1124453 - WebGL context alpha:false affects all framebuffers

Status: RESOLVED DUPLICATE of bug 1125445

(Core :: Graphics: CanvasWebGL, defect)

Description

[arthur]

Attachment: alphacontext.jpg

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0
Build ID: 20150108202552

Steps to reproduce:

1. Create WebGL context with alpha:false argument.
2. Create an RGBA texture and a framebuffer.
3. Render something into the texture writing to both color and alpha.
4. Read the texture.


Actual results:

Alpha channel is not written.


Expected results:

Both color and alpha must be written. Context argument should only affect main framebuffer blending with the page.

Test page: http://geom.io/pc33/testAlphaWrite.html
You should see 2 gradients (left is read from RGB, right is from A).
Works fine on Chrome/IE and even on Firefox 33.1.1, but broken in new (35).

Comment 1

[Alex Kowel]

Confirmed, see Blend4Web Cartoon Interior demo:
https://www.blend4web.com/tutorials/examples/cartoon_interior/cartoon_interior.html

Comment 2

[Alex Kowel]

Update: Cartoon Interiod demo has been already fixed (alpha:true workaround), check demos from bug 1124187

Comment 3

[Bas Schouten (:bas.schouten)]

Sounds like your bug Jeff.

Comment 4

[Matthew Amato]

This issue badly breaks Cesium (http://cesiumjs.org/) as well.

Compare any of our demos against Chrome or IE and you'll see that anything with translucency ends up either having a solid color or turns white.  For example: http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Geometry%20and%20Appearances.html&label=Showcases

What are the changes that this gets fixed and pushed out with a 35.02 update?