Download attribute There is a new download attribute in HTML5 that allow you to specify a file-name for links. I made this for saving canvas. It has a link (“Download as image”) – <a id=”downloadLnk” download=”YourFileName.jpg”>Download as image</a> And the function: function download() { var dt = canvas.toDataURL(‘image/jpeg’); this.href = dt; }; downloadLnk.addEventListener(‘click’, download, false); … Read more
The question as it stands is a bit unclear IMO. To give a more general answer that you can apply to a scenario where you need clipping you can use (at least) two approaches: Method 1 – Using composite mode to clip Composite mode is the simplest way but also the least flexible as you … Read more
Simple, just create an image object in JavaScript, set the src, and wait for the load event before drawing. Working Example: var c = document.getElementById(“myCanvas”); var ctx = c.getContext(“2d”); var img = new Image(); img.onload = function() { ctx.drawImage(img, 0, 0); }; img.src=”https://cdn.sstatic.net/stackexchange/img/logos/so/so-icon.png”; <canvas id=”myCanvas”></canvas>
Set the tabindex of the canvas element to 1 or something like this <canvas tabindex=’1′></canvas> It’s an old trick to make any element focusable
The second argument of the function is the quality. It ranges from 0.0 to 1.0 canvas.toDataURL(type,quality); Here you have extended information And I don’t think it’s possible to know the quality of the image once is converted. As you can see on this feedle the only information you get when printing the value on the … Read more
If the variable persists (e.g. it’s global or part of some persistent data structure) and the data it points to is large and you want that data to be eligible for garbage collection, then you are correct to assign something small to that variable. undefined or null or “” will all work. What you’re doing … Read more
HTML5 Canvas The HTML element is used to draw graphics, on the fly, via JavaScript. The element is only a container for graphics. You must use JavaScript to actually draw the graphics. Canvas has several methods for drawing paths, boxes, circles, text, and adding images. In general, to scroll the mousewheel up and down we … Read more
This has been already asked a few times, but never really as precise as it about Google Fonts. So the general ideas are that : To draw an svg on a canvas, we need to load it in an <img> element first. For security reasons, <img> inner documents can not make any external requests. This … Read more
With svg it is possible with a simple loop. I am using Snap as it makes it simple. First of all create a circle using snap then using a loop find the points we need from the circle i referenced this question for finding the points. After finding the points simply give the lines these … Read more
The DPI doesn’t matter at all when dealing with images. Images are measured in pixels so this is what you need to adjust. You can safely disregard DPI as it has no sense in this context. Scaling won’t help you here – remember you are working with a pixel device, not vectors, so the canvas … Read more