precision mediump float;
uniform vec4 black;
uniform vec4 outline;
uniform vec4 highlight;
uniform vec4 foreground;
uniform vec4 midground;
uniform vec4 shadow;
uniform vec4 background;
uniform vec4 lamp1; //vec3 position, float strength
uniform vec4 lamp2;
uniform vec4 lamp3; // max 3 lamps per shaded vertex
uniform vec4 lamp4;
uniform vec4 lamp5;
uniform vec4 lamp6;
uniform vec4 lamp7;
uniform vec4 lamp8;
uniform float streamer; // turn off the noise in the light
uniform float time; //used for noise
uniform sampler2D atlas;
uniform float nlamps;
uniform float water;
varying vec2 worldxy;
varying vec2 norm;

// Author @patriciogv - 2015
float random (vec2 st) {
	return fract(
			sin(
				dot(st.xy,vec2(12.9898,78.233))
			) *
			43758.5453123
	);
}

// stolen from https://www.shadertoy.com/view/Msf3WH
vec2 hash( vec2 p ) // replace this by something better
{
	p = vec2( dot(p,vec2(127.1,311.7)), dot(p,vec2(269.5,183.3)) );
	return -1.0 + 2.0*fract(sin(p)*43758.5453123);
}
float noise( in vec2 p )
{
	const float K1 = 0.366025404; // (sqrt(3)-1)/2;
	const float K2 = 0.211324865; // (3-sqrt(3))/6;

	vec2  i = floor( p + (p.x+p.y)*K1 );
	vec2  a = p - i + (i.x+i.y)*K2;
	float m = step(a.y,a.x); 
	vec2  o = vec2(m,1.0-m);
	vec2  b = a - o + K2;
	vec2  c = a - 1.0 + 2.0*K2;
	vec3  h = max( 0.5-vec3(dot(a,a), dot(b,b), dot(c,c) ), 0.0 );
	vec3  n = h*h*h*h*vec3( dot(a,hash(i+0.0)), dot(b,hash(i+o)), dot(c,hash(i+1.0)));
	return dot( n, vec3(70.0) );
}

void main() {
	vec4 coord = gl_FragCoord + vec4(worldxy * 256., 0, 0);
	/*
	coord.x -= worldxy.x;
	coord.y -= worldxy.y;
	*/
	//coord = coord / 1000.;
	// calculate color at this pixel
	vec4 normal = texture2D(atlas, norm);
	float color = 0.;
	vec4 lamp1_norm = lamp1 * 256.;
	color += lamp1_norm.w - distance(lamp1_norm.xy - worldxy, coord.xy);
	color = max(color,(lamp2.w * 256.) - distance((lamp2.xy * 256.) - worldxy, coord.xy));
	color = max(color,(lamp3.w * 256.) - distance((lamp3.xy * 256.) - worldxy, coord.xy));
	// divide to get a normalized color
	//color /= (256. * max(max(lamp1.w, lamp2.w), lamp3.w));
	color /= 256. * 5.;
	//color = sqrt(color / 2046.);
	// see the normal texture under the color
	color = dot(vec4(color),normal) / 1.;
	// make the colors fuzzy near the border (or don't if we're streaming)
	float rng = random(vec2(coord.x, coord.y) + vec2(color, time));
	color -= (pow(rng / 1.3, 10. * color)) * streamer;
	// add noise to water
	if(water > 1.)
		color += (noise(coord.xy + vec2(time, time)) - 0.0) * 0.1;
	/* */
	if(color > 1.)
		gl_FragColor = highlight * normal.a;
	else if(color > 0.8)
		gl_FragColor = foreground * normal.a;
	else if(color > 0.6)
		gl_FragColor = midground * normal.a;
	else if(color > 0.4)
		gl_FragColor = background * normal.a;
	else if(color > 0.2)
		gl_FragColor = shadow * normal.a;
	else
		gl_FragColor = black * normal.a;
	/*
	gl_FragColor = normal* vec4(color , color, color,1.);
	*/
	//gl_FragColor = normal* vec4(color , color / 10., color / 1024.,1.);
}