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reactos/dll/win32/glu32/libnurbs/nurbtess/monoTriangulation.cc
Ged Murphy 4019caae75 This really needs to go in a branch. It needs heavy testing and can't coincide with the current shell32 due to PSDK interface changes 
svn path=/branches/shell32_new-bringup/; revision=51893
2011-05-24 18:40:34 +00:00

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/*
** License Applicability. Except to the extent portions of this file are
** made subject to an alternative license as permitted in the SGI Free
** Software License B, Version 1.1 (the "License"), the contents of this
** file are subject only to the provisions of the License. You may not use
** this file except in compliance with the License. You may obtain a copy
** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
**
** http://oss.sgi.com/projects/FreeB
**
** Note that, as provided in the License, the Software is distributed on an
** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
**
** Original Code. The Original Code is: OpenGL Sample Implementation,
** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
** Copyright in any portions created by third parties is as indicated
** elsewhere herein. All Rights Reserved.
**
** Additional Notice Provisions: The application programming interfaces
** established by SGI in conjunction with the Original Code are The
** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
** Window System(R) (Version 1.3), released October 19, 1998. This software
** was created using the OpenGL(R) version 1.2.1 Sample Implementation
** published by SGI, but has not been independently verified as being
** compliant with the OpenGL(R) version 1.2.1 Specification.
**
** $Date$ $Revision: 1.1 $
*/
/*
** $Header: /cygdrive/c/RCVS/CVS/ReactOS/reactos/lib/glu32/libnurbs/nurbtess/monoTriangulation.cc,v 1.1 2004/02/02 16:39:13 navaraf Exp $
*/
#include <stdlib.h>
#include <stdio.h>
#include "gluos.h"
#include "glimports.h"
#include "zlassert.h"
#include "monoTriangulation.h"
#include "polyUtil.h" /*for area*/
#include "partitionX.h"
#include "monoPolyPart.h"
extern directedLine* polygonConvert(directedLine* polygon);
/*poly is NOT deleted
*/
void monoTriangulationOpt(directedLine* poly, primStream* pStream)
{
Int n_cusps;
Int n_edges = poly->numEdges();
directedLine** cusps = (directedLine**) malloc(sizeof(directedLine*)*n_edges);
assert(cusps);
findInteriorCuspsX(poly, n_cusps, cusps);
if(n_cusps ==0) //u monotine
{
monoTriangulationFun(poly, compV2InX, pStream);
}
else if(n_cusps == 1) // one interior cusp
{
directedLine* new_polygon = polygonConvert(cusps[0]);
directedLine* other = findDiagonal_singleCuspX(new_polygon);
//<other> should NOT be null unless there are self-intersecting
//trim curves. In that case, we don't want to core dump, instead,
//we triangulate anyway, and print out error message.
if(other == NULL)
{
monoTriangulationFun(poly, compV2InX, pStream);
}
else
{
directedLine* ret_p1;
directedLine* ret_p2;
new_polygon->connectDiagonal_2slines(new_polygon, other,
&ret_p1,
&ret_p2,
new_polygon);
monoTriangulationFun(ret_p1, compV2InX, pStream);
monoTriangulationFun(ret_p2, compV2InX, pStream);
ret_p1->deleteSinglePolygonWithSline();
ret_p2->deleteSinglePolygonWithSline();
}
}
else
{
//we need a general partitionX funtion (supposed to be in partitionX.C,
//not implemented yet. XXX
monoTriangulationFun(poly, compV2InY, pStream);
}
free(cusps);
}
void monoTriangulationRecOpt(Real* topVertex, Real* botVertex,
vertexArray* left_chain, Int left_current,
vertexArray* right_chain, Int right_current,
primStream* pStream)
{
Int i,j;
Int n_left = left_chain->getNumElements();
Int n_right = right_chain->getNumElements();
if(left_current>= n_left-1 ||
right_current>= n_right-1)
{
monoTriangulationRec(topVertex, botVertex, left_chain, left_current,
right_chain, right_current, pStream);
return;
}
//now both left and right have at least two vertices each.
