For some very unknown reason there's a line that fixes image size to
w*h*4, which would correspond to RGBA8 pixel format w/o alignment.
This is extremely incorrect for other pixel format, e.g. compressed
ones.
Not sure why this size-fixing was there, but removing it fixes sided
KTX2 compressed skybox corruption.
Engine imagelib already has skybox loader. It uses rgbdata_t
IMAGE_CUBEMAP flag.
1. Support IMAGE_CUBEMAP
2. Utilize imagelib skybox loader, do not try to load individual skybox
sides manually.
This will allow loading KTX2 cubemaps directly.
Known issues:
1. Compressed KTX2 sides are not rotated correctly. Engine/imagelib is
unable to rotate compressed images.
2. Some KTX2 sides are corrupted. Cause unknown.
* engine: common: imagelib: add KTX2 support
Adds basic KTX2 support for a few compressed formats. KTX2 essentially
is a Vulkan-centric texture format that supports literally hundreds of
pixel formats.
For now only support for these is added:
- `VK_FORMAT_BC4_UNORM_BLOCK`
- `VK_FORMAT_BC4_SNORM_BLOCK`
- `VK_FORMAT_BC5_UNORM_BLOCK`
- `VK_FORMAT_BC5_SNORM_BLOCK`
- `VK_FORMAT_BC6H_UFLOAT_BLOCK`
- `VK_FORMAT_BC6H_SFLOAT_BLOCK`
- `VK_FORMAT_BC7_UNORM_BLOCK`
- `VK_FORMAT_BC7_SRGB_BLOCK`
Adding more formats is relatively straightforward:
- Copy format definition from `VkFormat` enum in `vulkan_core.h`
- Add a new definition into `pixformat_t` enum.
- Add format size calculation into `Image_ComputeSize()`
While we're at it, also adds a few new formats to DDS:
- BC4_UNORM -- PF_BC4_UNSIGNED
- BC4_SNORM -- PF_BC4_SIGNED
- BC5_UNORM -- PF_BC5_UNSIGNED
- BC5_SNORM -- PF_BC5_SIGNED
- BC7 is expanded into BC7_UNORM and BC7_SRGB
ref_gl and ref_soft code is updated where it made sense. But not tested
really. Support for these formats has been tested with ref_vk.
* address spaces-vs-parentheses formatting where noticed
* parenthesize sizeofs
* move ktx2.h to imagelib as img_ktx2.h; massage it a bit
* use SetBits() instead of |=
* remove stale TODO comments
Only for BC5 and BC6H formats for now.
However, adding new formats is easy:
1. Copy format's definition from `VkFormat` to `ktx2.h`
2. Map it to `PF_` format in `Image_KTX2Format()`
3. Done
4. Really, that should be it.
5. I mean, most formats would require PF_ enum extension, but we're not
going to support all of them right?
It only does a very basic header validation, and passes the entire file
as PF_KTX2_RAW format. This is to simplify KTX2 reading in ref_vk and
trying out different formats. KTX2 has support for >200 format, and
passing all of them through PF_ types is a non-starter.
The plan is to figure out which formats we want to support, and add
their support to imagelib/ktx2 incrementally, leaving the rest as
PF_KTX2_RAW, so ref_vk still can use them.
Ivan Avdeev
Ivan Avdeev
Alibek Omarov
mittorn
Ivan Avdeev
Emil Tomczyk