#version 450

layout(triangles, invocations = 6) in;
layout(triangle_strip, max_vertices = 3) out;

struct DirectionalShadowMapSet
{
    uint entity_id;
    uint shadow_id;
    uint shadow_texture_id;   
    uint frame_buffer_id;
    float near_plane[8];
    float far_plane[8];
    mat4 light_space_proj[6];
    mat4 light_space_view[6];
};


//Push constants updated for each light
layout(binding = 0) uniform shadow_per_frame
{
	vec3 camera_pos;
	uint shadow_idxs;
};

layout (std430, binding = 5) readonly buffer directional_shadow_map_sets
{
	DirectionalShadowMapSet directional_shadows[];
};



layout (location=0) in VS_OUT
{
	vec2 vsUV;
    flat uint vsMaterialID;
}vs_in[];

layout (location=0) out GEOM_OUT
{
	vec2 vsUV;
    flat uint vsMaterialID; 
}geom_out;

void main()
{      
	mat4 view = directional_shadows[shadow_idxs].light_space_view[gl_InvocationID];
	mat4 proj = directional_shadows[shadow_idxs].light_space_proj[gl_InvocationID];

	for (int i = 0; i < 3; ++i)
	{
		gl_Layer = gl_InvocationID;
        vec4 clip_space_pos = proj * view * gl_in[i].gl_Position;
        
        gl_Position = clip_space_pos;

        geom_out.vsMaterialID = vs_in[gl_InvocationID].vsMaterialID;
        geom_out.vsUV = vs_in[gl_InvocationID].vsUV;

        EmitVertex();
	}
	EndPrimitive();
}