[Azure] Combination of low context.shadowBlur and context.shadowColor with a low alpha value produces a fully opaque shadow. when HWA Enabled

NEW
Assigned to

Status

()

6 years ago
4 months ago

People

(Reporter: smaren, Assigned: bas.schouten)

Tracking

({testcase})

7 Branch
x86_64
Windows 7
testcase
Points:
---

Firefox Tracking Flags

(Not tracked)

Details

(URL)

Attachments

(1 attachment)

(Reporter)

Description

6 years ago
Created attachment 757845 [details]
firefox bug.png

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36

Steps to reproduce:

Create an element with a shadow with low blur and alpha on shadow color.

var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
ctx.shadowBlur= 0.5;
ctx.shadowOffsetY = 20;
ctx.fillStyle="red";

ctx.shadowColor="rgba(0, 0, 0, 0.5)";
ctx.fillRect(20,20,100,80);

So far, only found the bug in windows 7.


Actual results:

The shadow looks fully opaque black


Expected results:

The shadow should have been transparent black.
(Reporter)

Updated

6 years ago
Summary: Low combination of context.shadowBlur and context.shadowColor with a low alpha value produces a fully opaque shadow. → Combination of low context.shadowBlur and context.shadowColor with a low alpha value produces a fully opaque shadow.

Comment 1

6 years ago
Could you attach a testcase (html file), please.
Flags: needinfo?(smaren)
Keywords: testcase-wanted

Comment 2

6 years ago
gfx.canvas.azure.backends;skia = cairo helps
Component: Untriaged → Canvas: 2D
Keywords: testcase-wanted → testcase
Product: Firefox → Core
Summary: Combination of low context.shadowBlur and context.shadowColor with a low alpha value produces a fully opaque shadow. → [Azure] Combination of low context.shadowBlur and context.shadowColor with a low alpha value produces a fully opaque shadow. when HWA Enabled
Version: 21 Branch → 7 Branch

Updated

6 years ago
Status: UNCONFIRMED → NEW
Ever confirmed: true

Updated

6 years ago
Blocks: 651858
(Reporter)

Comment 3

6 years ago
gfx.canvas.azure.backends = skia or cairo works. Only seems to malfunction when using direct2d
Flags: needinfo?(smaren)
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