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 products/Sources/formale Sprachen/C/Firefox/dom/canvas/test/test_toDataURL_alpha.html


<!DOCTYPE html>
<html>
<head>
<title>Canvas test: toDataURL parameters (Bug 564388)</title>
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" href="/tests/SimpleTest/test.css">
</head>
<body>
<p>
For image types that do not support an alpha channel, the image must be
composited onto a solid black background using the source-over operator,
and the resulting image must be the one used to create the data: URL.
</p>
<p> See:
<a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-canvas-todataurl">
http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-canvas-todataurl
</a>
</p>
<p>Mozilla
    <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=650720">Bug 650720</a>
</p>
<p class="output">Output:</p>
<!--
    Author's note:
    To add more cases to this test:
    - To add a row (another color value)
      * Add a row to the table below, using the canvas id format
        (c<row>-<col>)
      * Update runTests to include the new row in the loop
    - To add a column (another image format)
      * Add a column to the table below, using the canvas id format above
      * Update runTests to call do_canvas, passing your column number,
        the image format, and any options to pass to the toDataUrl function

    Vaguely derived from Philip Taylor's toDataURL.jpeg.alpha test:
    http://philip.html5.org/tests/canvas/suite/tests/toDataURL.jpeg.alpha.html
-->
<table>
    <tr>
        <th>Type:</th>
        <th>image/png</th>
        <th>image/jpeg</th>
        <th>image/bmp<br />(24 bpp)</th>
        <th>image/bmp<br />(32 bpp)</th>
    </tr>
    <tr>
        <td id="c1">rgba(128, 255, 128, 0.5)</td>
        <td><canvas id="c1-1" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c1-2" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c1-3" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c1-4" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
    </tr>
    <tr>
        <td id="c2">rgba(255, 128, 128, 0.75)</td>
        <td><canvas id="c2-1" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c2-2" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c2-3" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c2-4" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
    </tr>
    <tr>
        <td id="c3">rgba(128, 128, 255, 0.25)</td>
        <td><canvas id="c3-1" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c3-2" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c3-3" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c3-4" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
    </tr>
    <tr>
        <td id="c4">rgba(255, 255, 255, 1.0)</td>
        <td><canvas id="c4-1" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c4-2" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c4-3" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c4-4" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
    </tr>
    <tr>
        <td id="c5">rgba(255, 255, 255, 0)</td>
        <td><canvas id="c5-1" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c5-2" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c5-3" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c5-4" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
    </tr>
    <tr>
        <td id="c6">rgba(0, 0, 0, 1.0)</td>
        <td><canvas id="c6-1" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c6-2" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c6-3" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c6-4" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
    </tr>
    <tr>
        <td id="c7">rgba(0, 0, 0, 0)</td>
        <td><canvas id="c7-1" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c7-2" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c7-3" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
        <td><canvas id="c7-4" class="output" width="100" height="50">
            <p class="fallback">FAIL (fallback content)</p></canvas></td>
    </tr>
</table>

<script>
var finishedTests = [];

function isPixel(ctx, x,y, r,g,b,a, d)
{
    var pos = x + "," + y;
    var colour = r + "," + g + "," + b + "," + a;
    var pixel = ctx.getImageData(x, y, 1, 1);
    var pr = pixel.data[0],
        pg = pixel.data[1],
        pb = pixel.data[2],
        pa = pixel.data[3];
    ok(r-d <= pr && pr <= r+d &&
       g-d <= pg && pg <= g+d &&
       b-d <= pb && pb <= b+d &&
       a-d <= pa && pa <= a+d,
       "pixel "+pos+" of "+ctx.canvas.id+" is "+pr+","+pg+","+pb+","+pa+
         "; expected "+colour+" +/- "+d);
}


function do_canvas(row, col, type, options)
{
    finishedTests[row + '_' + col] = false;
    var canvas = document.getElementById('c' + row + '-' + col);
    var ctx = canvas.getContext('2d');

    ctx.fillStyle = document.getElementById('c' + row).textContent;
    ctx.fillRect(0, 0, 100, 50);
    var data = canvas.toDataURL(type, options);

    ctx.fillStyle = '#000';
    ctx.fillRect(0, 0, 100, 50);
    var img = new Image();

    var color = document.getElementById('c' + row).textContent;
    color = color.substr(5, color.length - 6); // strip off the 'argb()'
    var colors = color.replace(/ /g, '').split(',');
    var r = colors[0]*colors[3],
        g = colors[1]*colors[3],
        b = colors[2]*colors[3];

    img.onload = function ()
    {
        ctx.drawImage(img, 0, 0);
        isPixel(ctx, 50,25, r,g,b,255, 8);
        finishedTests[row + '_' + col] = true;
    };
    img.src = data;
}

function checkFinished()
{
    for (var t in finishedTests) {
        if (!finishedTests[t]) {
            setTimeout(checkFinished, 500);
            return;
        }
    }
    SimpleTest.finish();
}

function runTests()
{
    for (var row = 1; row <= 7; row++) {
        do_canvas(row, 1, 'image/png');
        do_canvas(row, 2, 'image/jpeg');
        do_canvas(row, 3, 'image/bmp');
        do_canvas(row, 4, 'image/bmp', '-moz-parse-options:bpp=32');
    }

    setTimeout(checkFinished, 500);
}

SimpleTest.waitForExplicitFinish();
SimpleTest.requestFlakyTimeout("untriaged");

addLoadEvent(runTests);

</script>

</html>

Messung V0.5 in Prozent
C=100 H=100 G=100

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