Pixman supports negative strides, but up until now they haven't been
tested outside of stress-test. This commit adds testing of negative
strides to blitters-test, scaling-test, affine-test, rotate-test, and
composite-traps-test.
The affine-test, blitters-test, and scaling-test all have the ability
to print out the bytes of the destination image. Share this code by
moving it to utils.c.
At the same time make the code work correctly with negative strides.
The default has been 7-bit for a while now, and the quality
improvement with 8-bit precision is not enough to justify keeping the
code around as a compile-time option.
Old functions pixman_transform_point() and pixman_transform_point_3d()
now become just wrappers for pixman_transform_point_31_16() and
pixman_transform_point_31_16_3d(). Eventually their uses should be
completely eliminated in the pixman code and replaced with their
extended range counterparts. This is needed in order to be able
to correctly handle any matrices and parameters that may come
to pixman from the code responsible for XRender implementation.
This function returns the name of the given format code, which is
useful for printing out debug information. The function is written as
a switch without a default value so that the compiler will warn if new
formats are added in the future. The fake formats used in the fast
path tables are also recognized.
The function is used in alpha_map.c, where it replaces an existing
format_name() function, and in blitters-test.c, affine-test.c, and
scaling-test.c.
This function returns the name of the given operator, which is useful
for printing out debug information. The function is done as a switch
without a default value so that the compiler will warn if new
operators are added in the future.
The function is used in affine-test.c, scaling-test.c, and
blitters-test.c.
After two fixed-point numbers are multiplied, the result is shifted
into place, but up until now pixman has simply discarded the low-order
bits instead of rounding to the closest number.
Fix that by adding 0x8000 (or 0x2 in one place) before shifting and
update the test checksums to match.
Printing out the translation and scale is a bit misleading because the
actual transformation matrix can be modified in various other ways.
Instead simply print the whole transformation matrix that is actually
used.
Macro BILINEAR_INTERPOLATION_BITS in pixman-private.h selects
the number of fractional bits used for bilinear interpolation.
scaling-test and affine-test have checksums for 4-bit, 7-bit
and 8-bit configurations.
The upcoming optimization which is going to be able to replace BILINEAR filter
with NEAREST where appropriate needs to analyze the transformation matrix
and not to make any mistakes.
The changes to affine-test include:
1. Higher chance of using the same scale factor for x and y axes. This can help
to stress some special cases (for example the case when both x and y scale
factors are integer). The same applies to x/y translation.
2. Introduced a small chance for "corrupting" transformation matrix by flipping
random bits. This supposedly can help to identify the cases when some of the
fast paths or other code logic is wrongly activated due to insufficient checks.
Green Hills Software MULTI compiler was producing a number
of warnings due to incorrect uses of int instead of the correct
corresponding pixman_*_t type.
This test tests compositing with various affine transformations. It is
almost identical to scaling-test, except that it also applies a random
rotation in addition to the random scaling and translation.
