summaryrefslogtreecommitdiffstats
path: root/progs/demos/morph3d.c
blob: eab520a9897c0b17aec832e14c602485bb2f8dc9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891

/*-
 * morph3d.c - Shows 3D morphing objects
 *
 * Converted to GLUT by brianp on 1/1/98
 *
 * This program was inspired on a WindowsNT(R)'s screen saver. It was written 
 * from scratch and it was not based on any other source code. 
 * 
 * Porting it to xlock (the final objective of this code since the moment I
 * decided to create it) was possible by comparing the original Mesa's gear
 * demo with it's ported version, so thanks for Danny Sung for his indirect
 * help (look at gear.c in xlock source tree). NOTE: At the moment this code
 * was sent to Brian Paul for package inclusion, the XLock Version was not
 * available. In fact, I'll wait it to appear on the next Mesa release (If you
 * are reading this, it means THIS release) to send it for xlock package 
 * inclusion). It will probably there be a GLUT version too.
 *
 * Thanks goes also to Brian Paul for making it possible and inexpensive
 * to use OpenGL at home.
 *
 * Since I'm not a native english speaker, my apologies for any gramatical
 * mistake.
 *
 * My e-mail addresses are
 *
 * vianna@cat.cbpf.br 
 *         and
 * marcelo@venus.rdc.puc-rio.br
 *
 * Marcelo F. Vianna (Feb-13-1997)
 */

/*
This document is VERY incomplete, but tries to describe the mathematics used
in the program. At this moment it just describes how the polyhedra are 
generated. On futhurer versions, this document will be probabbly improved.

Since I'm not a native english speaker, my apologies for any gramatical
mistake.

Marcelo Fernandes Vianna 
- Undergraduate in Computer Engeneering at Catholic Pontifical University
- of Rio de Janeiro (PUC-Rio) Brasil.
- e-mail: vianna@cat.cbpf.br or marcelo@venus.rdc.puc-rio.br
- Feb-13-1997

POLYHEDRA GENERATION

For the purpose of this program it's not sufficient to know the polyhedra
vertexes coordinates. Since the morphing algorithm applies a nonlinear 
transformation over the surfaces (faces) of the polyhedron, each face has
to be divided into smaller ones. The morphing algorithm needs to transform 
each vertex of these smaller faces individually. It's a very time consoming
task.

In order to reduce calculation overload, and since all the macro faces of
the polyhedron are transformed by the same way, the generation is made by 
creating only one face of the polyhedron, morphing it and then rotating it
around the polyhedron center. 

What we need to know is the face radius of the polyhedron (the radius of 
the inscribed sphere) and the angle between the center of two adjacent 
faces using the center of the sphere as the angle's vertex.

The face radius of the regular polyhedra are known values which I decided
to not waste my time calculating. Following is a table of face radius for
the regular polyhedra with edge length = 1:

    TETRAHEDRON  : 1/(2*sqrt(2))/sqrt(3)
    CUBE	 : 1/2
    OCTAHEDRON   : 1/sqrt(6)
    DODECAHEDRON : T^2 * sqrt((T+2)/5) / 2     -> where T=(sqrt(5)+1)/2
    ICOSAHEDRON  : (3*sqrt(3)+sqrt(15))/12

