mirror of
https://github.com/ptitSeb/Serious-Engine
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24cb244d43
This was a _ton_ of changes, made 15 years ago, so there are probably some problems to work out still. Among others: Engine/Base/Stream.* was mostly abandoned and will need to be re-ported. Still, this is a pretty good start, and probably holds a world record for lines of changes or something. :)
960 lines
30 KiB
C++
960 lines
30 KiB
C++
/* Copyright (c) 2002-2012 Croteam Ltd. All rights reserved. */
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#include "Engine/StdH.h"
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#include <Engine/Brushes/Brush.h>
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#include <Engine/Templates/DynamicArray.cpp>
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#include <Engine/Templates/StaticArray.cpp>
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#include <Engine/Templates/StaticStackArray.cpp>
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#include <Engine/Math/Float.h>
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#include <Engine/Math/Geometry.inl>
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#include <Engine/Base/Stream.h>
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#include <Engine/Base/Console.h>
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// define this to dump all triangularization steps to debugging output
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//#define DUMP_ALLSTEPS 1
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//#define OPERATEIN2D 1
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// this must not be caught by the dependency catcher!
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static CTFileName _fnmDebugOutput(CTString("Temp\\Triangularization.out"));
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// set if debug output file is open
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static BOOL _bDebugOutputOpen = FALSE;
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// file where debugging output is written to
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static CTFileStream _strmDebugOutput;
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// edge splitting epsilon
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//#define EPSILON 0.0
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//#define EPSILON (1.0/8388608.0) // 1/2^23
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#define EPSILON (1.0f/65536.0f) // 1/2^16
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//#define EPSILON DOUBLE(0.00390625) // 1/2^8
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//#define EPSILON 0.0009765625f // 1/2^10
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//#define EPSILON 0.03125f // 1/2^5
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//#define EPSILON 0.00390625f // 1/2^8
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// minimum triangle quality that is trivially accepted
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#define QUALITY_ACCEPTTRIVIALLY DOUBLE(0.01)
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// this function is here to satisfy compiler's weird need when compiling
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// the template for CDynamicArray<CBrushVertex *>
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inline void Clear(CBrushVertex *pbvx) {
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(void)pbvx;
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};
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/*
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Algorithm used:
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We take each edge and each vertex that is left of that edge, and try to find out
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if the edge and the vertex can span a triangle on the polygon without itersecting
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any other edges.
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A simple convex BSP is used for testing intersection. The triangle edges are
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represented by planes oriented outwards (to the right side of the edge).
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Triangle quality is defined as division of the area and square of the length of
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the longest edge. We always try to extract the triangle with the best quality. Note
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that clockwise triangles will have negative area.
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Also we remember if there is left and/or right edge that connects
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the edge and the vertex. That makes it posible to geometricaly remove the triangle
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from the array of edges if it satisfies.
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Although it is teoretically true that every polygon can be triangularized this way,
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it is not always possible to find triangle with positive area that doesn't intersect
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any edges in the polygon. This is due to the numerical inprecisions created during CSG
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or similar operations.
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Therefore, we define comparation between two triangles this way:
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(1) Triangle that doesn't intersect any edges is better than one that does.
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(2) When (1) is indeterminate, the one with greater quality is considered better.
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Note that a triangle with negative area can be found best. In such case, it is not really
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created, but only removed from the polygon. This is mostly the case with some small
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degenerate parts of polygons. This way, the problematic case is just eliminated without
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loosing too much precision in the triangularized representation of the polygon.
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This method can diverge by adding and removing same triangle repeatedly. Therefore,
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we don't always start at testing at the first edge in polygon, but move the starting
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point when we find some triangle, 'shuffling' the choices of new triangles that way.
