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
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;