Real left_v = left_chain->getVertex(left_current)[1];
Real right_v = right_chain->getVertex(right_current)[1];
if(left_v <= right_v) //first left vertex is below right
{
//find the last vertex of right which is above or equal to left
for(j=right_current; j<=n_right-1; j++)
{
if(right_chain->getVertex(j)[1] < left_v)
break;
}
monoTriangulationRecGen(topVertex, left_chain->getVertex(left_current),
left_chain, left_current, left_current,
right_chain, right_current, j-1,
pStream);
monoTriangulationRecOpt(right_chain->getVertex(j-1),
botVertex,
left_chain, left_current,
right_chain, j,
pStream);
}
else //first right vertex is strictly below left
{
//find the last vertex of left which is strictly above right
for(i=left_current; i<=n_left-1; i++)
{
if(left_chain->getVertex(i)[1] <= right_v)
break;
}
monoTriangulationRecGen(topVertex, right_chain->getVertex(right_current),
left_chain, left_current, i-1,
right_chain, right_current, right_current,
pStream);
monoTriangulationRecOpt(left_chain->getVertex(i-1),
botVertex,
left_chain, i,
right_chain, right_current,
pStream);
}
}
void monoTriangulationRecGenTBOpt(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_current, Int inc_end,
vertexArray* dec_chain, Int dec_current, Int dec_end,
primStream* pStream)
{
pStream->triangle(topVertex, inc_chain->getVertex(inc_current), dec_chain->getVertex(dec_current));
/*printf("**(%f,%f)\n", inc_chain->getArray()[0][0],inc_chain->getArray()[0][1]);*/
triangulateXYMonoTB(inc_end-inc_current+1, inc_chain->getArray()+inc_current, dec_end-dec_current+1, dec_chain->getArray()+dec_current, pStream);
pStream->triangle(botVertex, dec_chain->getVertex(dec_end), inc_chain->getVertex(inc_end));
}
/*n_left>=1
*n_right>=1
*the strip is going top to bottom. compared to the funtion
* triangulateXYmono()
*/
void triangulateXYMonoTB(Int n_left, Real** leftVerts,
Int n_right, Real** rightVerts,
primStream* pStream)
{
Int i,j,k,l;
Real* topMostV;
assert(n_left>=1 && n_right>=1);
if(leftVerts[0][1] >= rightVerts[0][1])
{
i=1;
j=0;
topMostV = leftVerts[0];
}
else
{
i=0;
j=1;
topMostV = rightVerts[0];
}
while(1)
{
if(i >= n_left) /*case1: no more in left*/
{
if(j<n_right-1) /*at least two vertices in right*/
{
pStream->begin();
pStream->insert(topMostV);
for(k=n_right-1; k>=j; k--)
pStream->insert(rightVerts[j]);
pStream->end(PRIMITIVE_STREAM_FAN);
}
break;
}
else if(j>= n_right) /*case2: no more in right*/
{
if(i<n_left-1) /*at least two vertices in left*/
{
pStream->begin();
pStream->insert(topMostV);
for(k=i; k<n_left; k++)
pStream->insert(leftVerts[k]);
pStream->end(PRIMITIVE_STREAM_FAN);
}
break;
}
else /* case3: neither is empty, plus the topMostV, there is at least one triangle to output*/
{
if(leftVerts[i][1] >= rightVerts[j][1])
{
pStream->begin();
pStream->insert(rightVerts[j]); /*the origin of this fan*/
pStream->insert(topMostV);
/*find the last k>=i such that
*leftverts[k][1] >= rightverts[j][1]
*/
k=i;
while(k<n_left)
{
if(leftVerts[k][1] < rightVerts[j][1])
break;
k++;
}
k--;
for(l=i; l<=k; l++)
{
pStream->insert(leftVerts[l]);
}
pStream->end(PRIMITIVE_STREAM_FAN);
//update i for next loop
i = k+1;
topMostV = leftVerts[k];
}
else /*leftVerts[i][1] < rightVerts[j][1]*/
{
pStream->begin();
pStream->insert(leftVerts[i]);/*the origion of this fan*/
/*find the last k>=j such that
*rightverts[k][1] > leftverts[i][1]*/
k=j;
while(k< n_right)
{
if(rightVerts[k][1] <= leftVerts[i][1])
break;
k++;
}
k--;
for(l=k; l>= j; l--)
pStream->insert(rightVerts[l]);
pStream->insert(topMostV);
pStream->end(PRIMITIVE_STREAM_FAN);
j=k+1;
topMostV = rightVerts[j-1];
}
}
}
}
static int chainConvex(vertexArray* inc_chain, Int inc_current, Int inc_end)
{
Int i;
//if there are no more than 2 vertices, return 1
if(inc_current >= inc_end-1) return 1;
for(i=inc_current; i<= inc_end-2; i++)
{
if(area(inc_chain->getVertex(i), inc_chain->getVertex(i+1), inc_chain->getVertex(i+2)) <0)
return 0;
}
return 1;
}
static int chainConcave(vertexArray* dec_chain, Int dec_current, Int dec_end)
{
Int i;
//if there are no more than 2 vertices, return 1
if(dec_current >= dec_end -1) return 1;
for(i=dec_current; i<=dec_end-2; i++)
{
if(area(dec_chain->getVertex(i), dec_chain->getVertex(i+1), dec_chain->getVertex(i+2)) >0)
return 0;
}
return 1;
}
void monoTriangulationRecGenInU(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_current, Int inc_end,
vertexArray* dec_chain, Int dec_current, Int dec_end,
primStream* pStream)
{
}
void monoTriangulationRecGenOpt(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_current, Int inc_end,
vertexArray* dec_chain, Int dec_current, Int dec_end,
primStream* pStream)
{
Int i;
//copy this to a polygon: directedLine Lioop
sampledLine* sline;
directedLine* dline;
directedLine* poly;
if(inc_current <= inc_end) //at least one vertex in inc_chain
{
sline = new sampledLine(topVertex, inc_chain->getVertex(inc_current));
poly = new directedLine(INCREASING, sline);
for(i=inc_current; i<=inc_end-1; i++)
{
sline = new sampledLine(inc_chain->getVertex(i), inc_chain->getVertex(i+1));
dline = new directedLine(INCREASING, sline);
poly->insert(dline);
}
sline = new sampledLine(inc_chain->getVertex(inc_end), botVertex);
dline = new directedLine(INCREASING, sline);
poly->insert(dline);
}
else //inc_chian is empty
{
sline = new sampledLine(topVertex, botVertex);
dline = new directedLine(INCREASING, sline);
poly = dline;
}
assert(poly != NULL);
if(dec_current <= dec_end) //at least on vertex in dec_Chain
{
sline = new sampledLine(botVertex, dec_chain->getVertex(dec_end));
dline = new directedLine(INCREASING, sline);
poly->insert(dline);
for(i=dec_end; i>dec_current; i--)
{
sline = new sampledLine(dec_chain->getVertex(i), dec_chain->getVertex(i-1));
dline = new directedLine(INCREASING, sline);
poly->insert(dline);
}
sline = new sampledLine(dec_chain->getVertex(dec_current), topVertex);
dline = new directedLine(INCREASING, sline);
poly->insert(dline);
}
else //dec_chain is empty
{
sline = new sampledLine(botVertex, topVertex);
dline = new directedLine(INCREASING, sline);
poly->insert(dline);
}
{
Int n_cusps;
Int n_edges = poly->numEdges();
directedLine** cusps = (directedLine**) malloc(sizeof(directedLine*)*n_edges);
assert(cusps);
findInteriorCuspsX(poly, n_cusps, cusps);
if(n_cusps ==0) //u monotine
{
monoTriangulationFun(poly, compV2InX, pStream);
}
else if(n_cusps == 1) // one interior cusp
{
directedLine* new_polygon = polygonConvert(cusps[0]);
directedLine* other = findDiagonal_singleCuspX(new_polygon);
//<other> should NOT be null unless there are self-intersecting
//trim curves. In that case, we don't want to core dump, instead,
//we triangulate anyway, and print out error message.
