Support KTX v2

[javifernandez]

Is your feature request related to a problem? Please describe.
Some Khronos tools like 'tktx' provide new capabilities to convert different image formats to KTX, However, most of the options and parameters imply generating KTX V2 signatures. Currently Wolvic requires textures in KTX v1.

Describe the solution you'd like

Describe alternatives you've considered
It's still possible to us other conversion tools that enforce KTX v1.

Additional context
KTX v1 spec - https://registry.khronos.org/KTX/specs/1.0/ktxspec.v1.html
KTX v2 spec - https://registry.khronos.org/KTX/specs/2.0/ktxspec.v2.html

[svillar]

Where is that dependency in Wolvic? I mean, where is the part in which we require v1? I don't remember having specific code for that...

[javifernandez]

Where is that dependency in Wolvic? I mean, where is the part in which we require v1? I don't remember having specific code for that...

https://github.com/Igalia/vrb/blob/e16bd5dd4842ddad0bb5502969b3d80c048c86e8/android/java/org/mozilla/vrb/ktx/KTXTexture.java#L51

[HollowMan6]

Tried to implement KTX v2 spec:
470beea4187881fc477bfc45a915b541a374ad7d.patch.txt

https://github.com/HollowMan6/vrb/blob/470beea4187881fc477bfc45a915b541a374ad7d/android/java/org/mozilla/vrb/ktx/KTXTextureV2.java
And then I realized that we actually have several issues if we want to support it here:

• KTX2 has introduced super compression, so we may want to support those compress schemes, and that can be complicated.
• KTX2 uses Vulkan VkFormat enum values, and it no longer contains the image size information in levelImages Structure. This means that we will need to have a table that converts VkFormat into glInternalFormat and identify the format-specific number of bytes by ourselves when we read the image data.

So instead of reinventing the wheels, maybe we want to find some library that parses the KTX2 format here.