I've not found any reference about the mentioned angles, so I needed to
calculate them, not a trivial task until I figured out how :)
Curiously these angles are the same for the tetrahedron and octahedron.
A way to obtain this value is inscribing the tetrahedron inside the cube
by matching their vertexes. So you'll notice that the remaining unmatched
vertexes are in the same straight line starting in the cube/tetrahedron
center and crossing the center of each tetrahedron's face. At this point
it's easy to obtain the bigger angle of the isosceles triangle formed by
the center of the cube and two opposite vertexes on the same cube face.
The edges of this triangle have the following lenghts: sqrt(2) for the base
and sqrt(3)/2 for the other two other edges. So the angle we want is:
     +-----------------------------------------------------------+
     | 2*ARCSIN(sqrt(2)/sqrt(3)) = 109.47122063449069174 degrees |
     +-----------------------------------------------------------+
For the cube this angle is obvious, but just for formality it can be
easily obtained because we also know it's isosceles edge lenghts:
sqrt(2)/2 for the base and 1/2 for the other two edges. So the angle we 
want is:
     +-----------------------------------------------------------+
     | 2*ARCSIN((sqrt(2)/2)/1)   = 90.000000000000000000 degrees |
     +-----------------------------------------------------------+
For the octahedron we use the same idea used for the tetrahedron, but now
we inscribe the cube inside the octahedron so that all cubes's vertexes
matches excatly the center of each octahedron's face. It's now clear that
this angle is the same of the thetrahedron one:
     +-----------------------------------------------------------+
     | 2*ARCSIN(sqrt(2)/sqrt(3)) = 109.47122063449069174 degrees |
     +-----------------------------------------------------------+
For the dodecahedron it's a little bit harder because it's only relationship
with the cube is useless to us. So we need to solve the problem by another
way. The concept of Face radius also exists on 2D polygons with the name
Edge radius:
  Edge Radius For Pentagon (ERp)
  ERp = (1/2)/TAN(36 degrees) * VRp = 0.6881909602355867905
  (VRp is the pentagon's vertex radio).
  Face Radius For Dodecahedron
  FRd = T^2 * sqrt((T+2)/5) / 2 = 1.1135163644116068404
Why we need ERp? Well, ERp and FRd segments forms a 90 degrees angle, 
completing this triangle, the lesser angle is a half of the angle we are 
looking for, so this angle is:
     +-----------------------------------------------------------+
     | 2*ARCTAN(ERp/FRd)	 = 63.434948822922009981 degrees |
     +-----------------------------------------------------------+
For the icosahedron we can use the same method used for dodecahedron (well
the method used for dodecahedron may be used for all regular polyhedra)
  Edge Radius For Triangle (this one is well known: 1/3 of the triangle height)
  ERt = sin(60)/3 = sqrt(3)/6 = 0.2886751345948128655
  Face Radius For Icosahedron
  FRi= (3*sqrt(3)+sqrt(15))/12 = 0.7557613140761707538
So the angle is:
     +-----------------------------------------------------------+
     | 2*ARCTAN(ERt/FRi)	 = 41.810314895778596167 degrees |
     +-----------------------------------------------------------+

*/


#include <stdio.h>
#include <stdlib.h>
#ifndef _WIN32
#include <unistd.h>
#endif
#include <GL/glut.h>
#include <math.h>

#define Scale                      0.3

#define VectMul(X1,Y1,Z1,X2,Y2,Z2) (Y1)*(Z2)-(Z1)*(Y2),(Z1)*(X2)-(X1)*(Z2),(X1)*(Y2)-(Y1)*(X2)
#define sqr(A)                     ((A)*(A))

/* Increasing this values produces better image quality, the price is speed. */
/* Very low values produces erroneous/incorrect plotting */
#define tetradivisions             23
#define cubedivisions              20
#define octadivisions              21
#define dodecadivisions            10
#define icodivisions               15

#define tetraangle                 109.47122063449069174
#define cubeangle                  90.000000000000000000
#define octaangle                  109.47122063449069174
#define dodecaangle                63.434948822922009981
#define icoangle                   41.810314895778596167

#ifndef Pi
#define Pi                         3.1415926535897932385
#endif
#define SQRT2                      1.4142135623730951455
#define SQRT3                      1.7320508075688771932
#define SQRT5                      2.2360679774997898051
#define SQRT6                      2.4494897427831778813
#define SQRT15                     3.8729833462074170214
#define cossec36_2                 0.8506508083520399322
#define cos72                      0.3090169943749474241
#define sin72                      0.9510565162951535721
#define cos36                      0.8090169943749474241
#define sin36                      0.5877852522924731292

