//
// Simple passthrough vertex shader
//
attribute vec3 in_Position;                  // (x,y,z)
//attribute vec3 in_Normal;                  // (x,y,z)     unused in this shader.
attribute vec4 in_Colour;                    // (r,g,b,a)
attribute vec2 in_TextureCoord;              // (u,v)

varying vec2 v_vTexcoord;
varying vec4 v_vColour;

void main()
{
    vec4 object_space_pos = vec4( in_Position.x, in_Position.y, in_Position.z, 1.0);
    gl_Position = gm_Matrices[MATRIX_WORLD_VIEW_PROJECTION] * object_space_pos;
    
    v_vColour = in_Colour;
    v_vTexcoord = in_TextureCoord;
}

//######################_==_YOYO_SHADER_MARKER_==_######################@~
varying vec2 v_vTexcoord;
varying vec4 v_vColour;

uniform sampler2D bg, fg;

void main() {
    vec4 _bc = texture2D(bg, v_vTexcoord);
    vec4 _fc = texture2D(fg, v_vTexcoord);
    
    // gl_FragColor = _fc; return;
    
    gl_FragColor = _bc;
    if(_fc.a == 0.) return;
    
    gl_FragColor = _bc.a == 0.? v_vColour : vec4(0.);
}