attractor-cl/resources/Kernel.cl

kernel void initialize(size_t width, size_t height, write_only image2d_t output){
	size_t x = get_global_id(0);
	size_t y = get_global_id(1);

	int2 coord = {x, y};
	const float xx = x / float(width - 1) - 0.5;
	const float yy = y / float(height - 1) - 0.5;
	float4 color = {0.066 * xx, 0.1 * yy, 0.1 * yy * xx, 1};

	write_imagef(output, coord, color);
}

kernel void hblur(size_t width, size_t height, read_only image2d_t input, write_only image2d_t output){
	int x = get_global_id(0);
	int y = get_global_id(1);

	const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE
				 | CLK_ADDRESS_NONE
				 | CLK_FILTER_NEAREST;

	float4 c = {0, 0, 0, 0};
	const int size = 7;
	float weights[] = {0.25, 0.1, 0.1, 0.1, 0.1, 0.1, 0.25};
	for(int i = 0; i < size; ++i){
		int x2 = (x - size/2 + i + width) % width;
		int2 read = {x2, y};
		c += read_imagef(input, sampler, read) * weights[i];
	}

	int2 coord = {x, y};
	write_imagef(output, coord, c);
}

kernel void vblur(size_t width, size_t height, read_only image2d_t input, write_only image2d_t output){
	int x = get_global_id(0);
	int y = get_global_id(1);

	const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE
				 | CLK_ADDRESS_NONE
				 | CLK_FILTER_NEAREST;

	float4 c = {0, 0, 0, 0};
	int size = 7;
	float weights[] = {0.25, 0.1, 0.1, 0.1, 0.1, 0.1, 0.25};
	for(int i = 0; i < size; ++i){
		int y2 = (y - size/2 + i + height) % height;
		int2 read = {x, y2};
		c += read_imagef(input, sampler, read) * weights[i];
	}

	int2 coord = {x, y};
	write_imagef(output, coord, c);
}

kernel void update(size_t width, size_t height, read_only image2d_t input, write_only image2d_t output){
	size_t x = get_global_id(0);
	size_t y = get_global_id(1);

	int2 coord = {x, y};

	const sampler_t samplerA = CLK_NORMALIZED_COORDS_FALSE
				 | CLK_ADDRESS_NONE
				 | CLK_FILTER_NEAREST;

	const float4 w = read_imagef(input, samplerA, coord);
	float4 v = w;

	const float s = 9.120836;
	const float r = 32.799129;
	const float b = 2.902814;
	const float dt = 0.019997;

	v.x += dt * s * (w.y - w.x);
	v.y += dt * (w.x * (r - w.z) - w.y);
	v.z += dt * (w.x * w.y - b * w.z);

	write_imagef(output, coord, v);
}