if(other == NULL)
{
monoTriangulationFun(poly, compV2InX, pStream);
}
else
{
directedLine* ret_p1;
directedLine* ret_p2;
new_polygon->connectDiagonal_2slines(new_polygon, other,
&ret_p1,
&ret_p2,
new_polygon);
monoTriangulationFun(ret_p1, compV2InX, pStream);
monoTriangulationFun(ret_p2, compV2InX, pStream);
ret_p1->deleteSinglePolygonWithSline();
ret_p2->deleteSinglePolygonWithSline();
}
}
else
{
//we need a general partitionX funtion (supposed to be in partitionX.C,
//not implemented yet. XXX
//monoTriangulationFun(poly, compV2InY, pStream);
directedLine* new_polygon = polygonConvert(poly);
directedLine* list = monoPolyPart(new_polygon);
for(directedLine* temp = list; temp != NULL; temp = temp->getNextPolygon())
{
monoTriangulationFun(temp, compV2InX, pStream);
}
//clean up
list->deletePolygonListWithSline();
}
free(cusps);
/*
if(numInteriorCuspsX(poly) == 0) //is u monotone
monoTriangulationFun(poly, compV2InX, pStream);
else //it is not u motone
monoTriangulationFun(poly, compV2InY, pStream);
*/
//clean up space
poly->deleteSinglePolygonWithSline();
return;
}
//apparently the following code is not reachable,
//it is for test purpose
if(inc_current > inc_end || dec_current>dec_end)
{
monoTriangulationRecGen(topVertex, botVertex, inc_chain, inc_current, inc_end,
dec_chain, dec_current, dec_end,
pStream);
return;
}
if(
area(dec_chain->getVertex(dec_current),
topVertex,
inc_chain->getVertex(inc_current)) >=0
&& chainConvex(inc_chain, inc_current, inc_end)
&& chainConcave(dec_chain, dec_current, dec_end)
&& area(inc_chain->getVertex(inc_end), botVertex, dec_chain->getVertex(dec_end)) >=0
)
{
monoTriangulationRecFunGen(topVertex, botVertex,
inc_chain, inc_current, inc_end,
dec_chain, dec_current, dec_end,
compV2InX, pStream);
}
else
{
monoTriangulationRecGen(topVertex, botVertex, inc_chain, inc_current, inc_end,
dec_chain, dec_current, dec_end,
pStream);
}
}
/*if inc_current>inc_end, then inc_chain has no points to be considered
*same for dec_chain
*/
void monoTriangulationRecGen(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_current, Int inc_end,
vertexArray* dec_chain, Int dec_current, Int dec_end,
primStream* pStream)
{
Real** inc_array ;
Real** dec_array ;
Int i;
if(inc_current > inc_end && dec_current>dec_end)
return;
else if(inc_current>inc_end) /*no more vertices on inc_chain*/
{
dec_array = dec_chain->getArray();
reflexChain rChain(100,0);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the dec_chain*/
for(i=dec_current; i<=dec_end; i++){
rChain.processNewVertex(dec_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else if(dec_current> dec_end) /*no more vertices on dec_chain*/
{
inc_array = inc_chain->getArray();
reflexChain rChain(100,1);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the inc_chain*/
for(i=inc_current; i<=inc_end; i++){
rChain.processNewVertex(inc_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else /*neither chain is empty*/
{
inc_array = inc_chain -> getArray();
dec_array = dec_chain -> getArray();
/*if top of inc_chain is 'lower' than top of dec_chain, process all the
*vertices on the dec_chain which are higher than top of inc_chain
*/
if(compV2InY(inc_array[inc_current], dec_array[dec_current]) <= 0)
{
reflexChain rChain(100, 0);
rChain.processNewVertex(topVertex, pStream);
for(i=dec_current; i<=dec_end; i++)
{
if(compV2InY(inc_array[inc_current], dec_array[i]) <= 0)
rChain.processNewVertex(dec_array[i], pStream);
else
break;
}
rChain.outputFan(inc_array[inc_current], pStream);
