src/glu/sgi/libnurbs/nurbtess/monoChain.h

   1 /*
   2 ** License Applicability. Except to the extent portions of this file are
   3 ** made subject to an alternative license as permitted in the SGI Free
   4 ** Software License B, Version 1.1 (the "License"), the contents of this
   5 ** file are subject only to the provisions of the License. You may not use
   6 ** this file except in compliance with the License. You may obtain a copy
   7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
   8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
   9 **
  10 ** http://oss.sgi.com/projects/FreeB
  11 **
  12 ** Note that, as provided in the License, the Software is distributed on an
  13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
  14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
  15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
  16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  17 **
  18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
  19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
  20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
  21 ** Copyright in any portions created by third parties is as indicated
  22 ** elsewhere herein. All Rights Reserved.
  23 **
  24 ** Additional Notice Provisions: The application programming interfaces
  25 ** established by SGI in conjunction with the Original Code are The
  26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
  27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
  28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
  29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
  30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
  31 ** published by SGI, but has not been independently verified as being
  32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
  33 **
  34 */
  35 /*
  36 */
  37
  38 #ifndef _MONO_CHAIN_H
  39 #define _MONO_CHAIN_H
  40
  41 #include "directedLine.h"
  42 #include "partitionY.h"
  43
  44 class monoChain;
  45
  46 class monoChain{
  47   directedLine* chainHead;
  48   directedLine* chainTail;
  49   monoChain* next;
  50   monoChain* prev;
  51   monoChain* nextPolygon; //a list of polygons
  52
  53   //cached informatin
  54   //bounding box
  55   Real minX, maxX, minY, maxY;
  56   Int isIncrease;
  57
  58   //for efficiently comparing two chains
  59
  60   directedLine* current;
  61
  62 public:
  63   monoChain(directedLine* cHead, directedLine* cTail);
  64   ~monoChain() {}
  65
  66   inline  void setNext(monoChain* n) {next = n;}
  67   inline void setPrev(monoChain* p) {prev = p;}
  68   inline void setNextPolygon(monoChain* np) {nextPolygon = np;}
  69   inline monoChain* getNext() {return next;}
  70   inline monoChain* getPrev() {return prev;}
  71   inline directedLine* getHead() {return chainHead;}
  72   inline directedLine* getTail() {return chainTail;}
  73
  74   inline void resetCurrent() { current = ((isIncrease==1)? chainHead:chainTail);}
  75
  76   void deleteLoop();
  77   void deleteLoopList();
  78
  79   //insert a new chain between prev and this
  80   void insert(monoChain* nc);
  81
  82   Int numChainsSingleLoop();
  83   Int numChainsAllLoops();
  84   monoChain** toArrayAllLoops(Int& num_chains);
  85   Int toArraySingleLoop(monoChain** array, Int index);
  86
  87   Int isKey;
  88   Real keyY; //the current horizotal line
  89   Real chainIntersectHoriz(Real y); //updates current incrementally for efficiency
  90   directedLine* find(Real y);//find dline so that y intersects dline.
  91
  92   void printOneChain();
  93   void printChainLoop();
  94   void printAllLoops();
  95
  96 };
  97
  98 monoChain* directedLineLoopToMonoChainLoop(directedLine* loop);
  99 monoChain* directedLineLoopListToMonoChainLoopList(directedLine* list);
 100 Int MC_sweepY(Int nVertices, monoChain** sortedVertices, sweepRange** ret_ranges);
 101
 102 void MC_findDiagonals(Int total_num_edges, monoChain** sortedVertices,
 103                    sweepRange** ranges, Int& num_diagonals,
 104                    directedLine** diagonal_vertices);
 105
 106 directedLine* MC_partitionY(directedLine *polygons, sampledLine **retSampledLines);
 107
 108 #endif