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*/
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// a class that handles triangularization of a polygon
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class CTriangularizer {
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public:
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DOUBLE3D tr_vPolygonNormal;
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// reference to original polygon (just for debugging)
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CBrushPolygon &tr_bpoOriginalPolygon;
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// reference to original array of polygon edges
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CStaticArray<CBrushPolygonEdge> &tr_abpeOriginalEdges;
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// temporary array of edges
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CDynamicArray<CBrushEdge> tr_abedEdges;
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// major axes of the polygon plane
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INDEX tr_iAxis0;
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INDEX tr_iAxis1;
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// these describe the triangle curently considered
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CBrushEdge *tr_pbedLeft; // left edge of the triangle if found
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CBrushEdge *tr_pbedRight; // right edge of the triangle if found
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CBrushEdge *tr_pbedBottom; // bottom edge of the triangle
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CBrushVertex *tr_pbvxTopVertex; // top vertex of the triangle
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DOUBLEplane3D tr_plLeft; // splitter plane of left edge
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DOUBLEplane3D tr_plRight; // splitter plane of right edge
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DOUBLEplane3D tr_plBottom; // splitter plane of bottom edge
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DOUBLEplane3D tr_plEdgeConsidered; // splitter plane of the edge considered bottom
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// these describe the best triangle found yet
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DOUBLE tr_fQualityBest; // quality of the best triangle
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BOOL tr_bIntersectedBest; // set if best triangle intersects some edges
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CBrushEdge *tr_pbedLeftBest; // left edge of the triangle if found
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CBrushEdge *tr_pbedRightBest; // right edge of the triangle if found
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CBrushEdge *tr_pbedBottomBest; // bottom edge of the triangle
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CBrushVertex *tr_pbvxTopVertexBest; // top vertex of the triangle
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// get a vertex coordinates
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inline DOUBLE3D GetVertex(CBrushVertex *pbvx) const;
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/* Create a splitter plane for an edge. */
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inline void EdgeToPlane(const DOUBLE3D &vVertex0, const DOUBLE3D &vVertex1,
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DOUBLEplane3D &plPlane) const;
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/* Clip edge to a plane and check if something remains behind. */
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BOOL ClipEdge(DOUBLE3D &vVertex0, DOUBLE3D &vVertex1, const DOUBLEplane3D &plPlane) const;
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/* Check if an edge is entirely or partially inside considered triangle. */
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BOOL EdgeInsideTriangle(const CBrushEdge *pbed) const;
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/* Calculate the quality of currently considered triangle. */
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DOUBLE TriangleQuality(void) const;
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/* Check that duplicate or reverse edges do not exist. */
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void CheckForInvalidEdges(void);
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/* Add given edge to temporary array. */
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void AddEdge(CBrushVertex *pbvxVertex0, CBrushVertex *pbvxVertex1);
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/* Create an array of forward oriented edges from polygon edges of a polygon. */
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void MakeEdgesForTriangularization(void);
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/* Test all edges for intersection with considered triangle. */
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BOOL CheckTriangleAgainstEdges(void);
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/* Find best triangle in array of edges. */
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void FindBestTriangle(void);
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/* Find if left/right triangle edges already exist. */
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void FindExistingTriangleEdges(void);
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/* Remove best triangle from edges. */
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void RemoveBestTriangleFromPolygon(void);
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/* Add best triangle to triangles. */
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void AddBestTriangleToTriangles(void);
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/* Print a statement to debugging output file. */
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void DPrintF(char *strFormat, ...);
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/* Dump triangle edges to debug output. */
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void DumpEdges(void);
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// find vertices used without duplication
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void FindVerticesUsed(void);
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// build array of element indices
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void MakeElements(void);
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public:
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// target array for resulting triangles
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CDynamicArray<CBrushVertex *> tr_apbvxTriangleVertices;
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// array for vertices without duplicates
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CStaticStackArray<CBrushVertex *> tr_apbvxVertices;
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// array for triangle elements
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CStaticArray<INDEX> tr_aiElements;
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/* Constructor - do triangularization for a polygon. */
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CTriangularizer(CBrushPolygon &bpoOriginalPolygon);
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INDEX tr_iError;
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};
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// get a vertex coordinates
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inline DOUBLE3D CTriangularizer::GetVertex(CBrushVertex *pbvx) const
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{
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#ifdef OPERATEIN2D
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return DOUBLE3D(
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pbvx->bvx_vdPreciseRelative(tr_iAxis0),
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pbvx->bvx_vdPreciseRelative(tr_iAxis1),
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0);
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#else
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return pbvx->bvx_vdPreciseRelative;
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#endif
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}
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/*
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* Create a splitter plane for an edge.
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*/
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inline void CTriangularizer::EdgeToPlane(const DOUBLE3D &vVertex0, const DOUBLE3D &vVertex1,
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DOUBLEplane3D &plPlane) const
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{
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// make a plane containing the edge, perpendicular to the polygon plane, looking
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// to the right of the edge
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plPlane = DOUBLEplane3D((vVertex1-vVertex0)*tr_vPolygonNormal, vVertex0);
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}
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/*
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* Clip edge to a plane and check if something remains behind.
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*/
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BOOL CTriangularizer::ClipEdge(DOUBLE3D &vVertex0, DOUBLE3D &vVertex1,
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const DOUBLEplane3D &plPlane) const
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{
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// calculate point distances from clip plane
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DOUBLE fDistance0 = plPlane.PointDistance(vVertex0);
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DOUBLE fDistance1 = plPlane.PointDistance(vVertex1);
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/* ---- first point behind plane ---- */
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if (fDistance0 < -EPSILON) {
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// if both are back
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if (fDistance1 < -EPSILON) {
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// whole edge is behind
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return TRUE;
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// if first is back, second front
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} else if (fDistance1 > +EPSILON) {
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// calculate intersection coordinates
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vVertex1 = vVertex0-(vVertex0-vVertex1)*fDistance0/(fDistance0-fDistance1);
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// the remaining part is behind
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return TRUE;
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// if first is back, second on the plane
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} else {
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// the whole edge is back
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return TRUE;
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}
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/* ---- first point in front of plane ---- */
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} else if (fDistance0 > +EPSILON) {
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// if first is front, second back
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if (fDistance1 < -EPSILON) {
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// calculate intersection coordinates
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vVertex0 = vVertex1-(vVertex1-vVertex0)*fDistance1/(fDistance1-fDistance0);
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// the remaining part is behind
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return TRUE;
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// if both are front
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} else if (fDistance1 > +EPSILON) {
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// whole edge is front
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return FALSE;
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// if first is front, second on the plane
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} else {
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// whole edge is front
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return FALSE;
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}
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/* ---- first point on the plane ---- */
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} else {
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// if first is on the plane, second back
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if (fDistance1 < -EPSILON) {
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// the whole edge is back
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return TRUE;
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// if first is on the plane, second front
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} else if (fDistance1 > +EPSILON) {
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// whole edge is front
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return FALSE;
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// if both are on the plane
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} else {
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// assume the whole edge is back (!!!! is this correct?)
