Windows2003-3790/multimedia/opengl/glu/nurbs/core/mesher.cxx
2020-09-30 16:53:55 +02:00

465 lines
10 KiB
C++

/**************************************************************************
* *
* Copyright (C) 1992, Silicon Graphics, Inc. *
* *
* These coded instructions, statements, and computer programs contain *
* unpublished proprietary information of Silicon Graphics, Inc., and *
* are protected by Federal copyright law. They may not be disclosed *
* to third parties or copied or duplicated in any form, in whole or *
* in part, without the prior written consent of Silicon Graphics, Inc. *
* *
**************************************************************************/
/*
* mesher.c++ - $Revision: 1.2 $
* Derrick Burns - 1991
*/
#include "glimport.h"
#include "myassert.h"
#include "mystdio.h"
#include "mesher.h"
#include "gridvert.h"
#include "gridtrim.h"
#include "jarcloc.h"
#include "gridline.h"
#include "trimline.h"
#include "uarray.h"
#include "backend.h"
const float Mesher::ZERO = 0.0;
Mesher::Mesher( Backend& b )
: backend( b ),
p( sizeof( GridTrimVertex ), 100, "GridTrimVertexPool" )
{
stacksize = 0;
vdata = 0;
lastedge = 0; //needed to prevent purify UMR
}
Mesher::~Mesher( void )
{
if( vdata ) delete[] vdata;
}
void
Mesher::init( unsigned int npts )
{
p.clear();
if( stacksize < npts ) {
stacksize = 2 * npts;
if( vdata ) delete[] vdata;
vdata = new GridTrimVertex_p[stacksize];
}
}
inline void
Mesher::push( GridTrimVertex *gt )
{
assert( itop+1 != stacksize );
vdata[++itop] = gt;
}
inline void
Mesher::pop( long )
{
}
inline void
Mesher::openMesh()
{
backend.bgntmesh( "addedge" );
}
inline void
Mesher::closeMesh()
{
backend.endtmesh();
}
inline void
Mesher::swapMesh()
{
backend.swaptmesh();
}
inline void
Mesher::clearStack()
{
itop = -1;
last[0] = 0;
}
void
Mesher::finishLower( GridTrimVertex *gtlower )
{
for( push(gtlower);
nextlower( gtlower=new(p) GridTrimVertex );
push(gtlower) )
addLower();
addLast();
}
void
Mesher::finishUpper( GridTrimVertex *gtupper )
{
for( push(gtupper);
nextupper( gtupper=new(p) GridTrimVertex );
push(gtupper) )
addUpper();
addLast();
}
void
Mesher::mesh( void )
{
GridTrimVertex *gtlower, *gtupper;
Hull::init( );
nextupper( gtupper = new(p) GridTrimVertex );
nextlower( gtlower = new(p) GridTrimVertex );
clearStack();
openMesh();
push(gtupper);
nextupper( gtupper = new(p) GridTrimVertex );
nextlower( gtlower );
assert( gtupper->t && gtlower->t );
if( gtupper->t->param[0] < gtlower->t->param[0] ) {
push(gtupper);
lastedge = 1;
if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
finishLower(gtlower);
return;
}
} else if( gtupper->t->param[0] > gtlower->t->param[0] ) {
push(gtlower);
lastedge = 0;
if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
finishUpper(gtupper);
return;
}
} else {
if( lastedge == 0 ) {
push(gtupper);
lastedge = 1;
if( nextupper(gtupper=new(p) GridTrimVertex) == 0 ) {
finishLower(gtlower);
return;
}
} else {
push(gtlower);
lastedge = 0;
if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
finishUpper(gtupper);
return;
}
}
}
while ( 1 ) {
if( gtupper->t->param[0] < gtlower->t->param[0] ) {
push(gtupper);
addUpper();
if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
finishLower(gtlower);
return;
}
} else if( gtupper->t->param[0] > gtlower->t->param[0] ) {
push(gtlower);
addLower();
if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
finishUpper(gtupper);
return;
}
} else {
if( lastedge == 0 ) {
push(gtupper);
addUpper();
if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
finishLower(gtlower);
return;
}
} else {
push(gtlower);
addLower();
if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
finishUpper(gtupper);
return;
}
}
}
}
}
inline int
Mesher::isCcw( int ilast )
{
REAL area = det3( vdata[ilast]->t, vdata[itop-1]->t, vdata[itop-2]->t );
return (area < ZERO) ? 0 : 1;
}
inline int
Mesher::isCw( int ilast )
{
REAL area = det3( vdata[ilast]->t, vdata[itop-1]->t, vdata[itop-2]->t );
return (area > -ZERO) ? 0 : 1;
}
inline int
Mesher::equal( int x, int y )
{
return( last[0] == vdata[x] && last[1] == vdata[y] );
}
inline void
Mesher::copy( int x, int y )
{
last[0] = vdata[x]; last[1] = vdata[y];
}
inline void
Mesher::move( int x, int y )
{
vdata[x] = vdata[y];
}
inline void
Mesher::output( int x )
{
backend.tmeshvert( vdata[x] );
}
/*---------------------------------------------------------------------------
* addedge - addedge an edge to the triangulation
*
* This code has been re-written to generate large triangle meshes
* from a monotone polygon. Although smaller triangle meshes
* could be generated faster and with less code, larger meshes
* actually give better SYSTEM performance. This is because
* vertices are processed in the backend slower than they are
* generated by this code and any decrease in the number of vertices
* results in a decrease in the time spent in the backend.
