kolibrios/programs/develop/libraries/pixman/pixman-utils.c
Sergey Semyonov (Serge) 4dd0483a93 pixman-1.0
git-svn-id: svn://kolibrios.org@1891 a494cfbc-eb01-0410-851d-a64ba20cac60
2011-02-27 17:46:46 +00:00

259 lines
6.7 KiB
C

/*
* Copyright © 2000 SuSE, Inc.
* Copyright © 1999 Keith Packard
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of SuSE not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. SuSE makes no representations about the
* suitability of this software for any purpose. It is provided "as is"
* without express or implied warranty.
*
* SuSE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SuSE
* BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Author: Keith Packard, SuSE, Inc.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include "pixman-private.h"
pixman_bool_t
pixman_multiply_overflows_int (unsigned int a,
unsigned int b)
{
return a >= INT32_MAX / b;
}
pixman_bool_t
pixman_addition_overflows_int (unsigned int a,
unsigned int b)
{
return a > INT32_MAX - b;
}
void *
pixman_malloc_ab (unsigned int a,
unsigned int b)
{
if (a >= INT32_MAX / b)
return NULL;
return malloc (a * b);
}
void *
pixman_malloc_abc (unsigned int a,
unsigned int b,
unsigned int c)
{
if (a >= INT32_MAX / b)
return NULL;
else if (a * b >= INT32_MAX / c)
return NULL;
else
return malloc (a * b * c);
}
/*
* Helper routine to expand a color component from 0 < n <= 8 bits to 16
* bits by replication.
*/
static inline uint64_t
expand16 (const uint8_t val, int nbits)
{
/* Start out with the high bit of val in the high bit of result. */
uint16_t result = (uint16_t)val << (16 - nbits);
if (nbits == 0)
return 0;
/* Copy the bits in result, doubling the number of bits each time, until
* we fill all 16 bits.
*/
while (nbits < 16)
{
result |= result >> nbits;
nbits *= 2;
}
return result;
}
/*
* This function expands images from ARGB8 format to ARGB16. To preserve
* precision, it needs to know the original source format. For example, if the
* source was PIXMAN_x1r5g5b5 and the red component contained bits 12345, then
* the expanded value is 12345123. To correctly expand this to 16 bits, it
* should be 1234512345123451 and not 1234512312345123.
*/
void
pixman_expand (uint64_t * dst,
const uint32_t * src,
pixman_format_code_t format,
int width)
{
/*
* Determine the sizes of each component and the masks and shifts
* required to extract them from the source pixel.
*/
const int a_size = PIXMAN_FORMAT_A (format),
r_size = PIXMAN_FORMAT_R (format),
g_size = PIXMAN_FORMAT_G (format),
b_size = PIXMAN_FORMAT_B (format);
const int a_shift = 32 - a_size,
r_shift = 24 - r_size,
g_shift = 16 - g_size,
b_shift = 8 - b_size;
const uint8_t a_mask = ~(~0 << a_size),
r_mask = ~(~0 << r_size),
g_mask = ~(~0 << g_size),
b_mask = ~(~0 << b_size);
int i;
/* Start at the end so that we can do the expansion in place
* when src == dst
*/
for (i = width - 1; i >= 0; i--)
{
const uint32_t pixel = src[i];
const uint8_t a = (pixel >> a_shift) & a_mask,
r = (pixel >> r_shift) & r_mask,
g = (pixel >> g_shift) & g_mask,
b = (pixel >> b_shift) & b_mask;
const uint64_t a16 = a_size ? expand16 (a, a_size) : 0xffff,
r16 = expand16 (r, r_size),
g16 = expand16 (g, g_size),
b16 = expand16 (b, b_size);
dst[i] = a16 << 48 | r16 << 32 | g16 << 16 | b16;
}
}
/*
* Contracting is easier than expanding. We just need to truncate the
* components.
*/
void
pixman_contract (uint32_t * dst,
const uint64_t *src,
int width)
{
int i;
/* Start at the beginning so that we can do the contraction in
* place when src == dst
*/
for (i = 0; i < width; i++)
{
const uint8_t a = src[i] >> 56,
r = src[i] >> 40,
g = src[i] >> 24,
b = src[i] >> 8;
dst[i] = a << 24 | r << 16 | g << 8 | b;
}
}
#define N_TMP_BOXES (16)
pixman_bool_t
pixman_region16_copy_from_region32 (pixman_region16_t *dst,
pixman_region32_t *src)
{
int n_boxes, i;
pixman_box32_t *boxes32;
pixman_box16_t *boxes16;
pixman_bool_t retval;
boxes32 = pixman_region32_rectangles (src, &n_boxes);
boxes16 = pixman_malloc_ab (n_boxes, sizeof (pixman_box16_t));
if (!boxes16)
return FALSE;
for (i = 0; i < n_boxes; ++i)
{
boxes16[i].x1 = boxes32[i].x1;
boxes16[i].y1 = boxes32[i].y1;
boxes16[i].x2 = boxes32[i].x2;
boxes16[i].y2 = boxes32[i].y2;
}
pixman_region_fini (dst);
retval = pixman_region_init_rects (dst, boxes16, n_boxes);
free (boxes16);
return retval;
}
pixman_bool_t
pixman_region32_copy_from_region16 (pixman_region32_t *dst,
pixman_region16_t *src)
{
int n_boxes, i;
pixman_box16_t *boxes16;
pixman_box32_t *boxes32;
pixman_box32_t tmp_boxes[N_TMP_BOXES];
pixman_bool_t retval;
boxes16 = pixman_region_rectangles (src, &n_boxes);
if (n_boxes > N_TMP_BOXES)
boxes32 = pixman_malloc_ab (n_boxes, sizeof (pixman_box32_t));
else
boxes32 = tmp_boxes;
if (!boxes32)
return FALSE;
for (i = 0; i < n_boxes; ++i)
{
boxes32[i].x1 = boxes16[i].x1;
boxes32[i].y1 = boxes16[i].y1;
boxes32[i].x2 = boxes16[i].x2;
boxes32[i].y2 = boxes16[i].y2;
}
pixman_region32_fini (dst);
retval = pixman_region32_init_rects (dst, boxes32, n_boxes);
if (boxes32 != tmp_boxes)
free (boxes32);
return retval;
}
#ifdef DEBUG
void
_pixman_log_error (const char *function, const char *message)
{
static int n_messages = 0;
if (n_messages < 10)
{
fprintf (stderr,
"*** BUG ***\n"
"In %s: %s\n"
"Set a breakpoint on '_pixman_log_error' to debug\n\n",
function, message);
n_messages++;
}
}
#endif