| Geant4 Cross Reference |
1 // see license file for original license. 1 // see license file for original license.
2 2
3 #ifndef tools_glutess_normal 3 #ifndef tools_glutess_normal
4 #define tools_glutess_normal 4 #define tools_glutess_normal
5 5
6 #include "_tess" 6 #include "_tess"
7 7
8 /* __gl_projectPolygon( tess ) determines the 8 /* __gl_projectPolygon( tess ) determines the polygon normal
9 * and project vertices onto the plane of the 9 * and project vertices onto the plane of the polygon.
10 */ 10 */
11 //void __gl_projectPolygon( GLUtesselator *tes 11 //void __gl_projectPolygon( GLUtesselator *tess );
12 12
13 ////////////////////////////////////////////// 13 ////////////////////////////////////////////////////////
14 /// inlined C code : ///////////////////////// 14 /// inlined C code : ///////////////////////////////////
15 ////////////////////////////////////////////// 15 ////////////////////////////////////////////////////////
16 #include <cmath> 16 #include <cmath>
17 17
18 #define Dot(u,v) (u[0]*v[0] + u[1]*v[1] + u[2 18 #define Dot(u,v) (u[0]*v[0] + u[1]*v[1] + u[2]*v[2])
19 19
20 inline/*static*/ int static_LongAxis( GLUdoubl 20 inline/*static*/ int static_LongAxis( GLUdouble v[3] )
21 { 21 {
22 int i = 0; 22 int i = 0;
23 23
24 if( GLU_ABS(v[1]) > GLU_ABS(v[0]) ) { i = 1; 24 if( GLU_ABS(v[1]) > GLU_ABS(v[0]) ) { i = 1; }
25 if( GLU_ABS(v[2]) > GLU_ABS(v[i]) ) { i = 2; 25 if( GLU_ABS(v[2]) > GLU_ABS(v[i]) ) { i = 2; }
26 return i; 26 return i;
27 } 27 }
28 28
29 inline/*static*/ void static_ComputeNormal( GL 29 inline/*static*/ void static_ComputeNormal( GLUtesselator *tess, GLUdouble norm[3] )
30 { 30 {
31 GLUvertex *v, *v1, *v2; 31 GLUvertex *v, *v1, *v2;
32 GLUdouble c, tLen2, maxLen2; 32 GLUdouble c, tLen2, maxLen2;
33 GLUdouble maxVal[3], minVal[3], d1[3], d2[3] 33 GLUdouble maxVal[3], minVal[3], d1[3], d2[3], tNorm[3];
34 GLUvertex *maxVert[3], *minVert[3]; 34 GLUvertex *maxVert[3], *minVert[3];
35 GLUvertex *vHead = &tess->mesh->vHead; 35 GLUvertex *vHead = &tess->mesh->vHead;
36 int i; 36 int i;
37 37
38 maxVal[0] = maxVal[1] = maxVal[2] = -2 * GLU 38 maxVal[0] = maxVal[1] = maxVal[2] = -2 * GLU_TESS_MAX_COORD;
39 minVal[0] = minVal[1] = minVal[2] = 2 * GLU_ 39 minVal[0] = minVal[1] = minVal[2] = 2 * GLU_TESS_MAX_COORD;
40 40
41 minVert[0] = 0;minVert[1] = 0;minVert[2] = 0 41 minVert[0] = 0;minVert[1] = 0;minVert[2] = 0; //G.Barrand : to quiet Coverity.
42 maxVert[0] = 0;maxVert[1] = 0;maxVert[2] = 0 42 maxVert[0] = 0;maxVert[1] = 0;maxVert[2] = 0; //G.Barrand : to quiet Coverity.
