/********************************************************************/
/* STRIPE: converting a polygonal model to triangle strips
Francine Evans, 1996.
SUNY @ Stony Brook
Advisors: Steven Skiena and Amitabh Varshney
*/
/********************************************************************/
/*---------------------------------------------------------------------*/
/* STRIPE: outputex.c
This file contains routines that are used for various functions in
the local algorithm.
*/
/*---------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include "global.h"
#include "outputex.h"
#include "triangulatex.h"
#include "polverts.h"
#include "ties.h"
#include "partial.h"
#include "sturctsex.h"
#include "options.h"
#include "output.h"
#include "common.h"
#include "util.h"
void Output_TriEx(int id1, int id2, int id3, FILE *output, int next_face, int flag,
int where)
{
/* We will save everything into a list, rather than output at once,
as was done in the old routine. This way for future modifications
we can change the strips later on if we want to.
*/
int swap,temp1,temp2,temp3;
static int total=0;
static int tri=0;
static int strips = 0;
static int cost = 0;
if (flag == -20)
{
cost = cost + where+total+tri+strips+strips;
printf("We will need to send %d vertices to the renderer\n",cost);
total = 0;
tri = 0;
strips = 0;
return ;
}
if (flag == -10)
/* We are finished, now is time to output the triangle list
*/
{
fprintf(output,"\nt ");
tri = tri + Finished(&swap,output,FALSE);
total = total + swap;
strips++;
/*printf("There are %d swaps %d tri %d strips\n",total,tri,strips);*/
}
else
{
Last_Edge(&temp1,&temp2,&temp3,0);
Add_Id_Strips(id1,where);
Add_Id_Strips(id2,where);
Add_Id_Strips(id3,where);
Last_Edge(&id1,&id2,&id3,1);
}
}
void Extend_BackwardsEx(int face_id, FILE *output, FILE *strip, int *ties,
int tie, int triangulate,
int swaps,int *next_id)
{
/* We just made a strip, now we are going to see if we can extend
backwards from the starting face, which had 2 or more adjacencies
to start with.
*/
int bucket,next_face,num,x,y,z,c,d=1,max,f;
ListHead *pListFace;
PF_FACES face;
P_ADJACENCIES temp;
/* Get the first triangle that we have saved the the strip data
structure, so we can see if there are any polygons adjacent
to this edge or a neighboring one
*/
First_Edge(&x,&y,&z);
pListFace = PolFaces[face_id];
face = (PF_FACES) PeekList(pListFace,LISTHEAD,0);
num = face->nPolSize;
/* Go through the edges to see if there is an adjacency
with a vertex in common to the first triangle that was
outputted in the strip. (maybe edge was deleted....)
*/
for (c=0; c<num ; c++)
{
if ( (c != (num-1)) &&
(( (*(face->pPolygon+c) == x) && (*(face->pPolygon+c+1) == y)) ||
(*(face->pPolygon+c) == y) && (*(face->pPolygon+c+1) == x)))
{
/* Input edge is still there see if there is an adjacency */
next_face = Find_Face(face_id, x, y, &bucket);
if (next_face == -1)
/* Could not find a face adjacent to the edge */
break;
pListFace = array[bucket];
max = NumOnList(pListFace);
for (f=0;;f++)
{
temp = (P_ADJACENCIES) PeekList(pListFace,LISTHEAD,f);
