Sawtooth Ripple - RealWorld forums

Code
Configuration

Configuration.AddSlider("xAmplitude", "X Amplitude", "", 0, 30, 5);
Configuration.AddSlider("yAmplitude", "Y Amplitude", "", 0, 30, 5);
Configuration.AddSlider("xWavelength", "X Wavelength", "", 1, 50, 16);
Configuration.AddSlider("yWavelength", "Y Wavelength", "", 1, 50, 16);

Execution

// Joel Besada
// https://github.com/JoelBesada/JSManipulate
// Plus PAEz touch here and there

function getBilerpixel(l, x, y, w, h) {
	var corner = [];
	var xi, yi, xip, xip1;
	var yip, yip1;

	xi = ~~x;
	yi = ~~y;
	xip = Math.max(Math.min(xi, w - 1), 0);
	xip1 = Math.max(Math.min(xi + 1, w - 1), 0);
	yip1 = Math.max(Math.min(yi + 1, h - 1), 0);
	yip = Math.max(Math.min(yi, h - 1), 0);

	corner[0] = l.GetPixel(xip, yip, 0, 0); //this.layers[l].data32[xip + yip];
	corner[1] = l.GetPixel(xip1, yip, 0, 0); //this.layers[l].data32[xip1 + yip];
	corner[2] = l.GetPixel(xip, yip1, 0, 0); //this.layers[l].data32[xip + yip1];
	corner[3] = l.GetPixel(xip1, yip1, 0, 0); //this.layers[l].data32[xip1 + yip1];

	return cosineInterpolate(corner, (x - xi), (y - yi));
}

function cosineInterpolate(v, x, y) {
	var f1, f2, mf1, mf2, g0, g1, g2, g3;
	var color, r, g, b;
	mf1 = (1 - Math.cos(x * Math.PI)) * 0.5;
	mf2 = (1 - Math.cos(y * Math.PI)) * 0.5;
	var f1 = 1 - mf1;
	var f2 = 1 - mf2;
	var g0 = f1 * f2;
	var g1 = mf1 * f2;
	var g2 = f1 * mf2;
	var g3 = mf1 * mf2;

	color = ((v[0] & 255) * g0 + (v[1] & 255) * g1 + (v[2] & 255) * g2 + (v[3] & 255) * g3);
	color = color | ((((v[0] >> 8 & 255) * g0 + (v[1] >> 8 & 255) * g1 + (v[2] >> 8 & 255) * g2 + (v[3] >> 8 & 255) * g3) & 255) << 8);
	color = color | ((((v[0] >> 16 & 255) * g0 + (v[1] >> 16 & 255) * g1 + (v[2] >> 16 & 255) * g2 + (v[3] >> 16 & 255) * g3) & 255) << 16);
	color = color | ((((v[0] >> 24 & 255) * g0 + (v[1] >> 24 & 255) * g1 + (v[2] >> 24 & 255) * g2 + (v[3] >> 24 & 255) * g3) & 255) << 24);
	return color;
}
transformFilter = function(inputData, outputData, transformInverse, width, height) {
	var out = [];
	for (var y = 0; y < height; y++) {
		for (var x = 0; x < width; x++) {
			transformInverse.apply(this, [x, y, out]);
			var srcX = out[0];
			var srcY = out[1];

			var w = width - 2;
			var h = height - 2;
			var direction = 1;

			while (srcX < 0 || srcX > w) {
				if (srcX > w) {
					srcX = w - (srcX - w);
					direction = -1;
				}
				if (srcX < 0) {
					srcX *= -1;
					direction = 1;
				}
			}
			while (srcY < 0 || srcY > h) {
				if (srcY > h) {
					srcY = h - (srcY - h);
					direction = -1;
				}
				if (srcY < 0) {
					srcY *= -1;
					direction = 1;
				}
			}

			//var srcX2=srcX+direction;
			//var srcY2=srcY+direction;

			var rgba = getBilerpixel(inputData, srcX, srcY, width - 1, height - 1);

			outputData.SetPixel(x, y, 0, 0, rgba);
		}
	}
}

mod = function(a, b) {
	var n = parseInt(a / b);
	a -= n * b;
	if (a < 0) {
		return a + b;
	}
	return a;
}

filter = function(xAmplitude, yAmplitude, xWavelength, yWavelength) {
	var input = Document.RasterImage;
	var width = input.sizeX;
	var height = input.sizeY;

	var clone;
	clone = Document.Duplicate();
	clone = clone.RasterImage;
                  var transInverse = function(x,y,out){
                          var nx = y/xWavelength;
                          var ny = x/yWavelength;
                          var fx = mod(nx,1)
                          var fy = mod(ny,1)
                          out[0] = x + xAmplitude * fx;
                          out[1] = y + yAmplitude * fy;
                }
	transformFilter(clone, input, transInverse, width, height);
}

var xAmplitude = Configuration.xAmplitude;
var yAmplitude = Configuration.yAmplitude;
var xWavelength = Configuration.xWavelength;
var yWavelength = Configuration.yWavelength;
filter(xAmplitude, yAmplitude, xWavelength, yWavelength);