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return TRUE;
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}
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}
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}
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/*
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* Check if an edge is entirely or partially inside considered triangle.
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*/
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BOOL CTriangularizer::EdgeInsideTriangle(const CBrushEdge *pbed) const
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{
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// copy edge vertices
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DOUBLE3D vVertex0, vVertex1;
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vVertex0 = GetVertex(pbed->bed_pbvxVertex0);
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vVertex1 = GetVertex(pbed->bed_pbvxVertex1);
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// try to clip it to each triangle edge in turn,
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// if anything remains behind - it is inside
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return (ClipEdge(vVertex0, vVertex1, tr_plLeft)
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&&ClipEdge(vVertex0, vVertex1, tr_plRight)
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&&ClipEdge(vVertex0, vVertex1, tr_plBottom));
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}
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/*
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* Calculate the quality of currently considered triangle.
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*/
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DOUBLE CTriangularizer::TriangleQuality(void) const
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{
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DOUBLE3D vEdgeBottom = GetVertex(tr_pbedBottom->bed_pbvxVertex1)
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- GetVertex(tr_pbedBottom->bed_pbvxVertex0);
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DOUBLE3D vEdgeLeft = GetVertex(tr_pbedBottom->bed_pbvxVertex0)
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- GetVertex(tr_pbvxTopVertex);
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DOUBLE3D vEdgeRight = GetVertex(tr_pbvxTopVertex)
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- GetVertex(tr_pbedBottom->bed_pbvxVertex1);
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// calculate triangle normal as cross product of two edges
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DOUBLE3D vNormal = vEdgeLeft*(-vEdgeRight);
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// calculate area as half the length of the normal
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DOUBLE fArea = vNormal.Length()/ DOUBLE(2.0);
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// area must be initially positive
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ASSERT(fArea>=0);
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// if triangle normal is opposite to the polygon normal
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if (vNormal%tr_vPolygonNormal<0) {
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// make area negative
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fArea = -fArea;
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}
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// find length of all edges
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DOUBLE fLengthBottom = vEdgeBottom.Length();
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DOUBLE fLengthLeft = vEdgeLeft .Length();
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DOUBLE fLengthRight = vEdgeRight .Length();
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// find maximum length
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DOUBLE fLengthMax = Max(fLengthBottom, Max(fLengthLeft, fLengthRight));
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// maximum length must be positive
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ASSERT(fLengthMax>0.0f);
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// quality is division of the area and square of the length of the longest edge
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return fArea/(fLengthMax*fLengthMax);
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}
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/*
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* Create an array of forward oriented edges from polygon edges of a polygon.
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*/
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void CTriangularizer::MakeEdgesForTriangularization(void)
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{
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// get number of edges in polygon
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INDEX ctEdges = tr_abpeOriginalEdges.Count();
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// create that much edges in the array
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CBrushEdge *pbedEdges = tr_abedEdges.New(ctEdges);
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tr_abedEdges.Lock();
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// for each edge
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for(INDEX iEdge=0; iEdge<ctEdges; iEdge++) {
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CBrushPolygonEdge &bpe = tr_abpeOriginalEdges[iEdge];
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CBrushEdge &bed = tr_abedEdges[iEdge];
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// if polygon edge is reversed
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if (bpe.bpe_bReverse) {
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// make edge in array reversed
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bed.bed_pbvxVertex0 = bpe.bpe_pbedEdge->bed_pbvxVertex1;
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bed.bed_pbvxVertex1 = bpe.bpe_pbedEdge->bed_pbvxVertex0;
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// if polygon edge is not reversed
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} else {
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// make edge in array normal
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bed.bed_pbvxVertex0 = bpe.bpe_pbedEdge->bed_pbvxVertex0;
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bed.bed_pbvxVertex1 = bpe.bpe_pbedEdge->bed_pbvxVertex1;
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}
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}
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tr_abedEdges.Unlock();
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}
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/*
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* Add given edge to temporary array.
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*/
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void CTriangularizer::AddEdge(CBrushVertex *pbvxVertex0, CBrushVertex *pbvxVertex1)
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{
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#ifndef NDEBUG
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// for each edge
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{FOREACHINDYNAMICARRAY(tr_abedEdges, CBrushEdge, itbed) {
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// must not exist
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if (itbed->bed_pbvxVertex0 == pbvxVertex0
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&&itbed->bed_pbvxVertex1 == pbvxVertex1) {
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return;
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}
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ASSERT(itbed->bed_pbvxVertex0 != pbvxVertex0
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||itbed->bed_pbvxVertex1 != pbvxVertex1);
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// must not have reverse
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ASSERT(itbed->bed_pbvxVertex0 != pbvxVertex1
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||itbed->bed_pbvxVertex1 != pbvxVertex0);
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}}
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#endif
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// add new edge
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CBrushEdge *pbedNew = tr_abedEdges.New(1);
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pbedNew->bed_pbvxVertex0 = pbvxVertex0;
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pbedNew->bed_pbvxVertex1 = pbvxVertex1;
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}
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/*
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* Check that duplicate or reverse edges do not exist.
