| <html> | |
| <head> | |
| <title>A canvas globalCompositeOperation example</title> | |
| <meta name="DC.creator" content="Kamiel Martinet, http://www.martinet.nl/"> | |
| <meta name="DC.publisher" content="Mozilla Developer Center, http://developer.mozilla.org"> | |
| <script type="application/x-javascript"> | |
| if (window.testRunner) | |
| testRunner.dumpAsText(true); | |
| // This test should show a table of canvas elements. The canvas elements have transforms | |
| // applied, and onto the background a blue square is drawn, either fully opaque or with some | |
| // transparency. | |
| // Then clip is added, which with the transform taken into account only allows drawing into | |
| // the bottom of the canvas. | |
| // Then either a green rectangle or a green ellipse is drawn, either fully opaque or with | |
| // some transparency. These are drawn with a different compositing mode for every row. | |
| // In each cell the top half should be same from one row to the next as changes here are | |
| // clipped out. | |
| // In each row the green rectangle or ellipse should be drawn with the appropriate compositing | |
| // mode, as per the HTML5 canvas spec. | |
| // In each cell the drawing should be contained within the cell boundary. | |
| // These map to the rows of the table | |
| var compositeTypes = [ | |
| 'source-over','source-in','source-out','source-atop', | |
| 'destination-over','destination-in','destination-out','destination-atop', | |
| 'lighter','darker','copy','xor' | |
| ]; | |
| // These map to the columns of the table | |
| var testNames = [ | |
| 'solid rect on solid', 'alpha rect on solid', 'solid rect on alpha', | |
| 'alpha rect on alpha', 'solid path on solid', 'alpha path on solid', | |
| 'solid path on alpha', 'alpha path on alpha', | |
| ]; | |
| function createOutputTable() { | |
| var tableEl = document.getElementById('outputtable'); | |
| var row = tableEl.insertRow(-1); | |
| var cell = row.insertCell(-1); | |
| var label; | |
| var canvas; | |
| for (var i = 0; i < compositeTypes.length; i++) { | |
| row = tableEl.insertRow(-1); | |
| for (var j = 0; j < testNames.length; j++) { | |
| canvas = document.createElement('canvas'); | |
| canvas.width = 65; | |
| canvas.height = 45; | |
| canvas.id = compositeTypes[i] + testNames[j]; | |
| cell = row.insertCell(-1); | |
| cell.appendChild(canvas); | |
| } | |
| } | |
| } | |
| function getContext(compositeIndex, testIndex) { | |
| var id = compositeTypes[compositeIndex] + testNames[testIndex]; | |
| var context = document.getElementById(id).getContext('2d'); | |
| return context; | |
| } | |
| function setupContext(context, alpha) { | |
| context.translate(40, 0); | |
| context.rotate(Math.PI / 2); | |
| context.scale(0.2, 0.4); | |
| context.translate(-1000, -2000); | |
| if (alpha) { | |
| context.fillStyle = 'rgba(00,100,255,0.5)'; | |
| } else { | |
| context.fillStyle = 'rgba(00,100,255,1)'; | |
| } | |
| context.fillRect(1020, 2010, 160, 80); | |
| context.beginPath(); | |
| context.moveTo(1100, 1900); | |
| context.lineTo(1500, 1900); | |
| context.lineTo(1500, 2200); | |
| context.lineTo(1100, 2200); | |
| context.clip(); | |
| } | |
| function doFill(context, compositeIndex, alpha, path) { | |
| context.globalCompositeOperation = compositeTypes[compositeIndex]; | |
| if (alpha) { | |
| context.fillStyle = 'rgba(64,255,0,0.5)'; | |
| } else { | |
| context.fillStyle = 'rgba(64,255,0,1)'; | |
| } | |
| if (path) { | |
| context.beginPath(); | |
| context.arc(1100, 2000, 50 , 0, Math.PI*2, true); | |
| context.fill(); | |
| } else { | |
| context.fillRect(1040, 1950, 120, 100); | |
| } | |
| } | |
| function draw() { | |
| createOutputTable(); | |
| for (var i = 0; i < compositeTypes.length; i++) { | |
| for (var j = 0; j < testNames.length; j++) { | |
| var context = getContext(i, j); | |
| setupContext(context, j % 4 > 1); | |
| doFill(context, i, j % 2, j > 3); | |
| } | |
| } | |
| } | |
| </script> | |
| <style type="text/css"> | |
| body { margin: 5px; font-family: arial,verdana,helvetica; background: #fff;} | |
| canvas { border: 1px solid #999; } | |
| td { margin: 0px; padding: 0px; } | |
| table { border-collapse: collapse; } | |
| </style> | |
| </head> | |
| <body onload="draw();"> | |
| <div> | |
| <table id='outputtable'> | |
| </table> | |
| </div> | |
| </body> | |
| </html> |