Files
UoL/CM2030 Graphics Programming/Week 13/13.3.1 Pixels/sketch.js
2021-07-28 20:12:31 -05:00

33 lines
903 B
JavaScript

let img;
function preload() {
img = loadImage('rockets.png');
}
function setup() {
createCanvas(640 * 2, 400);
pixelDensity(1);
}
function draw() {
background(150);
image(img, 0, 0);
// getting pixel information using get()
let c = img.get(mouseX, mouseY);
fill(c);
rect(mouseX, mouseY, 50, 50);
// getting color values manually
img.loadPixels(); // make the pixel array ready to be used with img.pixels[]
let index = (img.width * mouseY + mouseX) * 4; //index of first value
let channelRed = img.pixels[index + 0];
let channelGrn = img.pixels[index + 1];
let channelBlu = img.pixels[index + 2];
let channelAlp = img.pixels[index + 3];
fill('rgba(' + channelRed + ',' + channelGrn + ',' + channelBlu + ',' + channelAlp + ')');
//fill(channelRed, channelGrn, channelBlu, channelAlp);
rect(mouseX + 50, mouseY, 50, 50);
}