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