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*/
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void CTriangularizer::CheckForInvalidEdges(void)
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{
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// for each edge
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{FOREACHINDYNAMICARRAY(tr_abedEdges, CBrushEdge, itbed1) {
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// for each edge
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{FOREACHINDYNAMICARRAY(tr_abedEdges, CBrushEdge, itbed2) {
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// if same edge
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if (&*itbed1 == &*itbed2) {
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// skip
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continue;
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}
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CBrushEdge *pbed1 = itbed1;
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CBrushEdge *pbed2 = itbed2;
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// must not exist
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ASSERT(pbed1->bed_pbvxVertex0 != pbed2->bed_pbvxVertex0
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||pbed1->bed_pbvxVertex1 != pbed2->bed_pbvxVertex1);
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// must not have reverse
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ASSERT(pbed1->bed_pbvxVertex0 != pbed2->bed_pbvxVertex1
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||pbed1->bed_pbvxVertex1 != pbed2->bed_pbvxVertex0);
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}}
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}}
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}
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/*
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* Add best triangle to triangles.
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*/
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void CTriangularizer::AddBestTriangleToTriangles(void)
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{
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// add the triangle to triangles
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CBrushVertex **ppbvxTriangle = tr_apbvxTriangleVertices.New(3);
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ppbvxTriangle[0] = tr_pbedBottomBest->bed_pbvxVertex0;
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ppbvxTriangle[1] = tr_pbedBottomBest->bed_pbvxVertex1;
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ppbvxTriangle[2] = tr_pbvxTopVertexBest;
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}
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/*
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* Remove best triangle from edges.
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*/
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void CTriangularizer::RemoveBestTriangleFromPolygon(void)
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{
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tr_pbedBottom = tr_pbedBottomBest;
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tr_pbvxTopVertex = tr_pbvxTopVertexBest;
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FindExistingTriangleEdges();
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tr_pbedLeftBest = tr_pbedLeft;
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tr_pbedRightBest = tr_pbedRight;
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tr_pbedBottomBest = tr_pbedBottom;
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tr_pbvxTopVertexBest = tr_pbvxTopVertex;
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// if left edge was found
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if (tr_pbedLeftBest!=NULL) {
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// remove the left edge from the edges
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tr_abedEdges.Delete(tr_pbedLeftBest);
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// if left edge was not found
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} else {
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// add reverse of the left edge to the edges
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AddEdge(tr_pbedBottomBest->bed_pbvxVertex0, tr_pbvxTopVertexBest);
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}
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// if right edge was found
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if (tr_pbedRightBest!=NULL) {
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// remove the right edge from the edges
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tr_abedEdges.Delete(tr_pbedRightBest);
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// if right edge was not found
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} else {
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// add reverse of the right edge to the edges
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AddEdge(tr_pbvxTopVertexBest, tr_pbedBottomBest->bed_pbvxVertex1);
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}
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// remove the base edge from the edges
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tr_abedEdges.Delete(tr_pbedBottomBest);
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}
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/*
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* Find if left/right triangle edges already exist.
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*/
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void CTriangularizer::FindExistingTriangleEdges(void)
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{
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// initialize left edge as not existing
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tr_pbedLeft = NULL;
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// initialize right edge as not existing
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tr_pbedRight = NULL;
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// for each edge
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FOREACHINDYNAMICARRAY(tr_abedEdges, CBrushEdge, itbed) {
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CBrushEdge *pbed = itbed;
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// if it is the bottom edge of the triangle
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if (tr_pbedBottom == itbed) {
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// do not test it for intersection
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NOTHING;
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// if it is not bottom edge of triangle
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} else {
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ASSERT(itbed->bed_pbvxVertex0 != tr_pbedBottom->bed_pbvxVertex0
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||itbed->bed_pbvxVertex1 != tr_pbedBottom->bed_pbvxVertex1);
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// if it is the left edge of the triangle
|
|
if (itbed->bed_pbvxVertex1 == tr_pbedBottom->bed_pbvxVertex0
|
|
&&itbed->bed_pbvxVertex0 == tr_pbvxTopVertex) {
|
|
// remember it as the left edge
|
|
ASSERT(tr_pbedLeft==NULL);
|
|
tr_pbedLeft = itbed;
|
|
|
|
// if it is the right edge of the triangle
|
|
} else if (itbed->bed_pbvxVertex0 == tr_pbedBottom->bed_pbvxVertex1
|
|
&&itbed->bed_pbvxVertex1 == tr_pbvxTopVertex) {
|
|
// remember it as the right edge
|
|
ASSERT(tr_pbedRight==NULL);
|
|
tr_pbedRight = itbed;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Test all edges for intersection with considered triangle.
