Shader - Shadertoy BETA

This help only covers the parts of GLSL ES that are relevant for Shadertoy. For the complete specification please have a look at GLSL ES specification

Language:

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• Version: WebGL 2.0
• Arithmetic: ( ) + - ! * / %
• Logical/Relatonal: ~ < > <= >= == != && ||
• Bit Operators: & ^ | << >>
• Comments: // /* */
• Types: void bool int uint float vec2 vec3 vec4 bvec2 bvec3 bvec4 ivec2 ivec3 ivec4 uvec2 uvec3 uvec4 mat2 mat3 mat4 mat?x? sampler2D, sampler3D, samplerCube
• Format: float a = 1.0; int b = 1; uint i = 1U; int i = 0x1;
• Function Parameter Qualifiers: [none], in, out, inout
• Global Variable Qualifiers: const
• Vector Components: .xyzw .rgba .stpq
• Flow Control: if else for return break continue switch/case
• Output: vec4 fragColor
• Input: vec2 fragCoord
• Preprocessor: # #define #undef #if #ifdef #ifndef #else #elif #endif #error #pragma #line

Built-in Functions:

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• type radians (type degrees)
• type degrees (type radians)
• type sin (type angle)
• type cos (type angle)
• type tan (type angle)
• type asin (type x)
• type acos (type x)
• type atan (type y, type x)
• type atan (type y_over_x)
• type sinh (type x)
• type cosh (type x)
• type tanh (type x)
• type asinh (type x)
• type acosh (type x)
• type atanh (type x)

• type pow (type x, type y)
• type exp (type x)
• type log (type x)
• type exp2 (type x)
• type log2 (type x)
• type sqrt (type x)
• type inversesqrt (type x)

• type abs (type x)
• type sign (type x)
• type floor (type x)
• type ceil (type x)
• type trunc (type x)
• type fract (type x)
• type mod (type x, float y)
• type modf (type x, out type i)
• type min (type x, type y)
• type max (type x, type y)
• type clamp (type x, type minV, type maxV)
• type mix (type x, type y, type a)
• type step (type edge, type x)
• type smoothstep (type a, type b, type x)

• float length (type x)
• float distance (type p0, type p1)
• float dot (type x, type y)
• vec3 cross (vec3 x, vec3 y)
• type normalize (type x)
• type faceforward (type N, type I, type Nref)
• type reflect (type I, type N)
• type refract (type I, type N,float eta)
• float determinant(mat? m)
• mat?x? outerProduct(vec? c, vec? r)
• type matrixCompMult (type x, type y)
• type inverse (type inverse)
• type transpose (type inverse)

• vec4 texture( sampler? , vec? coord [, float bias])
• vec4 textureLod( sampler, vec? coord, float lod)
• vec4 textureLodOffset( sampler? sampler, vec? coord, float lod, ivec? offset)
• vec4 textureGrad( sampler? , vec? coord, vec2 dPdx, vec2 dPdy)
• vec4 textureGradOffset sampler? , vec? coord, vec? dPdx, vec? dPdy, vec? offset)
• vec4 textureProj( sampler? , vec? coord [, float bias])
• vec4 textureProjLod( sampler? , vec? coord, float lod)
• vec4 textureProjLodOffset( sampler? , vec? coord, float lod, vec? offset)
• vec4 textureProjGrad( sampler? , vec? coord, vec2 dPdx, vec2 dPdy)
• vec4 texelFetch( sampler? , ivec? coord, int lod)
• vec4 texelFetchOffset( sampler?, ivec? coord, int lod, ivec? offset )
• ivec? textureSize( sampler? , int lod)

• type dFdx (type x)
• type dFdy (type x)
• type fwidth (type p)

• type isnan (type x)
• type isinf (type x)
• float intBitsToFloat (int v)
• uint uintBitsToFloat (uint v)
• int floatBitsToInt (float v)
• uint floatBitsToUint (float v)
• uint packSnorm2x16 (vec2 v)
• uint packUnorm2x16 (vec2 v)
• vec2 unpackSnorm2x16 (uint p)
• vec2 unpackUnorm2x16 (uint p)

• bvec lessThan (type x, type y)
• bvec lessThanEqual (type x, type y)
• bvec greaterThan (type x, type y)
• bvec greaterThanEqual (type x, type y)
• bvec equal (type x, type y)
• bvec notEqual (type x, type y)
• bool any (bvec x)
• bool all (bvec x)
• bvec not (bvec x)

How-to

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• Use structs: struct myDataType { float occlusion; vec3 color; }; myDataType myData = myDataType(0.7, vec3(1.0, 2.0, 3.0));
• Initialize arrays:float[] x = float[] (0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6);
• Do conversions: int a = 3; float b = float(a);
• Do component swizzling: vec4 a = vec4(1.0,2.0,3.0,4.0); vec4 b = a.zyyw;
• Access matrix components: mat4 m; m[1] = vec4(2.0); m[0][0] = 1.0; m[2][3] = 2.0;

Be careful!

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• the f suffix for floating pont numbers: 1.0f is illegal in GLSL. You must use 1.0
• saturate(): saturate(x) doesn't exist in GLSL. Use clamp(x,0.0,1.0) instead
• pow/sqrt: please don't feed sqrt() and pow() with negative numbers. Add an abs() or max(0.0,) to the argument
• mod: please don't do mod(x,0.0). This is undefined in some platforms
• variables: initialize your variables! Don't assume they'll be set to zero by default
• functions: don't call your functions the same as some of your variables

Shadertoy Inputs

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vec3iResolutionimage/bufferThe viewport resolution (z is pixel aspect ratio, usually 1.0)floatiTimeimage/sound/bufferCurrent time in secondsfloatiTimeDeltaimage/bufferTime it takes to render a frame, in secondsintiFrameimage/bufferCurrent framefloatiFrameRateimage/bufferNumber of frames rendered per secondfloatiChannelTime[4]image/bufferTime for channel (if video or sound), in secondsvec3iChannelResolution[4]image/buffer/soundInput texture resolution for each channelvec4iMouseimage/bufferxy = current pixel coords (if LMB is down). zw = click pixelsampler2DiChannel{i}image/buffer/soundSampler for input textures ivec4iDateimage/buffer/soundYear, month, day, time in seconds in .xyzwfloatiSampleRateimage/buffer/soundThe sound sample rate (typically 44100)

Shadertoy Outputs

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Image shaders: fragColor is used as output channel. It is not, for now, mandatory but recommended to leave the alpha channel to 1.0.

Sound shaders: the mainSound() function returns a vec2 containing the left and right (stereo) sound channel wave data.