#version 300 es
precision highp float;

// Presenteert de 320×200-buffer van de authentieke modus in het 4:3-kader;
// nearest-neighbour komt van de textuurfilter.
out vec4 outColor;

uniform sampler2D uScene;
uniform vec4 uViewportRect; // x, y, breedte, hoogte in framebufferpixels

void main() {
  vec2 uv = (gl_FragCoord.xy - uViewportRect.xy) / uViewportRect.zw;
  if (uv.x < 0.0 || uv.x > 1.0 || uv.y < 0.0 || uv.y > 1.0) {
    outColor = vec4(0.0, 0.0, 0.0, 1.0);
    return;
  }
  outColor = vec4(texture(uScene, uv).rgb, 1.0);
}