/*************************************************************************/

static int       mono=0;
static int       smooth=1;
static int       anim=1;
static GLint     WindH, WindW;
static GLfloat   step=0;
static GLfloat   seno;
static int       object;
static int       edgedivisions;
static void      (*draw_object)( void );
static float     Magnitude;
static float     *MaterialColor[20];

static float front_shininess[] =   {60.0};
static float front_specular[]  =   { 0.7, 0.7, 0.7, 1.0 };
static float ambient[]         =   { 0.0, 0.0, 0.0, 1.0 };
static float diffuse[]         =   { 1.0, 1.0, 1.0, 1.0 };
static float position0[]       =   { 1.0, 1.0, 1.0, 0.0 };
static float position1[]       =   {-1.0,-1.0, 1.0, 0.0 };
static float lmodel_ambient[]  =   { 0.5, 0.5, 0.5, 1.0 };
static float lmodel_twoside[]  =   {GL_TRUE};

static float MaterialRed[]     =   { 0.7, 0.0, 0.0, 1.0 };
static float MaterialGreen[]   =   { 0.1, 0.5, 0.2, 1.0 };
static float MaterialBlue[]    =   { 0.0, 0.0, 0.7, 1.0 };
static float MaterialCyan[]    =   { 0.2, 0.5, 0.7, 1.0 };
static float MaterialYellow[]  =   { 0.7, 0.7, 0.0, 1.0 };
static float MaterialMagenta[] =   { 0.6, 0.2, 0.5, 1.0 };
static float MaterialWhite[]   =   { 0.7, 0.7, 0.7, 1.0 };
static float MaterialGray[]    =   { 0.2, 0.2, 0.2, 1.0 };

#define TRIANGLE(Edge, Amp, Divisions, Z)                                                                        \
{                                                                                                                \
  GLfloat   Xf,Yf,Xa,Yb,Xf2,Yf2;                                                                                 \
  GLfloat   Factor,Factor1,Factor2;                                                                              \
  GLfloat   VertX,VertY,VertZ,NeiAX,NeiAY,NeiAZ,NeiBX,NeiBY,NeiBZ;                                               \
  GLfloat   Ax,Ay,Bx;                                                                                            \
  int       Ri,Ti;                                                                                               \
  GLfloat   Vr=(Edge)*SQRT3/3;                                                                                   \
  GLfloat   AmpVr2=(Amp)/sqr(Vr);                                                                                \
  GLfloat   Zf=(Edge)*(Z);                                                                                       \
                                                                                                                 \
  Ax=(Edge)*(+0.5/(Divisions)), Ay=(Edge)*(-SQRT3/(2*Divisions));                                                \
  Bx=(Edge)*(-0.5/(Divisions));                                                                                  \
                                                                                                                 \
  for (Ri=1; Ri<=(Divisions); Ri++) {                                                                            \
    glBegin(GL_TRIANGLE_STRIP);                                                                                  \
    for (Ti=0; Ti<Ri; Ti++) {                                                                                    \
      Xf=(float)(Ri-Ti)*Ax + (float)Ti*Bx;                                                                       \
      Yf=Vr+(float)(Ri-Ti)*Ay + (float)Ti*Ay;                                                                    \
      Xa=Xf+0.001; Yb=Yf+0.001;                                                                                  \
      Factor=1-(((Xf2=sqr(Xf))+(Yf2=sqr(Yf)))*AmpVr2);                                                           \
      Factor1=1-((sqr(Xa)+Yf2)*AmpVr2);                                                                          \
      Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                          \
      VertX=Factor*Xf;        VertY=Factor*Yf;        VertZ=Factor*Zf;                                           \
      NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Yf-VertY; NeiAZ=Factor1*Zf-VertZ;                                    \
      NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                    \
      glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                             \
      glVertex3f(VertX, VertY, VertZ);                                                                           \
                                                                                                                 \
      Xf=(float)(Ri-Ti-1)*Ax + (float)Ti*Bx;                                                                     \
      Yf=Vr+(float)(Ri-Ti-1)*Ay + (float)Ti*Ay;                                                                  \
      Xa=Xf+0.001; Yb=Yf+0.001;                                                                                  \
      Factor=1-(((Xf2=sqr(Xf))+(Yf2=sqr(Yf)))*AmpVr2);                                                           \
      Factor1=1-((sqr(Xa)+Yf2)*AmpVr2);                                                                          \
      Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                          \
      VertX=Factor*Xf;        VertY=Factor*Yf;        VertZ=Factor*Zf;                                           \
      NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Yf-VertY; NeiAZ=Factor1*Zf-VertZ;                                    \
      NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                    \
      glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                             \
      glVertex3f(VertX, VertY, VertZ);                                                                           \
                                                                                                                 \
    }                                                                                                            \
    Xf=(float)Ri*Bx;                                                                                             \
    Yf=Vr+(float)Ri*Ay;                                                                                          \
    Xa=Xf+0.001; Yb=Yf+0.001;                                                                                    \
    Factor=1-(((Xf2=sqr(Xf))+(Yf2=sqr(Yf)))*AmpVr2);                                                             \
    Factor1=1-((sqr(Xa)+Yf2)*AmpVr2);                                                                            \
    Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                            \
    VertX=Factor*Xf;        VertY=Factor*Yf;        VertZ=Factor*Zf;                                             \
    NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Yf-VertY; NeiAZ=Factor1*Zf-VertZ;                                      \
    NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                      \
    glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                               \
    glVertex3f(VertX, VertY, VertZ);                                                                             \
    glEnd();                                                                                                     \
  }                                                                                                              \
}

