shaderdoll

Shadertoy clone

Comes with a crippled glsl clone

Usage

Basic template

vec3 main()
{
  return vec3(1, 1, 1);
};

Produces a white screen.

The program is run for each pixel on the screen, the return value of main will be the color of the pixel on the screen. vec3(0, 0, 0) is black, vec3(1, 1, 1) is white. x = red, y = green, z = blue.

Everything has to end with a semicolon - typically } will always have a semicolon that follows it unless it's inside of an if else if else chain.

Input variables

vec3 main()
{
  return vec3(uv.x, 0, 0);
};

Produces a red gradient that gets more intense as x increases. uv = (0, 0) represents top left and uv = (1, 1) represents bottom right. uv is automatically defined every time the program is run.

Define a function

float function_name(float param, vec3 other_param)
{
  return param;
};

Currently, a return statement won't exit the function, it will only set the return value that will be returned at the end of the function.

Control flow

If statements

if (expr)
{
}
else if (other expr)
{
}
else
{
};

Operators

+, -, *, / work on floats and vectors.

< and > can compare floats.

Operators can only have the same type on both sides, so if you want to scale a vector for example by 2:

vec3 a = vec3(1, 2, 3);
a = a * vec3(2, 2, 2);

Unary - doesn't exist, use 0- instead.

Builtin functions

• print: Print values. Debugging purposes typically
• sqrt: Square root of a float
• distance: Distance between two vectors of variable size
• dot: Dot product between two vectors of variable size
• normalize: Normalize vector of variable size
• length: Length of vector of variable size
• abs: Absolute value
• pow: pow(base, exp)
• sin: sine
• cos: cosine
• tan: tangent
• asin: arcsin
• acos: arccos
• atan: arctan