1 // Computer Graphics: HW3
2 // 3D Transformation:
3
4
5 #include <iostream>
6 #include <string>
7 #include <cstdlib>
8 #include <cmath>
9 #include <cstdio>
10 #include <vector>
11 #include <gl/glut.h>
12 #include <iomanip>
13 #include <fstream>
14
15 using namespace std;
16
17 const int dimension = 4;
18 const double PI = acos(-1);
19 const double eps = 0.0000001;
20
21 //定义向量
22 struct vec {
23 float x;
24 float y;
25 float z;
26 vec(float _x=0, float _y=0, float _z=0):x(_x), y(_y), z(_z){}
27 };
28
29 //向量的叉乘并化为单位向量
30 vec cross(vec a, vec b)
31 {
32 vec res;
33 res.x = a.y * b.z - b.y * a.z;
34 res.y = -(a.x * b.z - b.x * a.z);
35 res.z = a.x * b.y - b.x * a.y;
36 float l = sqrt(res.x*res.x+res.y*res.y+res.z*res.z);
37 res.x = res.x / l;
38 res.y = res.y / l;
39 res.z = res.z / l;
40 return res;
41 }
42
43 //定义多边形的点
44 struct poly_point {
45 float x;
46 float y;
47 float z;
48 float w;
49 poly_point(){ x=0; y=0; z=0; w=1;}
50 poly_point(float _x, float _y, float _z, float _w=1){ x=_x; y=_y; z=_z; w=_w;}
51 };
52
53 //定义矩阵用作变换操作
54 struct mat {
55 float m[4][4];
56 mat()
57 {
58 memset(m,0,sizeof(m));
59 m[0][0]=m[1][1]=m[2][2]=m[3][3]=1;
60 }
61 void reset_mat()
62 {
63 memset(m,0,sizeof(m));
64 m[0][0]=m[1][1]=m[2][2]=m[3][3]=1;
65 }
66 };
67
68 //新建各种变换矩阵，初始化为单位矩阵
69 mat T,S,R,Rx,Ry,Rz,Sh,TM, M,GRM,EM,Mirrorx, PM, WTVM;
70
71 //重载*号实现矩阵乘法
72 mat operator * (mat a, mat b)
73 {
74 mat c;
75 memset(c.m,0,sizeof(c.m)); //注意要先初始化为0
76 for(int i=0; i<dimension; i++)
77 for(int j=0; j<dimension; j++)
78 for(int k=0; k<dimension; k++)
79 c.m[i][j] += (a.m[i][k]*b.m[k][j]);
80 return c;
81 }
82
83 //定义矩阵乘以向量
84 poly_point mat_mul_vec(mat t, poly_point pp)
85 {
86 poly_point res;
87 res.x = t.m[0][0]*pp.x+t.m[0][1]*pp.y+t.m[0][2]*pp.z+t.m[0][3]*pp.w;
88 res.y = t.m[1][0]*pp.x+t.m[1][1]*pp.y+t.m[1][2]*pp.z+t.m[1][3]*pp.w;
89 res.z = t.m[2][0]*pp.x+t.m[2][1]*pp.y+t.m[2][2]*pp.z+t.m[2][3]*pp.w;
90 res.w = t.m[3][0]*pp.x+t.m[3][1]*pp.y+t.m[3][2]*pp.z+t.m[3][3]*pp.w;
91 return res;
92 }
93 //输出矩阵用作测试
94 void print_mat(mat M)
95 {
96 for(int i=0; i<dimension; i++)
97 {
98 for(int j=0; j<dimension; j++)
99 printf("%.2lf ", M.m[i][j]);
100 printf("\n");
101 }
102 printf("\n");
103 }
104
105 int num_tm=0; //记录输入object的个数
106 poly_point poly_vertex[10][2000], observe[10][2000]; //保存原来的输入的多边形的点，保存经历所有变换后的点用于输出
107 int poly_face[4000][4]; //保存多边形的面用于画线
108 string file_name; //读取asc文件的文件名
109 float VL,VR,VB,VT; //viewport的坐标
110 float Near, Far, FOV; //求PM投影矩阵用到的参数
111 int height, width, n; //n为多边形组成每个面的点的个数
112 int num_vertex, num_face; //记录输入的多边形的点的个数和面的个数
113 void displayFunc(void);
114 void ReadInput(bool& IsExit);
115
116 //hw3
117 void scale(float sx, float sy, float sz); //scale放缩变换
118 void rotate(float rx, float ry, float rz, int i=0); //rotate旋转变换
119 void translate(float tx, float ty, float tz); //translate平移变换
120 void reset();
121 //获得EM和PM矩阵
122 void observer(float PX, float PY, float PZ, float CX, float CY, float CZ, float Tilt, float Near, float Far, float FOV);
123 void view(float VL, float VR, float VB, float VT); //获得WTVM矩阵
124 void display(); //做observer和viewport变换并画点
125 void read_asc_file(); //读取asc文件
126 void transform(mat t); //输入一个矩阵，对poly_vertex里的每个点做一次变换
