Index: third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-2d-globalAlpha.html |
diff --git a/third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-2d-globalAlpha.html b/third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-2d-globalAlpha.html |
new file mode 100644 |
index 0000000000000000000000000000000000000000..bb20ad238b2c6da756b918629bb3058d7b6882d4 |
--- /dev/null |
+++ b/third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-2d-globalAlpha.html |
@@ -0,0 +1,21 @@ |
+<script src="../../resources/testharness.js"></script> |
+<script src="../../resources/testharnessreport.js"></script> |
+<script> |
+test(function() { |
+ function assertPixelApprox(ctx, x, y, r, g, b, a, pos, colour, tolerance) { |
+ var imgdata = ctx.getImageData(x, y, 1, 1); |
+ var diff = Math.max(Math.abs(r-imgdata.data[0]), Math.abs(g-imgdata.data[1]), Math.abs(b-imgdata.data[2]), Math.abs(a-imgdata.data[3])); |
+ assert_less_than_equal(diff, tolerance); |
+ } |
+ var offscreenCanvas = new OffscreenCanvas(100, 100); |
+ var ctx = offscreenCanvas.getContext('2d'); |
+ ctx.fillStyle = '#0f0'; |
+ ctx.fillRect(0, 0, 100, 100); |
+ ctx.globalAlpha = 0.01; // avoid any potential alpha = 0 optimisations. |
xlai (Olivia)
2016/11/23 17:26:43
Could you use a more obvious number like 0.2, 0.7
|
+ ctx.beginPath(); |
+ ctx.fillStyle = '#f00'; |
+ ctx.rect(0, 0, 100, 100); |
+ ctx.fill(); |
+ assertPixelApprox(ctx, 50, 25, 2, 253, 0, 255, "50,25", "2,253,0,255", 2); |
+}); |
+</script> |