+++ /dev/null
-/*
-** 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.
-**
-*/
-
-#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
-
-#undef ABS
-#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 );
- }
-}
projects / reactos.git / blobdiff