The alpha() function in p5.js is used to extract the alpha value from a color or pixel array.
Syntax:
alpha(c)
Parameters: The function accepts single parameter as mentioned above and described below:
Below program illustrates the alpha() function in p5.js:
Example-1:
function setup() {         //create Canvas of size 300*80      createCanvas(300, 80); }   function draw() {     background(220);         //initialize the parameter      let c = color(0, 126, 255, 102);         //extract the alpha value     let y = alpha(c);     textSize(16);     fill(color('red'));     text("Alpha Value is : " + y, 50, 30); } |
Output:
Example-2:
function setup() {         //create Canvas of size 300*80      createCanvas(160, 180); }   function draw() {     background(220);         //initialize the parameter      let c = color(0, 126, 255, 34);         // Sets 'value' to 34     let value = alpha(c);     fill(value);     rect(50, 15, 35, 70);     text("Value of alpha is : " + value, 22, 110); } |
Output:
Reference: https://p5js.org/reference/#/p5/alpha
