Mandelbrot kernel

mandelbrot.cl

//mandelbrot.cl

const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE | CLK_FILTER_NEAREST;

kernel void mandelbrot(write_only image2d_t output, float width, float height, int iter) {
    size_t x = get_global_id(0);
    size_t y = get_global_id(1);
    
    float2 z, c;
    
    c.x = (float)width / (float)height * ((float)x / width - 0.5) * 2.2 - 0.7;
    c.y = ((float)y / height - 0.5) * 2.2 - 0.0;
    
    int i;
    z = c;
    for(i = 0; i < iter; i++) {
        float x = (z.x * z.x - z.y * z.y) + c.x;
        float y = (z.y * z.x + z.x * z.y) + c.y;
        
        if((x * x + y * y) > 4.0) break;
        z.x = x;
        z.y = y;
    }
    
    float p = (float)i / (float)iter;
    float so = sin(p * 3.141592653) * 255.0;
    float co = (1 - cos(p * 3.141592653)) * 255.0;
    
    write_imageui(output, (int2)(x,y), (uint4)((uint)co, co, (uint)(co + so), 255));
}