#ifndef INC_RAND
#define INC_RAND

// https://thebookofshaders.com/10/
// https://byteblacksmith.com/improvements-to-the-canonical-one-liner-glsl-rand-for-opengl-es-2-0/

float rand(float seed){
    const float c =  43758.5453;
    return fract(sin(seed) * c);
}

float rand(vec2 co)
{
    const float a = 12.9898;
    const float b = 78.233;
    float dt= dot(co.xy ,vec2(a,b));
    return rand(dt);
}

#endif