CCLab Spring 2021 Exercise 13.1

sketch.js

let HORIZONTAL = "HORIZONTAL";
let VERTICAL = "VERTICAL";

function setup() {
	createCanvas(windowWidth, windowHeight);
	background(100);

	let whiteColor = color(255, 255, 255);
	let blackColor = color(0, 0, 0);
	let redColor = color(255, 0, 0);
	let greenColor = color(0, 255, 0);
	let blueColor = color(0, 0, 255);

	gradientRect(10, 20, 100, 50, redColor, blackColor, HORIZONTAL);
	gradientRect(10, 100, 100, 50, redColor, whiteColor, VERTICAL);

	gradientRect(150, 20, 100, 50, blackColor, greenColor, HORIZONTAL);
	gradientRect(150, 100, 100, 50, whiteColor, greenColor, VERTICAL);

	gradientRect(300, 20, 100, 50, blueColor, makeTransparent(blueColor), HORIZONTAL);
	gradientRect(300, 100, 100, 50, blueColor, makeTransparent(blueColor), VERTICAL);
}

function gradientRect() {
}

function makeTransparent(c) {
	return colorWithAlpha(c, 0);
}

function colorWithAlpha(c, a) {
	return color(red(c), green(c), blue(c), a);
}