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author | lecoanet | 2005-04-12 08:59:00 +0000 |
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committer | lecoanet | 2005-04-12 08:59:00 +0000 |
commit | b6fc435173b9a8680fd73011e08c92e456579bb6 (patch) | |
tree | 6dd2740ca0e232114b237de2d4f4a1dce06d507f /libtess/normal.c | |
parent | 11fc80de7f4f1a85588a76659bfd157f3b4f3973 (diff) | |
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Diffstat (limited to 'libtess/normal.c')
-rw-r--r-- | libtess/normal.c | 259 |
1 files changed, 0 insertions, 259 deletions
diff --git a/libtess/normal.c b/libtess/normal.c deleted file mode 100644 index feae622..0000000 --- a/libtess/normal.c +++ /dev/null @@ -1,259 +0,0 @@ -/* -** 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. -** -*/ -/* -** Author: Eric Veach, July 1994. -** -** $Date$ $Revision$ -** $Header$ -*/ - -#include "gluos.h" -#include "mesh.h" -#include "tess.h" -#include "normal.h" -#include <math.h> -#include <assert.h> - -#define TRUE 1 -#define FALSE 0 - -#define Dot(u,v) (u[0]*v[0] + u[1]*v[1] + u[2]*v[2]) - -#if 0 -static void Normalize( GLdouble v[3] ) -{ - GLdouble len = v[0]*v[0] + v[1]*v[1] + v[2]*v[2]; - - assert( len > 0 ); - len = sqrt( len ); - v[0] /= len; - v[1] /= len; - v[2] /= len; -} -#endif - -#define ABS(x) ((x) < 0 ? -(x) : (x)) - -static int LongAxis( GLdouble v[3] ) -{ - int i = 0; - - if( ABS(v[1]) > ABS(v[0]) ) { i = 1; } - if( ABS(v[2]) > ABS(v[i]) ) { i = 2; } - return i; -} - -static void ComputeNormal( GLUtesselator *tess, GLdouble norm[3] ) -{ - GLUvertex *v, *v1, *v2; - GLdouble c, tLen2, maxLen2; - GLdouble maxVal[3], minVal[3], d1[3], d2[3], tNorm[3]; - GLUvertex *maxVert[3], *minVert[3]; - GLUvertex *vHead = &tess->mesh->vHead; - int i; - - maxVal[0] = maxVal[1] = maxVal[2] = -2 * GLU_TESS_MAX_COORD; - minVal[0] = minVal[1] = minVal[2] = 2 * GLU_TESS_MAX_COORD; - - for( v = vHead->next; v != vHead; v = v->next ) { - for( i = 0; i < 3; ++i ) { - c = v->coords[i]; - if( c < minVal[i] ) { minVal[i] = c; minVert[i] = v; } - if( c > maxVal[i] ) { maxVal[i] = c; maxVert[i] = v; } - } - } - - /* Find two vertices separated by at least 1/sqrt(3) of the maximum - * distance between any two vertices - */ - i = 0; - if( maxVal[1] - minVal[1] > maxVal[0] - minVal[0] ) { i = 1; } - if( maxVal[2] - minVal[2] > maxVal[i] - minVal[i] ) { i = 2; } - if( minVal[i] >= maxVal[i] ) { - /* All vertices are the same -- normal doesn't matter */ - norm[0] = 0; norm[1] = 0; norm[2] = 1; - return; - } - - /* Look for a third vertex which forms the triangle with maximum area - * (Length of normal == twice the triangle area) - */ - maxLen2 = 0; - v1 = minVert[i]; - v2 = maxVert[i]; - d1[0] = v1->coords[0] - v2->coords[0]; - d1[1] = v1->coords[1] - v2->coords[1]; - d1[2] = v1->coords[2] - v2->coords[2]; - for( v = vHead->next; v != vHead; v = v->next ) { - d2[0] = v->coords[0] - v2->coords[0]; - d2[1] = v->coords[1] - v2->coords[1]; - d2[2] = v->coords[2] - v2->coords[2]; - tNorm[0] = d1[1]*d2[2] - d1[2]*d2[1]; - tNorm[1] = d1[2]*d2[0] - d1[0]*d2[2]; - tNorm[2] = d1[0]*d2[1] - d1[1]*d2[0]; - tLen2 = tNorm[0]*tNorm[0] + tNorm[1]*tNorm[1] + tNorm[2]*tNorm[2]; - if( tLen2 > maxLen2 ) { - maxLen2 = tLen2; - norm[0] = tNorm[0]; - norm[1] = tNorm[1]; - norm[2] = tNorm[2]; - } - } - - if( maxLen2 <= 0 ) { - /* All points lie on a single line -- any decent normal will do */ - norm[0] = norm[1] = norm[2] = 0; - norm[LongAxis(d1)] = 1; - } -} - - -static void