#Material
Name BillboardFixedSize
Base Std3D/Billboard

#VertexInput
vec2 TexCoord

#MaterialInstance
Length 8
Stage  Vertex

Code
{
    uvec2 BillboardSize;
}

#Vertex
Output
{
    vec2 BillboardSize
}

Code
{
    void main()
    {
        MaterialInstance mi=GetMI();

        Output.BillboardSize=mi.BillboardSize/viewport.canvas_resolution;

        gl_Position=GetPosition3D();
        gl_Position/=gl_Position.w;
    }
}

#Geometry
Output
{
    vec2 TexCoord
}

Code
{
    void main()
    {
        const vec2 BillboardVertex[4]=vec2[]
        (
            vec2(-0.5,-0.5),
            vec2(-0.5, 0.5),
            vec2( 0.5,-0.5),
            vec2( 0.5, 0.5)
        );

        for(int i=0;i<4;i++)
        {
            gl_Position=gl_in[0].gl_Position;
            gl_Position.xy+=BillboardVertex[i]*Input[0].BillboardSize;

            Output.TexCoord=BillboardVertex[i]+vec2(0.5);

            EmitVertex();
        }
        EndPrimitive();
    }
}

#Fragment

sampler2D TextureBaseColor

Output
{
    vec4 FragColor;
}

Code
{
    void main()
    {
        FragColor=texture(TextureBaseColor,Input.TexCoord);
    }
}