mirror of
https://github.com/italicsjenga/slang-shaders.git
synced 2024-11-23 00:01:31 +11:00
426 lines
11 KiB
Plaintext
426 lines
11 KiB
Plaintext
#version 450
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// Rolling Hills - 2013-07-29
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// https://www.shadertoy.com/view/Xsf3zX
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// Grassy fields. Ray marches a ray to a smooth hill, then enters detailed stepping through a grass like distance, erm, field.
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// Now uses eiffie's 'Circle of Confusion' function for blurred ray marching into the grass.
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// Thanks eiffie!
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// Rolling hills. By David Hoskins, November 2013.
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// License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
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// https://www.shadertoy.com/view/Xsf3zX
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// v.2.00 Uses eiffie's 'Circle of Confusion' function
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// for blurred ray marching into the grass.
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// v.1.02 Camera aberrations.
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// v.1.01 Added better grass, with wind movement.
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layout(std140, set = 0, binding = 0) uniform UBO
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{
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mat4 MVP;
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vec4 OutputSize;
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vec4 OriginalSize;
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vec4 SourceSize;
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uint FrameCount;
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} global;
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#pragma stage vertex
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layout(location = 0) in vec4 Position;
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layout(location = 1) in vec2 TexCoord;
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layout(location = 0) out vec2 vTexCoord;
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const vec2 madd = vec2(0.5, 0.5);
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void main()
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{
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gl_Position = global.MVP * Position;
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vTexCoord = gl_Position.xy;
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}
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#pragma stage fragment
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layout(location = 0) in vec2 vTexCoord;
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layout(location = 0) out vec4 FragColor;
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float iGlobalTime = float(global.FrameCount)*0.025;
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vec2 iResolution = global.OutputSize.xy;
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// For red/cyan 3D...
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//#define STEREO
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#define MOD2 vec2(3.07965, 7.4235)
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float PI = 4.0*atan(1.0);
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vec3 sunLight = normalize( vec3( 0.35, 0.2, 0.3 ) );
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vec3 cameraPos;
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vec3 sunColour = vec3(1.0, .75, .6);
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const mat2 rotate2D = mat2(1.932, 1.623, -1.623, 1.952);
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float gTime = 0.0;
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//--------------------------------------------------------------------------
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// Noise functions...
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float Hash( float p )
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{
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vec2 p2 = fract(vec2(p) / MOD2);
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p2 += dot(p2.yx, p2.xy+19.19);
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return fract(p2.x * p2.y);
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}
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//--------------------------------------------------------------------------
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float Hash(vec2 p)
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{
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p = fract(p / MOD2);
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p += dot(p.xy, p.yx+19.19);
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return fract(p.x * p.y);
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}
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//--------------------------------------------------------------------------
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float Noise( in vec2 x )
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{
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vec2 p = floor(x);
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vec2 f = fract(x);
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f = f*f*(3.0-2.0*f);
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float n = p.x + p.y*57.0;
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float res = mix(mix( Hash(n+ 0.0), Hash(n+ 1.0),f.x),
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mix( Hash(n+ 57.0), Hash(n+ 58.0),f.x),f.y);
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return res;
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}
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vec2 Voronoi( in vec2 x )
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{
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vec2 p = floor( x );
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vec2 f = fract( x );
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float res=100.0,id;
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for( int j=-1; j<=1; j++ )
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for( int i=-1; i<=1; i++ )
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{
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vec2 b = vec2( float(i), float(j) );
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vec2 r = vec2( b ) - f + Hash( p + b );
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float d = dot(r,r);
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if( d < res )
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{
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res = d;
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id = Hash(p+b);
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}
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}
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return vec2(max(.4-sqrt(res), 0.0),id);
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}
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//--------------------------------------------------------------------------
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vec2 Terrain( in vec2 p)
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{
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float type = 0.0;
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vec2 pos = p*0.003;
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float w = 50.0;
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float f = .0;
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for (int i = 0; i < 3; i++)
