precision mediump float;

#endif

​

// R = Energy

// G = Nutrition

// B = Moisture

// A = NA

​

varying vec2 pos;

​

uniform sampler2D soil_state;

​

uniform sampler2D filter_background;

uniform vec2 filter_res;

​

// uniform float sunlight;

float sunlight = 0.5;

​

vec3 absorption = vec3(0.2, 0.1, 0.1);

​

void main() {

  vec4 col = texture2D(filter_background, pos);

  vec4 avg = vec4(0.);

  // Check neighbours

  for(float i = -1.; i <= 1.; i ++) {

    for(float j = -1.; j <= 1.; j ++) {

      vec2 nPos = pos + (vec2(i, j)/filter_res);

      vec4 nCol = texture2D(filter_background, nPos);

      avg += nCol;

    }

  }

  avg /= 9.;

  col = avg * evaporation;

  gl_FragColor = vec4(col.rgb, 1.);

}