Add LFOs and envelopes

packages/superdough/helpers.mjs

@@ -97,6 +97,36 @@ export const getParamADSR = (
   param[ramp](min, end + release);
 };
 
+function getModulationShapeInput(val) {
+  if (typeof val === 'number') {
+    return val % 5;
+  }
+  return { tri: 0, triangle: 0, sine: 1, ramp: 2, saw: 3, square: 4 }[val] ?? 0;
+}
+
+export function getLfo(audioContext, begin, end, properties = {}) {
+  const { shape = 0, ...props } = properties;
+  const { dcoffset = -0.5, depth = 1 } = properties;
+  debugger;
+  const lfoprops = {
+    frequency: 1,
+    depth,
+    skew: 0.5,
+    phaseoffset: 0,
+    time: begin,
+    begin,
+    end,
+    shape: getModulationShapeInput(shape),
+    dcoffset,
+    min: dcoffset * depth,
+    max: dcoffset * depth + depth,
+    curve: 1,
+    ...props,
+  };
+
+  return getWorklet(audioContext, 'lfo-processor', lfoprops);
+}
+
 export function getCompressor(ac, threshold, ratio, knee, attack, release) {
   const options = {
     threshold: threshold ?? -3,