re-implement full_lighting shader point lights

data/full_lighting.frag

@@ -8,16 +8,17 @@ out vec4 color;
 
 uniform sampler2D sampler;
 
+// TODO: ambient light should be part of the lights uniform
 const vec4 ambient_color = vec4(0.1, 0.1, 0.1, 1);
 const uint NUM_LIGHTS = 32u;
 
 layout (std140) uniform lights
 {
-	uint buf_size;
 	uint max_p_lights;
 	uint active_p_lights;
 	uint max_d_lights;
 	uint active_d_lights;
+	uint padding;
 
 	vec4 pl_positions[NUM_LIGHTS];
 	vec4 pl_colors[NUM_LIGHTS];
@@ -28,12 +29,16 @@ layout (std140) uniform lights
 	uint dl_intensities[NUM_LIGHTS]; // NOTE: 16 bytes * NUM_LIGHTS
 };
 
+const float CONSTANT_ATTENUATION = 0.1;
+const float LINEAR_ATTENUATION = 0.2;
+const float QUADRATIC_ATTENUATION = 0.02;
+
 
 void main()
 {
-	// NOTE: directional lights
 	vec4 diffuse_color = vec4(0);
 
+	// NOTE: directional lights
 	for (uint i = 0u; i < active_d_lights; i++) {
 		vec4 light_direction = normalize(dl_directions[i]);
 		float diffuse_factor =
@@ -42,14 +47,21 @@ void main()
 			dl_intensities[i] * diffuse_factor * dl_colors[i];
 	}
 
-//#else // point light
-//	vec4 light_direction = pl1.pos - frag_pos;
-//	float len = length(light_direction);
-//	light_direction = normalize(light_direction);
-//	float diffuse_factor = dot(frag_normal, light_direction) / pow(len, 2);
-//	diffuse_factor = clamp(diffuse_factor, 0, 1);
-//	vec4 diffuse_color = pl1.intensity * vec4(pl1.color * diffuse_factor);
-//#endif
+	// NOTE: point lights
+	for (uint i = 0u; i < active_p_lights; i ++) {
+		vec3 direction = vec3(pl_positions[i]).xyz - frag_pos;
+		float distance = length(direction);
+		direction = direction / distance;
+
+		float attenuation = CONSTANT_ATTENUATION +
+							LINEAR_ATTENUATION * distance +
+							QUADRATIC_ATTENUATION * pow(distance, 2);
+		float diffuse_factor = clamp(dot(frag_normal, direction), 0, 1);
+		vec4 added_color = pl_colors[i] * pl_intensities[i]
+						* diffuse_factor / attenuation;
+
+		diffuse_color = diffuse_color + added_color;
+	}
 
 	color = (ambient_color + diffuse_color) * texture(sampler, frag_uv.st);
 }