721205 - GLContext::fReadPixels uses format GL_BGRA on Android, causing GL_INVALID_OPERATION

Status: RESOLVED FIXED

(Core :: Graphics: CanvasWebGL, defect)

Description

[Ali Juma [:ajuma]]

With Attachment 591529 [details] [diff], Bug 720467 applied, the WebGL demo at http://spidergl.org/example.php?id=1 on XUL Fennec on a Nexus S causes GLContext::fReadPixels to be called with format GL_BGRA and type GL_UNSIGNED_BYTE, resulting in GL_INVALID_OPERATION.

Since that patch doesn't change the logic used to choose the format for fReadPixels, we have a bug somewhere else.

Comment 1

[Kelsey Gilbert [:jgilbert]]

According to specs for ES extensions:
EXT_bgra explicitly adds support for GL_BGRA+GL_UNSIGNED_BYTE readPixels.
EXT_read_format_bgra and IMG_read_format allow for the auxiliary format discovery for BGRA+UBYTE via GL_IMPLEMENTATION_COLOR_READ_FORMAT/TYPE.

Comment 2

[Kelsey Gilbert [:jgilbert]]

Attachment: Add correct logic for enabling BGRA readPixels for GLES

Comment 3

[Kelsey Gilbert [:jgilbert]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/fccccb47213e

Comment 4

[Ali Juma [:ajuma]]

With this patch applied, I'm still seeing the same problem. GL_IMPLEMENTATION_COLOR_READ_FORMAT and TYPE are BGRA and UNSIGNED_BYTE on this device, so it still tries to use GL_BGRA and causes a GL_INVALID_OPERATION error. So we seem to be running into a driver bug.

Comment 5

[Marco Bonardo [:mak]]

https://hg.mozilla.org/mozilla-central/rev/fccccb47213e