396 lines
10 KiB
C
396 lines
10 KiB
C
/***********************************************************
|
||
|
||
Copyright 1987, 1998 The Open Group
|
||
|
||
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.
|
||
|
||
The above copyright notice and this permission notice shall be included in
|
||
all copies or substantial portions of the Software.
|
||
|
||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||
OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
|
||
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
||
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
||
|
||
Except as contained in this notice, the name of The Open Group shall not be
|
||
used in advertising or otherwise to promote the sale, use or other dealings
|
||
in this Software without prior written authorization from The Open Group.
|
||
|
||
|
||
Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
|
||
|
||
All Rights Reserved
|
||
|
||
Permission to use, copy, modify, and distribute this software and its
|
||
documentation for any purpose and without fee is hereby granted,
|
||
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 Digital not be
|
||
used in advertising or publicity pertaining to distribution of the
|
||
software without specific, written prior permission.
|
||
|
||
DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
|
||
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
|
||
DIGITAL 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 "regionstr.h"
|
||
#include "gc.h"
|
||
#include "miscanfill.h"
|
||
#include "mipoly.h"
|
||
#include "misc.h" /* MAXINT */
|
||
|
||
/*
|
||
* fillUtils.c
|
||
*
|
||
* Written by Brian Kelleher; Oct. 1985
|
||
*
|
||
* This module contains all of the utility functions
|
||
* needed to scan convert a polygon.
|
||
*
|
||
*/
|
||
|
||
/*
|
||
* InsertEdgeInET
|
||
*
|
||
* Insert the given edge into the edge table.
|
||
* First we must find the correct bucket in the
|
||
* Edge table, then find the right slot in the
|
||
* bucket. Finally, we can insert it.
|
||
*
|
||
*/
|
||
static Bool
|
||
miInsertEdgeInET(EdgeTable *ET, EdgeTableEntry *ETE, int scanline,
|
||
ScanLineListBlock **SLLBlock, int *iSLLBlock)
|
||
{
|
||
EdgeTableEntry *start, *prev;
|
||
ScanLineList *pSLL, *pPrevSLL;
|
||
ScanLineListBlock *tmpSLLBlock;
|
||
|
||
/*
|
||
* find the right bucket to put the edge into
|
||
*/
|
||
pPrevSLL = &ET->scanlines;
|
||
pSLL = pPrevSLL->next;
|
||
while (pSLL && (pSLL->scanline < scanline))
|
||
{
|
||
pPrevSLL = pSLL;
|
||
pSLL = pSLL->next;
|
||
}
|
||
|
||
/*
|
||
* reassign pSLL (pointer to ScanLineList) if necessary
|
||
*/
|
||
if ((!pSLL) || (pSLL->scanline > scanline))
|
||
{
|
||
if (*iSLLBlock > SLLSPERBLOCK-1)
|
||
{
|
||
tmpSLLBlock =
|
||
(ScanLineListBlock *)xalloc(sizeof(ScanLineListBlock));
|
||
if (!tmpSLLBlock)
|
||
return FALSE;
|
||
(*SLLBlock)->next = tmpSLLBlock;
|
||
tmpSLLBlock->next = (ScanLineListBlock *)NULL;
|
||
*SLLBlock = tmpSLLBlock;
|
||
*iSLLBlock = 0;
|
||
}
|
||
pSLL = &((*SLLBlock)->SLLs[(*iSLLBlock)++]);
|
||
|
||
pSLL->next = pPrevSLL->next;
|
||
pSLL->edgelist = (EdgeTableEntry *)NULL;
|
||
pPrevSLL->next = pSLL;
|
||
}
|
||
pSLL->scanline = scanline;
|
||
|
||
/*
|
||
* now insert the edge in the right bucket
|
||
*/
|
||
prev = (EdgeTableEntry *)NULL;
|
||
start = pSLL->edgelist;
|
||
while (start && (start->bres.minor < ETE->bres.minor))
|
||
{
|
||
prev = start;
|
||
start = start->next;
|
||
}
|
||
ETE->next = start;
|
||
|
||
if (prev)
|
||
prev->next = ETE;
|
||
else
|
||
pSLL->edgelist = ETE;
|
||
return TRUE;
|
||
}
|
||
|
||
/*
|
||
* CreateEdgeTable
|
||
*
|
||
* This routine creates the edge table for
|
||
* scan converting polygons.
