import msp_interface;

struct ShadowParameters
{
	int type;
	float darkness;
	int matrix_index;
	vec4 region;
	float bias;
};

uniform ShadowMap
{
	ShadowParameters shadows[max_lights];
	mat4 shd_world_matrix[max_lights];
};

uniform sampler2DShadow shadow_map;

layout(constant_id=auto) const bool use_shadow_map = false;

#pragma MSP stage(fragment)
virtual float get_shadow_factor(int index, vec4 world_pos)
{
	if(use_shadow_map)
	{
		int type = shadows[index].type;
		vec3 shadow_coord;
		if(type==1)
		{
			shadow_coord = (shd_world_matrix[shadows[index].matrix_index]*world_pos).xyz;
			shadow_coord.z -= shadows[index].bias;
		}
		else
			return 1.0;

		if(shadow_coord.x<0 || shadow_coord.x>1 || shadow_coord.y<0 || shadow_coord.y>1)
			return 1.0;

		vec4 region = shadows[index].region;
		float shadow_sample = texture(shadow_map, vec3(shadow_coord.xy*region.zw+region.xy, shadow_coord.z));
		return mix(1.0, shadow_sample, shadows[index].darkness);
	}
	else
		return 1.0;
}