43 43
44 for( v = vHead->next; v != vHead; v = v->nex 44 for( v = vHead->next; v != vHead; v = v->next ) {
45 for( i = 0; i < 3; ++i ) { 45 for( i = 0; i < 3; ++i ) {
46 c = v->coords[i]; 46 c = v->coords[i];
47 if( c < minVal[i] ) { minVal[i] = c; min 47 if( c < minVal[i] ) { minVal[i] = c; minVert[i] = v; }
48 if( c > maxVal[i] ) { maxVal[i] = c; max 48 if( c > maxVal[i] ) { maxVal[i] = c; maxVert[i] = v; }
49 } 49 }
50 } 50 }
51 51
52 /* Find two vertices separated by at least 1 52 /* Find two vertices separated by at least 1/sqrt(3) of the maximum
53 * distance between any two vertices 53 * distance between any two vertices
54 */ 54 */
55 i = 0; 55 i = 0;
56 if( maxVal[1] - minVal[1] > maxVal[0] - minV 56 if( maxVal[1] - minVal[1] > maxVal[0] - minVal[0] ) { i = 1; }
57 if( maxVal[2] - minVal[2] > maxVal[i] - minV 57 if( maxVal[2] - minVal[2] > maxVal[i] - minVal[i] ) { i = 2; }
58 if( minVal[i] >= maxVal[i] ) { 58 if( minVal[i] >= maxVal[i] ) {
59 /* All vertices are the same -- normal doe 59 /* All vertices are the same -- normal doesn't matter */
60 norm[0] = 0; norm[1] = 0; norm[2] = 1; 60 norm[0] = 0; norm[1] = 0; norm[2] = 1;
61 return; 61 return;
62 } 62 }
63 63
64 /* Look for a third vertex which forms the t 64 /* Look for a third vertex which forms the triangle with maximum area
65 * (Length of normal == twice the triangle a 65 * (Length of normal == twice the triangle area)
66 */ 66 */
67 maxLen2 = 0; 67 maxLen2 = 0;
68 v1 = minVert[i]; 68 v1 = minVert[i];
69 v2 = maxVert[i]; 69 v2 = maxVert[i];
70 if( !v1 || !v2 ) {norm[0] = 0; norm[1] = 0; 70 if( !v1 || !v2 ) {norm[0] = 0; norm[1] = 0; norm[2] = 1;return;} //G.Barrand.
71 d1[0] = v1->coords[0] - v2->coords[0]; 71 d1[0] = v1->coords[0] - v2->coords[0];
72 d1[1] = v1->coords[1] - v2->coords[1]; 72 d1[1] = v1->coords[1] - v2->coords[1];
73 d1[2] = v1->coords[2] - v2->coords[2]; 73 d1[2] = v1->coords[2] - v2->coords[2];
74 for( v = vHead->next; v != vHead; v = v->nex 74 for( v = vHead->next; v != vHead; v = v->next ) {
75 d2[0] = v->coords[0] - v2->coords[0]; 75 d2[0] = v->coords[0] - v2->coords[0];
76 d2[1] = v->coords[1] - v2->coords[1]; 76 d2[1] = v->coords[1] - v2->coords[1];
77 d2[2] = v->coords[2] - v2->coords[2]; 77 d2[2] = v->coords[2] - v2->coords[2];
78 tNorm[0] = d1[1]*d2[2] - d1[2]*d2[1]; 78 tNorm[0] = d1[1]*d2[2] - d1[2]*d2[1];
79 tNorm[1] = d1[2]*d2[0] - d1[0]*d2[2]; 79 tNorm[1] = d1[2]*d2[0] - d1[0]*d2[2];
80 tNorm[2] = d1[0]*d2[1] - d1[1]*d2[0]; 80 tNorm[2] = d1[0]*d2[1] - d1[1]*d2[0];
81 tLen2 = tNorm[0]*tNorm[0] + tNorm[1]*tNorm 81 tLen2 = tNorm[0]*tNorm[0] + tNorm[1]*tNorm[1] + tNorm[2]*tNorm[2];
82 if( tLen2 > maxLen2 ) { 82 if( tLen2 > maxLen2 ) {
83 maxLen2 = tLen2; 83 maxLen2 = tLen2;
84 norm[0] = tNorm[0]; 84 norm[0] = tNorm[0];
85 norm[1] = tNorm[1]; 85 norm[1] = tNorm[1];
86 norm[2] = tNorm[2]; 86 norm[2] = tNorm[2];
87 } 87 }
88 } 88 }
89 89
90 if( maxLen2 <= 0 ) { 90 if( maxLen2 <= 0 ) {
91 /* All points lie on a single line -- any 91 /* All points lie on a single line -- any decent normal will do */
92 norm[0] = norm[1] = norm[2] = 0; 92 norm[0] = norm[1] = norm[2] = 0;
93 norm[static_LongAxis(d1)] = 1; 93 norm[static_LongAxis(d1)] = 1;
94 } 94 }
95 } 95 }
96 96
97 97
98 inline/*static*/ void static_CheckOrientation( 98 inline/*static*/ void static_CheckOrientation( GLUtesselator *tess )
99 { 99 {
100 GLUdouble area; 100 GLUdouble area;
101 GLUface *f, *fHead = &tess->mesh->fHead; 101 GLUface *f, *fHead = &tess->mesh->fHead;
102 GLUvertex *v, *vHead = &tess->mesh->vHead; 102 GLUvertex *v, *vHead = &tess->mesh->vHead;
103 GLUhalfEdge *e; 103 GLUhalfEdge *e;
104 104
105 /* When we compute the normal automatically, 105 /* When we compute the normal automatically, we choose the orientation
106 * so that the sum of the signed areas of al 106 * so that the sum of the signed areas of all contours is non-negative.