if (temp->face_id == next_face)
{
Last_Edge(&z,&y,&x,1);
Polygon_OutputEx(temp,temp->face_id,bucket,pListFace,
output,strip,ties,tie,triangulate,swaps,next_id,0);
return;
}
if (temp == NULL)
{
printf("Error in the new buckets%d %d %d\n",bucket,max,0);
exit(0);
}
}
}
else if ( (c == (num -1)) &&
( ((*(face->pPolygon) == x) && (*(face->pPolygon+num-1) == y)) ||
(*(face->pPolygon) == y) && (*(face->pPolygon+num-1) == x)))
{
next_face = Find_Face(face_id,x,y,&bucket);
if (next_face == -1)
/* Could not find a face adjacent to the edge */
break;
pListFace = array[bucket];
max = NumOnList(pListFace);
for (f=0;;f++)
{
temp = (P_ADJACENCIES) PeekList(pListFace,LISTHEAD,f);
if (temp->face_id == next_face)
{
Last_Edge(&z,&y,&x,1);
Polygon_OutputEx(temp,temp->face_id,bucket,pListFace,
output,strip,ties,tie,triangulate,swaps,next_id,0);
return;
}
if (temp == NULL)
{
printf("Error in the new buckets%d %d %d\n",bucket,max,0);
exit(0);
}
}
}
}
}
void Polygon_OutputEx(P_ADJACENCIES temp,int face_id,int bucket,
ListHead *pListHead, FILE *output, FILE *strips,
int *ties, int tie,
int triangulate, int swaps,
int *next_id, int where)
{
ListHead *pListFace;
PF_FACES face;
P_ADJACENCIES pfNode;
static BOOL begin = TRUE;
int old_face,next_face_id,next_bucket,e1,e2,e3,other1,other2,other3;
P_ADJACENCIES lpListInfo;
/* We have a polygon to output, the id is face id, and the number
of adjacent polygons to it is bucket.
*/
Last_Edge(&e1,&e2,&e3,0);
/* Get the polygon with id face_id */
pListFace = PolFaces[face_id];
face = (PF_FACES) PeekList(pListFace,LISTHEAD,0);
if (face->nPolSize == 3)
{
/* It is already a triangle */
if (bucket == 0)
{
/* It is not adjacent to anything so we do not have to
worry about the order of the sides or updating adjacencies
*/
Last_Edge(&e1,&e2,&e3,0);
next_face_id = Different(*(face->pPolygon),*(face->pPolygon+1),*(face->pPolygon+2),
e1,e2,e3,&other1,&other2);
/* No input edge, at the start */
if ((e2 ==0) && (e3 == 0))
{
e2 = other1;
e3 = other2;
}
Output_TriEx(e2,e3,next_face_id,strips,-1,begin,where);
RemoveList(pListHead,(PLISTINFO) temp);
/* We will be at the beginning of the next strip. */
begin = TRUE;
}
/* It is a triangle with adjacencies. This means that we
have to:
1. Update the adjacencies in the list, because we are
using this polygon and it will be deleted.
2. Get the next polygon.
*/
else
{
/* Return the face_id of the next polygon we will be using,
while updating the adjacency list by decrementing the
adjacencies of everything adjacent to the current triangle.
*/
next_face_id = Update_AdjacenciesEx(face_id, &next_bucket, &e1,&e2,ties);
old_face = next_face_id;
/* Break the tie, if there was one */
if (tie != FIRST)
old_face = Get_Next_Face(tie,face_id,triangulate);
if (next_face_id == -1)
{
Polygon_OutputEx(temp,face_id,0,pListHead,output,strips,ties,tie,
triangulate,swaps,next_id,where);
return;
}
/* We are using a different face */
if ((tie != FIRST) && (old_face != next_face_id) && (swaps == ON))
{
next_face_id = old_face;
/* Get the new output edge, since e1 and e2 are for the
original next face that we got.
