This uses strtof rather than stringstream and provides a common location
that can be leveraged by the upcoming JNI bindings.
Note that this new method lives in KtxBundle rather than KtxUtility. The
latter creates Filament textures and therefore does not get built into
libimage.
- RGB_11_11_10 is exported in a RGBA PNG file where the 4 channels are
used as a uint32 storing a RGB_10_11_11_REV pixel.
We use the .rgb32f extension, and those PNG files contain garbage
when seen in a PNG viewer.
- This is now the default for the -x option.
- compressed KTX files don't encode RGBM, which means they can't
support HDR, unless an HDR compression scheme is used.
* Make CMake 3.10 the minimum version, add LTO option
* Install a newer CMake on Linux CI builds
* Update LLVM and Cmake on Windows CI
* Update build/windows/ci-common.bat
Co-Authored-By: Ben Doherty <benjdoherty15@gmail.com>
* Update formatting
* Apply suggestions from code review
* Update build/windows/ci-common.bat
* Update CMake
* Switch Android projects back to CMake 3.6
This adds some new functions to libimage for computing distance fields
and coordinate fields. This runs on the CPU but uses an efficient
algorithm. This will initially be leveraged by the baking pipeline to
dilate charts, but could be useful in other applications.
Background: with the Vulkan backend, RGB8 textures do
not work (at least not on my hadrware). This makes me unable to run some
examples, because they use normal maps in RGB8 format.
It appears that the following commit addresses the problem by adding a
special command line option to mipgen:
8dda07bf2c
However, processing normal maps with this option does not work: certain
assertions in the image library fail.
This PR changes these functions in the image library to handle 4-channel
images instead of failing.
* Improves linear to s/rgb
Adds rounding to nearest whole integer, supports copying over an alpha channel for linear to srgb conversion. Code would previously incorrectly apply sRGB conversion to alpha.
* reformatting previous change
In a lot of case the StaticString hash can be computed a compile time,
so we now take advantage of that.
Removed StaticString(const char*) ctor, and replaced it with a
StaticString::make() method.
Fixed a couple wrong uses of the old StaticString(const char*) ctor.
When cmgen creates ktx files, it creates a pair: one with an _ibl suffix
and one with _skybox. This convention is now honored by FilamentApp.
Note that we already have several KTX environments in the repo, so you
can clone a fresh repo and do:
gltf_viewer --ibl={FILAMENT}/docs/webgl/pillars_2k DamagedHelmet.gltf
Note that we have several hundred files in samples/envs, we should
consider replacing those or copying the environments in docs/webgl
(which git would internally de-dup, due to content hashing).
When using GAUSSIAN_NORMALS, image::resampleImage automatically unitizes
its output. This means that clients (e.g. mipgen) need to ensure that
the source image is in [-1,+1] rather than [0,+1].
This shrinks file size as follows, although it seems to darken the
rendered result.
```
1398209 Oct 2 16:22 ao.ktx
699172 Oct 2 16:20 ao_etc.ktx
1398209 Oct 2 16:22 metallic.ktx
699172 Oct 2 16:19 metallic_etc.ktx
1398209 Oct 2 16:22 roughness.ktx
699172 Oct 2 16:20 roughness_etc.ktx
```
At build time, mipgen now creates several compressed and non-compressed
variants for albedo.
For ASTC we use the ARM encoder, for S3TC we use the STB encoder. The
latter is somewhat limited so we may wish to investigate other libraries
in the future (e.g., AMD Compressenator).
At run time, we detect which of these variants to download, based on
available WebGL extensions. In practice, this means that desktop
browsers will use the S3TC variant and mobile browsers will use the ASTC
variant.
The makes unzipped albedo go from ~4 MB to 682 KB using S3TC.
Mobile support (ASTC and ETC2) is coming in a future PR, stay tuned.
I tested the validity of the resulting KTX files by using macOS Preview,
which can read some types of KTX files. (!)
This CL also adds mipgen to the WebGL build, although its outputs are
not yet used by the sample apps.
KtxBundle is basically an in-memory representation of a KTX file.
Our primary motivation for introducing this class is to have a
structured container for block-compressed textures.
Note that this class is defined in libimage rather than libimageio.
There are several reasons for this:
1. The texel data in a KtxBundle is not meant to be decoded by the CPU.
2. It has no dependendencies on any libraries (stb_image tinyexr etc).
3. We wish to use it with WebGL, which needs to avoid using imageio.
This does not add any samples or continuous integration, but it at least
allows developers to do a "-p webgl" and check if an actual wasm file
for the core Filament library can be succesfully built.
* Introduce mipgen frontend.
For now this is fairly simple although it does let you choose a filter.
Another cool feature is that an HTML file is generated which makes it
easy to review the generated miplevels.
This does not expose the Boundary enum to users because it has not yet
been implemented in the core Image library.
* Fix up mipgen per code review.