|
||
* The Edge Table (ET) looks like:
|
||
*
|
||
* EdgeTable
|
||
* --------
|
||
* | ymax | ScanLineLists
|
||
* |scanline|-->------------>-------------->...
|
||
* -------- |scanline| |scanline|
|
||
* |edgelist| |edgelist|
|
||
* --------- ---------
|
||
* | |
|
||
* | |
|
||
* V V
|
||
* list of ETEs list of ETEs
|
||
*
|
||
* where ETE is an EdgeTableEntry data structure,
|
||
* and there is one ScanLineList per scanline at
|
||
* which an edge is initially entered.
|
||
*
|
||
*/
|
||
|
||
Bool
|
||
miCreateETandAET(count, pts, ET, AET, pETEs, pSLLBlock)
|
||
int count;
|
||
DDXPointPtr pts;
|
||
EdgeTable *ET;
|
||
EdgeTableEntry *AET;
|
||
EdgeTableEntry *pETEs;
|
||
ScanLineListBlock *pSLLBlock;
|
||
{
|
||
DDXPointPtr top, bottom;
|
||
DDXPointPtr PrevPt, CurrPt;
|
||
int iSLLBlock = 0;
|
||
|
||
int dy;
|
||
|
||
if (count < 2) return TRUE;
|
||
|
||
/*
|
||
* initialize the Active Edge Table
|
||
*/
|
||
AET->next = (EdgeTableEntry *)NULL;
|
||
AET->back = (EdgeTableEntry *)NULL;
|
||
AET->nextWETE = (EdgeTableEntry *)NULL;
|
||
AET->bres.minor = MININT;
|
||
|
||
/*
|
||
* initialize the Edge Table.
|
||
*/
|
||
ET->scanlines.next = (ScanLineList *)NULL;
|
||
ET->ymax = MININT;
|
||
ET->ymin = MAXINT;
|
||
pSLLBlock->next = (ScanLineListBlock *)NULL;
|
||
|
||
PrevPt = &pts[count-1];
|
||
|
||
/*
|
||
* for each vertex in the array of points.
|
||
* In this loop we are dealing with two vertices at
|
||
* a time -- these make up one edge of the polygon.
|
||
*/
|
||
while (count--)
|
||
{
|
||
CurrPt = pts++;
|
||
|
||
/*
|
||
* find out which point is above and which is below.
|
||
*/
|
||
if (PrevPt->y > CurrPt->y)
|
||
{
|
||
bottom = PrevPt, top = CurrPt;
|
||
pETEs->ClockWise = 0;
|
||
}
|
||
else
|
||
{
|
||
bottom = CurrPt, top = PrevPt;
|
||
pETEs->ClockWise = 1;
|
||
}
|
||
|
||
/*
|
||
* don't add horizontal edges to the Edge table.
|
||
*/
|
||
if (bottom->y != top->y)
|
||
{
|
||
pETEs->ymax = bottom->y-1; /* -1 so we don't get last scanline */
|
||
|
||
/*
|
||
* initialize integer edge algorithm
|
||
*/
|
||
dy = bottom->y - top->y;
|
||
BRESINITPGONSTRUCT(dy, top->x, bottom->x, pETEs->bres);
|
||
|
||
if (!miInsertEdgeInET(ET, pETEs, top->y, &pSLLBlock, &iSLLBlock))
|
||
{
|
||
miFreeStorage(pSLLBlock->next);
|
||
return FALSE;
|
||
}
|
||
|
||
ET->ymax = max(ET->ymax, PrevPt->y);
|
||
ET->ymin = min(ET->ymin, PrevPt->y);
|
||
pETEs++;
|
||
}
|
||
|
||
PrevPt = CurrPt;
|
||
}
|
||
return TRUE;
|
||
}
|
||
|
||
/*
|
||
* loadAET
|
||
*
|
||
* This routine moves EdgeTableEntries from the
|
||
* EdgeTable into the Active Edge Table,
|
||
* leaving them sorted by smaller x coordinate.