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{
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f += Noise(pos) * w;
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w = w * 0.62;
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pos *= 2.5;
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}
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return vec2(f, type);
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}
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//--------------------------------------------------------------------------
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vec2 Map(in vec3 p)
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{
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vec2 h = Terrain(p.xz);
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return vec2(p.y - h.x, h.y);
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}
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//--------------------------------------------------------------------------
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float FractalNoise(in vec2 xy)
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{
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float w = .7;
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float f = 0.0;
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for (int i = 0; i < 3; i++)
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{
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f += Noise(xy) * w;
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w = w*0.6;
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xy = 2.0 * xy;
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}
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return f;
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}
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//--------------------------------------------------------------------------
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// Grab all sky information for a given ray from camera
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vec3 GetSky(in vec3 rd)
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{
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float sunAmount = max( dot( rd, sunLight), 0.0 );
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float v = pow(1.0-max(rd.y,0.0),6.);
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vec3 sky = mix(vec3(.1, .2, .3), vec3(.32, .32, .32), v);
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sky = sky + sunColour * sunAmount * sunAmount * .25;
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sky = sky + sunColour * min(pow(sunAmount, 800.0)*1.5, .3);
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return clamp(sky, 0.0, 1.0);
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}
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//--------------------------------------------------------------------------
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// Merge grass into the sky background for correct fog colouring...
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vec3 ApplyFog( in vec3 rgb, in float dis, in vec3 dir)
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{
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float fogAmount = clamp(dis*dis* 0.0000012, 0.0, 1.0);
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return mix( rgb, GetSky(dir), fogAmount );
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}
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//--------------------------------------------------------------------------
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vec3 DE(vec3 p)
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{
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float base = Terrain(p.xz).x - 1.9;
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float height = Noise(p.xz*2.0)*.75 + Noise(p.xz)*.35 + Noise(p.xz*.5)*.2;
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//p.y += height;
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float y = p.y - base-height;
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y = y*y;
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vec2 ret = Voronoi((p.xz*2.5+sin(y*4.0+p.zx*12.3)*.12+vec2(sin(iGlobalTime*2.3+1.5*p.z),sin(iGlobalTime*3.6+1.5*p.x))*y*.5));
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float f = ret.x * .6 + y * .58;
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return vec3( y - f*1.4, clamp(f * 1.5, 0.0, 1.0), ret.y);
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}
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//--------------------------------------------------------------------------
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// eiffie's code for calculating the aperture size for a given distance...
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float CircleOfConfusion(float t)
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{
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return max(t * .04, (2.0 / iResolution.y) * (1.0+t));
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}
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//--------------------------------------------------------------------------
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float Linstep(float a, float b, float t)
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{
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return clamp((t-a)/(b-a),0.,1.);
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}
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//--------------------------------------------------------------------------
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vec3 GrassBlades(in vec3 rO, in vec3 rD, in vec3 mat, in float dist)
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{
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float d = 0.0;
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// Only calculate cCoC once is enough here...
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float rCoC = CircleOfConfusion(dist*.3);
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float alpha = 0.0;
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vec4 col = vec4(mat*0.15, 0.0);
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for (int i = 0; i < 15; i++)
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{
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if (col.w > .99) break;
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vec3 p = rO + rD * d;
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vec3 ret = DE(p);
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ret.x += .5 * rCoC;
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if (ret.x < rCoC)
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{
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alpha = (1.0 - col.y) * Linstep(-rCoC, rCoC, -ret.x);//calculate the mix like cloud density
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// Mix material with white tips for grass...
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vec3 gra = mix(mat, vec3(.35, .35, min(pow(ret.z, 4.0)*35.0, .35)), pow(ret.y, 9.0)*.7) * ret.y;
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col += vec4(gra * alpha, alpha);
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}
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d += max(ret.x * .7, .1);
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}
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if(col.w < .2)
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col.xyz = vec3(0.1, .15, 0.05);
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return col.xyz;
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}
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//--------------------------------------------------------------------------
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// Calculate sun light...
