AS3: Sound wave scripting experiment

package
{
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.events.SampleDataEvent;
    import flash.geom.Rectangle;
    import flash.media.Sound;
    import flash.media.SoundChannel;
    import flash.text.TextField;
    import flash.text.TextFieldAutoSize;
    import flash.text.TextFieldType;
    import flash.text.TextFormat;
    import flash.utils.ByteArray;

    /**
     * ...
     * @author YellowAfterlife
     */
    public class Main extends Sprite
    {
        public var sb:ByteArray; // soundBytes
        public var so:Sound; // soundObject
        public var sc:SoundChannel; // soundChannel
        //
        public function Main():void {
            if (stage) init();
            else addEventListener(Event.ADDED_TO_STAGE, init);
        }
        // listener for sound.SampleData, for writing data into sound
        public function so_bytes(event:SampleDataEvent):void {
            var bytes:ByteArray = new ByteArray();
            sb.readBytes(bytes, 0, Math.min(sb.bytesAvailable, 8 * 8192));
            event.data.writeBytes(bytes, 0, bytes.length);
        }
        // event handler for sound.COMPLETE
        public function so_complete(event:Event):void {
            dispatchEvent(event);
        }
        // different types of sound generation
        // l is length in seconds, f is frequency
        public function so_add(l:Number, f:Number):void {
            if (f == 0) { so_sil(l); return; }
            var i:int, v:Number, m:Number;
            m = l * 44100;
            for (i = 0; i < m; i++) {
                v = Math.sin(i / f) * 0.5;
                sb.writeFloat(v);
                sb.writeFloat(v);
            }
        }
        // fade-in
        public function so_addu(l:Number, f:Number):void {
            if (f == 0) { so_sil(l); return; }
            var i:int, v:Number, m:Number;
            m = l * 44100;
            for (i = 0; i < m; i++) {
                v = Math.sin(i / f) * 0.5 * (i / m);
                sb.writeFloat(v);
                sb.writeFloat(v);
            }
        }
        // fade-out
        public function so_addl(l:Number, f:Number):void {
            if (f == 0) { so_sil(l); return; }
            var i:int, v:Number, m:Number;
            m = l * 44100;
            for (i = 0; i < m; i++) {
                v = Math.sin(i / f) * 0.5 * (1 - i / m);
                sb.writeFloat(v);
                sb.writeFloat(v);
            }
        }
        // smoothed
        public function so_adds(l:Number, f:Number):void {
            if (f == 0) { so_sil(l); return; }
            var i:int, v:Number, m:Number, t:Number;
            m = l * 44100;
            for (i = 0; i < m; i++) {
                t = i / m;
                v = Math.sin(i / f) * 0.5;
                if (t < 0.1) v *= t * t * 100;
                if (t > 0.9) v *= (1 - t) * (1 - t) * 100;
                sb.writeFloat(v);
                sb.writeFloat(v);
            }
        }
        // silence
        public function so_sil(l:Number):void
        {
            var i:int, m:Number;
            m = l * 44100;
            for (i = 0; i < m; i++)
            {
                sb.writeFloat(0);
                sb.writeFloat(0);
            }
        }
        private var tt:uint = 1; // time passed
        private var ts:Number = 0; // total time
        // handler for onFrame event of stage, increments time
        private function tick(e:Event = null):void {
            tt++;
            ts = tt / stage.frameRate;
        }
        // parses string and converts it into sound
        private function psound(s:String = null):void
        {
            sb = new ByteArray();
            var i:int, z:String, l:Number, f:Number, c:String;
            for (i = 0; i < s.length; i++)
            {
                if (s.charAt(i) == "#") for (i++; s.charCodeAt(i) != 13 && i < s.length; i++) { }
                if (s.charAt(i) == "{")
                {
                    l = 0;
                    for (i++; (s.charAt(i) != "}" || l != 0) && i < s.length; i++) l += (s.charAt(i) == "{" ? 1 : (s.charAt(i) == "}" ? -1 : 0));
                }
                c = s.charAt(i);
                if (c == "~" || c == "*" || c == "=" || c == "/" || c == "\\")
                {
                    z = "";
                    for (i++; s.charAt(i) != "," && s.charAt(i) != "{" && s.charAt(i) != "#" && s.charCodeAt(i) != 13 && i < s.length; i++) z += s.charAt(i);
                    l = parseFloat(z);
                    z = "";
                    for (i++; s.charAt(i) != ";" && s.charAt(i) != "{" && s.charAt(i) != "#" && s.charCodeAt(i) != 13 && i < s.length; i++) z += s.charAt(i);
                    f = parseFloat(z);
                    switch(c)
                    {
                        case "*": so_adds(l, f); break;
                        case "~": so_adds(l, f); break;
                        case "=": so_add(l, f); break;
                        case "/": so_addu(l, f); break;
