Created
November 26, 2016 13:28
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| <!DOCTYPE html> | |
| <html lang="en"> | |
| <head> | |
| <meta charset="UTF-8"> | |
| <title>canvas image spike</title> | |
| </head> | |
| <body> | |
| <div id="root"> | |
| <h2>Hello, world.</h2> | |
| <canvas id="canvas" style="border:1px solid black;" width="256" height="256"></canvas> | |
| </div> | |
| <script src="main.js"></script> | |
| </body> | |
| </html> |
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| // Canvas Object | |
| var canvas = document.getElementById('canvas'), | |
| ctx = canvas.getContext('2d'), | |
| // load image from data url | |
| imageObj = new Image(), | |
| data = null, | |
| blob = null, | |
| collection = [], | |
| cl = null, | |
| n = 0; | |
| imageObj.onload = function() { | |
| ctx.drawImage(this, 0, 0); | |
| }; | |
| imageObj.src = 'panda_dark.png'; | |
| function dataURItoBlob(dataURI) { | |
| var byteString = atob(dataURI.split(',')[1]), | |
| ab = new ArrayBuffer(byteString.length), | |
| ia = new Uint8Array(ab), | |
| i = 0, | |
| length = byteString.length; | |
| while (i < length){ | |
| ia[i] = byteString.charCodeAt(i); | |
| i = i + 1; | |
| } | |
| return new Blob([ab], {type: 'image/png'}); | |
| } | |
| // this would get passed into whatever function needs a data url | |
| // in the example at http://gorigins.com/posting-a-canvas-image-to-facebook-and-twitter/ | |
| // it is in the Twitter example in the callback at `data.append` | |
| data = document.getElementById('canvas').toDataURL("image/png"); | |
| collection.push(data) | |
| // this would get passed into whatever function needs a blob | |
| // in the example at http://gorigins.com/posting-a-canvas-image-to-facebook-and-twitter/ | |
| // it is `postImageToFacebook` and | |
| blob = dataURItoBlob(data); | |
| collection.push(blob); | |
| cl = collection.length; | |
| while ( n < cl){ | |
| console.log(collection[n]); | |
| n = n + 1; | |
| } |
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