Originally GL::hasTextureFormat() returned false on ES2 for
PixelFormat::R8Unorm, RG8Unorm, RGB8Unorm and RGBA8Unorm because
glTexStorage() didn't work with the matching Luminance, LuminanceAlpha,
RGB and RGBA formats. But since the only ES2 platform is nowadays
basically just WebGL 1, which has neither EXT_texture_rg nor
EXT_texture_storage, this implicit failure made no sense and just made
the textureFormat() (and the new genericPixelFormat() API) useless
there.
Now it maps to them, and it's up to the caller to make sure
glTexStorage() doesn't get called with those, only glTexImage does.
Furthermore, if formats from EXT_texture_rg are used, the
genericPixelFormat() now also provides inverse mapping of them back to
the generic PixelFormat. Before it was basically *no* ES2 TextureFormat
that'd work with either of these, now it's all that have a (vaguely)
corresponding PixelFormat.
An ad-hoc solution was already done in DebugTools::screenshot(), now I
need it in another place. While not as fast as the O(1) mapping from
the generic format to the API-specific ones due to the potentially
linear lookup, it definitely could be useful in general.
Most of the testing scaffolding here is a preparation for the actually
complex formats like BC6/7 or ASTC. Also, it's great to be able to use
Magnum from Python to prepare data for testing the C++ Magnum APIs.
Useful for creating pixel formats with different channel count,
adding/removing the sRGB bit and such. Counterpart to
vertexFormat(VertexFormat, UnsignedInt, bool) that got added back in
2020.06 already.
Doing so usually points to some error in user code, so directly disallow
it, instead of returning false. Such behavior is consistent with
pixelFormatChannelCount() and other helper APIs.
These headers are included quite often and because
<Corrade/Utility/StlForwardString.h> expands to the whole <string>, it
has quite a significant impact.
Other cases like Math/ConfigurationValue.h are not changed at the
moment, as that header is only included together with Utility::Arguments
or Utility::Configuration -- and these classes are still STL-heavy, so
avoiding std::string usage in just the ConfigurationValue
specializations doesn't help anything at the moment.
Similar to what VertexFormat already has -- getting channel count,
channel format, sRGB and color vs depth/stencil properties out of a
PixelFormat value. Very useful for various image conversion plugins.
For consistency with how VertexFormat and other enum helpers are named.
The compressedBlockSize() and compressedBlockDataSize() is also renamed
to compressedPixelFormatBlockSize() and
compressedPixelFormatBlockDataSize().
While backwards compatibility aliases are in place, a breaking change
is that Image classes now look for pixelFormatSize() instead of
pixelSize(). This is used e.g. when passing GL::PixelFormat /
GL::PixelType to the image classes, instead of the generic PixelFormat.
While useful, it's unlikely that any project was defining their own
pixel format enum and pixelSize() for a D3D or Metal renderer or
whatnot, so the breakage should have no practical impact.
The 32-bit float depth be needed for the upcoming OpenEXR plugin, added
also the remaining ones that will be eventually supported by KTX and DDS
plugins.
Apparently "pixel size" could have meant "image size in pixels" as well.
Additionally also clarify what image size means, since it might be
unclear especially for the block-compressed images.
Except for formats like ETC, which do have the actual size in their
name, these are just confusing -- the compression is more like 565 than
a byte in some cases and it just doesn't give any useful information.
I was slowly getting cancer from having to write the unreadably awful
VK_FORMAT_R666G666B666A666_SRGB all the time. Besides that:
- All pixel formats are documented to show what's guaranteed for them
by the spec. Pretty useful I'd say.
- The old hasVkFormat() and vkFormat() converters operating on a
VkFormat are deprecated in favor of new hasPixelFormat() and
pixelFormat() that use the PixelFormat enum. Similarly as done in the
GL wrapper.
- All APIs that took a VkFormat before take a PixelFormat now, together
with having conveinience overloads for Magnum::PixelFormat and
Magnum::CompressedPixelFormat. Again similarly as done in the GL
wrapper, also the first step on being able to *directly* use data
imported with the Trade library with Vulkan.
Originally, \def_vk was used for enum values (equivalently to how
\def_gl is used for "enum" values in GL), but I also need to reference
actual defines such as VK_VERSION_MINOR(), so renamed it to \val_vk and
reused \def_vk for actual defines.
This deliberately doesn't follow the PixelFormat enum naming, as RGBA
components make no sense for most vertex data. Checking Metal and
WebGPU, they seem to have arrived at a similar conclusion, only VkFormat
is an outlier.
Should make new things more discoverable, avoid confusion when a
documented API isn't there and reduce the need for maintaining multiple
separate versions of the docs.
GL has an extension, but only for ES, not on desktop. Vulkan has
nothing yet (due to there being just ARM that implements it, no other
vendor), except those being listed in a KTX format specification.
Those are now also available under WebGL 1/2 and OpenGL ES 3.O (strangely
not OpenGL ES 2.0) under EXT_texture_compression_{rgtc,bptc}. The GL names
are extra weird-ass now that all other APIs use the BC names.
Deprecated for 2018.04, it's been almost a year since. Whoever is using
Magnum regularly updated already, and who not can always upgrade
gradually (2018.02, 2018.04, 2018.10, 2019.01 etc.).
This is quite big, so:
* There are new Magnum::PixelFormat and Magnum::CompressedPixelFormat
enums, which contain generic API-independent formats. In particular,
PixelFormat replaces GL::PixelFormat and GL::PixelType with a single
value.
* There's GL::pixelFormat(), GL::pixelType(),
GL::compressedPixelFormat() to convert the generic enums to
GL-specific. The mapping is only in one direction, done with a lookup
table (generic enums are indices to that table).
* GL classes taking the formats directly (such as GL::BufferImage) have
overloads that take both the GL-specific and generic format.
* The generic Image, CompressedImage, ImageView, CompressedImageView,
and Trade::ImageData classes now accept the generic formats
first-class. However, it's also possible to store an
implementation-specific value to cover cases where a generic format
enum doesn't have support for a particular format. This is done by
wrapping the value using pixelFormatWrap() or
compressedPixelFormatWrap(). Particular GPU APIs then assume it's
their implementation-specific value and extract the value back using
pixelFormatUnwrap() or compressedPixelFormatUnwrap(). There's also an
isPixelFormatImplementationSpecific() and
isCompressedPixelFormatImplementationSpecific() that distinguishes
these values.
* Many operations need pixel size and in order to have it even for
implementation-specific formats, a corresponding pixelSize()
overload is found via ADL on construction and the calculated size
stored along the format. Previously the pixel size was only
calculated on demand, but that's not possible now. In case such
overload is not available, it's possible to pass pixel size manually
as well.
* In order to support the GL format+type pair, Image, ImageView and
Trade::ImageData, there's now an additional untyped formatExtra()
field that holds the second value.
* The CompressedPixelStorage class is now unconditionally available on
all targets, including OpenGL ES and WebGL. However, on OpenGL ES the
GL APIs expect that it's all at default values.
I attempted to preserve backwards compatibility as much as possible:
* The PixelFormat and CompressedPixelFormat enum now contains generic
API-independent values. The GL-specific formats are present there,
but marked as deprecated. Use either the generic values or
GL::PixelFormat (togehter with GL::PixelType) and
GL::CompressedPixelFormat instead. There's a lot of ugliness caused
by this, but seems to work well.
* *Image::type() functions are deprecated as they were too
GL-specific. Use formatExtra() and cast it to GL::PixelType instead.
* Image constructors take templated format or format+extra arguments,
so passing GL-specific values to them should still work.
Vladimír Vondruš