|
|
*/
|
|
BOOL CTriangularizer::CheckTriangleAgainstEdges(void)
|
|
{
|
|
// for each edge
|
|
FOREACHINDYNAMICARRAY(tr_abedEdges, CBrushEdge, itbed) {
|
|
CBrushEdge *pbed = itbed;
|
|
|
|
// if it is the bottom edge of the triangle
|
|
if (tr_pbedBottom == itbed) {
|
|
// do not test it for intersection
|
|
NOTHING;
|
|
|
|
// if it is not bottom edge of triangle
|
|
} else {
|
|
ASSERT(itbed->bed_pbvxVertex0 != tr_pbedBottom->bed_pbvxVertex0
|
|
||itbed->bed_pbvxVertex1 != tr_pbedBottom->bed_pbvxVertex1);
|
|
|
|
// if it is the left edge of the triangle
|
|
if (itbed->bed_pbvxVertex1 == tr_pbedBottom->bed_pbvxVertex0
|
|
&&itbed->bed_pbvxVertex0 == tr_pbvxTopVertex) {
|
|
// do not test it for intersection
|
|
NOTHING;
|
|
|
|
// if it is the right edge of the triangle
|
|
} else if (itbed->bed_pbvxVertex0 == tr_pbedBottom->bed_pbvxVertex1
|
|
&&itbed->bed_pbvxVertex1 == tr_pbvxTopVertex) {
|
|
// do not test it for intersection
|
|
NOTHING;
|
|
|
|
// if it is neither of triangle edges
|
|
} else {
|
|
// if this edge intersects with any of the triangle edges
|
|
if (EdgeInsideTriangle(itbed)) {
|
|
return TRUE;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// if no intersections are found
|
|
return FALSE;
|
|
}
|
|
|
|
// calculate edge direction (COPIED FROM CTMATH!)
|
|
void EdgeDir(const DOUBLE3D &vPoint0, const DOUBLE3D &vPoint1,
|
|
DOUBLE3D &vDirection, DOUBLE3D &vReferencePoint)
|
|
{
|
|
// if the vertices are reversed
|
|
/* if (CompareVertices(vPoint0, vPoint1)<0) {
|
|
// swap them
|
|
Swap(vPoint0, vPoint1);
|
|
// mark edge as reversed
|
|
edx_bReverse = TRUE;
|
|
|
|
// if the vertices are not reversed
|
|
} else {
|
|
// mark edge as not reversed
|
|
edx_bReverse = FALSE;
|
|
}
|
|
*/
|
|
|
|
// normalize the direction
|
|
vDirection = (vPoint1-vPoint0).Normalize();
|
|
/* calculate the reference point on the line from any point on line (p) and direction (d):
|
|
r = p - ((p.d)/(d.d))*d
|
|
*/
|
|
vReferencePoint = vPoint0 -
|
|
vDirection * ((vPoint0 % vDirection))/(vDirection % vDirection);
|
|
}
|
|
|
|
/*
|
|
* Print a statement to debugging output file.
|
|
*/
|
|
void CTriangularizer::DPrintF(char *strFormat, ...)
|
|
{
|
|
char strBuffer[256];
|
|
// format the message in buffer
|
|
va_list arg;
|
|
va_start(arg, strFormat);
|
|
vsprintf(strBuffer, strFormat, arg);
|
|
va_end(arg);
|
|
|
|
// if the debug output file is not open
|
|
if (!_bDebugOutputOpen) {
|
|
// open it
|
|
try {
|
|
_strmDebugOutput.Create_t(_fnmDebugOutput, CTStream::CM_TEXT);
|
|
_bDebugOutputOpen = TRUE;
|
|
// if not successful
|
|
} catch (char *strError) {
|
|
(void) strError;
|
|
// print nothing
|
|
return;
|
|
}
|
|
}
|
|
// write the message to the file
|
|
_strmDebugOutput.Write_t(strBuffer, strlen(strBuffer));
|
|
}
|
|
|
|
/*
|
|
* Dump triangle edges to debug output.
|
|
*/
|
|
void CTriangularizer::DumpEdges(void)
|
|
{
|
|
DPrintF("%d\n", tr_abedEdges.Count());
|
|
FOREACHINDYNAMICARRAY(tr_abedEdges, CBrushEdge, itbed) {
|
|
DPrintF("(%f, %f) ->",
|
|
GetVertex(itbed->bed_pbvxVertex0)(1),
|
|
GetVertex(itbed->bed_pbvxVertex0)(2));
|
|
DPrintF(" (%f, %f) ",
|
|
GetVertex(itbed->bed_pbvxVertex1)(1),
|
|
GetVertex(itbed->bed_pbvxVertex1)(2));
|
|
|
|
DOUBLE3D vDirection, vReferencePoint;
|
|
EdgeDir(
|
|
GetVertex(itbed->bed_pbvxVertex0), GetVertex(itbed->bed_pbvxVertex1),
|
|
vDirection, vReferencePoint);
|
|
|
|
DPrintF("[(%f, %f), ",
|
|
vDirection(1),
|
|
vDirection(2));
|
|
DPrintF("(%f, %f)]\n",
|
|
vReferencePoint(1),
|
|
vReferencePoint(2));
|
|
}
|
|
}
|
|
|
|
// edge offsets used to 'shuffle' triangularization
|
|
static INDEX iBottomEdgeOffset;
|
|
static INDEX iTopEdgeOffset;
|
|
|
|
/*
|
|
* Find best triangle in array of edges.
