API: merged IMB_scalefastImBuf, IMB_scaleImBuf, IMB_scaleImBuf_threaded
into one function IMB_scale with enum IMBScaleFilter {Nearest, Bilinear, Box}
and bool "threaded" param.
Performance:
- Box filtering (nee IMB_scaleImBuf) can be multi-threaded now.
- Nearest filtering (nee IMB_scalefastImBuf) can be multi-threaded now.
Also fix performance regression on float images caused by fix in #126234
- Bilinear filtering (nee IMB_scaleImBuf_threaded) is several times faster now.
Correctness:
- Nearest and Box filtering: no longer loses half of edge pixels when scaling
up.
- Box: fixed garbage results (and possible out of bounds reads) for non-4
channel float images.
- Bilinear: no longer shifts image when scaling up.
- Bilinear: properly filters when scaling down by 2x2.
Test coverage:
- Add gtest coverage for various IMB_scale modes.
- Add a IMB_performance_test performance test, ran manually.
More details, images and performance numbers in PR.
Pull Request: https://projects.blender.org/blender/blender/pulls/126390
Also see 06be295946.
These aren't all cases, but a few that I found by addding a static
assert in `MEM_new` so that it fails for trivially constructible types.
Using a non-virtual derived struct for polymorphism is error prone,
especially combined with the requirements of DNA. Instead, use a
separately allocated runtime struct as done for many other DNA structs.
In a followup commit, the remaining runtime members of `PreviewImage`
could be moved to the new runtime struct.
Pull Request: https://projects.blender.org/blender/blender/pulls/121509
This makes the read and write API functions match more closely, and adds
asserts to check that the data size is as expected.
There are still a few places remaining that use BLO_read_data_address
and similar generic functions, these should eventually be replaced as well.
Pull Request: https://projects.blender.org/blender/blender/pulls/120994
When data-block/asset previews were not stored in the thumbnail cache
yet (or were outdated), we'd read them from .blend files. This could
lead to random crashes (but quite reliable with a small number of
previews to be read).
Wasn't clearing runtime memory which could lead to the
`PRV_TAG_DEFFERED` bit being set. This meant we would try to free
deferred preview data since eefee47a8a, which was just garbage memory.
Previously, BKE level preview image code was in `BKE_icons.h` and `icons.hh`.
While these types are related, I always found this quite hard to navigate since
preview image stuff was just in the middle of icon functions. Plus, people
don't expect preview image functions in icon files, the relationship is not
obvious.
Instead, use focused files that make it easy to quickly navigate them
and see what they are dealing with.
Pull Request: https://projects.blender.org/blender/blender/pulls/111709
