#version 460 core

layout(std430, binding = 3) buffer layoutName {
  vec2 o_Points[];
};

layout(local_size_x = 64) in;

highp float rand(vec2 co)
{
    highp float a = 12.9898;
    highp float b = 78.233;
    highp float c = 43758.5453;
    highp float dt= dot(co.xy ,vec2(a,b));
    highp float sn= mod(dt,3.14);
    return fract(sin(sn) * c);
}

void main() {
	const uint total = gl_NumWorkGroups.x * gl_WorkGroupSize.x;
    uint currentPoint = gl_GlobalInvocationID.x;
	uint index = uint(rand(o_Points[currentPoint] + currentPoint) * 69);
	mat3 transformation;
	switch (index % 3) {
		case 0:
			transformation = mat3(0.5, 0, 0, 0, 0.5, 0, 0, 0.36, 1);
			break;

		case 1:
			transformation = mat3(0.5, 0, 0, 0, 0.5, 0, -0.5, -0.5, 1);
			break;

		case 2:
			transformation = mat3(0.5, 0, 0, 0, 0.5, 0, 0.5, -0.5, 1);
			break;
	}
	o_Points[currentPoint] = (transformation * vec3(o_Points[currentPoint], 1.0)).xy;
}