*/
e3 = Get_EdgeEx(&e1,&e2,face->pPolygon,next_face_id,face->nPolSize,0,0);
}
/* Find the other vertex to transmit in the triangle */
e3 = Return_Other(face->pPolygon,e1,e2);
Last_Edge(&other1,&other2,&other3,0);
if ((other1 != 0) && (other2 != 0))
{
/* See which vertex in the output edge is not in the input edge */
if ((e1 != other2) && (e1 != other3))
e3 = e1;
else if ((e2 != other2) && (e2 != other3))
e3 = e2;
/* can happen with > 2 polys on an edge but won't form a good strip so stop
the strip here
*/
else
{
Polygon_OutputEx(temp,face_id,0,pListHead,output,strips,ties,tie,
triangulate,swaps,next_id,where);
return;
}
/* See which vertex of the input edge is not in the output edge */
if ((other2 != e1) && (other2 != e2))
{
other1 = other2;
other2 = other3;
}
else if ((other3 != e1) && (other3 != e2))
other1 = other3;
else
{
/* Degenerate triangle just return*/
Output_TriEx(other1,other2,e3,strips,next_face_id,begin,where);
RemoveList(pListHead,(PLISTINFO) temp);
begin = FALSE;
return;
}
}
/* There was not an input edge, we are the first triangle in a strip */
else
{
/* Find the correct order to transmit the triangle, what is
the output edge that we want ?
*/
other1 = e3;
e3 = e2;
other2 = e1;
}
/* At this point the adjacencies have been updated and we
have the next polygon id
*/
Output_TriEx(other1,other2,e3,strips,next_face_id,begin,where);
RemoveList(pListHead,(PLISTINFO) temp);
begin = FALSE;
if (Done(next_face_id,59,&next_bucket) == NULL)
return;
pListHead = array[next_bucket];
pfNode = (P_ADJACENCIES) malloc(sizeof(ADJACENCIES) );
if ( pfNode )
pfNode->face_id = next_face_id;
lpListInfo = (P_ADJACENCIES) (SearchList(array[next_bucket], pfNode,
(int (*)(void *,void *)) (Compare)));
if (lpListInfo == NULL)
{
printf("There is an error finding the next polygon3 %d\n",next_face_id);
exit(0);
}
Polygon_OutputEx(lpListInfo,next_face_id,next_bucket,
pListHead, output, strips,ties,tie,triangulate,swaps,next_id,where);
}
}
else
{
/* It is not a triangle, we have to triangulate it .
Since it is not adjacent to anything we can triangulate it
blindly
*/
if (bucket == 0)
{
/* Check to see if there is not an input edge */
Last_Edge(&other1,&other2,&other3,0);
if ((other1 == 0) && (other2 ==0))
Blind_TriangulateEx(face->nPolSize,face->pPolygon, strips,
output,TRUE,where);
else
Blind_TriangulateEx(face->nPolSize,face->pPolygon,strips,
output,FALSE,where);
RemoveList(pListHead,(PLISTINFO) temp);
/* We will be at the beginning of the next strip. */
begin = TRUE;
}
/* If we have specified PARTIAL triangulation then
we will go to special routines that will break the
polygon and update the data structure. Else everything
below will simply triangulate the whole polygon
*/
else if (triangulate == PARTIAL)
{
/* Return the face_id of the next polygon we will be using,
*/
next_face_id = Min_Face_AdjEx(face_id,&next_bucket,ties);
/* Don't do it partially, because we can go inside and get
less adjacencies, for a quad we can do the whole thing.