#define SQUARE(Edge, Amp, Divisions, Z)                                                                          \
{                                                                                                                \
  int       Xi,Yi;                                                                                               \
  GLfloat   Xf,Yf,Y,Xf2,Yf2,Y2,Xa,Yb;                                                                            \
  GLfloat   Factor,Factor1,Factor2;                                                                              \
  GLfloat   VertX,VertY,VertZ,NeiAX,NeiAY,NeiAZ,NeiBX,NeiBY,NeiBZ;                                               \
  GLfloat   Zf=(Edge)*(Z);                                                                                       \
  GLfloat   AmpVr2=(Amp)/sqr((Edge)*SQRT2/2);                                                                    \
                                                                                                                 \
  for (Yi=0; Yi<(Divisions); Yi++) {                                                                             \
    Yf=-((Edge)/2.0) + ((float)Yi)/(Divisions)*(Edge);                                                           \
    Yf2=sqr(Yf);                                                                                                 \
    Y=Yf+1.0/(Divisions)*(Edge);                                                                                 \
    Y2=sqr(Y);                                                                                                   \
    glBegin(GL_QUAD_STRIP);                                                                                      \
    for (Xi=0; Xi<=(Divisions); Xi++) {                                                                          \
      Xf=-((Edge)/2.0) + ((float)Xi)/(Divisions)*(Edge);                                                         \
      Xf2=sqr(Xf);                                                                                               \
                                                                                                                 \
      Xa=Xf+0.001; Yb=Y+0.001;                                                                                   \
      Factor=1-((Xf2+Y2)*AmpVr2);                                                                                \
      Factor1=1-((sqr(Xa)+Y2)*AmpVr2);                                                                           \
      Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                          \
      VertX=Factor*Xf;        VertY=Factor*Y;         VertZ=Factor*Zf;                                           \
      NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Y-VertY;  NeiAZ=Factor1*Zf-VertZ;                                    \
      NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                    \
      glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                             \
      glVertex3f(VertX, VertY, VertZ);                                                                           \
                                                                                                                 \
      Xa=Xf+0.001; Yb=Yf+0.001;                                                                                  \
      Factor=1-((Xf2+Yf2)*AmpVr2);                                                                               \
      Factor1=1-((sqr(Xa)+Yf2)*AmpVr2);                                                                          \
      Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                          \
      VertX=Factor*Xf;        VertY=Factor*Yf;        VertZ=Factor*Zf;                                           \
      NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Yf-VertY; NeiAZ=Factor1*Zf-VertZ;                                    \
      NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                    \
      glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                             \
      glVertex3f(VertX, VertY, VertZ);                                                                           \
    }                                                                                                            \
    glEnd();                                                                                                     \
  }                                                                                                              \
}