monoTriangulationRecGen(dec_array[i-1], botVertex,
inc_chain, inc_current, inc_end,
dec_chain, i, dec_end,
pStream);
}
else /*compV2InY(inc_array[inc_current], dec_array[dec_current]) > 0*/
{
reflexChain rChain(100, 1);
rChain.processNewVertex(topVertex, pStream);
for(i=inc_current; i<=inc_end; i++)
{
if(compV2InY(inc_array[i], dec_array[dec_current]) >0)
rChain.processNewVertex(inc_array[i], pStream);
else
break;
}
rChain.outputFan(dec_array[dec_current], pStream);
monoTriangulationRecGen(inc_array[i-1], botVertex,
inc_chain, i, inc_end,
dec_chain, dec_current,dec_end,
pStream);
}
}/*end case neither is empty*/
}
void monoTriangulationFun(directedLine* monoPolygon, Int (*compFun)(Real*, Real*), primStream* pStream)
{
Int i;
/*find the top vertex, bottom vertex, inccreasing chain, and decreasing chain,
*then call monoTriangulationRec
*/
directedLine* tempV;
directedLine* topV;
directedLine* botV;
topV = botV = monoPolygon;
for(tempV = monoPolygon->getNext(); tempV != monoPolygon; tempV = tempV->getNext())
{
if(compFun(topV->head(), tempV->head())<0) {
topV = tempV;
}
if(compFun(botV->head(), tempV->head())>0) {
botV = tempV;
}
}
/*creat increase and decrease chains*/
vertexArray inc_chain(20); /*this is a dynamic array*/
for(i=1; i<=topV->get_npoints()-2; i++) { /*the first vertex is the top vertex which doesn't belong to inc_chain*/
inc_chain.appendVertex(topV->getVertex(i));
}
for(tempV = topV->getNext(); tempV != botV; tempV = tempV->getNext())
{
for(i=0; i<=tempV->get_npoints()-2; i++){
inc_chain.appendVertex(tempV->getVertex(i));
}
}
vertexArray dec_chain(20);
for(tempV = topV->getPrev(); tempV != botV; tempV = tempV->getPrev())
{
for(i=tempV->get_npoints()-2; i>=0; i--){
dec_chain.appendVertex(tempV->getVertex(i));
}
}
for(i=botV->get_npoints()-2; i>=1; i--){
dec_chain.appendVertex(tempV->getVertex(i));
}
monoTriangulationRecFun(topV->head(), botV->head(), &inc_chain, 0, &dec_chain, 0, compFun, pStream);
}
void monoTriangulation(directedLine* monoPolygon, primStream* pStream)
{
Int i;
/*find the top vertex, bottom vertex, inccreasing chain, and decreasing chain,
*then call monoTriangulationRec
*/
directedLine* tempV;
directedLine* topV;
directedLine* botV;
topV = botV = monoPolygon;
for(tempV = monoPolygon->getNext(); tempV != monoPolygon; tempV = tempV->getNext())
{
if(compV2InY(topV->head(), tempV->head())<0) {
topV = tempV;
}
if(compV2InY(botV->head(), tempV->head())>0) {
botV = tempV;
}
}
/*creat increase and decrease chains*/
vertexArray inc_chain(20); /*this is a dynamic array*/
for(i=1; i<=topV->get_npoints()-2; i++) { /*the first vertex is the top vertex which doesn't belong to inc_chain*/
inc_chain.appendVertex(topV->getVertex(i));
}
for(tempV = topV->getNext(); tempV != botV; tempV = tempV->getNext())
{
for(i=0; i<=tempV->get_npoints()-2; i++){
inc_chain.appendVertex(tempV->getVertex(i));
}
}
vertexArray dec_chain(20);
for(tempV = topV->getPrev(); tempV != botV; tempV = tempV->getPrev())
{
for(i=tempV->get_npoints()-2; i>=0; i--){
dec_chain.appendVertex(tempV->getVertex(i));
}
}
for(i=botV->get_npoints()-2; i>=1; i--){
dec_chain.appendVertex(tempV->getVertex(i));
}
monoTriangulationRec(topV->head(), botV->head(), &inc_chain, 0, &dec_chain, 0, pStream);
}
/*the chain could be increasing or decreasing, although we use the
* name inc_chain.
*the argument is_increase_chain indicates whether this chain
*is increasing (left chain in V-monotone case) or decreaing (right chain
*in V-monotone case).
