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xserver/render/mitrap.c

82 lines
2.6 KiB
C

/*
*
* Copyright © 2002 Keith Packard, member of The XFree86 Project, 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 Keith Packard not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. Keith Packard makes no
* representations about the suitability of this software for any purpose. It
* is provided "as is" without express or implied warranty.
*
* KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL KEITH PACKARD 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.
*/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif
#include "scrnintstr.h"
#include "gcstruct.h"
#include "pixmapstr.h"
#include "windowstr.h"
#include "servermd.h"
#include "mi.h"
#include "picturestr.h"
#include "mipict.h"
static xFixed
miLineFixedX(xLineFixed * l, xFixed y, Bool ceil)
{
xFixed dx = l->p2.x - l->p1.x;
xFixed_32_32 ex = (xFixed_32_32) (y - l->p1.y) * dx;
xFixed dy = l->p2.y - l->p1.y;
if (ceil)
ex += (dy - 1);
return l->p1.x + (xFixed) (ex / dy);
}
void
miTrapezoidBounds(int ntrap, xTrapezoid * traps, BoxPtr box)
{
box->y1 = MAXSHORT;
box->y2 = MINSHORT;
box->x1 = MAXSHORT;
box->x2 = MINSHORT;
for (; ntrap; ntrap--, traps++) {
INT16 x1, y1, x2, y2;
if (!xTrapezoidValid(traps))
continue;
y1 = xFixedToInt(traps->top);
if (y1 < box->y1)
box->y1 = y1;
y2 = xFixedToInt(xFixedCeil(traps->bottom));
if (y2 > box->y2)
box->y2 = y2;
x1 = xFixedToInt(min(miLineFixedX(&traps->left, traps->top, FALSE),
miLineFixedX(&traps->left, traps->bottom, FALSE)));
if (x1 < box->x1)
box->x1 = x1;
x2 = xFixedToInt(xFixedCeil
(max
(miLineFixedX(&traps->right, traps->top, TRUE),
miLineFixedX(&traps->right, traps->bottom, TRUE))));
if (x2 > box->x2)
box->x2 = x2;
}
}