|
|
*/
|
|
/* NOTE: Currently only searching for first acceptable triangle.
|
|
*/
|
|
void CTriangularizer::FindBestTriangle(void)
|
|
{
|
|
// clear best triangle description
|
|
tr_fQualityBest = DOUBLE(-1E30);
|
|
tr_bIntersectedBest = TRUE;
|
|
tr_pbedLeftBest = NULL;
|
|
tr_pbedRightBest = NULL;
|
|
tr_pbedBottomBest = NULL;
|
|
tr_pbvxTopVertexBest = NULL;
|
|
|
|
iBottomEdgeOffset++;
|
|
// for each edge
|
|
tr_abedEdges.Lock();
|
|
INDEX ctEdges = tr_abedEdges.Count();
|
|
for(INDEX ibedBottom=0; ibedBottom<tr_abedEdges.Count(); ibedBottom++) {
|
|
// consider this edge as bottom edge of triangle
|
|
tr_pbedBottom = &tr_abedEdges[(ibedBottom+iBottomEdgeOffset)%ctEdges];
|
|
|
|
ASSERT(tr_pbedBottom->bed_pbvxVertex0 != tr_pbedBottom->bed_pbvxVertex1);
|
|
// create bottom splitter
|
|
EdgeToPlane(GetVertex(tr_pbedBottom->bed_pbvxVertex0),
|
|
GetVertex(tr_pbedBottom->bed_pbvxVertex1), tr_plEdgeConsidered);
|
|
|
|
iTopEdgeOffset++;
|
|
// for each edge
|
|
for(INDEX ibedTop=0; ibedTop<ctEdges; ibedTop++) {
|
|
// consider first vertex of this edge as top vertex of triangle
|
|
tr_pbvxTopVertex = tr_abedEdges[(ibedTop+ibedBottom+iTopEdgeOffset)%ctEdges].bed_pbvxVertex0;
|
|
|
|
// if the top vertex is one of the vertices of bottom edge
|
|
if ( tr_pbvxTopVertex == tr_pbedBottom->bed_pbvxVertex0
|
|
|| tr_pbvxTopVertex == tr_pbedBottom->bed_pbvxVertex1) {
|
|
// skip this triangle
|
|
continue;
|
|
}
|
|
|
|
// create bottom splitter from the bottom edge splitter
|
|
tr_plBottom = tr_plEdgeConsidered;
|
|
// create left splitter
|
|
EdgeToPlane(GetVertex(tr_pbvxTopVertex),
|
|
GetVertex(tr_pbedBottom->bed_pbvxVertex0), tr_plLeft);
|
|
// create right splitter
|
|
EdgeToPlane(GetVertex(tr_pbedBottom->bed_pbvxVertex1),
|
|
GetVertex(tr_pbvxTopVertex), tr_plRight);
|
|
|
|
// calculate its quality
|
|
DOUBLE fCurrentQuality = TriangleQuality();
|
|
// if triangle is clockwise
|
|
if (fCurrentQuality<0) {
|
|
continue;
|
|
// reverse its splitters
|
|
tr_plLeft.Flip();
|
|
tr_plRight.Flip();
|
|
tr_plBottom.Flip();
|
|
}
|
|
// check if no edges intersect with considered triangle
|
|
BOOL bCurrentIntersected = CheckTriangleAgainstEdges();
|
|
|
|
// if the current triangle is better than the best triangle yet
|
|
if ((tr_bIntersectedBest && !bCurrentIntersected)
|
|
||(tr_bIntersectedBest==bCurrentIntersected && fCurrentQuality>tr_fQualityBest)) {
|
|
|
|
// find if left/right triangle edges already exist.
|
|
FindExistingTriangleEdges();
|
|
// set current triangle as best triangle
|
|
tr_bIntersectedBest = bCurrentIntersected;
|
|
tr_fQualityBest = fCurrentQuality;
|
|
tr_pbedLeftBest = tr_pbedLeft;
|
|
tr_pbedRightBest = tr_pbedRight;
|
|
tr_pbedBottomBest = tr_pbedBottom;
|
|
tr_pbvxTopVertexBest = tr_pbvxTopVertex;
|
|
// if the triangle is trivially acceptable
|
|
if (!bCurrentIntersected && fCurrentQuality>=QUALITY_ACCEPTTRIVIALLY) {
|
|
// finish searching
|
|
tr_abedEdges.Unlock();
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
tr_abedEdges.Unlock();
|
|
|
|
#if 0
|
|
// if no acceptable triangles have been found
|
|
if (tr_fQualityBest</*???*/sdfsdfd) {
|
|
/* dump all sector's vertices */
|
|
/*
|
|
FOREACHINSTATICARRAY(tr_bpoOriginalPolygon.bpo_pbscSector->bsc_abvxVertices,
|
|
CBrushVertex, itbvx) {
|
|
DPrintF("(0x%p, %f, %f, %f)\n", &(*itbvx),
|
|
(*itbvx)(1), (*itbvx)(2), (*itbvx)(3));
|
|
}
|
|
*/
|
|
|
|
// dump remaining edges
|
|
DPrintF("Triangularization failed!\n");
|
|
DPrintF("best quality found: %f\n", tr_fQualityBest);
|
|
DPrintF("Remaining edges:\n");
|
|
DumpEdges();
|
|
/* // dump all edges
|
|
tr_abedEdges.Clear();
|
|
MakeEdgesForTriangularization();
|
|
DumpEdges();
|
|
*/
|
|
|
|
// error!
