/* VERTEX SHADER */
/*****************/
#version 330 core

layout(location = 0) in vec3 vertexpos_vec3;

uniform vec4 scale;
uniform vec4 window_to_unit;

uniform mat4 model_translation;
uniform mat4 model_rotation;
uniform mat4 projection;

out vec4 vertexpos_gamespace;
out vec4 vertexpos_pre_projection;
out vec4 vertexpos_post_projection;

uniform mat4 camera_translation;

void main()
{
    vec4 vertexpos;
    vertexpos.xyz = vertexpos_vec3;
    vertexpos.w = 1.0;

    vertexpos_gamespace = vertexpos;
    vertexpos = scale * vertexpos;

    vertexpos = model_translation * vertexpos;
    gl_Position = vertexpos;
}


/* GEOMETRY SHADER */
/*******************/
#version 330 core

uniform mat4 shadowmap_rotation_matrices[6];

out vec4 pos_from_gs;

void main()
{
    for(gl_Layer = 0; gl_Layer < 6; ++gl_Layer)
    {
        for(int tri_vert = 0; tri_vert < 3; ++tri_vert)
        {
            pos_from_gs = gl_in[tri_vert].gl_Position;
            gl_Position = shadowmap_rotation_matrices[gl_Layer] * pos_from_gs;
            EmitVertex();
        }
        EndPrimitive();
    }
}


/* FRAGMENT SHADER */
/*******************/
#version 330 core

uniform vec2 near_far;
uniform vec4 light_pos;

in vec4 pos_from_gs;

void main()
{
    float dist = distance(pos_from_gs, light_pos);
    dist = dist / near_far.y; // divide by far plane distance
    gl_FragDepth = dist;
}