Similarly like pixel size is stored in uncompressed images, block size
makes it possible to perform size checks on passed data, slice the images
and so on. It only took over a decade to get that done.
The block properties coming from CompressedPixelStorage are currently
expected to be either not set at all or exactly match what's stored in
the image for given format. The PixelStorage will get eventually
deprecated in favor of a simpler and more flexible representation, but
that's another big chunk of work so it's first done like this.
The GL library tests currently blow up on various assertions and it
isn't yet updated to make use of the known format properties instead of
querying them from GL. That'll be done in the following commits.
Similarly as done in Aug 2024 in Corrade. When these were a part of the
function signature, they ended up being encoded into the exported
symbol. There are still cases of StridedArrayView slice() having
enable_if in the signature, which amounts to about 18 kB symbols in all
libMagnum*-d.so libraries, but apart from that this is the state before:
$ strings libMagnum*-d.so | grep enable_if | grep -v slice | wc -c
29591
And this is after. All of those are coming from STL, thus from
old or deprecated APIs that still use std::vector, std::tuple and such,
and from the few std::sort() uses.
$ strings libMagnum*-d.so | grep enable_if | grep -v slice | wc -c
4103
In a non-deprecated build it's just this, which is a 10x reduction.
Can't really do much about these maybe exceút for implementing my own
swap() specializations (sigh?), but I think it's fine.
$ strings libMagnum*-d.so | grep enable_if | grep -v slice | wc -c
2904
I also made it consistently use
typename std::enable_if<..., int>::type = 0
instead of
class = typename std::enable_if<...>::type
because the former works correctly also in presence of overloads and
having it used consistently everywhere makes it easier to grep & change
later. All SFINAE is now also excluded from Doxygen output, because it
doesn't make much sense there. It's better to just explain the
restriction in words than with this nasty hack.
They got added in 6d41597d1d in 2018 to
selectively suppress a deprecation warning. But later on the deprecated
API got removed and these stayed, being useless. So just call the
ADL pixelFormatSize() APIs directly.
Because there's no format that'd have more than 256-byte pixels anyway,
the theoretically biggest one would be RGBA64F or some such with 32
bytes. Nevertheless, an assert is now in place to verify the bounds as
well as ensuring the pixel size is not zero.
And document that. Because the pixel size cannot be determined for it,
and one has to either pass it explicitly or use the templated overload
that figures it out implicitly via ADL. This asserted before, but only
deep inside in pixelFormatSize(), which may be confusing.
I need to do a similar treatment for compressed images with block size
properties so let's first make it behave properly for uncompressed.
It looked like it was last touched in 2012. Not great. Also, with this I
can finally stop explaining the four-byte-aligned-row defaults to people
and can just point them to docs.
With the intention that those will eventually contain also things like
YUp / YDown, PremultipliedAlpha and such.
This commit is mostly just busywork, wiring this into [Compressed]Image,
[Compressed]ImageView and Trade::ImageData and ensuring the flags get
correctly propagated during moves and conversions. Unfortunately in case
of Trade::ImageData it meant deprecating the current set of constructor
in order to insert an ImageFlags parameter before the importer state
pointer.
The only non-trivial piece of logic is when a 2D
[Compressed]ImageView gets converted to a 3D one, then the Array bit is
implicitly dropped, as 2D arrays of 1D images are not really a thing.
Instead, it's now possible to add new flags when doing the conversion --
for example to turn a 2D image to a (single-layer) 2D array image.
Ahem, missed those in 36ee7835d6. Yes,
putting compressed images into atlases is a desirable thing to do as
well, although it's now rather shitty due to lack of slicing.
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.
Allows creating a StridedArrayView slice on the sizes to feed them to
various algorithms, instead of first having to copy the sizes out to a
freshly allocated array.
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.
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.
This one returned a raw pointer, losing all size information, One should
instead use the non-templated data() along with Containers::arrayCast()
for a properly type-checked conversion.
There's *a lot* of tests using the deprecated functionality. I need to
change one more thing before updating those.
It's potentially dangerous because the user is responsible for choosing
a correct type, on the other hand forcing them to do it verbosely
through arrayCast() is both too annoying and too hard to explain.
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.).
It was returning either pixel size or compressed block size, which is
now available directly via other means.
This is a breaking change, but I don't expect these functions to be
used widely beyond Magnum internals.
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.
At the moment just the GL library itself w/o the tests, and without
backwards compatibility aliases. The following types were left in the
root namespace, despite being in the GL/ directory, as they will get
moved back soon:
* Image, CompressedImage and their dimensional typedefs
* ImageView, CompressedImageView and their dimensional typedefs
* PixelStorage
Not PixelFormat etc., that one will stay in the GL namespace and a
completely new PixelFormat enum will be provided in the root namespace.
Vladimír Vondruš