|
|
ASSERTALWAYS("No acceptable triangles found for triangularization!");
|
|
FatalError("No acceptable triangles found for triangularization!\n"
|
|
"Debugging information written to file '%s'.", _fnmDebugOutput);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
|
|
// find vertices used without duplication
|
|
void CTriangularizer::FindVerticesUsed(void)
|
|
{
|
|
// make an empty array that will contain the vertices
|
|
tr_apbvxVertices.PopAll();
|
|
// for each triangle vertex
|
|
tr_apbvxTriangleVertices.Lock();
|
|
for(INDEX ipbvx=0; ipbvx<tr_apbvxTriangleVertices.Count(); ipbvx++) {
|
|
CBrushVertex *pbvx = tr_apbvxTriangleVertices[ipbvx];
|
|
// for each vertex already added
|
|
BOOL bFound=FALSE;
|
|
for(INDEX ipbvxAdded=0; ipbvxAdded<tr_apbvxVertices.Count(); ipbvxAdded++) {
|
|
// if it is the same one, stop searching
|
|
if (tr_apbvxVertices[ipbvxAdded]==pbvx) {
|
|
bFound = TRUE;
|
|
break;
|
|
}
|
|
}
|
|
// if not found
|
|
if (!bFound) {
|
|
// add it to the array
|
|
tr_apbvxVertices.Push() = pbvx;
|
|
}
|
|
}
|
|
tr_apbvxTriangleVertices.Unlock();
|
|
}
|
|
// build array of element indices
|
|
void CTriangularizer::MakeElements(void)
|
|
{
|
|
// make elements array
|
|
INDEX ctElements = tr_apbvxTriangleVertices.Count();
|
|
tr_aiElements.Clear();
|
|
tr_aiElements.New(ctElements);
|
|
// for each triangle vertex
|
|
tr_apbvxTriangleVertices.Lock();
|
|
for(INDEX i=0; i<ctElements; i++) {
|
|
CBrushVertex *pbvx = tr_apbvxTriangleVertices[i];
|
|
// find its element index
|
|
BOOL bFound=FALSE;
|
|
for(INDEX ipbvx=0; ipbvx<tr_apbvxVertices.Count(); ipbvx++) {
|
|
// if it is the same one, stop searching
|
|
if (tr_apbvxVertices[ipbvx]==pbvx) {
|
|
tr_aiElements[i] = ipbvx;
|
|
bFound = TRUE;
|
|
break;
|
|
}
|
|
}
|
|
ASSERT(bFound);
|
|
}
|
|
tr_apbvxTriangleVertices.Unlock();
|
|
}
|
|
|
|
/*
|
|
* Constructor - do triangularization for a polygon.
|
|
*/
|
|
CTriangularizer::CTriangularizer(CBrushPolygon &bpoOriginalPolygon)
|
|
: tr_bpoOriginalPolygon(bpoOriginalPolygon)
|
|
, tr_abpeOriginalEdges(bpoOriginalPolygon.bpo_abpePolygonEdges) // remember original edges
|
|
{
|
|
// find polygon normal and major axes
|
|
#ifdef OPERATEIN2D
|
|
INDEX iMaxNormal = bpoOriginalPolygon.bpo_pbplPlane->bpl_pldPreciseRelative.GetMaxNormal();
|
|
INDEX iMaxSign = Sgn(bpoOriginalPolygon.bpo_pbplPlane->bpl_pldPreciseRelative(iMaxNormal));
|
|
ASSERT(iMaxSign!=0);
|
|
switch(iMaxNormal) {
|
|
case 1:
|
|
if (iMaxSign==-1) {
|
|
tr_iAxis0 = 3; tr_iAxis1 = 2; tr_vPolygonNormal = DOUBLE3D(-1,0,0);
|
|
} else {
|
|
tr_iAxis0 = 2; tr_iAxis1 = 3; tr_vPolygonNormal = DOUBLE3D(1,0,0);
|
|
}
|
|
break;
|
|
case 2:
|
|
if (iMaxSign==-1) {
|
|
tr_iAxis0 = 1; tr_iAxis1 = 3; tr_vPolygonNormal = DOUBLE3D(0,-1,0);
|
|
} else {
|
|
tr_iAxis0 = 3; tr_iAxis1 = 1; tr_vPolygonNormal = DOUBLE3D(0,1,0);
|
|
}
|
|
break;
|
|
case 3:
|
|
if (iMaxSign==-1) {
|
|
tr_iAxis0 = 2; tr_iAxis1 = 1; tr_vPolygonNormal = DOUBLE3D(0,0,-1);
|
|
} else {
|
|
tr_iAxis0 = 1; tr_iAxis1 = 2; tr_vPolygonNormal = DOUBLE3D(0,0,1);
|
|
}
|
|
break;
|
|
default:
|
|
ASSERT(FALSE);
|
|
tr_iAxis0 = 2; tr_iAxis1 = 3; tr_vPolygonNormal = DOUBLE3D(1,0,0);
|
|