                        case "\\": so_addl(l, f); break;
                    }
                }
            }
            // making the actual sound:
            sb.position = 0;
            so = new Sound();
            so.addEventListener(SampleDataEvent.SAMPLE_DATA, so_bytes);
            sc = so.play();
            sc.addEventListener(Event.SOUND_COMPLETE, so_complete);
        }
        private function click(e:MouseEvent = null):void
        {
            if (e.stageY < 32 && e.stageX < 128)
            {
                psound(ti.text);
            }
        }
        public var ti:TextField = new TextField(), ty:TextField = new TextField();
        // Slider stuff
        public var sd_bmdt:BitmapData = new BitmapData(320, 8, false, 0x000000);
        public var sd_bmdt0:BitmapData = new BitmapData(320, 8, false, 0x000000);
        public var sd_bm:Bitmap = new Bitmap(sd_bmdt);
        public var sd_bm0:Bitmap = new Bitmap(sd_bmdt0);
        public var sd_v0:Number = 1, sd_v1:Number = 1;
        public var sd_a0:Number = 0, sd_b0:Number = 4;
        public var sd_a1:Number = 0, sd_b1:Number = 64;
        public function sd_click(e:MouseEvent):void
        {
            var r:Rectangle = new Rectangle(), n:Number;
            if (sd_bm0.hitTestPoint(e.stageX, e.stageY, false))
            {
                n = e.stageX - sd_bm.x;
                sd_v0 = n / sd_bm.width;
                ty.text = "*" + (sd_a0 + sd_v0 * (sd_b0 - sd_a0)) + "," + (sd_a1 + sd_v1 * (sd_b1 - sd_a1)) + ";";
                psound(ty.text + "*0.1,0;");
                r.x = r.y = 0;
                r.height = 8;
                r.width = n;
                sd_bmdt0.fillRect(r, 0x000000);
                r.x = r.width;
                r.width = sd_bm.width - r.width;
                sd_bmdt0.fillRect(r, 0xCCCCCC);
            }
            if (sd_bm.hitTestPoint(e.stageX, e.stageY, false))
            {
                n = e.stageX - sd_bm.x;
                sd_v1 = n / sd_bm.width;
                ty.text = "*" + (sd_a0 + sd_v0 * (sd_b0 - sd_a0)) + "," + (sd_a1 + sd_v1 * (sd_b1 - sd_a1)) + ";";
                psound(ty.text + "*0.1,0;");
                r.x = r.y = 0;
                r.height = 8;
                r.width = n;
                sd_bmdt.fillRect(r, 0x000000);
                r.x = r.width;
                r.width = sd_bm.width - r.width;
                sd_bmdt.fillRect(r, 0xCCCCCC);
            }
            if (ty.hitTestPoint(e.stageX, e.stageY, false))
            {
                ti.appendText(ty.text);
            }
        }
        public function sd_init():void
        {
            sd_bm.x = sd_bm0.x = 128;
            sd_bm.y = 20; sd_bm0.y = 8;
            stage.addEventListener(MouseEvent.CLICK, sd_click);
            addChild(sd_bm);
            addChild(sd_bm0);
        }
        private function init(e:Event = null):void
        {
            stage.scaleMode = StageScaleMode.NO_SCALE;
            stage.align = StageAlign.TOP_LEFT;
            removeEventListener(Event.ADDED_TO_STAGE, init);
            stage.addEventListener(Event.ENTER_FRAME, tick);
            stage.addEventListener(MouseEvent.CLICK, click);
            stage.addEventListener(Event.RESIZE, function(e:Event = null):void { ti.width = stage.stageWidth - 32; ti.height = stage.stageHeight - 48; } );
            // entry point
            sd_init();
            ty.autoSize = TextFieldAutoSize.LEFT;
            ty.y = 8;
            ty.x = 456;
            ty.text = "*";
            stage.addChild(ty);
            var tj:TextField = new TextField();
            tj.x = 24;
            tj.y = 12;
            tj.selectable = false;
            tj.defaultTextFormat = ty.defaultTextFormat = ti.defaultTextFormat = new TextFormat("Courier New", 12, 0x333333);
            tj.text = "[Play sound]";
            stage.addChild(tj);
            // main textfield:
            ti.border = true;
            ti.backgroundColor = 0xFEFEFE;
            ti.background = true;
            ti.x = 16;
            ti.y = 32;
            ti.width = stage.stageWidth - 32;
            ti.height = stage.stageHeight - 48;
            ti.type = TextFieldType.INPUT;
            ti.multiline = true;
            ti.tabEnabled = true;
            ti.text =
            "{" +
            "\n SoundTest 0.0.1" +
            "\n Sound format:" +
            "\n  (type)(length),(freq)(;)" +
            "\n   type : sound type" +
            "\n    * Smooth" +
            "\n    / Fade-in" +
            "\n    = Plain" +
            "\n    \\ Fade-out" +
            "\n   length : sound length (in seconds)" +
            "\n   freq : frequency. Range of [0.1 .. 23] can be heard." +
            "\n   ; is required if placing several commands on one line"+
            "\n Other:" +
            "\n  { text } : multi-line comment." +
            "\n  # text : single-line comment." +
            "\n Example:" +
            "\n  *1, 15 # play sound with freq. 15 for 1 second"+
            "\n}\n"
            stage.addChild(ti);
        }

    }

}