107 */ 107 */
108 area = 0; 108 area = 0;
109 for( f = fHead->next; f != fHead; f = f->nex 109 for( f = fHead->next; f != fHead; f = f->next ) {
110 e = f->anEdge; 110 e = f->anEdge;
111 if( e->winding <= 0 ) continue; 111 if( e->winding <= 0 ) continue;
112 do { 112 do {
113 area += (e->Org->s - e->Dst->s) * (e->Or 113 area += (e->Org->s - e->Dst->s) * (e->Org->t + e->Dst->t);
114 e = e->Lnext; 114 e = e->Lnext;
115 } while( e != f->anEdge ); 115 } while( e != f->anEdge );
116 } 116 }
117 if( area < 0 ) { 117 if( area < 0 ) {
118 /* Reverse the orientation by flipping all 118 /* Reverse the orientation by flipping all the t-coordinates */
119 for( v = vHead->next; v != vHead; v = v->n 119 for( v = vHead->next; v != vHead; v = v->next ) {
120 v->t = - v->t; 120 v->t = - v->t;
121 } 121 }
122 tess->tUnit[0] = - tess->tUnit[0]; 122 tess->tUnit[0] = - tess->tUnit[0];
123 tess->tUnit[1] = - tess->tUnit[1]; 123 tess->tUnit[1] = - tess->tUnit[1];
124 tess->tUnit[2] = - tess->tUnit[2]; 124 tess->tUnit[2] = - tess->tUnit[2];
125 } 125 }
126 } 126 }
127 127
128 #if defined(SLANTED_SWEEP) 128 #if defined(SLANTED_SWEEP)
129 /* The "feature merging" is not intended to be 129 /* The "feature merging" is not intended to be complete. There are
130 * special cases where edges are nearly parall 130 * special cases where edges are nearly parallel to the sweep line
131 * which are not implemented. The algorithm s 131 * which are not implemented. The algorithm should still behave
132 * robustly (ie. produce a reasonable tesselat 132 * robustly (ie. produce a reasonable tesselation) in the presence
133 * of such edges, however it may miss features 133 * of such edges, however it may miss features which could have been
134 * merged. We could minimize this effect by c 134 * merged. We could minimize this effect by choosing the sweep line
135 * direction to be something unusual (ie. not 135 * direction to be something unusual (ie. not parallel to one of the
136 * coordinate axes). 136 * coordinate axes).
137 */ 137 */
138 #define S_UNIT_X 0.50941539564955385 /* Pre-n 138 #define S_UNIT_X 0.50941539564955385 /* Pre-normalized */
139 #define S_UNIT_Y 0.86052074622010633 139 #define S_UNIT_Y 0.86052074622010633
140 #else 140 #else
141 #define S_UNIT_X 1.0 141 #define S_UNIT_X 1.0
142 #define S_UNIT_Y 0.0 142 #define S_UNIT_Y 0.0
143 #endif 143 #endif
144 144
145 /* Determine the polygon normal and project ve 145 /* Determine the polygon normal and project vertices onto the plane
146 * of the polygon. 146 * of the polygon.
