The setAlpha() method in p5.js is used to set the alpha component of a p5.Color object. The range of the alpha value is dependent on the current color mode. In the default RGB color mode, the value can be between 0 and 255.
Syntax:
setAlpha( alpha )
Parameters: This method accepts a single parameter as mentioned above and described below:
- alpha: It is a number that denotes the new alpha value.
The example below illustrates the setAlpha() method in p5.js:
Example 1:
Javascript
function setup() { createCanvas(600, 300); alphaSlider = createSlider(0, 255, 128); alphaSlider.position(30, 50); } function draw() { clear(); textSize(18); // Get the alpha value from the slider let alphaValue = alphaSlider.value(); let newColor = color(128, 255, 128); // Set the alpha value of the color newColor.setAlpha(alphaValue); background(newColor); fill( 'black' ); text( "Move the slider to change the " + "alpha component of the background color" , 20, 20); } |
Output:
Example 2:
Javascript
function setup() { createCanvas(600, 300); alphaSlider = createSlider(0, 255, 128); alphaSlider.position(30, 50); } function draw() { clear(); textSize(18); noFill(); stroke(0); strokeWeight(50); ellipse(width / 2, height / 2, 150); strokeWeight(1); // Get the alpha value from the slider let alphaValue = alphaSlider.value(); let newColor = color(255, 128, 128); // Set the alpha value of the color newColor.setAlpha(alphaValue); noStroke(); background(newColor); fill( 'black' ); text( "Move the slider to change the " + "alpha component of the background color" , 20, 20); } |
Output:
Online editor: https://editor.p5js.org/
Environment Setup: https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/
Reference: https://p5js.org/reference/#/p5.Color/setAlpha