#define PENTAGON(Edge, Amp, Divisions, Z)                                                                        \
{                                                                                                                \
  int       Ri,Ti,Fi;                                                                                            \
  GLfloat   Xf,Yf,Xa,Yb,Xf2,Yf2;                                                                                 \
  GLfloat   x[6],y[6];                                                                                           \
  GLfloat   Factor,Factor1,Factor2;                                                                              \
  GLfloat   VertX,VertY,VertZ,NeiAX,NeiAY,NeiAZ,NeiBX,NeiBY,NeiBZ;                                               \
  GLfloat   Zf=(Edge)*(Z);                                                                                       \
  GLfloat   AmpVr2=(Amp)/sqr((Edge)*cossec36_2);                                                                 \
                                                                                                                 \
  for(Fi=0;Fi<6;Fi++) {                                                                                          \
    x[Fi]=-cos( Fi*2*Pi/5 + Pi/10 )/(Divisions)*cossec36_2*(Edge);                                                \
    y[Fi]=sin( Fi*2*Pi/5 + Pi/10 )/(Divisions)*cossec36_2*(Edge);                                                \
  }                                                                                                              \
                                                                                                                 \
  for (Ri=1; Ri<=(Divisions); Ri++) {                                                                            \
    for (Fi=0; Fi<5; Fi++) {                                                                                     \
      glBegin(GL_TRIANGLE_STRIP);                                                                                \
      for (Ti=0; Ti<Ri; Ti++) {                                                                                  \
        Xf=(float)(Ri-Ti)*x[Fi] + (float)Ti*x[Fi+1];                                                             \
        Yf=(float)(Ri-Ti)*y[Fi] + (float)Ti*y[Fi+1];                                                             \
        Xa=Xf+0.001; Yb=Yf+0.001;                                                                                \
	Factor=1-(((Xf2=sqr(Xf))+(Yf2=sqr(Yf)))*AmpVr2);                                                         \
	Factor1=1-((sqr(Xa)+Yf2)*AmpVr2);                                                                        \
	Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                        \
        VertX=Factor*Xf;        VertY=Factor*Yf;        VertZ=Factor*Zf;                                         \
        NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Yf-VertY; NeiAZ=Factor1*Zf-VertZ;                                  \
        NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                  \
        glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                           \
	glVertex3f(VertX, VertY, VertZ);                                                                         \
                                                                                                                 \
        Xf=(float)(Ri-Ti-1)*x[Fi] + (float)Ti*x[Fi+1];                                                           \
        Yf=(float)(Ri-Ti-1)*y[Fi] + (float)Ti*y[Fi+1];                                                           \
        Xa=Xf+0.001; Yb=Yf+0.001;                                                                                \
	Factor=1-(((Xf2=sqr(Xf))+(Yf2=sqr(Yf)))*AmpVr2);                                                         \
	Factor1=1-((sqr(Xa)+Yf2)*AmpVr2);                                                                        \
	Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                        \
        VertX=Factor*Xf;        VertY=Factor*Yf;        VertZ=Factor*Zf;                                         \
        NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Yf-VertY; NeiAZ=Factor1*Zf-VertZ;                                  \
        NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                  \
        glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                           \
	glVertex3f(VertX, VertY, VertZ);                                                                         \
                                                                                                                 \
      }                                                                                                          \
      Xf=(float)Ri*x[Fi+1];                                                                                      \
      Yf=(float)Ri*y[Fi+1];                                                                                      \
      Xa=Xf+0.001; Yb=Yf+0.001;                                                                                  \
      Factor=1-(((Xf2=sqr(Xf))+(Yf2=sqr(Yf)))*AmpVr2);                                                           \
      Factor1=1-((sqr(Xa)+Yf2)*AmpVr2);                                                                          \
      Factor2=1-((Xf2+sqr(Yb))*AmpVr2);                                                                          \
      VertX=Factor*Xf;        VertY=Factor*Yf;        VertZ=Factor*Zf;                                           \
      NeiAX=Factor1*Xa-VertX; NeiAY=Factor1*Yf-VertY; NeiAZ=Factor1*Zf-VertZ;                                    \
      NeiBX=Factor2*Xf-VertX; NeiBY=Factor2*Yb-VertY; NeiBZ=Factor2*Zf-VertZ;                                    \
      glNormal3f(VectMul(NeiAX, NeiAY, NeiAZ, NeiBX, NeiBY, NeiBZ));                                             \
      glVertex3f(VertX, VertY, VertZ);                                                                           \
      glEnd();                                                                                                   \
    }                                                                                                            \
  }                                                                                                              \
}