*/
void monoTriangulation2(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_smallIndex,
Int inc_largeIndex,
Int is_increase_chain,
primStream* pStream)
{
assert( inc_chain != NULL);
Real** inc_array ;
if(inc_smallIndex > inc_largeIndex)
return; //no triangles
if(inc_smallIndex == inc_largeIndex)
{
if(is_increase_chain)
pStream->triangle(inc_chain->getVertex(inc_smallIndex), botVertex, topVertex);
else
pStream->triangle(inc_chain->getVertex(inc_smallIndex), topVertex, botVertex);
return;
}
Int i;
if(is_increase_chain && botVertex[1] == inc_chain->getVertex(inc_largeIndex)[1])
{
pStream->triangle(botVertex, inc_chain->getVertex(inc_largeIndex-1),
inc_chain->getVertex(inc_largeIndex));
monoTriangulation2(topVertex, botVertex, inc_chain, inc_smallIndex,
inc_largeIndex-1,
is_increase_chain,
pStream);
return;
}
else if( (!is_increase_chain) && topVertex[1] == inc_chain->getVertex(inc_smallIndex)[1])
{
pStream->triangle(topVertex, inc_chain->getVertex(inc_smallIndex+1),
inc_chain->getVertex(inc_smallIndex));
monoTriangulation2(topVertex, botVertex, inc_chain, inc_smallIndex+1,
inc_largeIndex, is_increase_chain, pStream);
return ;
}
inc_array = inc_chain->getArray();
reflexChain rChain(20,is_increase_chain); /*1 means the chain is increasing*/
rChain.processNewVertex(topVertex, pStream);
for(i=inc_smallIndex; i<=inc_largeIndex; i++){
rChain.processNewVertex(inc_array[i], pStream);
}
rChain.processNewVertex(botVertex, pStream);
}
/*if compFun == compV2InY, top to bottom: V-monotone
*if compFun == compV2InX, right to left: U-monotone
*/
void monoTriangulationRecFunGen(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_current, Int inc_end,
vertexArray* dec_chain, Int dec_current, Int dec_end,
Int (*compFun)(Real*, Real*),
primStream* pStream)
{
assert( inc_chain != NULL && dec_chain != NULL);
assert( ! (inc_current> inc_end &&
dec_current> dec_end));
Real** inc_array ;
Real** dec_array ;
Int i;
assert( ! ( (inc_chain==NULL) && (dec_chain==NULL)));
if(inc_current> inc_end) /*no more vertices on inc_chain*/
{
dec_array = dec_chain->getArray();
reflexChain rChain(20,0);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the dec_chain*/
for(i=dec_current; i<=dec_end; i++){
rChain.processNewVertex(dec_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else if(dec_current> dec_end) /*no more vertices on dec_chain*/
{
inc_array = inc_chain->getArray();
reflexChain rChain(20,1);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the inc_chain*/
for(i=inc_current; i<=inc_end; i++){
rChain.processNewVertex(inc_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else /*neither chain is empty*/
{
inc_array = inc_chain -> getArray();
dec_array = dec_chain -> getArray();
/*if top of inc_chain is 'lower' than top of dec_chain, process all the
*vertices on the dec_chain which are higher than top of inc_chain
*/
if(compFun(inc_array[inc_current], dec_array[dec_current]) <= 0)
{
reflexChain rChain(20, 0);
rChain.processNewVertex(topVertex, pStream);
for(i=dec_current; i<=dec_end; i++)
{
if(compFun(inc_array[inc_current], dec_array[i]) <= 0)
rChain.processNewVertex(dec_array[i], pStream);
else
break;
}
rChain.outputFan(inc_array[inc_current], pStream);
monoTriangulationRecFunGen(dec_array[i-1], botVertex,
inc_chain, inc_current, inc_end,
dec_chain, i, dec_end,
compFun,
pStream);
}
else /*compFun(inc_array[inc_current], dec_array[dec_current]) > 0*/
{
reflexChain rChain(20, 1);
rChain.processNewVertex(topVertex, pStream);
for(i=inc_current; i<=inc_end; i++)
{
if(compFun(inc_array[i], dec_array[dec_current]) >0)
rChain.processNewVertex(inc_array[i], pStream);
else
break;
}
rChain.outputFan(dec_array[dec_current], pStream);
monoTriangulationRecFunGen(inc_array[i-1], botVertex,
inc_chain, i,inc_end,
dec_chain, dec_current,dec_end,
compFun,
pStream);
}
}/*end case neither is empty*/
}
/*if compFun == compV2InY, top to bottom: V-monotone
*if compFun == compV2InX, right to left: U-monotone
*/
void monoTriangulationRecFun(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_current,
vertexArray* dec_chain, Int dec_current,
Int (*compFun)(Real*, Real*),
primStream* pStream)
{
assert( inc_chain != NULL && dec_chain != NULL);
assert( ! (inc_current>=inc_chain->getNumElements() &&
dec_current>=dec_chain->getNumElements()));
Int inc_nVertices;
Int dec_nVertices;
Real** inc_array ;
Real** dec_array ;
Int i;
assert( ! ( (inc_chain==NULL) && (dec_chain==NULL)));
if(inc_current>=inc_chain->getNumElements()) /*no more vertices on inc_chain*/
{
dec_array = dec_chain->getArray();
dec_nVertices = dec_chain->getNumElements();
reflexChain rChain(20,0);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the dec_chain*/
for(i=dec_current; i<dec_nVertices; i++){
rChain.processNewVertex(dec_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else if(dec_current>= dec_chain->getNumElements()) /*no more vertices on dec_chain*/