147 */ 147 */
148 inline void __gl_projectPolygon( GLUtesselator 148 inline void __gl_projectPolygon( GLUtesselator *tess )
149 { 149 {
150 GLUvertex *v, *vHead = &tess->mesh->vHead; 150 GLUvertex *v, *vHead = &tess->mesh->vHead;
151 GLUdouble norm[3]; 151 GLUdouble norm[3];
152 GLUdouble *sUnit, *tUnit; 152 GLUdouble *sUnit, *tUnit;
153 int i, computedNormal = TOOLS_GLU_FALSE; 153 int i, computedNormal = TOOLS_GLU_FALSE;
154 154
155 norm[0] = tess->normal[0]; 155 norm[0] = tess->normal[0];
156 norm[1] = tess->normal[1]; 156 norm[1] = tess->normal[1];
157 norm[2] = tess->normal[2]; 157 norm[2] = tess->normal[2];
158 if( norm[0] == 0 && norm[1] == 0 && norm[2] 158 if( norm[0] == 0 && norm[1] == 0 && norm[2] == 0 ) {
159 static_ComputeNormal( tess, norm ); 159 static_ComputeNormal( tess, norm );
160 computedNormal = TOOLS_GLU_TRUE; 160 computedNormal = TOOLS_GLU_TRUE;
161 } 161 }
162 sUnit = tess->sUnit; 162 sUnit = tess->sUnit;
163 tUnit = tess->tUnit; 163 tUnit = tess->tUnit;
164 i = static_LongAxis( norm ); 164 i = static_LongAxis( norm );
165 165
166 #if defined(FOR_TRITE_TEST_PROGRAM) || defined 166 #if defined(FOR_TRITE_TEST_PROGRAM) || defined(TRUE_PROJECT)
167 /* Choose the initial sUnit vector to be app 167 /* Choose the initial sUnit vector to be approximately perpendicular
168 * to the normal. 168 * to the normal.
169 */ 169 */
170 Normalize( norm ); 170 Normalize( norm );
171 171
172 sUnit[i] = 0; 172 sUnit[i] = 0;
173 sUnit[(i+1)%3] = S_UNIT_X; 173 sUnit[(i+1)%3] = S_UNIT_X;
174 sUnit[(i+2)%3] = S_UNIT_Y; 174 sUnit[(i+2)%3] = S_UNIT_Y;
175 175
176 /* Now make it exactly perpendicular */ 176 /* Now make it exactly perpendicular */
177 w = Dot( sUnit, norm ); 177 w = Dot( sUnit, norm );
178 sUnit[0] -= w * norm[0]; 178 sUnit[0] -= w * norm[0];
179 sUnit[1] -= w * norm[1]; 179 sUnit[1] -= w * norm[1];
180 sUnit[2] -= w * norm[2]; 180 sUnit[2] -= w * norm[2];
181 Normalize( sUnit ); 181 Normalize( sUnit );
182 182
183 /* Choose tUnit so that (sUnit,tUnit,norm) f 183 /* Choose tUnit so that (sUnit,tUnit,norm) form a right-handed frame */
184 tUnit[0] = norm[1]*sUnit[2] - norm[2]*sUnit[ 184 tUnit[0] = norm[1]*sUnit[2] - norm[2]*sUnit[1];
185 tUnit[1] = norm[2]*sUnit[0] - norm[0]*sUnit[ 185 tUnit[1] = norm[2]*sUnit[0] - norm[0]*sUnit[2];
186 tUnit[2] = norm[0]*sUnit[1] - norm[1]*sUnit[ 186 tUnit[2] = norm[0]*sUnit[1] - norm[1]*sUnit[0];
187 Normalize( tUnit ); 187 Normalize( tUnit );
188 #else 188 #else
189 /* Project perpendicular to a coordinate axi 189 /* Project perpendicular to a coordinate axis -- better numerically */
190 sUnit[i] = 0; 190 sUnit[i] = 0;
191 sUnit[(i+1)%3] = S_UNIT_X; 191 sUnit[(i+1)%3] = S_UNIT_X;
192 sUnit[(i+2)%3] = S_UNIT_Y; 192 sUnit[(i+2)%3] = S_UNIT_Y;
193 193
194 tUnit[i] = 0; 194 tUnit[i] = 0;
195 tUnit[(i+1)%3] = (norm[i] > 0) ? -S_UNIT_Y : 195 tUnit[(i+1)%3] = (norm[i] > 0) ? -S_UNIT_Y : S_UNIT_Y;
196 tUnit[(i+2)%3] = (norm[i] > 0) ? S_UNIT_X : 196 tUnit[(i+2)%3] = (norm[i] > 0) ? S_UNIT_X : -S_UNIT_X;
197 #endif 197 #endif
198 198
199 /* Project the vertices onto the sweep plane 199 /* Project the vertices onto the sweep plane */
200 for( v = vHead->next; v != vHead; v = v->nex 200 for( v = vHead->next; v != vHead; v = v->next ) {
201 v->s = Dot( v->coords, sUnit ); 201 v->s = Dot( v->coords, sUnit );
202 v->t = Dot( v->coords, tUnit ); 202 v->t = Dot( v->coords, tUnit );
203 } 203 }
204 if( computedNormal ) { 204 if( computedNormal ) {
205 static_CheckOrientation( tess ); 205 static_CheckOrientation( tess );
206 } 206 }
207 } 207 }
208 208
209 #endif 209 #endif