46 lines
1.1 KiB
HTML
46 lines
1.1 KiB
HTML
<html>
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<head>
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<script>
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var isMouseDown=false;
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function attachEvents() {
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document.onmousedown = function(event) {
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isMouseDown=true;
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draw(event.clientX, event.clientY);
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}
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document.onmouseup = function(event) {
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isMouseDown=false;
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}
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document.onmousemove = function(event) {
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if ( isMouseDown ) {
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draw(event.clientX, event.clientY);
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}
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}
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}
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function draw(xoffset,yoffset) {
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var canvas = document.getElementById("canvas");
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var context = canvas.getContext('2d');
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// remove previous translation if any
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context.save();
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// over-write previous content, with a grey rectangle
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context.fillStyle="#DDDDDD";
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context.fillRect(0,0,600,600);
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// translate based on position of mouseclick
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context.translate(xoffset,yoffset);
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// purple rectangle
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context.fillStyle="#CC00FF";
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context.fillRect(-25,-25,50,50); // centred on coord system
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context.restore();
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}
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</script>
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</head>
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<body onload="attachEvents(); draw(0,0);">
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hello<br>
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<div id='canvasdiv' style='position:absolute; left:0px; top:0px;'><canvas id="canvas" width="600" height="600"></canvas></div>
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</body>
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</html>
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