GL_INVALID_ENUM : glBindFramebuffer: target was GL_READ_FRAMEBUFFER_ANGLE

[Tibor den Ouden]

After upgrading to chrome stable 64 bit 37.0.2062.94 unknown-m (64-bit) 

I got this error :

 

While tested my site (http://www.borbitsoft.com/) I got 

[Tibor den Ouden]

(Sorry hit the wrong button)

After upgrading to chrome stable 64 bit 37.0.2062.94 unknown-m (64-bit) 

I got this error :

    GL_INVALID_ENUM : glBindFramebuffer: target was GL_READ_FRAMEBUFFER_ANGLE demo.js:374

    GL_INVALID_ENUM : glBindFramebuffer: target was GL_DRAW_FRAMEBUFFER_ANGLE demo.js:374

    GL_INVALID_ENUM : glBindFramebuffer: target was GL_READ_FRAMEBUFFER_ANGLE demo.js:374

    GL_INVALID_ENUM : glBindFramebuffer: target was GL_DRAW_FRAMEBUFFER_ANGLE demo.js:374

    2WebGL: CONTEXT_LOST_WEBGL: loseContext: context lost demo.js:374

in the debugger while testing my site (http://www.borbitsoft.com/)

I have not seen this error before.

The weirdest thing is that I could reproduce the issue a few times. Also after closing and relaunching the browser.

(I checked in the task manager that there was no instance of chrome running)

I always launch the browser with the following commandline so shaders are always compiled again :

--disable-gpu-program-cache --disable-gpu-shader-disk-cache --disable-shader-name-hashing --enable-privileged-webgl-extensions --disable-background-mode

 

But after a few times of being able to reproduce the issue, it disappeared.

I switched back to the 32 bit version and back to 64 bit again but the issue did not show up.

(In the mean time chrome stable is updated to 7.0.2062.102 unknown-m (64-bit).

This is in Windows 7 64 bit with all patches applied.

When is a frame buffer a read frame buffer and when is it a draw frame buffer ?

[Shannon Woods]

Hi Tibor,

Separate read/draw framebuffer targets in ANGLE are introduced by ANGLE_framebuffer_blit. I don't think these are exposed via WebGL 1.0-- they're just used internally by Chrome. I'm not sure what would have been going on to cause the errors that you were seeing-- ANGLE doesn't generate INVALID_ENUM for glBindFramebuffer with target==GL_READ_FRAMEBUFFER_ANGLE or GL_DRAW_FRAMEBUFFER_ANGLE. Chrome's WebGL validation would generate such an error, but Chrome's internal blit calls shouldn't be getting validated as though they were WebGL. If it continues happening, or happens again, please file a bug with Chrome-- those errors are getting generated outside of ANGLE.