{
inc_array = inc_chain->getArray();
inc_nVertices= inc_chain->getNumElements();
reflexChain rChain(20,1);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the inc_chain*/
for(i=inc_current; i<inc_nVertices; i++){
rChain.processNewVertex(inc_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else /*neither chain is empty*/
{
inc_array = inc_chain -> getArray();
dec_array = dec_chain -> getArray();
inc_nVertices= inc_chain->getNumElements();
dec_nVertices= dec_chain->getNumElements();
/*if top of inc_chain is 'lower' than top of dec_chain, process all the
*vertices on the dec_chain which are higher than top of inc_chain
*/
if(compFun(inc_array[inc_current], dec_array[dec_current]) <= 0)
{
reflexChain rChain(20, 0);
rChain.processNewVertex(topVertex, pStream);
for(i=dec_current; i<dec_nVertices; i++)
{
if(compFun(inc_array[inc_current], dec_array[i]) <= 0)
rChain.processNewVertex(dec_array[i], pStream);
else
break;
}
rChain.outputFan(inc_array[inc_current], pStream);
monoTriangulationRecFun(dec_array[i-1], botVertex,
inc_chain, inc_current,
dec_chain, i,
compFun,
pStream);
}
else /*compFun(inc_array[inc_current], dec_array[dec_current]) > 0*/
{
reflexChain rChain(20, 1);
rChain.processNewVertex(topVertex, pStream);
for(i=inc_current; i<inc_nVertices; i++)
{
if(compFun(inc_array[i], dec_array[dec_current]) >0)
rChain.processNewVertex(inc_array[i], pStream);
else
break;
}
rChain.outputFan(dec_array[dec_current], pStream);
monoTriangulationRecFun(inc_array[i-1], botVertex,
inc_chain, i,
dec_chain, dec_current,
compFun,
pStream);
}
}/*end case neither is empty*/
}
void monoTriangulationRec(Real* topVertex, Real* botVertex,
vertexArray* inc_chain, Int inc_current,
vertexArray* dec_chain, Int dec_current,
primStream* pStream)
{
assert( inc_chain != NULL && dec_chain != NULL);
assert( ! (inc_current>=inc_chain->getNumElements() &&
dec_current>=dec_chain->getNumElements()));
Int inc_nVertices;
Int dec_nVertices;
Real** inc_array ;
Real** dec_array ;
Int i;
assert( ! ( (inc_chain==NULL) && (dec_chain==NULL)));
if(inc_current>=inc_chain->getNumElements()) /*no more vertices on inc_chain*/
{
dec_array = dec_chain->getArray();
dec_nVertices = dec_chain->getNumElements();
reflexChain rChain(20,0);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the dec_chain*/
for(i=dec_current; i<dec_nVertices; i++){
rChain.processNewVertex(dec_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else if(dec_current>= dec_chain->getNumElements()) /*no more vertices on dec_chain*/
{
inc_array = inc_chain->getArray();
inc_nVertices= inc_chain->getNumElements();
reflexChain rChain(20,1);
/*put the top vertex into the reflex chain*/
rChain.processNewVertex(topVertex, pStream);
/*process all the vertices on the inc_chain*/
for(i=inc_current; i<inc_nVertices; i++){
rChain.processNewVertex(inc_array[i], pStream);
}
/*process the bottom vertex*/
rChain.processNewVertex(botVertex, pStream);
}
else /*neither chain is empty*/
{
inc_array = inc_chain -> getArray();
dec_array = dec_chain -> getArray();
inc_nVertices= inc_chain->getNumElements();
dec_nVertices= dec_chain->getNumElements();
/*if top of inc_chain is 'lower' than top of dec_chain, process all the
*vertices on the dec_chain which are higher than top of inc_chain
*/
if(compV2InY(inc_array[inc_current], dec_array[dec_current]) <= 0)
{
reflexChain rChain(20, 0);
rChain.processNewVertex(topVertex, pStream);
for(i=dec_current; i<dec_nVertices; i++)
{
if(compV2InY(inc_array[inc_current], dec_array[i]) <= 0)
rChain.processNewVertex(dec_array[i], pStream);
else
break;
}
rChain.outputFan(inc_array[inc_current], pStream);
monoTriangulationRec(dec_array[i-1], botVertex,
inc_chain, inc_current,
dec_chain, i,
pStream);
}
else /*compV2InY(inc_array[inc_current], dec_array[dec_current]) > 0*/
{
reflexChain rChain(20, 1);
rChain.processNewVertex(topVertex, pStream);
for(i=inc_current; i<inc_nVertices; i++)
{
if(compV2InY(inc_array[i], dec_array[dec_current]) >0)
rChain.processNewVertex(inc_array[i], pStream);
else
break;
}
rChain.outputFan(dec_array[dec_current], pStream);
monoTriangulationRec(inc_array[i-1], botVertex,
inc_chain, i,
dec_chain, dec_current,
pStream);
}
}/*end case neither is empty*/
}
/* the name here assumes that the polygon is Y-monotone, but
*this function also works for X-monotone polygons.
* a monotne polygon consists of two extrem verteices: topVertex and botVertex, and
*two monotone chains: inc_chain, and dec_chain. The edges of the increasing chain (inc_chain)
*is ordered by following pointer: next, while the edges of the decreasing chain (dec_chain)
*is ordered by following pointer: prev
* inc_index index the vertex which is the toppest of the inc_chain which we are handling currently.
* dec_index index the vertex which is the toppest of the dec_chain which we are handling currently.
