#ifdef GL_ES
precision highp float;
#endif
varying vec3 modelPos;
varying vec4 worldPos;
varying vec3 n;
varying vec2 texCoord;

uniform vec3 lightPos;
uniform vec3 lightCol;
uniform vec3 ambient;
uniform vec3 attenuation;

uniform sampler2D texture;
uniform sampler2D shadowMap;

float unpack (vec4 colour) {
  const vec4 bitShifts = vec4(1.0 / (256.0 * 256.0 * 256.0),
			      1.0 / (256.0 * 256.0),
			      1.0 / 256.0,
			      1.0);
  return dot(colour, bitShifts);
}

void main(void) {
  vec4 col = texture2D(texture, texCoord);
  vec3 lightDirection = normalize(lightPos - worldPos.xyz);
  float w = max(dot(normalize(n), lightDirection), 0.0);
  float dist = length(lightPos - worldPos.xyz);

  float attenuate =  1.0 / ((attenuation.x) + 
			    (attenuation.y * dist) +
			    (attenuation.z * dist * dist));


  vec3 lighting = ambient + lightCol * w * attenuate;
  lighting = col.rgb * lighting;
  gl_FragColor = vec4(lighting, 1.0);
}