import msp_interface;

uniform ShadowMap
{
	float shadow_darkness;
	mat4 shd_world_matrix;
};

uniform sampler2DShadow shadow_map;

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

#pragma MSP stage(vertex)
void shadow_transform(vec4 world_vertex)
{
	out vec3 shadow_coord = (shd_world_matrix*world_vertex).xyz;
}

#pragma MSP stage(fragment)
virtual float get_shadow_factor(int index)
{
	if(use_shadow_map)
	{
		if(shadow_coord.x<0 || shadow_coord.x>1 || shadow_coord.y<0 || shadow_coord.y>1)
			return 1.0;
		float shadow_sample = texture(shadow_map, shadow_coord);
		return mix(1.0, shadow_sample, shadow_darkness);
	}
	else
		return 1.0;
}