#version 430 core

struct particle_t {
    vec2 pos;
    vec2 dir;
};

struct cell_t {
    float pheromone;
    float result;
    int population;
};

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

uniform uint map_width;
uniform uint map_height;

uniform float display_population_value;
uniform float display_pheromone_value;

layout(std430, binding = 1) coherent buffer particles_buffer
{
    particle_t particles[];
};

layout(std430, binding = 2) coherent buffer map_buffer
{
    cell_t map[];
};

layout(local_size_x = 16, local_size_y = 16, local_size_z = 1) in;
void main(){
    uint x = gl_GlobalInvocationID.x;
    uint y = gl_GlobalInvocationID.y;
    if(x >= map_width || y >= map_height){
        return;
    }
    uint cell_id = y * map_width + x;
    cell_t cell = map[cell_id]; 

    float pop_value = cell.population / display_population_value / 2.5;
    float phe_value = cell.pheromone / display_pheromone_value;

    imageStore(canvas, ivec2(gl_GlobalInvocationID.xy), 
        vec4(phe_value/2,
             phe_value/5,
             pop_value,
             1));
}