Closed asimiklit closed 5 years ago
This sounds like a test bug if it expects zeros in the unused portion of the bitfield. The value of those unused bits is undefined and they should be ignored.
Could I write something except zeros into this field using glTexImage2D?
Yes, they should be ignored by the implementation.
What values of this unused field I should expect using glGetTexImage: unspecified, unchanged, zeroes, ...?
Unspecified, the app should ignore them.
Thanks a lot for clarification.
@asimiklit can we close the issue, or are there additional questions? Thanks.
Think yes, I don't have additional questions, everything is clear for me now) Thanks.
I am working on mesa issue: https://bugs.freedesktop.org/show_bug.cgi?id=110305
There is an issue with a FLOAT_32_UNSIGNED_INT_24_8_REV. OpenGL spec "8.4.4.2 Special Interpretations" is saying:
the second word contains a packed 24-bit unused field, followed by an 8-bit index
for example:
0x00000088
to each pixel of a textureglTexImage2D
0xfbac1488
. (just for case in this example was used a little endian machine)Could you please clarify the following questions: Could I write something except zeros into this field using
glTexImage2D
? What values of this unused field I should expect usingglGetTexImage
: unspecified, unchanged, zeroes, ...?Note: I guess that any usage of this bit field is a unspecified behavior but maybe I missed something.