}
|
|
tr_vPolygonNormal = DOUBLE3D(0,0,1);
|
|
#else
|
|
tr_iAxis0 = -1; tr_iAxis1 = -1; tr_vPolygonNormal = bpoOriginalPolygon.bpo_pbplPlane->bpl_pldPreciseRelative;
|
|
#endif
|
|
|
|
// create a dynamic array of edges
|
|
MakeEdgesForTriangularization();
|
|
tr_iError = -1;
|
|
|
|
// estimate max number of triangles
|
|
INDEX ctOrgEdges = tr_abpeOriginalEdges.Count();
|
|
INDEX ctMaxHoles = ctOrgEdges;
|
|
INDEX ctMaxTriangles = ctOrgEdges-2+2*ctMaxHoles;
|
|
|
|
iBottomEdgeOffset = 0;
|
|
iTopEdgeOffset = 0;
|
|
|
|
#ifdef DUMP_ALLSTEPS
|
|
DPrintF("PolygonBegin\n");
|
|
#endif
|
|
|
|
// ASSERT(tr_abedEdges.Count()!=8);
|
|
// while the array of edges is not empty
|
|
//*
|
|
INDEX iPasses = 0;
|
|
while (tr_abedEdges.Count()>0) {
|
|
// if total number of triangles is too large, or searching too long
|
|
INDEX ctTriangles = tr_apbvxTriangleVertices.Count()/3;
|
|
if (ctTriangles>ctMaxTriangles*2 || iPasses>ctMaxTriangles*2) {
|
|
// error, quit triangulation
|
|
tr_iError = 2;
|
|
return;
|
|
}
|
|
|
|
#ifdef DUMP_ALLSTEPS
|
|
// dump remaining edges
|
|
DumpEdges();
|
|
#endif
|
|
|
|
// find best triangle
|
|
FindBestTriangle();
|
|
#ifdef DUMP_ALLSTEPS
|
|
DPrintF("BestQuality=%f\n", tr_fQualityBest);
|
|
#endif
|
|
// if no triangle is found
|
|
if (tr_fQualityBest<0.0) {
|
|
// quit searching
|
|
tr_iError = 1;
|
|
return;
|
|
}
|
|
if (tr_bIntersectedBest) {
|
|
// quit searching
|
|
tr_iError = 3;
|
|
return;
|
|
}
|
|
|
|
// if best triangle has positive quality
|
|
if (tr_fQualityBest>0.0) {
|
|
// add it to triangles
|
|
AddBestTriangleToTriangles();
|
|
}
|
|
// remove best triangle from edges
|
|
RemoveBestTriangleFromPolygon();
|
|
|
|
#ifndef NDEBUG
|
|
// check that there are no invalid edges after creating
|
|
CheckForInvalidEdges();
|
|
#endif
|
|
iPasses++;
|
|
}
|
|
tr_iError = 0;
|
|
//*/
|
|
}
|
|
|
|
/*
|
|
* Make triangular representation of the polygon.
|
|
*/
|
|
void CBrushPolygon::Triangulate(void)
|
|
{
|
|
// if already triangulated
|
|
if (bpo_apbvxTriangleVertices.Count()>0) {
|
|
// do nothing
|
|
return;
|
|
}
|
|
|
|
// triangularize the polygon
|
|
CTriangularizer tr(*this);
|
|
|
|
// find vertices used without duplication
|
|
tr.FindVerticesUsed();
|
|
// build array of element indices
|
|
tr.MakeElements();
|
|
|
|
// if there was an error
|
|
if (tr.tr_iError!=0) {
|
|
// report it
|
|
// CPrintF( TRANS("Cannot properly triangulate a polygon: error %d!\n"), tr.tr_iError);
|
|
// mark the polygon
|
|
bpo_ulFlags|=BPOF_INVALIDTRIANGLES;
|
|
// if there no errors
|
|
} else {
|
|
// mark the polygon as triangulated well
|
|
bpo_ulFlags&=~BPOF_INVALIDTRIANGLES;
|
|
}
|
|
|
|
// copy dynamic array of triangles to the triangular representation of the polygon
|
|
INDEX ctVertices = tr.tr_apbvxVertices.Count();
|
|
bpo_apbvxTriangleVertices.Clear();
|
|
bpo_apbvxTriangleVertices.New(ctVertices);
|
|
for (INDEX iVertex=0; iVertex<ctVertices; iVertex++) {
|
|
bpo_apbvxTriangleVertices[iVertex] = tr.tr_apbvxVertices[iVertex];
|
|
}
|
|
bpo_aiTriangleElements = tr.tr_aiElements;
|
|
|
|
if (_bDebugOutputOpen) {
|
|
_strmDebugOutput.Close();
|
|
_bDebugOutputOpen = FALSE;
|
|
}
|
|
}
|