CC-2301 : showing waveform cue/fade editors inside of a jquery dialog box.

airtime_mvc/public/js/waveformplaylist/curves.js

@@ -0,0 +1,72 @@
+var Curves = {};
+
+Curves.createLinearBuffer = function createLinearBuffer(length, rotation) {
+    var curve = new Float32Array(length),
+        i, x,
+        scale = length - 1;
+
+    for (i = 0; i < length; i++) {
+        x = i / scale;
+
+        if (rotation > 0) {
+            curve[i] = x;
+        }
+        else {
+            curve[i] = 1 - x;
+        }  
+    }
+    return curve;
+};
+
+Curves.createExponentialBuffer = function createExponentialBuffer(length, rotation) {
+    var curve = new Float32Array(length),
+        i, x,
+        scale = length - 1,
+        index;
+
+    for (i = 0; i < length; i++) {
+        x = i / scale;
+        index = rotation > 0 ? i : length - 1 - i;
+       
+        curve[index] = Math.exp(2 * x - 1) / Math.exp(1);
+    }
+    return curve;
+};
+
+//creating a curve to simulate an S-curve with setValueCurveAtTime.
+Curves.createSCurveBuffer = function createSCurveBuffer(length, phase) {
+    var curve = new Float32Array(length),
+        i;
+
+    for (i = 0; i < length; ++i) {
+        curve[i] = (Math.sin((Math.PI * i / length) - phase)) /2 + 0.5;
+    }
+    return curve;
+};
+
+//creating a curve to simulate a logarithmic curve with setValueCurveAtTime.
+Curves.createLogarithmicBuffer = function createLogarithmicBuffer(length, base, rotation) {
+    var curve = new Float32Array(length),
+        index,
+        key = ""+length+base+rotation,
+        store = [],
+        x = 0,
+        i;
+
+    if (store[key]) {
+        return store[key];
+    }
+
+    for (i = 0; i < length; i++) {
+        //index for the curve array.
+        index = rotation > 0 ? i : length - 1 - i;
+
+        x = i / length;
+        curve[index] = Math.log(1 + base*x) / Math.log(1 + base);
+    }
+
+    store[key] = curve;
+
+    return curve;
+};
+