*/
void monoTriangulationRec(directedLine* inc_chain, Int inc_index,
directedLine* dec_chain, Int dec_index,
directedLine* topVertex, Int top_index,
directedLine* botVertex,
primStream* pStream)
{
Int i;
directedLine *temp, *oldtemp = NULL;
Int tempIndex, oldtempIndex = 0;
assert(inc_chain != NULL && dec_chain != NULL);
if(inc_chain == botVertex) {
reflexChain rChain(20, 0);
rChain.processNewVertex(topVertex->getVertex(top_index), pStream);
for(i=dec_index; i< dec_chain->get_npoints(); i++){
rChain.processNewVertex(dec_chain->getVertex(i), pStream);
}
for(temp = dec_chain->getPrev(); temp != botVertex; temp = temp->getPrev())
{
for(i=0; i<temp->get_npoints(); i++){
rChain.processNewVertex(temp->getVertex(i), pStream);
}
}
}
else if(dec_chain==botVertex) {
reflexChain rChain(20, 1);
rChain.processNewVertex(topVertex->getVertex(top_index), pStream);
for(i=inc_index; i< inc_chain->get_npoints(); i++){
rChain.processNewVertex(inc_chain->getVertex(i), pStream);
}
for(temp = inc_chain->getPrev(); temp != botVertex; temp = temp->getNext())
{
for(i=0; i<temp->get_npoints(); i++){
rChain.processNewVertex(temp->getVertex(i), pStream);
}
}
}
else /*neither reached the bottom*/{
if(compV2InY(inc_chain->getVertex(inc_index), dec_chain->getVertex(dec_index)) <=0) {
reflexChain rChain(20, 0);
rChain.processNewVertex(topVertex -> getVertex(top_index), pStream);
temp = dec_chain;
tempIndex = dec_index;
while( compV2InY(inc_chain->getVertex(inc_index), temp->getVertex(tempIndex))<=0) {
oldtemp = temp;
oldtempIndex = tempIndex;
rChain.processNewVertex(temp->getVertex(tempIndex), pStream);
if(tempIndex == temp->get_npoints()-1){
tempIndex = 0;
temp = temp->getPrev();
}
else{
tempIndex++;
}
}
rChain.outputFan(inc_chain->getVertex(inc_index), pStream);
monoTriangulationRec(inc_chain, inc_index, temp, tempIndex, oldtemp, oldtempIndex, botVertex, pStream);
}
else /* >0*/ {
reflexChain rChain(20, 1);
rChain.processNewVertex(topVertex -> getVertex(top_index), pStream);
temp = inc_chain;
tempIndex = inc_index;
while( compV2InY(temp->getVertex(tempIndex), dec_chain->getVertex(dec_index))>0){
oldtemp = temp;
oldtempIndex = tempIndex;
rChain.processNewVertex(temp->getVertex(tempIndex), pStream);
if(tempIndex == temp->get_npoints()-1){
tempIndex = 0;
temp = temp->getNext();
}
else{
tempIndex++;
}
}
rChain.outputFan(dec_chain->getVertex(dec_index), pStream);
monoTriangulationRec(temp, tempIndex, dec_chain, dec_index, oldtemp, oldtempIndex, botVertex, pStream);
}
} /*end case neither reached the bottom*/
}
/***************************vertexArray begin here**********************************/
vertexArray::vertexArray(Real2* vertices, Int nVertices)
{
Int i;
size = index = nVertices;
array = (Real**) malloc(sizeof(Real*) * nVertices);
assert(array);
for(i=0; i<nVertices; i++)
{
array[i] = vertices[i];
array[i] = vertices[i];
}
}
vertexArray::vertexArray(Int s)
{
size = s;
array = (Real**) malloc(sizeof(Real*) * s);
assert(array);
index = 0;
}
vertexArray::~vertexArray()
{
free(array);
}
void vertexArray::appendVertex(Real* ptr)
{
Int i;
if(index >= size){
Real** temp = (Real**) malloc(sizeof(Real*) * (2*size +1));
assert(temp);
for(i=0; i<index; i++)
temp[i] = array[i];
free(array);
array = temp;
size = 2*size+1;
}
array[index++] = ptr;
}
void vertexArray::print()
{
printf("vertex Array:index=%i, size=%i\n", index, size);
for(Int i=0; i<index; i++)
{
printf("(%f,%f) ", array[i][0], array[i][1]);
}
printf("\n");
}
/*find the first i such that array[i][1] >= v
* and array[i+1][1] <v
* if index == 0 (the array is empty, return -1.
* if v is above all, return -1.
* if v is below all, return index-1.
*/
Int vertexArray::findIndexAbove(Real v)
{
Int i;
if(index == 0)
return -1;
else if(array[0][1] < v)
return -1;
else
{
for(i=1; i<index; i++)
{
if(array[i][1] < v)
break;
}
return i-1;
}
}
/*find the first i<=endIndex such that array[i][1] <= v
* and array[i-1][1] > v
*if sartIndex>endIndex, then return endIndex+1.
*otherwise, startIndex<=endIndex, it is assumed that
* 0<=startIndex<=endIndex<index.
* if v is below all, return endIndex+1
* if v is above all, return startIndex.
*/
Int vertexArray::findIndexBelowGen(Real v, Int startIndex, Int endIndex)
{
Int i;
if(startIndex > endIndex)
return endIndex+1;
else if(array[endIndex][1] > v)
return endIndex+1;
else //now array[endIndex][1] <= v
{
for(i=endIndex-1; i>=startIndex; i--)
{
if(array[i][1] > v)
break;
}
return i+1;
}
}
/*find the first i<=endIndex such that array[i-1][1] >= v
* and array[i][1] < v
*if sartIndex>endIndex, then return endIndex+1.
*otherwise, startIndex<=endIndex, it is assumed that
* 0<=startIndex<=endIndex<index.
* if v is below or equal to all, return endIndex+1
* if v is strictly above all, return startIndex.
*/
Int vertexArray::findIndexStrictBelowGen(Real v, Int startIndex, Int endIndex)
{
Int i;
if(startIndex > endIndex)
return endIndex+1;
else if(array[endIndex][1] >= v)
return endIndex+1;
else //now array[endIndex][1] < v
{
for(i=endIndex-1; i>=startIndex; i--)
{
if(array[i][1] >= v)
break;
}
return i+1;
}
}
/*find the first i>startIndex such that array[i-1][1] > v
* and array[i][1] >=v
*if sartIndex>endIndex, then return startIndex-1.
