add chorus command

doc/README.md

@@ -62,6 +62,8 @@ Parameters:
 
 ## `mbeq split index band_1 band_2 band_3 band_4 band_5 band_6 band_7 band_8 band_9 band_10 band_11 band_12 band_13 band_14 band_15`
 
+Multiband EQ from the SWH plugins.
+
 In respective order, the band arugments represent the:
 50Hz, 100Hz, 156Hz, 220Hz, 311Hz, 440Hz, 622Hz, 880Hz 1250Hz, 1750Hz, 2500Hz,
 3500Hz, 5000Hz, 10000Hz and 20000Hz frequencies.
@@ -69,6 +71,18 @@ In respective order, the band arugments represent the:
 All of them represent the band's gain in dB. The range is -70 to +30dB,
 default is 0.
 
+## `chorus split index voices delay_base voice_spread detune law_freq attendb`
+
+Multivoice Chrorus from the SWH plugins.
+
+Parameters:
+ - `voices`: Number of voices (int), 1..8, default 1
+ - `delay_base`: Delay base (ms), 10..40, default 10
+ - `voice_spread`: Voice separation (ms), 0-2, default 0.5
+ - `detune`: Detune (%), 0..5, default 1
+ - `law_freq`: LFO frequency (Hz), 2..30, default 9
+ - `attendb`: Output attenuation (dB), -20..0, default 0
+
 ## TODO `echo split index delay`
 
 Run an echo filter on the given loaded file.

examples/chorus.scri

@@ -0,0 +1,3 @@
+load :0;
+chorus 3 1 3 10 0.5 1 9 0;
+quicksave;

src/lang.zig

@@ -18,6 +18,7 @@ pub const CommandType = enum {
     Eq,
     Phaser,
     Mbeq,
+    Chorus,
 };
 
 pub const Command = struct {
@@ -82,6 +83,19 @@ pub const Command = struct {
 
         return arr.toSliceConst();
     }
+
+    pub fn appendParam(
+        self: *const Command,
+        params: *plugin.ParamList,
+        symbol: []const u8,
+        idx: usize,
+    ) !void {
+        var val = try self.floatArgAt(idx);
+        try params.append(plugin.Param{
+            .sym = symbol,
+            .value = val,
+        });
+    }
 };
 
 pub const CommandList = std.ArrayList(*Command);
@@ -111,6 +125,7 @@ pub const Lang = struct {
         _ = try self.keywords.put("eq", .Eq);
         _ = try self.keywords.put("mbeq", .Mbeq);
         _ = try self.keywords.put("phaser", .Phaser);
+        _ = try self.keywords.put("chorus", .Chorus);
     }
 
     pub fn parse(self: *Lang, data: []const u8) !CommandList {

src/runner.zig

@@ -248,7 +248,19 @@ pub const Runner = struct {
         try image.runPlugin("http://plugin.org.uk/swh-plugins/mbeq", position, params);
     }
 
+    fn chorusCmd(
+        self: *Runner,
+        pos: plugin.Position,
+        params: plugin.ParamList,
+    ) !void {
+        var image = try self.getImage();
+        try image.runPlugin("http://plugin.org.uk/swh-plugins/multivoiceChorus", pos, params);
+    }
+
     fn runCommand(self: *Runner, cmd: *lang.Command) !void {
+        var params = plugin.ParamList.init(self.allocator);
+        defer params.deinit();
+
         return switch (cmd.command) {
             .Noop => {},
             .Load => blk: {
@@ -301,8 +313,21 @@ pub const Runner = struct {
                 try self.mbeqCmd(pos, bands);
             },
 
+            .Chorus => blk: {
+                const pos = try cmd.consumePosition();
+
+                try cmd.appendParam(&params, "voices", 2);
+                try cmd.appendParam(&params, "delay_base", 3);
+                try cmd.appendParam(&params, "voice_spread", 4);
+                try cmd.appendParam(&params, "detune", 5);
+                try cmd.appendParam(&params, "law_freq", 6);
+                try cmd.appendParam(&params, "attendb", 7);
+
+                try self.chorusCmd(pos, params);
+            },
+
             else => blk: {
-                std.debug.warn("Unknown command: {}\n", cmd.command);
+                std.debug.warn("Unsupported command: {}\n", cmd.command);
                 break :blk RunError.UnknownCommand;
             },
         };