/** Convolve with a 2D kernel */
public static void convolveHV(
Kernel kernel,
int[] inPixels,
int[] outPixels,
int width,
int height,
boolean alpha,
int edgeAction) {
int index = 0;
float[] matrix = kernel.getKernelData(null);
int rows = kernel.getHeight();
int cols = kernel.getWidth();
int rows2 = rows / 2;
int cols2 = cols / 2;
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
float r = 0, g = 0, b = 0, a = 0;
for (int row = -rows2; row <= rows2; row++) {
int iy = y + row;
int ioffset;
if (0 <= iy && iy < height) ioffset = iy * width;
else if (edgeAction == CLAMP_EDGES) ioffset = y * width;
else if (edgeAction == WRAP_EDGES) ioffset = ((iy + height) % height) * width;
else continue;
int moffset = cols * (row + rows2) + cols2;
for (int col = -cols2; col <= cols2; col++) {
float f = matrix[moffset + col];
if (f != 0) {
int ix = x + col;
if (!(0 <= ix && ix < width)) {
if (edgeAction == CLAMP_EDGES) ix = x;
else if (edgeAction == WRAP_EDGES) ix = (x + width) % width;
else continue;
}
int rgb = inPixels[ioffset + ix];
a += f * ((rgb >> 24) & 0xff);
r += f * ((rgb >> 16) & 0xff);
g += f * ((rgb >> 8) & 0xff);
b += f * (rgb & 0xff);
}
}
}
int ia = alpha ? PixelUtils.clamp((int) (a + 0.5)) : 0xff;
int ir = PixelUtils.clamp((int) (r + 0.5));
int ig = PixelUtils.clamp((int) (g + 0.5));
int ib = PixelUtils.clamp((int) (b + 0.5));
outPixels[index++] = (ia << 24) | (ir << 16) | (ig << 8) | ib;
}
}
}
public static void convolve(
Kernel kernel,
int[] inPixels,
int[] outPixels,
int width,
int height,
boolean alpha,
int edgeAction) {
if (kernel.getHeight() == 1)
convolveH(kernel, inPixels, outPixels, width, height, alpha, edgeAction);
else if (kernel.getWidth() == 1)
convolveV(kernel, inPixels, outPixels, width, height, alpha, edgeAction);
else convolveHV(kernel, inPixels, outPixels, width, height, alpha, edgeAction);
}
/** Convolve with a kernel consisting of one row */
public static void convolveH(
Kernel kernel,
int[] inPixels,
int[] outPixels,
int width,
int height,
boolean alpha,
int edgeAction) {
int index = 0;
float[] matrix = kernel.getKernelData(null);
int cols = kernel.getWidth();
int cols2 = cols / 2;
for (int y = 0; y < height; y++) {
int ioffset = y * width;
for (int x = 0; x < width; x++) {
float r = 0, g = 0, b = 0, a = 0;
int moffset = cols2;
for (int col = -cols2; col <= cols2; col++) {
float f = matrix[moffset + col];
if (f != 0) {
int ix = x + col;
if (ix < 0) {
if (edgeAction == CLAMP_EDGES) ix = 0;
else if (edgeAction == WRAP_EDGES) ix = (x + width) % width;
} else if (ix >= width) {
if (edgeAction == CLAMP_EDGES) ix = width - 1;
else if (edgeAction == WRAP_EDGES) ix = (x + width) % width;
}
int rgb = inPixels[ioffset + ix];
a += f * ((rgb >> 24) & 0xff);
r += f * ((rgb >> 16) & 0xff);
g += f * ((rgb >> 8) & 0xff);
b += f * (rgb & 0xff);
}
}
int ia = alpha ? PixelUtils.clamp((int) (a + 0.5)) : 0xff;
int ir = PixelUtils.clamp((int) (r + 0.5));
int ig = PixelUtils.clamp((int) (g + 0.5));
int ib = PixelUtils.clamp((int) (b + 0.5));
outPixels[index++] = (ia << 24) | (ir << 16) | (ig << 8) | ib;
}
}
}