48 lines
1018 B
HTML
48 lines
1018 B
HTML
<html>
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<head>
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<script>
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var x=0, y=0;
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var dx=4, dy=5;
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var now = Date.now();
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function draw() {
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// do it all again in 1/60th of a second
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window.requestAnimationFrame(draw);
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var elapsedMs = Date.now() - now;
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now = Date.now();
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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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// perform movement, and translate to position
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x+=dx*elapsedMs/16.7;
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y+=dy*elapsedMs/16.7;
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if (x<=0)
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dx=4;
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else if (x>=550)
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dx=-4;
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if (y<=0)
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dy=5;
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else if (y>=550)
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dy=-5;
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context.translate(x,y);
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// purple rectangle
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context.fillStyle="#CC00FF";
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context.fillRect(0,0,50,50);
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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="draw();">
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<canvas id="canvas" width="600" height="600"></canvas>
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</body>
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</html>
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