//
// Simple passthrough vertex shader
//
attribute vec3 in_Position;                  // (x,y,z)
//attribute vec3 in_Normal;                  // (x,y,z)     unused in this shader.
attribute vec4 in_Colour;                    // (r,g,b,a)
attribute vec2 in_TextureCoord;              // (u,v)

varying vec2 v_vTexcoord;
varying vec4 v_vColour;

void main() {
    vec4 object_space_pos = vec4( in_Position.x, in_Position.y, in_Position.z, 1.0);
    gl_Position = gm_Matrices[MATRIX_WORLD_VIEW_PROJECTION] * object_space_pos;
    
    v_vColour = in_Colour;
    v_vTexcoord = in_TextureCoord;
}

//######################_==_YOYO_SHADER_MARKER_==_######################@~
// Cellular noise

varying vec2 v_vTexcoord;
varying vec4 v_vColour;

uniform vec2  dimension;
uniform vec2  position;
uniform float seed;
uniform float contrast;
uniform float middle;
uniform float radiusScale;
uniform float radiusShatter;
uniform int   pattern;
uniform float rotation;
uniform int   tiled;

uniform vec2      scale;
uniform int       scaleUseSurf;
uniform sampler2D scaleSurf;

#define TAU 6.283185307179586
#define PI 3.14159265359

vec2 random2( vec2 p ) { return fract(sin(vec2(dot(p, vec2(127.1, 311.7)), dot(p, vec2(269.5, 183.3)))) * 43758.5453); }

float random (in vec2 st) { return fract(sin(dot(st.xy, vec2(12.9898, 78.233))) * 43758.5453123); }

void main() {
	
		float sca    = scale.x;
		float scaMax = max(scale.x, scale.y);
		if(scaleUseSurf == 1) {
			vec4 _vMap = texture2D( scaleSurf, v_vTexcoord );
			sca = mix(scale.x, scale.y, (_vMap.r + _vMap.g + _vMap.b) / 3.);
		}
		
		float ang = rotation;
	
	
	vec2 ntx = v_vTexcoord * vec2(1., dimension.y / dimension.x);
	vec2 pos = position / dimension;
    vec2 st  = (ntx - pos) * mat2(cos(ang), -sin(ang), sin(ang), cos(ang)) * sca;
	
    float md = 8.;
    vec2 mg, mr;

	if(pattern < 2) {
		vec2 i_st = floor(st);
	    vec2 f_st = fract(st);
	
	    for (int y = -1; y <= 1; y++)
	    for (int x = -1; x <= 1; x++) {
	        vec2 neighbor = vec2(float(x), float(y));
	        vec2 point = random2(pattern == 0? mod(i_st + neighbor, scaMax) : i_st + neighbor);
			point = 0.5 + 0.5 * sin(seed + TAU * point);
			
	        vec2 _diff = neighbor + point - f_st;
	        float dist = length(_diff);

	        if(dist < md) {
				md = dist;
				mr = _diff;
				mg = neighbor;
			}
	    }
		
		md = 8.;
		for(int y = -2; y <= 2; y++)
		for(int x = -2; x <= 2; x++) {
			vec2 g = mg + vec2(float(x), float(y));
			vec2 point = random2(mod(i_st + g, scaMax));
			point = 0.5 + 0.5 * sin(seed + TAU * point);
		
			vec2 r = g + point - f_st;
			if(dot(mr - r, mr - r) > .000001)
				md = min( md, dot( 0.5 * (mr + r), normalize(r - mr)) );
		}
	} else if(pattern == 2) {
		for (int j = 0; j <= int(sca / 2.); j++) {
			int _amo = int(sca) + int(float(j) * radiusShatter);
			for (int i = 0; i <= _amo; i++) {
				float ang = TAU / float(_amo) * float(i) + float(j) + seed;
				float rad = pow(float(j) / sca, radiusScale) * sca * .5 + random(vec2(ang)) * 0.1;
				vec2 neighbor = vec2(cos(ang) * rad, sin(ang) * rad);
				vec2 point = neighbor + pos;
				
			    vec2 _diff = point - ntx;
			    float dist = length(_diff);
			    
				if(dist < md) {
					md = dist;
					mr = _diff;
					mg = neighbor;
				}
			}
		}
		
		md = 1.;
		for (int j = 0; j <= int(sca / 2.); j++) {
			int _amo = int(sca) + int(float(j) * radiusShatter);
			for (int i = 0; i <= _amo; i++) {
				float ang = TAU / float(_amo) * float(i) + float(j) + random(vec2(0.684, 1.387)) + seed;
				float rad = pow(float(j) / sca, radiusScale) * sca * .5 + random(vec2(ang)) * 0.1;
				vec2 neighbor = vec2(cos(ang) * rad, sin(ang) * rad);
				vec2 point = neighbor + pos;
			
			    vec2 r = point - ntx;
				if(dot(mr - r, mr - r) > .0001)
					md = min( md, dot( 0.5 * (mr + r), normalize(r - mr)) );
			}
		}
	}
	
	float c = middle + (md - middle) * contrast;
    gl_FragColor = vec4(vec3(c), 1.0);
}