#version 460 core

// gbuffer textures
uniform sampler2D s_albedo;
uniform sampler2D s_depth;
uniform sampler2D s_normal;
uniform sampler2D s_material;
uniform sampler2D s_position;

// lights
#define MAX_LIGHT_COUNT 100
#define POINT       0
#define SPOT        1
#define DIRECTIONAL 2
#define AMBIENT     3

struct light_t {
  vec3 color;
  vec3 position;
  vec3 direction;
  float intensity;
  int type;
};

uniform light_t lights[MAX_LIGHT_COUNT];
uniform int light_count;

uniform vec3 view_pos;

// from vertex shader
in vec3 pos;
in vec2 tex;

out vec4 FragColor;

vec3 albedo;
float depth;
vec3 normal;
vec3 material; // specular, roughness, metalic
vec3 position;

float specular;
float roughness;
float metalic;

void main() {
  // albedo,   normal
  // material, position
  albedo = texture(s_albedo, tex*2).rgb;
  depth = texture(s_depth, tex*2).x;
  normal = normalize(texture(s_normal, tex*2).rgb);
  material = texture(s_material, tex*2).xyz;
  {
    specular = material.x;
    roughness = material.y;
    metalic = material.z;
  }
  position = texture(s_position, tex*2).xyz;

  FragColor = vec4(
    (pos.x < 0 ? (pos.y < 0 ? material : albedo) : (pos.y < 0 ? position : normal)),
    1);
}