Issues with specifications

[mcraiha]

I assume this is the right place to report issues related to documentation in https://www.khronos.org/opengles/sdk/tools/KTX/file_format_spec/

Issues in An example KTX file: section

1. 0x0D, 0x0A, 0x1A, 0x0A. // final four bytes of Byte[12] identifier should be 0x0D, 0x0A, 0x1A, 0x0A, // final four bytes of Byte[12] identifier
2. 0x6A, 0x6F, 0x6B, 0x65, // UTF8 v: 'gles2\0' 0x6A, 0x6F, 0x6B, 0x65 means j o k e, not g l e s

Suggestions:

1. It would be nice to have actual KTX binary file linked to the documentation because Example file section does not contain full KTX file
2. Explain what are valid values for padding bytes
3. There is no reasoning why multiple of 4 are used, so maybe add a small text about it (and also mention modulo 4 since it is a bit easier to understand than Byte valuePadding[3 - ((keyAndValueByteSize + 3) % 4)]).

[MarkCallow]

I assume this is the right place
No, but don't worry. I understand you had problems trying to use the Khronos Bugzilla. I'll add a repo for specification issues and move this issue there once it is set up. I'll fix the issues in a little while.

Congratulations on being the first person to spot the hidden cookie. I am afraid there is no prize.

1. You can find KTX files in https://github.com/KhronosGroup/KTX-Software/tree/master/testimages. You can find some more complex ones, including a cubemap texture in https://github.com/msc-/KTX-Software/tree/incoming/tests/testimages. I'll be moving these to this repo's incoming branch in the near future.

2. The padding bytes can be any value. They are ignored by loaders and are there simply to maintain 4-byte alignment for the imageSize fields.

3. Mobile devices were a major target for KTX. These require that 32-bit values be aligned on 4-byte boundaries. To keep loaders a little simpler we make sure that all 32-bit values in the the KTX file are 4-byte aligned. One does not typically explain this sort of thing in specifications but I suppose I can add a footnote. Isn't "% 4" sufficient clue that this is about modulo 4?

[MarkCallow]

Please refile this at https://github.com/KhronosGroup/KTX-Specification/issues and close this one. Sorry to ask but I have not found a way to mark an issue as filed by somebody else or ensure a particular user will receive notifications about updates to the issue.

[mcraiha]

Moved to KhronosGroup/KTX-Specification#1

[MarkCallow]

Thanks.