layout(set=0) uniform EnvMap
{
	mat3 env_world_matrix;
};

layout(set=0) uniform samplerCube environment_map;
layout(set=0) uniform samplerCube irradiance_map;

#pragma MSP stage(fragment)
virtual vec3 get_environment_sample(vec3 direction, float roughness)
{
	float lod = (2-roughness)*roughness*(textureQueryLevels(environment_map)-1);
	return textureLod(environment_map, env_world_matrix*direction, lod).rgb;
}

virtual vec3 get_reflection(vec3 normal, vec3 look)
{
	vec3 reflect_dir = reflect(look, normal);
	return get_environment_sample(reflect_dir, 0.0);
}

virtual vec3 get_irradiance_sample(vec3 normal)
{
	return texture(irradiance_map, env_world_matrix*normal).rgb;
}