[Pixman] [PATCH 02/14] Add new test of filter reduction from BILINEAR to NEAREST

[Bill Spitzak]

Reviewed-by: Bill Spitzak <spitzak at gmail.com>

On 04/11/2016 07:36 PM, Søren Sandmann Pedersen wrote:
> This new test tests a bunch of bilinear downscalings, where many have
> a transformation such that the BILINEAR filter can be reduced to
> NEAREST (and many don't).
>
> A CRC32 is computed for all the resulting images and compared to a
> known-good value for both 4-bit and 7-bit interpolation.
>
> V2: Remove leftover comment, some minor formatting fixes, use a
> timestamp as the PRNG seed.
>
> Signed-off-by: Søren Sandmann <soren.sandmann at gmail.com>
> ---
>   test/Makefile.sources        |   1 +
>   test/filter-reduction-test.c | 112 +++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 113 insertions(+)
>   create mode 100644 test/filter-reduction-test.c
>
> diff --git a/test/Makefile.sources b/test/Makefile.sources
> index 5d55e67..0a56231 100644
> --- a/test/Makefile.sources
> +++ b/test/Makefile.sources
> @@ -21,6 +21,7 @@ TESTPROGRAMS =			      \
>   	gradient-crash-test	      \
>   	pixel-test		      \
>   	matrix-test		      \
> +	filter-reduction-test         \
>   	composite-traps-test	      \
>   	region-contains-test	      \
>   	glyph-test		      \
> diff --git a/test/filter-reduction-test.c b/test/filter-reduction-test.c
> new file mode 100644
> index 0000000..705fa4b
> --- /dev/null
> +++ b/test/filter-reduction-test.c
> @@ -0,0 +1,112 @@
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include "utils.h"
> +
> +static const pixman_fixed_t entries[] =
> +{
> +    pixman_double_to_fixed (-1.0),
> +    pixman_double_to_fixed (-0.5),
> +    pixman_double_to_fixed (-1/3.0),
> +    pixman_double_to_fixed (0.0),
> +    pixman_double_to_fixed (0.5),
> +    pixman_double_to_fixed (1.0),
> +    pixman_double_to_fixed (1.5),
> +    pixman_double_to_fixed (2.0),
> +    pixman_double_to_fixed (3.0),
> +};
> +
> +#define SIZE 12
> +
> +static uint32_t
> +test_scale (const pixman_transform_t *xform, uint32_t crc)
> +{
> +    uint32_t *srcbuf, *dstbuf;
> +    pixman_image_t *src, *dest;
> +
> +    srcbuf = malloc (SIZE * SIZE * 4);
> +    prng_randmemset (srcbuf, SIZE * SIZE * 4, 0);
> +    src = pixman_image_create_bits (
> +	PIXMAN_a8r8g8b8, SIZE, SIZE, srcbuf, SIZE * 4);
> +
> +    dstbuf = malloc (SIZE * SIZE * 4);
> +    prng_randmemset (dstbuf, SIZE * SIZE * 4, 0);
> +    dest = pixman_image_create_bits (
> +	PIXMAN_a8r8g8b8, SIZE, SIZE, dstbuf, SIZE * 4);
> +
> +    pixman_image_set_transform (src, xform);
> +    pixman_image_set_repeat (src, PIXMAN_REPEAT_NORMAL);
> +    pixman_image_set_filter (src, PIXMAN_FILTER_BILINEAR, NULL, 0);
> +
> +    image_endian_swap (src);
> +    image_endian_swap (dest);
> +
> +    pixman_image_composite (PIXMAN_OP_SRC,
> +			    src, NULL, dest,
> +			    0, 0, 0, 0, 0, 0,
> +			    SIZE, SIZE);
> +
> +    crc = compute_crc32_for_image (crc, dest);
> +
> +    pixman_image_unref (src);
> +    pixman_image_unref (dest);
> +
> +    free (srcbuf);
> +    free (dstbuf);
> +
> +    return crc;
> +}
> +
> +#if BILINEAR_INTERPOLATION_BITS == 7
> +#define CHECKSUM 0x02169677
> +#elif BILINEAR_INTERPOLATION_BITS == 4
> +#define CHECKSUM 0xE44B29AC
> +#else
> +#define CHECKSUM 0x00000000
> +#endif
> +
> +int
> +main (int argc, const char *argv[])
> +{
> +    const pixman_fixed_t *end = entries + ARRAY_LENGTH (entries);
> +    const pixman_fixed_t *t0, *t1, *t2, *t3, *t4, *t5;
> +    uint32_t crc = 0;
> +
> +    prng_srand (0x56EA1DBD);
> +
> +    for (t0 = entries; t0 < end; ++t0)
> +    {
> +	for (t1 = entries; t1 < end; ++t1)
> +	{
> +	    for (t2 = entries; t2 < end; ++t2)
> +	    {
> +		for (t3 = entries; t3 < end; ++t3)
> +		{
> +		    for (t4 = entries; t4 < end; ++t4)
> +		    {
> +			for (t5 = entries; t5 < end; ++t5)
> +			{
> +			    pixman_transform_t xform = {
> +				{ { *t0, *t1, *t2 },
> +				  { *t3, *t4, *t5 },
> +				  { 0, 0, pixman_fixed_1 } }
> +			    };
> +
> +			    crc = test_scale (&xform, crc);
> +			}
> +		    }
> +		}
> +	    }
> +	}
> +    }
> +
> +    if (crc != CHECKSUM)
> +    {
> +	printf ("filter-reduction-test failed! (checksum=0x%08X, expected 0x%08X)\n", crc, CHECKSUM);
> +	return 1;
> +    }
> +    else
> +    {
> +	printf ("filter-reduction-test passed (checksum=0x%08X)\n", crc);
> +	return 0;
> +    }
> +}
>