The necessity is justified by a message in the pixman mailing list:
http://lists.freedesktop.org/archives/pixman/2011-July/001330.html
NONE repeat is not supported, but could be added by tweaking
the interpretation and making use of 'fully_transparent_src'
scanline function argument.
Add a comment to explain why the tests guarantee that the code always
computes the greatest valid root.
Rename "det" as "discr" to make it match the mathematical name
"discriminant".
Based on a patch by Jeff Muizelaar <jmuizelaar@mozilla.com>.
To avoid function call and other calculation overhead, extend source
scanline into temporary buffer when source width is too small.
Temporary buffer will be repeatedly accessed, so extension cost is
very small due to cache effect.
Now bilinear template support REPEAT_NORMAL, so functions for that
is added to PIXMAN_ARM_BIND_SCALED_BILINEAR_ macros. Fast path
entries are not enabled yet.
The basic idea is to break down normal repeat into a set of
non-repeat scanline compositions and stitching them together.
Bilinear may interpolate last and first pixels of source scanline.
In this case, we can use temporary wrap around buffer.
By replacing boolean arguments with flags, the code can be more
readable and flags can be extended to do some more things later.
Currently following flags are defined.
FLAG_NONE
- No flags are turned on.
FLAG_HAVE_SOLID_MASK
- Template will generate solid mask composite functions.
FLAG_HAVE_NON_SOLID_MASK
- Template will generate bits mask composite functions.
FLAG_HAVE_SOLID_MASK and FLAG_NON_SOLID_MASK should be mutually
exclusive.
The first bug is that a vmull.u8 instruction would store its result in
the q1 register, clobbering the d2 register used later on. The second
is that a vraddhn instruction would overwrite d25, corrupting the q12
register used later.
Fixing the second bug caused a pipeline bubble where the d18 register
would be unavailable for a clock cycle. This is fixed by swapping the
instruction with its successor.
Move the eight most common formats to the top of the list of image
formats and make create_random_image() much more likely to select one
of those eight formats.
This should help catch more bugs in SIMD optimized operations.
Autoconf 2.86 reports:
warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body
Every code fragment must be wrapped in [AC_LANG_SOURCE([...])]
The variables in question were dst_x, dst_y, dst_image. The majority
of _x and _y uses were already dest_x and dest_y, while the majority
of _image uses were dst_image.
When the image is a8r8g8b8 and not transformed, and the fetched
rectangle is within the image bounds, scanlines can be fetched by
simply returning a pointer instead of copying the bits.
It will at some point become useful to have CPU specific destination
iterators. However, a problem with that, is that such iterators should
not be used if we can composite directly in the destination image.
By moving the noop destination iterator to the noop implementation, we
can ensure that it will be chosen before any CPU specific iterator.
The DST operator doesn't actually do anything, so add a noop "fast
path" for it, instead of checking in pixman_image_composite32().
The performance tradeoff here is that we get rid of a test for DST in
the common case where the operator is not DST, in return for an extra
walk over the clip rectangles in the uncommon case where the operator
actually is DST.
This new implementation is ahead of all other implementations in the
fallback chain and is supposed to contain operations that are "noops",
ie., they don't require any work. For example, it might contain a
"fast path" for the DST operator that doesn't actually do anything or
an iterator for a8r8g8b8 that just returns a pointer into the image.
