cairo/pixman/src/ictransform.c
2005-03-02 07:43:33 +00:00

64 lines
2 KiB
C

/*
* Copyright © 2000 SuSE, Inc.
*
* 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.
*/
#include "icint.h"
#define MAX_FIXED_48_16 ((xFixed_48_16) 0x7fffffff)
#define MIN_FIXED_48_16 (-((xFixed_48_16) 1 << 31))
int
pixman_transform_point (pixman_transform_t *transform,
pixman_vector_t *vector)
{
pixman_vector_t result;
int i, j;
xFixed_32_32 partial;
xFixed_48_16 v;
for (j = 0; j < 3; j++)
{
v = 0;
for (i = 0; i < 3; i++)
{
partial = ((xFixed_48_16) transform->matrix[j][i] *
(xFixed_48_16) vector->vector[i]);
v += partial >> 16;
}
if (v > MAX_FIXED_48_16 || v < MIN_FIXED_48_16)
return 0;
result.vector[j] = (xFixed) v;
}
if (!result.vector[2])
return 0;
for (j = 0; j < 2; j++)
{
partial = (xFixed_48_16) result.vector[j] << 16;
v = partial / result.vector[2];
if (v > MAX_FIXED_48_16 || v < MIN_FIXED_48_16)
return 0;
vector->vector[j] = (xFixed) v;
}
vector->vector[2] = xFixed1;
return 1;
}