javascript - Drawing a single pixel wcanvas - Stack Overflow

admin管理员组

文章数量:1328366

Is it possible to make say, a zoomed in canvas where every 5x5 block is actually 1 pixel in the final image and how do you "paint" the pixel with a color stored in a variable onclick? Any code I've tested ends up being strokes, clicking does nothing for some reason.

Is it possible to make say, a zoomed in canvas where every 5x5 block is actually 1 pixel in the final image and how do you "paint" the pixel with a color stored in a variable onclick? Any code I've tested ends up being strokes, clicking does nothing for some reason.

• javascript
• jquery
• html
• canvas

Share Improve this question Follow asked Mar 4, 2012 at 21:52 jmoonjmoon 57633 gold badges77 silver badges1818 bronze badges 1

• Does this answer your question? What's the best way to set a single pixel in an HTML5 canvas? – handle Commented Feb 11, 2020 at 10:24

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 4

Something like this?

<canvas id="canvas" style="width:100px; height:100px" width="5" height="5"></canvas>

<script>

    var canvas = document.getElementById("canvas");

    var context = canvas.getContext("2d");

    //Background
    context.fillStyle = "#000";
    context.fillRect(0, 0, canvas.width, canvas.height);



    canvas.addEventListener("click", function(e) {

        var x = Math.floor(e.x * canvas.width / parseInt(canvas.style.width));
        var y = Math.floor(e.y * canvas.height / parseInt(canvas.style.height));


        //Zoomed in red 'square'
        context.fillStyle = "#F00";
        context.fillRect(x, y, 1, 1);

    }, true);

</script>

Edit: Added click functionality

Demo: http://jsfiddle/Cmpde/

本文标签： javascriptDrawing a single pixel wcanvasStack Overflow