#version 460 core

layout(std430, binding = 3) buffer layoutName {
  float 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);
}

vec3 unpack(uint index) {
	return vec3(o_Points[index * 3], o_Points[index * 3 + 1], o_Points[index * 3 + 2]);
}

void store(vec3 vect, uint index) {
	o_Points[index * 3] = vect.x;
	o_Points[index * 3 + 1] = vect.y;
	o_Points[index * 3 + 2] = vect.z;
}

void main() {
	const uint total = gl_NumWorkGroups.x * gl_WorkGroupSize.x;
    uint currentIndex = gl_GlobalInvocationID.x;
	vec3 currentPoint = unpack(currentIndex);
	uint index = uint(rand(currentPoint.xy + currentPoint.z + currentIndex) * 69);
	mat4 transformation;
	switch (index % 3) {
		case 0:
			transformation = mat4(0.5, 0, 0, 0,   0, 0.5, 0, 0,  0, 0, 0, 0,   0, 0.36, 0, 1);
			break;

		case 1:
			transformation = mat4(0.5, 0, 0, 0,   0, 0.5, 0, 0,  0, 0, 0, 0,   -0.5, -0.5, 0, 1);
			break;

		case 2:
			transformation = mat4(0.5, 0, 0, 0,   0, 0.5, 0, 0,  0, 0, 0, 0,   0.5, -0.5, 0, 1);
			break;
	}
	vec3 result = (transformation * vec4(currentPoint, 1.0)).xyz;
	store(result, currentIndex);
}