1312669 - Missing constants in WebGL blendFunc

Status: RESOLVED FIXED

(Developer Documentation Graveyard :: General, defect)

Description

[gilbertson.david]

What did you do?
================
Went to this page: https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/blendFunc

What happened?
==============
Noticed that some constants mentioned in the Khronos spec (e.g. CONSTANT_COLOR) aren't listed.

What should have happened?
==========================
I'm not sure, but I think the following constants should be added:
CONSTANT_COLOR
ONE_MINUS_CONSTANT_COLOR
CONSTANT_ALPHA
ONE_MINUS_CONSTANT_ALPHA

With the caveat about using them in certain combinations as mentioned in the spec: https://www.khronos.org/registry/webgl/specs/latest/1.0/#CONSTANT_COLOR_BLEND

In the MDN article, in the Specifications section, it says those "constants can't be used", unless I'm misunderstanding things, that should be removed too.

Is there anything else we should know?
======================================
You should know that I don't know anything about WebGL, I'm just reading the spec and noticed the discrepancy (otherwise I'd make the change myself).

Comment 1

[Florian Scholz (Open Web Docs)]

Thanks for your bug report! I think you are right here, what the spec in section 6.13 means is that the combination of the values is invalid and not that these constants are completely invalid.

I think I verified this by looking at this test page and the webgl conformance tests:
http://voxelent.com/html/beginners-guide/chapter_6/ch6_Blending.html
https://github.com/KhronosGroup/WebGL/blob/master/conformance-suites/1.0.0/conformance/webgl-specific.html#L34

I've updated these two pages:
https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/blendFunc
https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/blendFuncSeparate

Thanks again!