[Piglit] [PATCH v3] pbo: delete unmapping the GL_PIXEL_UNPACK_BUFFER before using it and correct the data expected form glGetMapusv This fixes tests/spec/gl-2.1/pbo on Windows Intel driver. According to OpenGL Core spec 4.5, section 6.3.1 (Unmapping Buffers), page 75 "Unmapping a mapped buffer object invalidates the pointers to its data store" and to section 8.11.4 (Texture Image Queries) of the same spec on page 34 "If a pixel pack buffer is bound (as indicated by a non-zero value of PIXEL PACK BUFFER BINDING), data is an offset into the pixel pack buffer; otherwise,data is a pointer to client memory".

sandra koroniewska sandra.koroniewska at gmail.com
Thu May 25 14:38:01 UTC 2017

Hi Józef,
sorry for responding here, but I didn't manage to send the corrections in
response to your previous mail. Thanks for your answer. The fragment of
your previous mail is:

"> -                               glUnmapBufferARB(GL_PIXEL_UNP

This change is suspicious. The buffer was mapped to fill it with
values above, and it can be safely unmapped at this point. Why do you
need this change?

>                                 glPixelMapusv(GL_PIXEL_MAP_R_TO_R, max,
>                                 glPixelMapusv(GL_PIXEL_MAP_G_TO_G, max,
>                                 glPixelMapusv(GL_PIXEL_MAP_B_TO_B, max,
> @@ -353,7 +352,7 @@ test_pixel_map(void)
>                         }
>                         for (i = 0; i < max; i++) {
> -                               if (pbo_mem[i] != (255 - i)) {
> +                if (pbo_mem[i] != (max - i - 1)) {

Please use tabs instead of spaces. Otherwise, this seems to be a
correct fix. I guess that the previous version of the test passes with
some drivers probably because "max" is equal to 256."

When it comes to unmapping the buffer, I don't know if I'm thinking right,
but I read in OpenGL 4.5 spec that "Unmapping a mapped buffer object
invalidates the pointer to its data store" and glUnmapBuffer is using a

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