amp = effect("Amplitude")("Slider"); // max wave height (px)
wavelength = effect("Wavelength")("Slider"); // px per cycle
l = effect("Length")("Slider"); // total wave length (px)
biasS = effect("Bias")("Slider"); // -100 = peak at left, 0 = center, 100 = right
ptsCount = 200; // more points = smoother line but heavier rendering
cycles = l / wavelength;
b = clamp((biasS + 100) / 200, 0, 1);
pts = [];
for (i = 0; i < ptsCount; i++) {
 t = i / (ptsCount - 1);
 x = t * l - l / 2;
 if (b <= 0) falloff = 1 - t;
 else if (b >= 1) falloff = t;
 else {
   m = Math.max(b, 1 - b);
   falloff = clamp(1 - Math.abs(t - b) / m, 0, 1);
 }
 y = amp * falloff * Math.sin(t * cycles * 2 * Math.PI);
 pts.push([x, y]);
}
createPath(pts, [], [], false);