Bug 202836 – Enable WebGL's ASTC extension all the time

• Status: RESOLVED
• Resolution: FIXED
• Component: WebGL

[Kenneth Russell]

In Bug 185272 ASTC compressed texture support was added to the WebGL implementation. Currently it's behind a run-time flag. It should be removed from behind this flag and just enabled whenever the underlying OpenGL (ES) extensions are available, so it auto-enables whenever sufficient support is present.

[Kenneth Russell]

Blocking on the ETC1/ETC2 bug, which alphabetizes the compressed texture extensions in some of the code.

[Kenneth Russell]

Created attachment 383175 [details]
Patch

[Kenneth Russell]

Built on macOS. Still building for the iOS Simulator, with WebKit modified to always use an OpenGL ES 3.0 context, to verify the WebGL conformance test passes.

[Kenneth Russell]

I built this patch for the iOS Simulator, plus a couple of changes to GraphicsContext3DCocoa.mm to force the use of ES 3.0 contexts:


diff --git a/Source/WebCore/platform/graphics/cocoa/GraphicsContext3DCocoa.mm b/Source/WebCore/platform/graphics/cocoa/GraphicsContext3DCocoa.mm
index d1af803f38d..6a7c5eaa598 100644
--- a/Source/WebCore/platform/graphics/cocoa/GraphicsContext3DCocoa.mm
+++ b/Source/WebCore/platform/graphics/cocoa/GraphicsContext3DCocoa.mm
@@ -192,6 +192,8 @@ GraphicsContext3D::GraphicsContext3D(GraphicsContext3DAttributes attrs, HostWind
     m_powerPreferenceUsedForCreation = GraphicsContext3DPowerPreference::Default;
 #endif
 
+    m_attrs.isWebGL2 = true;
+
 #if !USE(ANGLE)
 #if USE(OPENGL_ES)
     if (m_attrs.isWebGL2)
@@ -215,6 +217,7 @@ GraphicsContext3D::GraphicsContext3D(GraphicsContext3DAttributes attrs, HostWind
 
     if (m_attrs.isWebGL2)
         ::glEnable(GraphicsContext3D::PRIMITIVE_RESTART_FIXED_INDEX);
+    m_isForWebGL2 = m_attrs.isWebGL2;
 #elif USE(OPENGL)
 
     bool useMultisampling = m_attrs.antialias;





Unfortunately https://www.khronos.org/registry/webgl/sdk/tests/conformance/extensions/webgl-compressed-texture-astc.html still reported no support for ASTC textures on the iPhone SE for WebKit Development.

Appreciate others' help getting this patch tested and over the finish line. Thanks.

I know this patch is for NonAngle case.
The debugging shows it's Extensions3DOpenGLCommon::m_availableExtensions that doesn't include the ASTC extension string. Given that it is initialized by calling glGetStringi, I doubt if the iPhone Simulator on Mac could ever populate such extension if the underlying gpu hardware doesn't support the ASTC extension? If this could be verified I think we could only test this patch on real iPhone. Could Dean or Justin help to verify this? Thanks!

[Dean Jackson]

(In reply to shrekshao from comment #5)
> I know this patch is for NonAngle case.
> The debugging shows it's Extensions3DOpenGLCommon::m_availableExtensions
> that doesn't include the ASTC extension string. Given that it is initialized
> by calling glGetStringi, I doubt if the iPhone Simulator on Mac could ever
> populate such extension if the underlying gpu hardware doesn't support the
> ASTC extension? If this could be verified I think we could only test this
> patch on real iPhone. Could Dean or Justin help to verify this? Thanks!

I'll test, but from what I recall, ASTC is only supported on device (and as Ken pointed out, > iPhone SE)

[Dean Jackson]

Oh. I also think ASTC was only supported on devices when using a GLES 3 context, not a GLES 2 context :(

That's why Justin put it behind a flag for now.

[Dean Jackson]

Comment on attachment 383175 [details]
Patch

r=me

I'll test manually before landing this.

[Kenneth Russell]

Thanks Dean for helping with this. Please see the diff in https://bugs.webkit.org/show_bug.cgi?id=202836#c4 which was needed to force WebGL to use an ES3 context by default. Still the simulator didn't appear to support ASTC compressed textures - maybe not surprising since the emulation path would be much more complex than ETC? ETC is supported by the simulator.

[Radar WebKit Bug Importer]

<rdar://problem/57627592>

[Dean Jackson]

I confirmed this works on devices (that themselves support ASTC).

[Radar WebKit Bug Importer]

<rdar://problem/57627600>

[Dean Jackson]

Committed r253108: <https://trac.webkit.org/changeset/253108>

[Kenneth Russell]

Thank you Dean for testing and landing this!

[Kenneth Russell]

*** Bug 194751 has been marked as a duplicate of this bug. ***