*/
if ((face_id == next_face_id) && (face->nPolSize == 4) && (swaps == ON))
{
next_face_id = Update_AdjacenciesEx(face_id, &next_bucket, &e1,&e2,ties);
if (next_face_id == -1)
{
/* There is no sequential face to go to, end the strip */
Polygon_OutputEx(temp,face_id,0,pListHead,output,strips,ties,tie,
triangulate,swaps,next_id,where);
return;
}
/* Break the tie, if there was one */
if (tie != FIRST)
next_face_id = Get_Next_Face(tie,face_id,triangulate);
Non_Blind_TriangulateEx(face->nPolSize,face->pPolygon, strips,
output,next_face_id,face_id,where);
RemoveList(pListHead,(PLISTINFO) temp);
}
/* Was not a quad but we still do not want to do it partially for
now, since we want to only do one triangle at a time
*/
else if ((face_id == next_face_id) && (swaps == ON))
Inside_Polygon(face->nPolSize,face->pPolygon,strips,output,
next_face_id,face_id,next_id,pListHead,temp,where);
else
{
if ((tie != FIRST) && (swaps == ON))
next_face_id = Get_Next_Face(tie,face_id,triangulate);
Partial_Triangulate(face->nPolSize,face->pPolygon,strips,
output,next_face_id,face_id,next_id,pListHead,temp,where);
/* Check the next bucket again ,maybe it changed
We calculated one less, but that might not be the case
*/
}
if (Done(next_face_id,59,&next_bucket) == NULL)
{
/* Check to see if there is not an input edge */
Last_Edge(&other1,&other2,&other3,0);
if ((other1 == 0) && (other2 ==0))
Blind_TriangulateEx(face->nPolSize,face->pPolygon, strips,
output,TRUE,where);
else
Blind_TriangulateEx(face->nPolSize,face->pPolygon,strips,
output,FALSE,where);
if (Done(face_id,59,&bucket) != NULL)
{
pListHead = array[bucket];
pfNode = (P_ADJACENCIES) malloc(sizeof(ADJACENCIES) );
if ( pfNode )
pfNode->face_id = face_id;
lpListInfo = (P_ADJACENCIES) (SearchList(array[bucket], pfNode,
(int (*)(void *,void *)) (Compare)));
RemoveList(pListHead,(PLISTINFO)lpListInfo);
}
begin = TRUE;
return;
}
begin = FALSE;
pListHead = array[next_bucket];
pfNode = (P_ADJACENCIES) malloc(sizeof(ADJACENCIES) );
if ( pfNode )
pfNode->face_id = next_face_id;
lpListInfo = (P_ADJACENCIES) (SearchList(array[next_bucket], pfNode,
(int (*)(void *,void *)) (Compare)));
if (lpListInfo == NULL)
{
printf("There is an error finding the next polygon1 %d %d\n",next_face_id,next_bucket);
exit(0);
}
Polygon_OutputEx(lpListInfo,next_face_id,next_bucket,
pListHead, output, strips,ties,tie,triangulate,swaps,next_id,where);
}
else
{
/* WHOLE triangulation */
/* It is not a triangle and has adjacencies.
This means that we have to:
1. TriangulateEx this polygon, not blindly because
we have an edge that we want to come out on, that
is the edge that is adjacent to a polygon with the
least number of adjacencies. Also we must come in
on the last seen edge.
2. Update the adjacencies in the list, because we are
using this polygon .
3. Get the next polygon.
*/
/* Return the face_id of the next polygon we will be using,
while updating the adjacency list by decrementing the
adjacencies of everything adjacent to the current polygon.
*/
next_face_id = Update_AdjacenciesEx(face_id, &next_bucket, &e1,&e2,ties);
if (Done(next_face_id,59,&next_bucket) == NULL)
{
Polygon_OutputEx(temp,face_id,0,pListHead,output,strips,ties,tie,
triangulate,swaps,next_id,where);
/* Because maybe there was more than 2 polygons on the edge */
return;
}
/* Break the tie, if there was one */
else if (tie != FIRST)
next_face_id = Get_Next_Face(tie,face_id,triangulate);
Non_Blind_TriangulateEx(face->nPolSize,face->pPolygon, strips,
output,next_face_id,face_id,where);
RemoveList(pListHead,(PLISTINFO) temp);
begin = FALSE;
pListHead = array[next_bucket];
pfNode = (P_ADJACENCIES) malloc(sizeof(ADJACENCIES) );
if ( pfNode )
pfNode->face_id = next_face_id;
lpListInfo = (P_ADJACENCIES) (SearchList(array[next_bucket], pfNode,
(int (*)(void *,void *)) (Compare)));
if (lpListInfo == NULL)
{
printf("There is an error finding the next polygon2 %d %d\n",next_face_id,next_bucket);
exit(0);
}
Polygon_OutputEx(lpListInfo,next_face_id,next_bucket,
pListHead, output, strips,ties,tie,triangulate,swaps,next_id,where);
}
}
Last_Edge(&e1,&e2,&e3,0);
}