#version 450

layout (binding = 0, rgba32f) uniform writeonly image2D image;

layout (push_constant) uniform constants
{
    uint width;
    uint height;
} PushConstants;

layout (local_size_x = 16, local_size_y = 16, local_size_z = 1) in;
void main()
{
    vec2 pos = vec2(float(gl_GlobalInvocationID.x) / float(PushConstants.width) - 0.5f, float(gl_GlobalInvocationID.y) / float(PushConstants.height) - 0.5f) * 3.f;
    
    int iter = 0;
    float re = 0;
    float im = 0;
    while(iter < 200)
    {
        float new_im = pos.y + 2. * re * im;
        float new_re = pos.x + (re * re - im * im);
        re = new_re;
        im = new_im;

        if(re * re + im * im > 4.f)
        { 
            float c = float(iter) / 200;
            imageStore(image, ivec2(gl_GlobalInvocationID.xy), vec4(c, 0.2, 1.0 - c, 1.0));

            return;
        }
        iter += 1;
    }

    imageStore(image, ivec2(gl_GlobalInvocationID.xy), vec4(0.f));
}