CheckOrientation( GLUtesselator *tess ) -{ - GLdouble area; - GLUface *f, *fHead = &tess->mesh->fHead; - GLUvertex *v, *vHead = &tess->mesh->vHead; - GLUhalfEdge *e; - - /* When we compute the normal automatically, we choose the orientation - * so that the the sum of the signed areas of all contours is non-negative. - */ - area = 0; - for( f = fHead->next; f != fHead; f = f->next ) { - e = f->anEdge; - if( e->winding <= 0 ) continue; - do { - area += (e->Org->s - e->Dst->s) * (e->Org->t + e->Dst->t); - e = e->Lnext; - } while( e != f->anEdge ); - } - if( area < 0 ) { - /* Reverse the orientation by flipping all the t-coordinates */ - for( v = vHead->next; v != vHead; v = v->next ) { - v->t = - v->t; - } - tess->tUnit[0] = - tess->tUnit[0]; - tess->tUnit[1] = - tess->tUnit[1]; - tess->tUnit[2] = - tess->tUnit[2]; - } -} - -#ifdef FOR_TRITE_TEST_PROGRAM -#include <stdlib.h> -extern int RandomSweep; -#define S_UNIT_X (RandomSweep ? (2*drand48()-1) : 1.0) -#define S_UNIT_Y (RandomSweep ? (2*drand48()-1) : 0.0) -#else -#if defined(SLANTED_SWEEP) -/* The "feature merging" is not intended to be complete. There are - * special cases where edges are nearly parallel to the sweep line - * which are not implemented. The algorithm should still behave - * robustly (ie. produce a reasonable tesselation) in the presence - * of such edges, however it may miss features which could have been - * merged. We could minimize this effect by choosing the sweep line - * direction to be something unusual (ie. not parallel to one of the - * coordinate axes). - */ -#define S_UNIT_X 0.50941539564955385 /* Pre-normalized */ -#define S_UNIT_Y 0.86052074622010633 -#else -#define S_UNIT_X 1.0 -#define S_UNIT_Y 0.0 -#endif -#endif - -/* Determine the polygon normal and project vertices onto the plane - * of the polygon. - */ -void __gl_projectPolygon( GLUtesselator *tess ) -{ - GLUvertex *v, *vHead = &tess->mesh->vHead; - GLdouble norm[3]; - GLdouble *sUnit, *tUnit; - int i, computedNormal = FALSE; - - norm[0] = tess->normal[0]; - norm[1] = tess->normal[1]; - norm[2] = tess->normal[2]; - if( norm[0] == 0 && norm[1] == 0 && norm[2] == 0 ) { - ComputeNormal( tess, norm ); - computedNormal = TRUE; - } - sUnit = tess->sUnit; - tUnit = tess->tUnit; - i = LongAxis( norm ); - -#if defined(FOR_TRITE_TEST_PROGRAM) || defined(TRUE_PROJECT) - /* Choose the initial sUnit vector to be approximately perpendicular - * to the normal. - */ - Normalize( norm ); - - sUnit[i] = 0; - sUnit[(i+1)%3] = S_UNIT_X; - sUnit[(i+2)%3] = S_UNIT_Y; - - /* Now make it exactly perpendicular */ - w = Dot( sUnit, norm ); - sUnit[0] -= w * norm[0]; - sUnit[1] -= w * norm[1]; - sUnit[2] -= w * norm[2]; - Normalize( sUnit ); - - /* Choose tUnit so that (sUnit,tUnit,norm) form a right-handed frame */ - tUnit[0] = norm[1]*sUnit[2] - norm[2]*sUnit[1]; - tUnit[1] = norm[2]*sUnit[0] - norm[0]*sUnit[2]; - tUnit[2] = norm[0]*sUnit[1] - norm[1]*sUnit[0]; - Normalize( tUnit ); -#else - /* Project perpendicular to a coordinate axis -- better numerically */ - sUnit[i] = 0; - sUnit[(i+1)%3] = S_UNIT_X; - sUnit[(i+2)%3] = S_UNIT_Y; - - tUnit[i] = 0; - tUnit[(i+1)%3] = (norm[i] > 0) ? -S_UNIT_Y : S_UNIT_Y; - tUnit[(i+2)%3] = (norm[i] > 0) ? S_UNIT_X : -S_UNIT_X; -#endif - - /* Project the vertices onto the sweep plane */ - for( v = vHead->next; v != vHead; v = v->next ) { - v->s = Dot( v->coords, sUnit ); - v->t = Dot( v->coords, tUnit ); - } - if( computedNormal ) { - CheckOrientation( tess ); - } -} |