texture cube

[shrekshao]

• Mouse Input
• Render Loop
• helper function: load multi images
• use gl-Matrix
• a skybox demo, not a exact port from ogl sample, because:
  • TEXTURE_CUBE_MAP_SEAMLESS is not found in webgl2 document
  • I did not fully understand the meaning of ogl sample, for it using a constant normal vector
  • I think a skybox demo is more direct to demonstrate cubemap

[shrekshao]

Since I use gl-Matrix min, which fail the travis test, is there a way to ignore this file? @pjcozzi

[pjcozzi]

Since I use gl-Matrix min, which fail the travis test, is there a way to ignore this file

If it's easy, fix the warnings and open a pull request for that project.

Otherwise, ignore it by modifying this line of the build script: https://github.com/WebGLSamples/WebGL2Samples/blob/master/gulpfile.js#L7

[pjcozzi]

samples/gl-matrix-min.js

Move this to a sub-directory, e.g., samples/third-party/gl-matrix-min.js

[pjcozzi]

What is specific to WebGL 2 about this sample?

I don't think TEXTURE_CUBE_MAP_SEAMLESS is in ES 3.0 so it will not be in WebGL 2.

See Sections 3.8.9 and F.2 of the ES 3.0 spec (in general, please check the ES spec when in doubt).

OpenGL ES 3.0 requires that all cube map filtering be seamless. OpenGL ES 2.0 specified that a single cube map face be selected and used for filtering

[shrekshao]

Yeah, I agree with TEXTURE_CUBE_MAP_SEAMLESS is not available in WebGL 2. In light of this, merely using TEXTURE_CUBE_MAP is meaningless for WebGL 2. Shall I close this pull request later?

Anyway, with this try we now have :

• Mouse Control
• Render loop
• gl-Matrix support

Not bad

[shrekshao]

For Seamless cube map, https://docs.google.com/presentation/d/1Orx0GB0cQcYhHkYsaEcoo5js3c5-pv7ahPniIRIzzfg/edit#slide=id.gd15060520_0_38 It is mentioned in WebGL 2 spec, yet I can't find it in either ES 3 or WebGL 2 conformance test

[pjcozzi]

@shrekshao the enum is not in the spec because it is always enabled. As I said above:

See Sections 3.8.9 and F.2 of the ES 3.0 spec (in general, please check the ES spec when in doubt).

OpenGL ES 3.0 requires that all cube map filtering be seamless. OpenGL ES 2.0 specified that a single cube map face be selected and used for filtering

[shrekshao]

Oh oh, I misunderstand it. Besides this, I fail to find anything specific to WebGL 2

[pjcozzi]

OK, let's delete the sample and keep any potential useful code in this branch until we need it - then we can git cherry-pick the commits.

[kenrussell]

FYI: es3fShaderTextureFunctionTests.js , es3fTextureFilteringTests.js and es3fTextureShadowTests.js should be testing whether cube maps are seamless in WebGL 2.0.

[shrekshao]

Hi @kenrussell , I took a look at these js files. However I noticed that the "seamless flag" are all related to the testing framework, but I failed to find any GL calls that setting the TEXTURE_CUBE_MAP_SEAMLESS. So I am a bit confused here. I don't understand why there's no such a call.

[kenrussell]

The reason there's no such parameter is that cube maps are always seamless in OpenGL ES 3.0 and there's no way to disable that behavior.

[shrekshao]

Ok.. Thank you for the clarification!