transform-tracker/transform-tracker.html at master · vbravest/transform-tracker · GitHub

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<!DOCTYPE html>
<html>
    <body>
        <canvas id="my-canvas" width="800" height="600"></canvas>

        <script type="text/javascript" src="transform-tracker.js"></script>
        <script type="text/javascript">
            var canvas = document.getElementById('my-canvas');
            var context = canvas.getContext('2d');

            // create transform tracker object
            context.transform = new Transform(context);

            // apply transformations
            context.transform.save();
            context.transform.translate(200, 0);

            context.transform.save();
            context.transform.rotate(Math.PI / 4);

            context.transform.save();
            context.transform.scale(2, 2);

            // retrieve current state of transformations
            var matrix = context.transform.getMatrix();
            console.log('matrix:', JSON.stringify(matrix));
            var stack = context.transform.stack;
            console.log('stack:', JSON.stringify(stack));

            // render
            context.fillStyle = 'red';
            context.fillRect(0,0,100,100);

            context.transform.restore();
            context.transform.restore();
            context.transform.restore();
        </script>
    </body>
</html>