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void DoLighting(inout vec3 mat, in vec3 pos, in vec3 normal, in vec3 eyeDir, in float dis)
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{
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float h = dot(sunLight,normal);
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mat = mat * sunColour*(max(h, 0.0)+.2);
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}
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//--------------------------------------------------------------------------
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vec3 TerrainColour(vec3 pos, vec3 dir, vec3 normal, float dis, float type)
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{
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vec3 mat;
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if (type == 0.0)
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{
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// Random colour...
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mat = mix(vec3(.0,.3,.0), vec3(.2,.3,.0), Noise(pos.xz*.025));
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// Random shadows...
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float t = FractalNoise(pos.xz * .1)+.5;
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// Do grass blade tracing...
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mat = GrassBlades(pos, dir, mat, dis) * t;
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DoLighting(mat, pos, normal,dir, dis);
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}
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mat = ApplyFog(mat, dis, dir);
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return mat;
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}
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//--------------------------------------------------------------------------
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// Home in on the surface by dividing by two and split...
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float BinarySubdivision(in vec3 rO, in vec3 rD, float t, float oldT)
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{
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float halfwayT = 0.0;
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for (int n = 0; n < 5; n++)
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{
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halfwayT = (oldT + t ) * .5;
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if (Map(rO + halfwayT*rD).x < .05)
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{
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t = halfwayT;
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}else
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{
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oldT = halfwayT;
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}
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}
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return t;
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}
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//--------------------------------------------------------------------------
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bool Scene(in vec3 rO, in vec3 rD, out float resT, out float type )
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{
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float t = 5.;
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float oldT = 0.0;
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float delta = 0.;
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vec2 h = vec2(1.0, 1.0);
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bool hit = false;
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for( int j=0; j < 70; j++ )
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{
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vec3 p = rO + t*rD;
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h = Map(p); // ...Get this position's height mapping.
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// Are we inside, and close enough to fudge a hit?...
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if( h.x < 0.05)
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{
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hit = true;
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break;
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}
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delta = h.x + (t*0.03);
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oldT = t;
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t += delta;
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}
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type = h.y;
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resT = BinarySubdivision(rO, rD, t, oldT);
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return hit;
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}
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//--------------------------------------------------------------------------
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vec3 CameraPath( float t )
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{
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//t = time + t;
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vec2 p = vec2(200.0 * sin(3.54*t), 200.0 * cos(2.0*t) );
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return vec3(p.x+55.0, 12.0+sin(t*.3)*6.5, -94.0+p.y);
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}
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//--------------------------------------------------------------------------
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vec3 PostEffects(vec3 rgb, vec2 xy)
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{
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// Gamma first...
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rgb = pow(rgb, vec3(0.45));
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// Then...
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#define CONTRAST 1.1
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#define SATURATION 1.3
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#define BRIGHTNESS 1.3
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rgb = mix(vec3(.5), mix(vec3(dot(vec3(.2125, .7154, .0721), rgb*BRIGHTNESS)), rgb*BRIGHTNESS, SATURATION), CONTRAST);
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// Vignette...