|
||
*
|
||
*/
|
||
|
||
void
|
||
miloadAET(AET, ETEs)
|
||
EdgeTableEntry *AET, *ETEs;
|
||
{
|
||
EdgeTableEntry *pPrevAET;
|
||
EdgeTableEntry *tmp;
|
||
|
||
pPrevAET = AET;
|
||
AET = AET->next;
|
||
while (ETEs)
|
||
{
|
||
while (AET && (AET->bres.minor < ETEs->bres.minor))
|
||
{
|
||
pPrevAET = AET;
|
||
AET = AET->next;
|
||
}
|
||
tmp = ETEs->next;
|
||
ETEs->next = AET;
|
||
if (AET)
|
||
AET->back = ETEs;
|
||
ETEs->back = pPrevAET;
|
||
pPrevAET->next = ETEs;
|
||
pPrevAET = ETEs;
|
||
|
||
ETEs = tmp;
|
||
}
|
||
}
|
||
|
||
/*
|
||
* computeWAET
|
||
*
|
||
* This routine links the AET by the
|
||
* nextWETE (winding EdgeTableEntry) link for
|
||
* use by the winding number rule. The final
|
||
* Active Edge Table (AET) might look something
|
||
* like:
|
||
*
|
||
* AET
|
||
* ---------- --------- ---------
|
||
* |ymax | |ymax | |ymax |
|
||
* | ... | |... | |... |
|
||
* |next |->|next |->|next |->...
|
||
* |nextWETE| |nextWETE| |nextWETE|
|
||
* --------- --------- ^--------
|
||
* | | |
|
||
* V-------------------> V---> ...
|
||
*
|
||
*/
|
||
void
|
||
micomputeWAET(AET)
|
||
EdgeTableEntry *AET;
|
||
{
|
||
EdgeTableEntry *pWETE;
|
||
int inside = 1;
|
||
int isInside = 0;
|
||
|
||
AET->nextWETE = (EdgeTableEntry *)NULL;
|
||
pWETE = AET;
|
||
AET = AET->next;
|
||
while (AET)
|
||
{
|
||
if (AET->ClockWise)
|
||
isInside++;
|
||
else
|
||
isInside--;
|
||
|
||
if ((!inside && !isInside) ||
|
||
( inside && isInside))
|
||
{
|
||
pWETE->nextWETE = AET;
|
||
pWETE = AET;
|
||
inside = !inside;
|
||
}
|
||
AET = AET->next;
|
||
}
|
||
pWETE->nextWETE = (EdgeTableEntry *)NULL;
|
||
}
|
||
|
||
/*
|
||
* InsertionSort
|
||
*
|
||
* Just a simple insertion sort using
|
||
* pointers and back pointers to sort the Active
|
||
* Edge Table.
|
||
*
|
||
*/
|
||
|
||
int
|
||
miInsertionSort(AET)
|
||
EdgeTableEntry *AET;
|
||
{
|
||
EdgeTableEntry *pETEchase;
|
||
EdgeTableEntry *pETEinsert;
|
||
EdgeTableEntry *pETEchaseBackTMP;
|
||
int changed = 0;
|
||
|
||
AET = AET->next;
|
||
while (AET)
|
||
{
|
||
pETEinsert = AET;
|
||
pETEchase = AET;
|
||
while (pETEchase->back->bres.minor > AET->bres.minor)
|
||
pETEchase = pETEchase->back;
|
||
|
||
AET = AET->next;
|
||
if (pETEchase != pETEinsert)
|
||
{
|
||
pETEchaseBackTMP = pETEchase->back;
|
||
pETEinsert->back->next = AET;
|
||
if (AET)
|
||
AET->back = pETEinsert->back;
|
||
pETEinsert->next = pETEchase;
|
||
pETEchase->back->next = pETEinsert;
|
||
pETEchase->back = pETEinsert;
|
||
pETEinsert->back = pETEchaseBackTMP;
|
||
changed = 1;
|
||
}
|
||
}
|
||
return(changed);
|
||
}
|
||
|
||
/*
|
||
* Clean up our act.
|
||
*/
|
||
void
|
||
miFreeStorage(pSLLBlock)
|
||
ScanLineListBlock *pSLLBlock;
|
||
{
|
||
ScanLineListBlock *tmpSLLBlock;
|
||
|
||
while (pSLLBlock)
|
||
{
|
||
tmpSLLBlock = pSLLBlock->next;
|
||
xfree(pSLLBlock);
|
||
pSLLBlock = tmpSLLBlock;
|
||
}
|
||
}
|