#version 450
#extension GL_ARB_separate_shader_objects : enable

#define WIDTH 3200
#define HEIGHT 2400
#define WORKGROUP_SIZE 32
layout (local_size_x = WORKGROUP_SIZE, local_size_y = WORKGROUP_SIZE, local_size_z = 1 ) in;

layout ( binding = 0, rgba8 ) uniform writeonly image2D buf;

void main() {

	/*
	In order to fit the work into workgroups, some unnecessary threads are launched.
	We terminate those threads here.
	*/
	if(gl_GlobalInvocationID.x >= WIDTH || gl_GlobalInvocationID.y >= HEIGHT)
	return;

	float x = float(gl_GlobalInvocationID.x) / float(WIDTH);
	float y = float(gl_GlobalInvocationID.y) / float(HEIGHT);

	imageStore(buf, ivec2(gl_GlobalInvocationID.xy), vec4(1,0,0,1));
}