add thruzero command

doc/README.md

@@ -258,3 +258,14 @@ other presets:
  - gain\_min (dB): -20..40
  - gain\_max (dB): -20..40
  - rms (signal level, dB): -80..10
+ 
+## `thruzero split index 
+
+> 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

examples/thruzero.scri

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

src/lang.zig

@@ -33,6 +33,7 @@ pub const CommandType = enum {
     RePsycho,
     TalkBox,
     DynComp,
+    ThruZero,
 
     Noise,
     WildNoise,
@@ -195,6 +196,7 @@ pub const Lang = struct {
         _ = try self.keywords.put("detune", .Detune);
         _ = try self.keywords.put("overdrive", .Overdrive);
         _ = try self.keywords.put("talkbox", .TalkBox);
+        _ = try self.keywords.put("thruzero", .ThruZero);
 
         // custom implementations (not lv2)
         _ = try self.keywords.put("noise", .Noise);

src/printer.zig

@@ -27,6 +27,7 @@ pub fn printList(list: langs.CommandList, stream: var) !void {
             .RePsycho => "repsycho",
             .TalkBox => "talkbox",
             .DynComp => "dyncomp",
+            .ThruZero => "thruzero",
 
             .Noise => "noise",
             .WildNoise => "wildnoise",

src/runner.zig

@@ -329,6 +329,11 @@ pub const Runner = struct {
         try image.runPlugin("http://gareus.org/oss/lv2/darc#mono", pos, params);
     }
 
+    fn thruZeroCmd(self: *Runner, pos: Position, params: ParamList) !void {
+        var image = try self.getImage();
+        try image.runPlugin("http://drobilla.net/plugins/mda/ThruZero", pos, params);
+    }
+
     fn runCommand(self: *Runner, cmd: *lang.Command) !void {
         var params = ParamList.init(self.allocator);
         defer params.deinit();
@@ -587,6 +592,15 @@ pub const Runner = struct {
                 try self.dynCompCmd(pos, params);
             },
 
+            .ThruZero => {
+                const pos = try cmd.consumePosition();
+                try cmd.appendParam(&params, "rate");
+                try cmd.appendParam(&params, "mix");
+                try cmd.appendParam(&params, "feedback");
+                try cmd.appendParam(&params, "depth_mod");
+                try self.thruZeroCmd(pos, params);
+            },
+
             else => blk: {
                 std.debug.warn("Unsupported command: {}\n", .{cmd.command});
                 break :blk RunError.UnknownCommand;