48 lines
1.5 KiB
HTML
48 lines
1.5 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"
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height="600"></canvas></div>
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</body>
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</html>
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