static void draw_tetra( void )
{
  GLuint list;

  list = glGenLists( 1 );
  glNewList( list, GL_COMPILE );
  TRIANGLE(2,seno,edgedivisions,0.5/SQRT6);
  glEndList();

  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[0]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-tetraangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[1]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+tetraangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[2]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+tetraangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[3]);
  glCallList(list);

  glDeleteLists(list,1);
}

static void draw_cube( void )
{
  GLuint list;

  list = glGenLists( 1 );
  glNewList( list, GL_COMPILE );
  SQUARE(2, seno, edgedivisions, 0.5)
  glEndList();

  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[0]);
  glCallList(list);
  glRotatef(cubeangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[1]);
  glCallList(list);
  glRotatef(cubeangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[2]);
  glCallList(list);
  glRotatef(cubeangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[3]);
  glCallList(list);
  glRotatef(cubeangle,0,1,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[4]);
  glCallList(list);
  glRotatef(2*cubeangle,0,1,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[5]);
  glCallList(list);

  glDeleteLists(list,1);
}

static void draw_octa( void )
{
  GLuint list;

  list = glGenLists( 1 );
  glNewList( list, GL_COMPILE );
  TRIANGLE(2,seno,edgedivisions,1/SQRT6);
  glEndList();

  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[0]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-180+octaangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[1]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-octaangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[2]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-octaangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[3]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[4]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-180+octaangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[5]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-octaangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[6]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-octaangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[7]);
  glCallList(list);

  glDeleteLists(list,1);
}

static void draw_dodeca( void )
{
  GLuint list;

#define TAU ((SQRT5+1)/2)

  list = glGenLists( 1 );
  glNewList( list, GL_COMPILE );
  PENTAGON(1,seno,edgedivisions,sqr(TAU) * sqrt((TAU+2)/5) / 2);
  glEndList();

  glPushMatrix();
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[0]);
  glCallList(list);
  glRotatef(180,0,0,1);
  glPushMatrix();
  glRotatef(-dodecaangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[1]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(-dodecaangle,cos72,sin72,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[2]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(-dodecaangle,cos72,-sin72,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[3]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(dodecaangle,cos36,-sin36,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[4]);
  glCallList(list);
  glPopMatrix();
  glRotatef(dodecaangle,cos36,sin36,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[5]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[6]);
  glCallList(list);
  glRotatef(180,0,0,1);
  glPushMatrix();
  glRotatef(-dodecaangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[7]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(-dodecaangle,cos72,sin72,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[8]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(-dodecaangle,cos72,-sin72,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[9]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(dodecaangle,cos36,-sin36,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[10]);
  glCallList(list);
  glPopMatrix();
  glRotatef(dodecaangle,cos36,sin36,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[11]);
  glCallList(list);

  glDeleteLists(list,1);
}

static void draw_ico( void )
{
  GLuint list;

  list = glGenLists( 1 );
  glNewList( list, GL_COMPILE );
  TRIANGLE(1.5,seno,edgedivisions,(3*SQRT3+SQRT15)/12);
  glEndList();

  glPushMatrix();

