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Viewsjavascript: Display different color circles in different sizes
I have a homework assignment that asks me to print two alternating circle colors with different sizes. The end-result would look like this:
Right now, I am struggling to print the blue color circle on top of the red color circle and this is the code, i have written:
canvas = document.getElementById("testCanvas");
context = canvas.getContext("2d");
centerX = canvas.width / 2;
centerY = canvas.height / 2;
//Creates a red color circle
context.arc(centerX, centerY, 200, 0, 2 * Math.PI);
context.fillStyle = 'red';
context.fill();
//Creates a blue color circle on top of the red color circle
context.arc(centerX, centerY, 150, 0, 2 * Math.PI);
// context.lineWidth=5;
context.fillStyle = 'blue';
context.stroke();<canvas id="testCanvas" width="400" height="400"></canvas>I am having trouble with the last block of code because if I say fill() on the last line of code, then blue color dominates the canvas. Any help would be greatly appreciated. Thanks in advance.
·
Juan Pablo Isaza
1 answers
Answer question0
You have to loop through and draw circles increasing/decreasing radius. And toggle the color inside the loop. Each time to draw a circle you need to use beginPath() to start and closePath() to prevent overlaps.
const canvas = document.getElementById("testCanvas");
const context = canvas.getContext("2d");
const centerX = canvas.width / 2;
const centerY = canvas.height / 2;
let radius = centerX;
let color = "red";
while (radius > 0) {
context.beginPath();
context.fillStyle = color;
context.arc(centerX, centerY, radius, 0, 2 * Math.PI);
context.fill();
context.closePath();
color = color === "red" ? "blue" : "red";
radius -= 25;
}<canvas id="testCanvas" width="400" height="400"></canvas>
·
Juan Pablo Isaza
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