*---------------------------------------------------------------------------
*/
void
Mesher::addLast( )
{
register int ilast = itop;
if( lastedge == 0 ) {
if( equal( 0, 1 ) ) {
output( ilast );
swapMesh();
for( register int i = 2; i < ilast; i++ ) {
swapMesh();
output( i );
}
copy( ilast, ilast-1 );
} else if( equal( ilast-2, ilast-1) ) {
swapMesh();
output( ilast );
for( register int i = ilast-3; i >= 0; i-- ) {
output( i );
swapMesh();
}
copy( 0, ilast );
} else {
closeMesh(); openMesh();
output( ilast );
output( 0 );
for( register int i = 1; i < ilast; i++ ) {
swapMesh();
output( i );
}
copy( ilast, ilast-1 );
}
} else {
if( equal( 1, 0) ) {
swapMesh();
output( ilast );
for( register int i = 2; i < ilast; i++ ) {
output( i );
swapMesh();
}
copy( ilast-1, ilast );
} else if( equal( ilast-1, ilast-2) ) {
output( ilast );
swapMesh();
for( register int i = ilast-3; i >= 0; i-- ) {
swapMesh();
output( i );
}
copy( ilast, 0 );
} else {
closeMesh(); openMesh();
output( 0 );
output( ilast );
for( register int i = 1; i < ilast; i++ ) {
output( i );
swapMesh();
}
copy( ilast-1, ilast );
}
}
closeMesh();
//for( register long k=0; k<=ilast; k++ ) pop( k );
}
void
Mesher::addUpper( )
{
register int ilast = itop;
if( lastedge == 0 ) {
if( equal( 0, 1 ) ) {
output( ilast );
swapMesh();
for( register int i = 2; i < ilast; i++ ) {
swapMesh();
output( i );
}
copy( ilast, ilast-1 );
} else if( equal( ilast-2, ilast-1) ) {
swapMesh();
output( ilast );
for( register int i = ilast-3; i >= 0; i-- ) {
output( i );
swapMesh();
}
copy( 0, ilast );
} else {
closeMesh(); openMesh();
output( ilast );
output( 0 );
for( register int i = 1; i < ilast; i++ ) {
swapMesh();
output( i );
}
copy( ilast, ilast-1 );
}
lastedge = 1;
//for( register long k=0; k<ilast-1; k++ ) pop( k );
move( 0, ilast-1 );
move( 1, ilast );
itop = 1;
} else {
if( ! isCcw( ilast ) ) return;
do {
itop--;
} while( (itop > 1) && isCcw( ilast ) );
if( equal( ilast-1, ilast-2 ) ) {
output( ilast );
swapMesh();
for( register int i=ilast-3; i>=itop-1; i-- ) {
swapMesh();
output( i );
}
copy( ilast, itop-1 );
} else if( equal( itop, itop-1 ) ) {
swapMesh();
output( ilast );
for( register int i = itop+1; i < ilast; i++ ) {
output( i );
swapMesh();
}
copy( ilast-1, ilast );
} else {
closeMesh(); openMesh();
output( ilast );
output( ilast-1 );
for( register int i=ilast-2; i>=itop-1; i-- ) {
swapMesh();
output( i );
}
copy( ilast, itop-1 );
}
//for( register int k=itop; k<ilast; k++ ) pop( k );
move( itop, ilast );
}
}
void
Mesher::addLower()
{
register int ilast = itop;
if( lastedge == 1 ) {
if( equal( 1, 0) ) {
swapMesh();
output( ilast );
for( register int i = 2; i < ilast; i++ ) {
output( i );
swapMesh();
}
copy( ilast-1, ilast );
} else if( equal( ilast-1, ilast-2) ) {
output( ilast );
swapMesh();
for( register int i = ilast-3; i >= 0; i-- ) {
swapMesh();
output( i );
}
copy( ilast, 0 );
} else {
closeMesh(); openMesh();
output( 0 );
output( ilast );
for( register int i = 1; i < ilast; i++ ) {
output( i );
swapMesh();
}
copy( ilast-1, ilast );
}
lastedge = 0;
//for( register long k=0; k<ilast-1; k++ ) pop( k );
move( 0, ilast-1 );
move( 1, ilast );
itop = 1;
} else {
if( ! isCw( ilast ) ) return;
do {
itop--;
} while( (itop > 1) && isCw( ilast ) );
if( equal( ilast-2, ilast-1) ) {
swapMesh();
output( ilast );
for( register int i=ilast-3; i>=itop-1; i--) {
output( i );
swapMesh( );
}
copy( itop-1, ilast );
} else if( equal( itop-1, itop) ) {
output( ilast );
swapMesh();
for( register int i=itop+1; i<ilast; i++ ) {
swapMesh( );
output( i );
}
copy( ilast, ilast-1 );
} else {
closeMesh(); openMesh();
output( ilast-1 );
output( ilast );
for( register int i=ilast-2; i>=itop-1; i-- ) {
output( i );
swapMesh( );
}
copy( itop-1, ilast );
}
//for( register int k=itop; k<ilast; k++ ) pop( k );
move( itop, ilast );
}
}