When decoding data into bitmaps, we end up with different alpha types
(premultiplied vs. unpremultiplied color data). Unfortunately, Skia only
seems to handle premultiplied color data well when scaling bitmaps with
an alpha channel. This might be due to Skia historically only supporting
premultiplied color blending, with unpremultiplied support having been
added more recently.
When using Skia to blend bitmaps, we need the color data to be
premultiplied. ImmutableBitmap gains a new method to enforce the alpha
type to be used, which is now used by SharedResourceRequest and
CanvasRenderingContext2D to enforce the right alpha type.
Our LibWeb tests actually had a couple of screenshot tests that exposed
the graphical glitches caused by Skia; see the big smiley faces in the
CSS backgrounds tests for example. The failing tests are now updated to
accommodate the new behavior.
Chromium and Firefox both seem to apply the same behavior; e.g. they
actively decode PNGs (which are unpremultiplied in nature) to a
premultiplied bitmap.
Fixes#3691.
- Hue now wraps properly when negative or larger than 360
- The hsl to rgb conversion now closely mirrors the code example from
the spec.
This fixes a number of WPT tests in
/css/css-color/parsing/color-computed-hsl.html
This color space is often used as a reference in WPT tests, having
support for it makes us pass 15 new tests:
- css/css-color/rec2020-001.html
- css/css-color/rec2020-002.html
- css/css-color/rec2020-003.html
- css/css-color/rec2020-004.html
- css/css-color/rec2020-005.html
- css/css-color/predefined-011.html
- css/css-color/predefined-012.html
That makes us pass the following WPT tests:
- css/css-color/prophoto-rgb-001.html
- css/css-color/prophoto-rgb-002.html
- css/css-color/prophoto-rgb-003.html
- css/css-color/prophoto-rgb-004.html
- css/css-color/prophoto-rgb-005.html
- css/css-color/predefined-009.html
- css/css-color/predefined-010.html
This color space is often used as a reference in WPT tests, having
support for it makes us pass 15 new tests:
- css/css-color/display-p3-001.html
- css/css-color/display-p3-002.html
- css/css-color/display-p3-003.html
- css/css-color/display-p3-004.html
- css/css-color/display-p3-005.html
- css/css-color/display-p3-006.html
- css/css-color/lab-008.html
- css/css-color/lch-008.html
- css/css-color/oklab-008.html
- css/css-color/oklch-008.html
- css/css-color/predefined-005.html
- css/css-color/predefined-006.html
- css/css-color/xyz-005.html
- css/css-color/xyz-d50-005.html
- css/css-color/xyz-d65-005.html
This makes us pass the following WPT tests:
- css/css-color/a98rgb-001.html
- css/css-color/a98rgb-002.html
- css/css-color/a98rgb-003.html
- css/css-color/a98rgb-004.html
- css/css-color/predefined-007.html
- css/css-color/predefined-008.html
Problem:
- Functions are duplicated in [PBM,PGM,PPM]Loader class
implementations. They are functionally equivalent. This does not
follow the DRY (Don't Repeat Yourself) principle.
Solution:
- Factor out the common functions into a separate file.
- Refactor common code to generic functions.
- Change `PPM_DEBUG` macro to be `PORTABLE_IMAGE_LOADER_DEBUG` to work
with all the supported types. This requires adding the image type to
the debug log messages for easier debugging.
Switch over to gamma-aware interpolation. This causes color gradients
to not look so dark in the middle. SIMD optimized code is provided for
sse1 enabled builds.
Fixes#1342.
Problem:
- `constexpr` functions are decorated with the `inline` specifier
keyword. This is redundant because `constexpr` functions are
implicitly `inline`.
- [dcl.constexpr], §7.1.5/2 in the C++11 standard): "constexpr
functions and constexpr constructors are implicitly inline (7.1.2)".
Solution:
- Remove the redundant `inline` keyword.
Instead of passing the BufferStream, pass the Decoder. I'd like to stop
using BufferStream eventually anyway, so it's good to get it out of any
API's where it's in currently.
This shaves ~5 seconds off of a full build, not too bad. Also it just
seems nicer to push this logic out to classes. It could be better but
it's a start. :^)
