Collection of GLSL code throughout my learning journey

collection.glsl

#define PI 3.1415926538
#define TWO_PI 6.28318530718

vec2 scaleFromCenter = (uv - 0.5) + 0.5;

mat2 scale(vec2 scale){
    return mat2(scale.x, 0.0,
                0.0, scale.y);
}

mat2 rotate2d(float angle){
    return mat2(cos(angle), -sin(angle),
                sin(angle), cos(angle));
}

mat3 yuv2rgb = mat3(1.0, 0.0, 1.13983,
                    1.0, -0.39465, -0.58060,
                    1.0, 2.03211, 0.0);

mat3 rgb2yuv = mat3(0.2126, 0.7152, 0.0722,
                    -0.09991, -0.33609, 0.43600,
                    0.615, -0.5586, -0.05639);

vec2 id = floor(uv * repeat);

float hash11(float p) {
    p = fract(p * .1031);
    p *= p + 33.33;
    p *= p + p;
    return fract(p);
}

float random(vec2 st) {
    return fract(sin(dot(st.xy,
                         vec2(12.9898,78.233)))*
        43758.5453123);
}

float map(float value, float inMin, float inMax, float outMin, float outMax) {
  return outMin + (outMax - outMin) * (value - inMin) / (inMax - inMin);
}

vec3 cosPalette(float t) {
  vec3 brightness = vec3(0.5, 0.5, 0.5);
  vec3 contrast = vec3(0.5, 0.5, 0.5);
  vec3 oscillation = vec3(1.0);
  vec3 phase = vec3(0.00, 0.10, 0.20);

  return brightness + contrast * cos(6.28318 * (oscillation * t + phase));
}