*otherwise, startIndex<=endIndex, it is assumed that
* 0<=startIndex<=endIndex<index.
* if v is strictly above all, return startIndex-1
* if v is strictly below all, return endIndex.
*/
Int vertexArray::findIndexFirstAboveEqualGen(Real v, Int startIndex, Int endIndex)
{
Int i;
if(startIndex > endIndex)
return startIndex-1;
else if(array[startIndex][1] < v)
return startIndex-1;
else //now array[startIndex][1] >= v
{
for(i=startIndex; i<=endIndex; i++)
{
if(array[i][1] <= v)
break;
}
if(i>endIndex) // v is strictly below all
return endIndex;
else if(array[i][1] == v)
return i;
else
return i-1;
}
}
/*find the first i>=startIndex such that array[i][1] >= v
* and array[i+1][1] <v
*if sartIndex>endIndex, then return startIndex-1.
*otherwise, startIndex<=endIndex, it is assumed that
* 0<=startIndex<=endIndex<index.
* if v is above all, return startIndex-1
* if v is below all, return endIndex.
*/
Int vertexArray::findIndexAboveGen(Real v, Int startIndex, Int endIndex)
{
Int i;
if(startIndex > endIndex)
return startIndex-1;
else if(array[startIndex][1] < v)
return startIndex-1;
else //now array[startIndex][1] >= v
{
for(i=startIndex+1; i<=endIndex; i++)
{
if(array[i][1] < v)
break;
}
return i-1;
}
}
Int vertexArray::findDecreaseChainFromEnd(Int begin, Int end)
{
Int i = end;
Real prevU = array[i][0];
Real thisU;
for(i=end-1; i>=begin; i--){
thisU = array[i][0];
if(thisU < prevU)
prevU = thisU;
else
break;
}
return i;
}
//if(V(start) == v, return start, other wise return the
//last i so that V(i)==v
Int vertexArray::skipEqualityFromStart(Real v, Int start, Int end)
{
Int i;
if(array[start][1] != v)
return start;
//now array[start][1] == v
for(i=start+1; i<= end; i++)
if(array[i][1] != v)
break;
return i-1;
}
/***************************vertexArray end****************************************/
/***************************relfex chain stuff begin here*****************************/
reflexChain::reflexChain(Int size, Int is_increasing)
{
queue = (Real2*) malloc(sizeof(Real2) * size);
assert(queue);
index_queue = 0;
size_queue = size;
isIncreasing = is_increasing;
}
reflexChain::~reflexChain()
{
free(queue);
}
/*put (u,v) at the end of the queue
*pay attention to space
*/
void reflexChain::insert(Real u, Real v)
{
Int i;
if(index_queue >= size_queue) {
Real2 *temp = (Real2*) malloc(sizeof(Real2) * (2*size_queue+1));
assert(temp);
/*copy*/
for(i=0; i<index_queue; i++){
temp[i][0] = queue[i][0];
temp[i][1] = queue[i][1];
}
free(queue);
queue = temp;
size_queue = 2*size_queue + 1;
}
queue[index_queue][0] = u;
queue[index_queue][1] = v;
index_queue ++;
}
void reflexChain::insert(Real v[2])
{
insert(v[0], v[1]);
}
/*
static Real area(Real A[2], Real B[2], Real C[2])
{
Real Bx, By, Cx, Cy;
Bx = B[0] - A[0];
By = B[1] - A[1];
Cx = C[0] - A[0];
Cy = C[1] - A[1];
return Bx*Cy - Cx*By;
}
*/
/*the chain is reflex, and the vertex v is
*on the other side of the chain, so that
*we can outout the fan with v as the
*the center
*/
void reflexChain::outputFan(Real v[2], primStream* pStream)
{
Int i;
pStream->begin();
pStream->insert(v);
if(isIncreasing) {
for(i=0; i<index_queue; i++)
pStream->insert(queue[i]);
}
else {
for(i=index_queue-1; i>=0; i--)
pStream->insert(queue[i]);
}
pStream->end(PRIMITIVE_STREAM_FAN);
}
void reflexChain::processNewVertex(Real v[2], primStream* pStream)
{
Int i,j,k;
Int isReflex;
/*if there are at most one vertex in the queue, then simply insert
*/
if(index_queue <=1){
insert(v);
return;
}
/*there are at least two vertices in the queue*/
j=index_queue-1;
for(i=j; i>=1; i--) {
if(isIncreasing) {
isReflex = (area(queue[i-1], queue[i], v) <= 0.0);
}
else /*decreasing*/{
isReflex = (area(v, queue[i], queue[i-1]) <= 0.0);
}
if(isReflex) {
break;
}
}
/*
*if i<j then vertices: i+1--j are convex
* output triangle fan:
* v, and queue[i], i+1, ..., j
*/
if(i<j)
{
pStream->begin();
pStream->insert(v);
if(isIncreasing) {
for(k=i; k<=j; k++)
pStream->insert(queue[k]);
}
else {
for(k=j; k>=i; k--)
pStream->insert(queue[k]);
}
pStream->end(PRIMITIVE_STREAM_FAN);
}
/*delete vertices i+1--j from the queue*/
index_queue = i+1;
/*finally insert v at the end of the queue*/
insert(v);
}
void reflexChain::print()
{
Int i;
printf("reflex chain: isIncreasing=%i\n", isIncreasing);
for(i=0; i<index_queue; i++) {
printf("(%f,%f) ", queue[i][0], queue[i][1]);
}
printf("\n");
}
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