  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[0]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-icoangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[1]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[2]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[3]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[4]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[5]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-icoangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[6]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[7]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[8]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-icoangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[9]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[10]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-icoangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[11]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[12]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[13]);
  glCallList(list);
  glPopMatrix();
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[14]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[15]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-icoangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[16]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[17]);
  glCallList(list);
  glPushMatrix();
  glRotatef(180,0,1,0);
  glRotatef(-180+icoangle,0.5,-SQRT3/2,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[18]);
  glCallList(list);
  glPopMatrix();
  glRotatef(180,0,0,1);
  glRotatef(-icoangle,1,0,0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialColor[19]);
  glCallList(list);

  glDeleteLists(list,1);
}

static void draw ( void ) {
  glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

  glPushMatrix();

    glTranslatef( 0.0, 0.0, -10.0 );
    glScalef( Scale*WindH/WindW, Scale, Scale );
    glTranslatef(2.5*WindW/WindH*sin(step*1.11),2.5*cos(step*1.25*1.11),0);
    glRotatef(step*100,1,0,0);
    glRotatef(step*95,0,1,0);
    glRotatef(step*90,0,0,1);

  seno=(sin(step)+1.0/3.0)*(4.0/5.0)*Magnitude;

  draw_object();

  glPopMatrix();

  glFlush();

  glutSwapBuffers();

}

static void idle_( void )
{
  static double t0 = -1.;
  double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
  if (t0 < 0.0)
     t0 = t;
  dt = t - t0;
  t0 = t;

  step += dt;

   glutPostRedisplay();
}

static void reshape( int width, int height )
{
  glViewport(0, 0, WindW=(GLint)width, WindH=(GLint)height);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 15.0 );
  glMatrixMode(GL_MODELVIEW);
}

static void pinit(void);

static void key( unsigned char k, int x, int y )
{
  (void) x;
  (void) y;
  switch (k) {
    case '1': object=1; break;
    case '2': object=2; break;
    case '3': object=3; break;
    case '4': object=4; break;
    case '5': object=5; break;
    case ' ': mono^=1; break;
    case 's': smooth^=1; break;
    case 'a':
       anim^=1;
       if (anim)
          glutIdleFunc( idle_ );
       else
          glutIdleFunc(NULL);
       break;
    case 27:
       exit(0);
  }
  pinit();
  glutPostRedisplay();
}

