<!--
TODO
- nozzles -> particle+cones+lensflare
- texture -> ??
- starship lights
-->
<script type='x-shader/x-vertex' id='vShader'>
varying vec3 vPosition ;
varying vec3 vNormal ;
	
void main(){
	vNormal=normal;
	vPosition=position;
	
	gl_Position = projectionMatrix * modelViewMatrix * vec4(position,1.);
	
}
</script>
<script type='x-shader/x-fragment' id='fShader'>
	
uniform float time ;
uniform float maxZ ;
uniform vec3 light ;
	
varying vec3 vPosition;
varying vec3 vNormal ;
	
void main () {
	
	float lightCoeff = ( dot( vNormal, light ) + .5 ) ;
	vec3 color = vec3(.16,.2,.0) * ( .1 + lightCoeff );
	if( vPosition.y > 3.7 && vPosition.y < 3.78 && abs( vPosition.x ) > 1.25 && abs( vPosition.x ) < 1.3 ) color = vec3( 1. );
	
	float transition = ( maxZ - time + 5. ) - ( vPosition.z + cos( gl_FragCoord.y / 10. + time * 3. ) / 10. ) ;
	
	vec4 result = vec4( color, transition ) ;
	
	float positiveBlue = max( ( cos( transition / 4. - .08 ) - .99995 ), .0 );
	
	if ( transition < .0 ) {
		color = vec3( .15) ;
		transition = .15 ;
		result = vec4( color, transition );
	}
	
	//result += vec4(.2, 0., 1., 1.) * positiveBlue * 35000. * ( 1. + sin( dot( gl_FragCoord.xy , vec2( 12.9898, 78.233 ) ) * 100. ) );
	/*
	if( cos( vPosition.x * 10. ) > .99 ) result.x *= 3.;
	if( cos( vPosition.y * 10. ) > .99 ) result.y *= 3.;
	if( cos( vPosition.z * 10. ) > .99 ) result.z *= 3.;
	if( cos( vPosition.x ) > .97 ) result.x *= 3.;
	if( cos( vPosition.y ) > .97 ) result.y *= 3.;
	if( cos( vPosition.z ) > .97 ) result.z *= 3.;*/
			
	gl_FragColor = result;
	
}
</script>
	
<script type='x-shader/x-vertex' id='starVShader'>
void main(){
	gl_Position = projectionMatrix * modelViewMatrix * vec4(position,1.);
}
</script>
<script type='x-shader/x-fragment' id='starFShader'>
uniform float width;
uniform float height;
#define OCTAVES 5

vec3 mod289(vec3 x){
    return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec2 mod289(vec2 x) {
    return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec3 permute(vec3 x) {
    return mod289(((x*34.0)+1.0)*x);
}

// Simplex noise 
// https://github.com/ashima/webgl-noise 
// Copyright (C) 2011 Ashima Arts. All rights reserved.
float snoise(vec2 v) {
    const vec4 C = vec4(0.211324865405187, 
                        0.366025403784439, 
                        -0.577350269189626, 
                        0.024390243902439); 
    vec2 i  = floor(v + dot(v, C.yy) );
    vec2 x0 = v -   i + dot(i, C.xx);

    vec2 i1;
    i1 = (x0.x > x0.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
    vec4 x12 = x0.xyxy + C.xxzz;
    x12.xy -= i1;

    i = mod289(i);
    vec3 p = permute( permute( i.y + vec3(0.0, i1.y, 1.0 ))
                     + i.x + vec3(0.0, i1.x, 1.0 ));

    vec3 m = max(0.5 - vec3(dot(x0,x0), dot(x12.xy,x12.xy), dot(x12.zw,x12.zw)), 0.0);
    m = m*m ;
    m = m*m ;

    vec3 x = 2.0 * fract(p * C.www) - 1.0;
    vec3 h = abs(x) - 0.5;
    vec3 ox = floor(x + 0.5);
    vec3 a0 = x - ox;

    m *= 1.79284291400159 - 0.85373472095314 * ( a0*a0 + h*h );

    vec3 g;
    g.x  = a0.x  * x0.x  + h.x  * x0.y;
    g.yz = a0.yz * x12.xz + h.yz * x12.yw;
    return 130.0 * dot(m, g);
}

float fractalNoise(in vec2 coord, in float persistence, in float lacunarity){    
    float n = 0.;
    float frequency = 1.;
    float amplitude = 2.;
    for (int o = 0; o < OCTAVES ; ++o) {
        n += amplitude * snoise(coord * frequency);
        amplitude *= persistence;
        frequency *= lacunarity;
    }
    return n;
}

vec3 fractalNebula(in vec2 coord, vec3 color, float transparency){
    float n = fractalNoise(coord, .5, 3.);
    return n * color * transparency;
}

vec3 correct(in vec3 v){
    return vec3(max(.0,v.x),max(.0,v.y),max(.0,v.z));
}

void main(){
    
    vec2 b=gl_FragCoord.xy/vec2(height,height);
    
    float stars=max((fract(dot(sin(gl_FragCoord.xy),gl_FragCoord.xy))-.99)*90.,.0);
    
    vec3 galaxyArea=vec3(1.)*.5-length(b-vec2(.5,.5));
    galaxyArea*=max(.0,100.*(sin(b.y*3.14+.05*cos(b.x*15.))-.8));
    
    vec3 galaxy=correct(fractalNebula(2.*b+vec2(1.8,1.5),vec3(.4,.4,.6),.03)); 
    galaxy+=correct(fractalNebula(2.*b+vec2(1.2,1.3),vec3(.4,.4,.6),.03)); 
    
    vec3 result=vec3(stars)+vec3(1.)*galaxyArea*galaxy;

    gl_FragColor=vec4(result,1.);
}
</script>
<div>
	<button>Toggle visibility</button>
</div>