#define PROCESSING_TEXLIGHT_SHADER
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

uniform int lightCount;
uniform vec4 lightPosition[8];
uniform vec3 lightDiffuse[8];
uniform vec3 lightAmbient[8];
uniform vec3 lightSpecular[8];
uniform sampler2D texture;

varying vec4 vertColor;
varying vec4 vertEmissive;
varying float vertShininess;
varying vec3 ecNormal;
varying vec3 ecPosition;
varying vec2 uv;

float lambertFactor(vec3 lightDir, vec3 vecNormal) {
	return max(0.0, dot(normalize(lightDir), normalize(vecNormal)));
}

float blinnPhongFactor(vec3 lightDir, vec3 vertPos, vec3 vecNormal, float shininess) {
	vec3 np = normalize(vertPos);
	vec3 ldp = normalize(lightDir - np);
	return pow(max(0.0, dot(ldp, normalize(vecNormal))), shininess);
}

void main() {
	vec3  dfColor  = vec3(0);
	vec3  amColor  = vec3(0);
	vec3  spColor  = vec3(0);
	vec3  normal   = normalize(ecNormal);
	vec4  texColor = texture2D(texture, uv.st);

	if(vertEmissive.x > 0 || vertEmissive.y > 0 || vertEmissive.z > 0) {
		gl_FragColor = vertEmissive;
	} else {
		for(int i=0; i<lightCount; i++) {
			vec3  lightDir  = normalize(lightPosition[i].xyz - ecPosition);
			float intensity = lambertFactor(lightDir, normal);
			float spec = 0;
			if(vertShininess >= 0) {
				spec = blinnPhongFactor(lightDir, ecPosition, normal, vertShininess);
			}
			//      dfColor += vertColor.rgb * lightDiffuse[i] * intensity;
			dfColor += vertColor.rgb * texColor.rgb * lightDiffuse[i] * intensity;
			spColor += lightSpecular[i] * spec;
			amColor += lightAmbient[i];
		}

		gl_FragColor = vec4(dfColor + amColor + spColor, vertColor.a * texColor.a);
	}
}