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#ifndef UNSUPPORTED
static void do_rotate(void *data, struct taskinfo *task, int r1, int r2)
{
struct filter *f = (struct filter *) data;
struct rotatedata *s = (struct rotatedata *) f->data;
double xstep = (s->x2 - s->x1) * 65536 / f->image->height;
double ystep = (s->y2 - s->y1) * 65536 / f->image->height;
double x = (s->x1) * 65536, y = (s->y1) * 65536;
int ixstep = (int) ((s->xx1 - s->x1) * 65536);
int iystep = (int) ((s->yy1 - s->y1) * 65536);
int i;
if (x < 0)
x = 0; /*avoid shifting problems */
if (y < 0)
y = 0;
ixstep /= f->image->width;
iystep /= f->image->width;
/* I do floating point dda here since I expect that registers used by dda will
* not conflict with registers of integer one used by main loop so it will be
* faster than dda from stack :)
*/
x += r1 * xstep;
y += r1 * ystep;
for (i = r1; i < r2; i++) {
{
register int ix = (int) x;
register int iy = (int) y;
register cpixel_t **vbuff =
(cpixel_t **) f->childimage->currlines;
register cpixel_t *end =
p_add((cpixel_t *) f->image->currlines[i],
f->image->width), *dest =
(cpixel_t *) f->image->currlines[i];
register int iixstep = ixstep, iiystep = iystep;
while (dest < end) {
p_copy(dest, 0, (cpixel_t *) (vbuff[iy >> 16]),
(ix >> 16));
p_inc(dest, 1);
ix += iixstep;
iy += iiystep;
}
}
x += xstep;
y += ystep;
}
}
#endif
#undef do_rotate
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