static void pinit(void)
{
  switch(object) {
    case 1:
      draw_object=draw_tetra;
      MaterialColor[0]=MaterialRed;
      MaterialColor[1]=MaterialGreen;
      MaterialColor[2]=MaterialBlue;
      MaterialColor[3]=MaterialWhite;
      edgedivisions=tetradivisions;
      Magnitude=2.5;
      break;
    case 2:
      draw_object=draw_cube;
      MaterialColor[0]=MaterialRed;
      MaterialColor[1]=MaterialGreen;
      MaterialColor[2]=MaterialCyan;
      MaterialColor[3]=MaterialMagenta;
      MaterialColor[4]=MaterialYellow;
      MaterialColor[5]=MaterialBlue;
      edgedivisions=cubedivisions;
      Magnitude=2.0;
      break;
    case 3:
      draw_object=draw_octa;
      MaterialColor[0]=MaterialRed;
      MaterialColor[1]=MaterialGreen;
      MaterialColor[2]=MaterialBlue;
      MaterialColor[3]=MaterialWhite;
      MaterialColor[4]=MaterialCyan;
      MaterialColor[5]=MaterialMagenta;
      MaterialColor[6]=MaterialGray;
      MaterialColor[7]=MaterialYellow;
      edgedivisions=octadivisions;
      Magnitude=2.5;
      break;
    case 4:
      draw_object=draw_dodeca;
      MaterialColor[ 0]=MaterialRed;
      MaterialColor[ 1]=MaterialGreen;
      MaterialColor[ 2]=MaterialCyan;
      MaterialColor[ 3]=MaterialBlue;
      MaterialColor[ 4]=MaterialMagenta;
      MaterialColor[ 5]=MaterialYellow;
      MaterialColor[ 6]=MaterialGreen;
      MaterialColor[ 7]=MaterialCyan;
      MaterialColor[ 8]=MaterialRed;
      MaterialColor[ 9]=MaterialMagenta;
      MaterialColor[10]=MaterialBlue;
      MaterialColor[11]=MaterialYellow;
      edgedivisions=dodecadivisions;
      Magnitude=2.0;
      break;
    case 5:
      draw_object=draw_ico;
      MaterialColor[ 0]=MaterialRed;
      MaterialColor[ 1]=MaterialGreen;
      MaterialColor[ 2]=MaterialBlue;
      MaterialColor[ 3]=MaterialCyan;
      MaterialColor[ 4]=MaterialYellow;
      MaterialColor[ 5]=MaterialMagenta;
      MaterialColor[ 6]=MaterialRed;
      MaterialColor[ 7]=MaterialGreen;
      MaterialColor[ 8]=MaterialBlue;
      MaterialColor[ 9]=MaterialWhite;
      MaterialColor[10]=MaterialCyan;
      MaterialColor[11]=MaterialYellow;
      MaterialColor[12]=MaterialMagenta;
      MaterialColor[13]=MaterialRed;
      MaterialColor[14]=MaterialGreen;
      MaterialColor[15]=MaterialBlue;
      MaterialColor[16]=MaterialCyan;
      MaterialColor[17]=MaterialYellow;
      MaterialColor[18]=MaterialMagenta;
      MaterialColor[19]=MaterialGray;
      edgedivisions=icodivisions;
      Magnitude=2.5;
      break;
  }
  if (mono) {
    int loop;
    for (loop=0; loop<20; loop++) MaterialColor[loop]=MaterialGray;
  }
  if (smooth) {
    glShadeModel( GL_SMOOTH );
  } else {
    glShadeModel( GL_FLAT );
  }

}

int main(int argc, char **argv)
{
  printf("Morph 3D - Shows morphing platonic polyhedra\n");
  printf("Author: Marcelo Fernandes Vianna (vianna@cat.cbpf.br)\n\n");
  printf("  [1]    - Tetrahedron\n");
  printf("  [2]    - Hexahedron (Cube)\n");
  printf("  [3]    - Octahedron\n");
  printf("  [4]    - Dodecahedron\n");
  printf("  [5]    - Icosahedron\n");
  printf("[SPACE]  - Toggle colored faces\n");
  printf("[RETURN] - Toggle smooth/flat shading\n");
  printf(" [ESC]   - Quit\n");

  object=1;

  glutInit(&argc, argv);
  glutInitWindowPosition(0,0);
  glutInitWindowSize(640,480);

  glutInitDisplayMode( GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGB );

  if (glutCreateWindow("Morph 3D - Shows morphing platonic polyhedra") <= 0) {
     exit(0);
  }

  glClearDepth(1.0);
  glClearColor( 0.0, 0.0, 0.0, 1.0 );
  glColor3f( 1.0, 1.0, 1.0 );

  glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  glFlush();
  glutSwapBuffers();

  glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
  glLightfv(GL_LIGHT0, GL_POSITION, position0);
  glLightfv(GL_LIGHT1, GL_AMBIENT, ambient);
  glLightfv(GL_LIGHT1, GL_DIFFUSE, diffuse);
  glLightfv(GL_LIGHT1, GL_POSITION, position1);
  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
  glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, lmodel_twoside);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_NORMALIZE);

  glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, front_shininess);
  glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, front_specular);

  glHint(GL_FOG_HINT, GL_FASTEST);
  glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
  glHint(GL_POLYGON_SMOOTH_HINT, GL_FASTEST);

  pinit();

  glutReshapeFunc( reshape );
  glutKeyboardFunc( key );
  glutIdleFunc( idle_ );
  glutDisplayFunc( draw );
  glutMainLoop();

  return 0;
}