//modified version of [this shader](https://github.com/wessles/GLSL-CRT/blob/master/shader.frag)
const float scaleFactor = 0.7;

float clamp(float x, float min, float max) {
  if (x > max) return max;
  if (x < min) return min;
  return x;
}

void windowShader(inout vec4 color) {
  // color += vec4(cos(x_TexCoord.x)/4., sin(x_TexCoord.y)/4., 0., 1.);
  color += vec4(cos(v_texcoord.x)/4., cos(v_texcoord.y)/8., sin(v_texcoord.y)/4., 1.);

	color = vec4(clamp(color.x, 0., 1.), clamp(color.y, 0., 1.), clamp(color.z, 0., 1.), color.w);
}