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rgb *= .4+0.5*pow(40.0*xy.x*xy.y*(1.0-xy.x)*(1.0-xy.y), 0.2 );
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return rgb;
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}
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//--------------------------------------------------------------------------
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void mainImage( out vec4 fragColor, in vec2 fragCoord )
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{
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#ifdef MOUSE
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float m = (iMouse.x/iResolution.x)*300.0;
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##else
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float m = (0.0/iResolution.x)*300.0;
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#endif
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float gTime = (iGlobalTime*5.0+m+2352.0)*.006;
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vec2 xy = fragCoord.xy / iResolution.xy;
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vec2 uv = (-1.0 + 2.0 * xy) * vec2(iResolution.x/iResolution.y,1.0);
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vec3 camTar;
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if (xy.y < .13 || xy.y >= .87)
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{
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// Top and bottom cine-crop - what a waste! :)
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fragColor=vec4(vec4(0.0));
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return;
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}
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#ifdef STEREO
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float isCyan = mod(fragCoord.x + mod(fragCoord.y,2.0),2.0);
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#endif
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cameraPos = CameraPath(gTime + 0.0);
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cameraPos.x -= 3.0;
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camTar = CameraPath(gTime + .009);
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cameraPos.y += Terrain(CameraPath(gTime + .009).xz).x;
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camTar.y = cameraPos.y;
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float roll = .4*sin(gTime+.5);
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vec3 cw = normalize(camTar-cameraPos);
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vec3 cp = vec3(sin(roll), cos(roll),0.0);
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vec3 cu = cross(cw,cp);
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vec3 cv = cross(cu,cw);
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vec3 dir = normalize(uv.x*cu + uv.y*cv + 1.3*cw);
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mat3 camMat = mat3(cu, cv, cw);
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#ifdef STEREO
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cameraPos += .85*cu*isCyan; // move camera to the right - the rd vector is still good
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#endif
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vec3 col;
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float distance;
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float type;
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if( !Scene(cameraPos, dir, distance, type) )
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{
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// Missed scene, now just get the sky...
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col = GetSky(dir);
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}
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else
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{
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// Get world coordinate of landscape...
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vec3 pos = cameraPos + distance * dir;
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// Get normal from sampling the high definition height map
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// Use the distance to sample larger gaps to help stop aliasing...
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vec2 p = vec2(0.1, 0.0);
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vec3 nor = vec3(0.0, Terrain(pos.xz).x, 0.0);
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vec3 v2 = nor-vec3(p.x, Terrain(pos.xz+p).x, 0.0);
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vec3 v3 = nor-vec3(0.0, Terrain(pos.xz-p.yx).x, -p.x);
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nor = cross(v2, v3);
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nor = normalize(nor);
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// Get the colour using all available data...
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col = TerrainColour(pos, dir, nor, distance, type);
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}
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// bri is the brightness of sun at the centre of the camera direction.
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// Yeah, the lens flares is not exactly subtle, but it was good fun making it.
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float bri = dot(cw, sunLight)*.75;
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if (bri > 0.0)
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{
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vec2 sunPos = vec2( dot( sunLight, cu ), dot( sunLight, cv ) );
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vec2 uvT = uv-sunPos;
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uvT = uvT*(length(uvT));
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bri = pow(bri, 6.0)*.8;
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// glare = the red shifted blob...
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float glare1 = max(dot(normalize(vec3(dir.x, dir.y+.3, dir.z)),sunLight),0.0)*1.4;
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// glare2 is the yellow ring...
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float glare2 = max(1.0-length(uvT+sunPos*.5)*4.0, 0.0);
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uvT = mix (uvT, uv, -2.3);
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// glare3 is a purple splodge...
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float glare3 = max(1.0-length(uvT+sunPos*5.0)*1.2, 0.0);
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col += bri * vec3(1.0, .0, .0) * pow(glare1, 12.5)*.05;
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col += bri * vec3(1.0, 1.0, 0.2) * pow(glare2, 2.0)*2.5;
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col += bri * sunColour * pow(glare3, 2.0)*3.0;
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}
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col = PostEffects(col, xy);
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#ifdef STEREO
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col *= vec3( isCyan, 1.0-isCyan, 1.0-isCyan );
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#endif
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fragColor=vec4(col,1.0);
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}
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void main(void)
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{
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//just some shit to wrap shadertoy's stuff
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vec2 FragmentCoord = vTexCoord.xy*global.OutputSize.xy;
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FragmentCoord.y = -FragmentCoord.y;
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mainImage(FragColor,FragmentCoord);
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}
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