forked from web-platform-tests/wpt
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathcontext-creation-with-alpha.html
75 lines (68 loc) · 2.69 KB
/
context-creation-with-alpha.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
<!DOCTYPE html>
<meta charset="utf-8">
<title>Canvas's ImageBitmapRenderingContext test</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<link rel="help" href="https://html.spec.whatwg.org/multipage/scripting.html#the-imagebitmap-rendering-context">
<script>
var width = 10;
var height = 10;
function testCanvas(ctx, r, g, b, a)
{
var color = ctx.getImageData(5, 5, 1, 1).data;
assert_array_equals(color, [r, g, b, a]);
}
function consumeImageBitmap(image, alphaVal, expectedR, expectedG, expectedB, expectedA)
{
var dstCanvas = document.createElement('canvas');
dstCanvas.width = width;
dstCanvas.height = height;
var dstCtx;
if (alphaVal == 'true')
dstCtx = dstCanvas.getContext('bitmaprenderer', { alpha: true });
else if (alphaVal == 'false')
dstCtx = dstCanvas.getContext('bitmaprenderer', { alpha: false });
else
dstCtx = dstCanvas.getContext('bitmaprenderer');
dstCtx.transferFromImageBitmap(image);
var myCanvas = document.createElement('canvas');
myCanvas.width = width;
myCanvas.height = height;
var myCtx = myCanvas.getContext('2d');
myCtx.drawImage(dstCanvas, 0, 0);
testCanvas(myCtx, expectedR, expectedG, expectedB, expectedA);
}
promise_test(function() {
var srcCanvas = document.createElement('canvas');
srcCanvas.width = width;
srcCanvas.height = height;
var ctx = srcCanvas.getContext('2d');
ctx.fillStyle = 'rgba(0, 255, 0, 0.5)';
ctx.fillRect(0, 0, width, height);
return createImageBitmap(srcCanvas).then(function(image) {
consumeImageBitmap(image, 'false', 0, 127, 0, 255);
});
}, "Test that an ImageBitmapRenderingContext with alpha disabled makes the canvas opaque");
promise_test(function() {
var srcCanvas = document.createElement('canvas');
srcCanvas.width = width;
srcCanvas.height = height;
var ctx = srcCanvas.getContext('2d');
ctx.fillStyle = 'rgba(0, 255, 0, 0.5)';
ctx.fillRect(0, 0, width, height);
return createImageBitmap(srcCanvas).then(function(image) {
consumeImageBitmap(image, 'true', 0, 255, 0, 127);
});
}, "Test that an ImageBitmapRenderingContext with alpha enabled preserves the alpha");
promise_test(function() {
var srcCanvas = document.createElement('canvas');
srcCanvas.width = width;
srcCanvas.height = height;
var ctx = srcCanvas.getContext('2d');
ctx.fillStyle = 'rgba(0, 255, 0, 0.5)';
ctx.fillRect(0, 0, width, height);
return createImageBitmap(srcCanvas).then(function(image) {
consumeImageBitmap(image, '', 0, 255, 0, 127);
});
}, "Test that the 'alpha' context creation attribute is true by default");
</script>