basic.frag

// casey conchinha - @kcconch ( https://github.com/kcconch )
// louise lessel - @louiselessel ( https://github.com/louiselessel )
// more p5.js + shader examples: https://itp-xstory.github.io/p5js-shaders/
// this is a modification of a shader by adam ferriss
// https://github.com/aferriss/p5jsShaderExamples/tree/gh-pages/2_texture-coordinates/2-1_basic

precision mediump float;

// this is the same variable we declared in the vertex shader
// we need to declare it here too!
varying vec2 vTexCoord;

void main() {
    
    // copy the vTexCoord
    // vTexCoord is a value that goes from 0.0 - 1.0 depending on the pixels location
    // we can use it to access every pixel on the screen
    vec2 coord = vTexCoord;
    
    // x values for red, y values for green, both for blue
    gl_FragColor = vec4(coord.x, coord.y, (coord.x+coord.y), 1.0 );
}