -422,9 +421,10 @@ pub const Image = struct {
         self: *Image,
         comptime Plugin: type,
         position: plugins.Position,
-        params: *plugins.ParamMap,
+        comptime ExtraType: type,
+        extra: ExtraType,
     ) !void {
-        var plugin_opt: ?Plugin = Plugin.init(self.allocator, params);
+        var plugin_opt: ?Plugin = Plugin.init(self.allocator, extra);
         if (plugin_opt == null) {
             return ImageError.PluginLoadFail;
         }
@@ -432,6 +432,13 @@ pub const Image = struct {
         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);

src/lang.zig

@@ -30,6 +30,7 @@ pub const CommandType = enum {
     Noise,
     WildNoise,
     Write,
+    Embed,
 
     Rotate,
 };
@@ -187,6 +188,7 @@ pub const Lang = struct {
         _ = try self.keywords.put("noise", .Noise);
         _ = try self.keywords.put("wildnoise", .WildNoise);
         _ = try self.keywords.put("write", .Write);
+        _ = try self.keywords.put("embed", .Embed);
 
         // even more custom
         _ = try self.keywords.put("rotate", .Rotate);
@@ -225,6 +227,7 @@ pub const Lang = struct {
             "noise",
             "wildnoise",
             "write",
+            "embed",
             "rotate",
         };
 
@@ -250,6 +253,7 @@ pub const Lang = struct {
             .Noise,
             .WildNoise,
             .Write,
+            .Embed,
 
             .Rotate,
         };
@@ -312,6 +316,7 @@ pub const Lang = struct {
             .WildNoise => try self.expectFloat(4, cmd.args),
             .Write => try self.expectFloat(3, cmd.args),
             .Rotate => try self.expectAny(2, cmd.args),
+            .Embed => try self.expectAny(3, cmd.args),
             else => std.debug.warn("WARN unchecked command {}\n", cmd.command),
         }
     }

src/printer.zig

@@ -24,6 +24,7 @@ pub fn printList(list: langs.CommandList, stream: var) !void {
             .Noise => "noise",
             .WildNoise => "wildnoise",
             .Write => "write",
+            .Embed => "embed",
 
             .Rotate => "rotate",
         };

src/runner.zig

@@ -266,17 +266,22 @@ pub const Runner = struct {
 
     fn noiseCmd(self: *Runner, pos: Position, map: *ParamMap) !void {
         var image = try self.getImage();
-        try image.runCustomPlugin(custom.RandomNoise, pos, map);
+        try image.runCustomPlugin(custom.RandomNoise, pos, *ParamMap, map);
     }
 
     fn wildNoiseCmd(self: *Runner, pos: Position, map: *ParamMap) !void {
         var image = try self.getImage();
-        try image.runCustomPlugin(custom.WildNoise, pos, map);
+        try image.runCustomPlugin(custom.WildNoise, pos, *ParamMap, map);
     }
 
     fn writeCmd(self: *Runner, pos: Position, map: *ParamMap) !void {
         var image = try self.getImage();
-        try image.runCustomPlugin(custom.Write, pos, map);
+        try image.runCustomPlugin(custom.Write, pos, *ParamMap, map);
+    }
+
+    fn embedCmd(self: *Runner, pos: Position, path: []const u8) !void {
+        var image = try self.getImage();
+        try image.runCustomPlugin(custom.Embed, pos, []const u8, path);
     }
 
     fn rotateCmd(
@@ -303,6 +308,8 @@ pub const Runner = struct {
             .Load => blk: {
                 var path = cmd.args.at(0);
                 try self.loadCmd(path);
+
+                // TODO is this needed?
                 break :blk;
             },
             .Quicksave => try self.quicksaveCmd(),
@@ -460,6 +467,12 @@ pub const Runner = struct {
                 try self.writeCmd(pos, &map);
             },
 
+            .Embed => blk: {
+                const pos = try cmd.consumePosition();
+                const path = cmd.args.at(2);
+                try self.embedCmd(pos, path);
+            },
+
             .Rotate => blk: {
                 const deg = try cmd.floatArgAt(0);
                 const bgfill = try cmd.argAt(1);