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Diffstat (limited to 'src/glu/sgi/libnurbs/nurbtess/partitionX.cc')
| -rw-r--r-- | src/glu/sgi/libnurbs/nurbtess/partitionX.cc | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/src/glu/sgi/libnurbs/nurbtess/partitionX.cc b/src/glu/sgi/libnurbs/nurbtess/partitionX.cc new file mode 100644 index 00000000000..0887009a0f0 --- /dev/null +++ b/src/glu/sgi/libnurbs/nurbtess/partitionX.cc @@ -0,0 +1,164 @@ +/* +** 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: 2001/03/17 00:25:41 $ $Revision: 1.1 $ +*/ +/* +** $Header: /cvs/mesa/Mesa/src/glu/sgi/libnurbs/nurbtess/partitionX.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $ +*/ + +#include <stdlib.h> +#include <stdio.h> + +#include "partitionX.h" + +#define CONCAVITY_ZERO 1.0e-6 //this number is used to test whether a vertex is concave (refelx) + //or not. The test needs to compute the area of the three adjacent + //vertices to see if the are is positive or negative. + +Int isCuspX(directedLine *v) +{ + //if v->prev <= v && v->next <= v + //|| v->prev >= v && v->next >= v + Real* T = v->head(); + Real* P = v->getPrev()->head(); + Real* N = v->getNext()->head(); + if( + (compV2InX(T,P) != -1 && + compV2InX(T,N) != -1 + ) || + (compV2InX(T,P) != 1 && + compV2InX(T,N) != 1 + ) + ) + return 1; + else + return 0; +} + +Int isReflexX(directedLine* v) +{ + Real* A = v->getPrev()->head(); + Real* B = v->head(); + Real* C = v->tail(); + Real Bx,By, Cx, Cy; + //scale them in case they are too small + Bx = 10*(B[0] - A[0]); + By = 10*(B[1] - A[1]); + Cx = 10*(C[0] - A[0]); + Cy = 10*(C[1] - A[1]); + + if(Bx*Cy - Cx*By < -CONCAVITY_ZERO) return 1; + else return 0; +} + + +/*return + *0: not-cusp + *1: interior cusp + *2: exterior cusp + */ +Int cuspTypeX(directedLine *v) +{ + if(! isCuspX(v)) return 0; + else + { +//printf("isCusp,%f,%f\n", v->head()[0], v->head()[1]); + if(isReflexX(v)) + { +// printf("isReflex\n"); + return 1; + } + else + { +// printf("not isReflex\n"); + return 2; + } + } +} + +Int numInteriorCuspsX(directedLine *polygon) +{ + directedLine *temp; + int ret = 0; + if(cuspTypeX(polygon) == 1) + ret++; + for(temp = polygon->getNext(); temp != polygon; temp = temp->getNext()) + if(cuspTypeX(temp) == 1) + ret++; + return ret; +} + + +void findInteriorCuspsX(directedLine *polygon, Int& ret_n_interior_cusps, + directedLine** ret_interior_cusps) +{ + directedLine *temp; + ret_n_interior_cusps = 0; + if(cuspTypeX(polygon) == 1) + { + ret_interior_cusps[ret_n_interior_cusps++] = polygon; + } + for(temp = polygon->getNext(); temp != polygon; temp = temp->getNext()) + if(cuspTypeX(temp) == 1) + { + ret_interior_cusps[ret_n_interior_cusps++] = temp; + } +} + +directedLine* findDiagonal_singleCuspX(directedLine* cusp) +{ + directedLine* temp; + Int is_minimal = ((compV2InX(cusp->head(), cusp->tail()) == -1)? 1:0); + + if(is_minimal) + for(temp = cusp->getNext(); temp != cusp; temp = temp->getNext()) + { + if(compV2InX(cusp->head(), temp->head()) == 1) + { + return temp; + } + } + else //is maxmal + for(temp = cusp->getNext(); temp != cusp; temp = temp->getNext()) + { + if(compV2InX(cusp->head(), temp->head()) == -1) + { + return temp; + } + } + return NULL; +} + + + |