This commit replaces usages of `Color::interpolate()` with
`Color::mixed_with()` in image scaling functions. The latter
uses premultiplied alpha, which results in more visually
pleasing edges when images are scaled against a transparent
background.
These changes affect the SmoothPixels and BilinearBlend scaling modes
of `Painter::draw_scaled_bitmap()` as well as the `Bitmap::scaled()`
function.
Fixes#17153.
While returning the same image is a cute optimization, it violates the
expectation that the returned Bitmap is a new bitmap, not shared with
anyone else.
The method was only used in `load_from_file(StringView path)` and
replacing it with `load_from_file(NonnullOwnPtr<Core::File>)` is very
straightforward.
We essentially just end up moving `release_value_but_fixme_...` one
layer down, but it makes adding more fallible operations in the
serialization function more comfortable.
Originally I simply thought that passing file paths is quite OK, but as
Linus pointed to, it turned out that passing file paths to ensure some
files are able to be decoded is awkward because it does not work with
images being served over HTTP.
Therefore, ideally we should just use the MIME type as an optional
argument to ensure that we can always fallback to use that in case
sniffing for the correct image type has failed so we can still detect
files like with the TGA format, which has no magic bytes.
Because TGA images don't have magic bytes as a signature to be detected,
instead assume a sequence of ReadonlyBytes is a possible TGA image only
if we are given a path so we could check the extension of the file and
see if it's a TGA image.
When we know the path of the file being loaded, we will try to first
check its extension, and only if there's no match to a known decoder,
based on simple extension lookup, then we would probe for other formats
as usual with the normal sniffing method.
The existing try_create_from_serialized_byte_buffer function accepts a
ByteBuffer, but in reality it requires only a ReadonlyBytes, since
internally the only thing it does is calling buffer.bytes(). There is
thus no reason to have a function that simply accepts ReadonlyBytes, and
implement the former in terms of the newer.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
This change implements a flood fill algorithm for the Bitmap class. This
will be leveraged by various Tools in PixelPaint. Moving the code into
Bitmap reduces the duplication of the algorithm throughout the
PixelPaint Tools (currently Bucket Tool and Wand Select).
The flood fill function requires you to pass in a threshold value (0 -
100) as well as a lambda for what to do when a pixel gets reached. The
lambda is provided an IntPoint representing the coordinates of the pixel
that was just reached.
The genericized lambda approach allows for a variety of things to be
done as the flood algorithm progresses. For example, the Bucket Tool
will paint each pixel that gets reached with the fill_color. The Wand
Select tool wont actually alter the bitmap itself, instead it uses the
reached pixels to alter a selection mask.
This will be needed so we can apply filter effects to the backdrop
of an element in LibWeb.
This now also allows getting a crop of a bitmap in a different format
than the source bitmap. This is for if the painter's bitmap does not
have an alpha channel, but you want to ensure the cropped bitmap does.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
Error::from_string_literal now takes direct char const*s, while
Error::from_string_view does what Error::from_string_literal used to do:
taking StringViews. This change will remove the need to insert `sv`
after error strings when returning string literal errors once
StringView(char const*) is removed.
No functional changes.
This function returns an Optional<Color> and is given an
alpha_threshold. If all pixels above that alpha threshold are the
same color, it returns the color, otherwise it returns an empty
optional.
The ARGB32 typedef is used for 32-bit #AARRGGBB quadruplets. As such,
the name RGBA32 was misleading, so let's call it ARGB32 instead.
Since endianness is a thing, let's not encode any assumptions about byte
order in the name of this type. ARGB32 is basically a "machine word"
of color.
Apologies for the enormous commit, but I don't see a way to split this
up nicely. In the vast majority of cases it's a simple change. A few
extra places can use TRY instead of manual error checking though. :^)
... and bring it back to try_load_from_file().
Prior to this change, changing the scaling option to x2 in the Display
Settings resulted in the following crash:
WindowServer(15:15): ASSERTION FAILED: bitmap->width() % scale_factor
== 0 ./Userland/Libraries/LibGfx/Bitmap.cpp:126
That was caused by two minor overlooked yaks:
- First, Bitmap::try_load_from_fd_and_close() tried to respect your
scale factor.
While requesting a bitmap from file can make a switcheroo to give you
a higher resolution bitmap, doing the same when you already have an fd
might violate the unveil agreement.
... but, it didn't do that.
It read bitmaps from requested fds, but also pretended all system
bitmaps in /res/ are the HiDPI ones when you enabled that mode.
- d85d741c59 used this function to deduplicate try_load_from_file().
It actually made this bug a lot easier to replicate!
Closes#10920
Before this patch, both Bitmap and ImageDecoder had logic for guessing
which image codec to use for a chunk of data. Bitmap now defers to
ImageDecoder so that we only have to do this in one place.
There's room for improvement in the ImageDecoder heuristic, but that's
outside the scope of this change.
We had a bunch of old unused wrapper functions for each image codec that
would load a supported image with a given path. Nobody actually used
them, so let's just get rid of load_png(), load_gif(), etc.
This also allows us to get rid of the ShareableBitmap(Bitmap)
constructor which was easy to misuse. Everyone now uses Bitmap's
to_shareable_bitmap() helper instead.