127 void projection(float AR, float Near, float Far, float FOV);//投影变换，即获得PM矩阵
128 void per_div(); //perspective divide
129 void transform_observe(mat t); //对observe中的每个点进行矩阵变换
130 void DrawWindow(); //画框框
131 void print_mat(mat t); //输出矩阵测试
132 void print(); //输出点测试
133
134 //hw1中已经实现的函数
135 void drawDot(int x, int y, float r, float g, float b);
136 void drawLine1(int x0, int x1, int y0, int y1, bool xy_interchange);
137 void drawLine2(int x0, int x1, int y0, int y1, bool xy_interchange);
138 void drawLine3(int x0, int x1, int y0, int y1, bool xy_interchange);
139 void drawLine4(int x0, int x1, int y0, int y1, bool xy_interchange);
140 void DrawLines_4(int x1, int y1, int x2, int y2);
141
142 void myKeyboard(unsigned char key, int x, int y)
143 {
144 cout << "KEYYYY" << endl;
145 switch(key) {
146 // Draw dots with 'd' or 'D'
147 case 'q':
148 case 'Q':
149 //glutMouseFunc(Mymouse);
150 exit(0);
151 break;
152 }
153 }
154 void ReadInput(bool& IsExit)
155 {
156 float sx,sy,sz, tx,ty,tz, rx,ry,rz;
157 float PX, PY, PZ, CX, CY, CZ, Tilt;
158 string command,comment;
159 cin>>command;
160 if (command=="scale")
161 {
162 cout<<command<<endl;
163 cin>>sx>>sy>>sz;
164 scale(sx,sy,sz);
165 }
166 else if (command=="rotate")
167 {
168 cout<<command<<endl;
169 cin>>rx>>ry>>rz;
170 rotate(rx,ry,rz,0);
171 }
172 else if (command=="translate")
173 {
174 cout<<command<<endl;
175 cin>>tx>>ty>>tz;
176 translate(tx,ty,tz);
177 }
178 else if (command=="reset")
179 {
180 cout<<command<<endl;
181 //reset();
182 }
183 else if (command=="observer")
184 {
185 cout<<command<<endl;
186 cin>>PX>>PY>>PZ>>CX>>CY>>CZ>>Tilt>>Near>>Far>>FOV;
187 observer(PX,PY,PZ,CX,CY,CZ,Tilt,Near,Far,FOV);
188 }
189 else if (command=="viewport")
190 {
191 cout<<command<<endl;
192 cin>>VL>>VR>>VB>>VT;
193 view(VL,VR,VB,VT);
194 }
195 else if (command=="end")
196 {
197 cout<<command<<endl;
198 IsExit=true;
199 //exit(0);
200 }
201 else if (command=="#")
202 {
203 getline(cin, comment);
204 }
205 else if (command=="display")
206 {
207 cout<<command<<endl;
208 display();
209 }
210 else if (command=="object")
211 {
212 cout<<command<<endl;
213 cin >> file_name;
214 read_asc_file();
215 }
216 }
217
218
219 // Display function
220 void displayFunc(void){
221
222 freopen("test.in", "r", stdin);
223 bool IsExit;
224 IsExit=false;
225 // clear the entire window to the background color
226 glClear(GL_COLOR_BUFFER_BIT);
227 while (!IsExit)
228 {
229 glClearColor(0.0, 0.0, 0.0, 0.0);
230 // redraw();
231 // draw the contents!!! Iterate your object's data structure!
232 // flush the queue to actually paint the dots on the opengl window
233 glFlush();
234 ReadInput(IsExit);
235 }
236 // infile.close();
237 //exit(0);
238 }
239
240
241 // Main
242 void main(int ac, char** av) {
243 //initial();
244
245 int winSizeX, winSizeY;
246 string name;
247
248 if(ac == 3) {
249 winSizeX = atoi(av[1]);
250 winSizeY = atoi(av[2]);
251 // cout<<"Done";
252 }
253 else { // default window size
254 winSizeX = 800;
255 winSizeY = 600;
256
257 }
258
259
260 // cout<<"Please input file name:"<<endl;
261 // cin>>name;
262 // infile.open(name.c_str());
263 // exit(0);
264 // infile.open("inp3.txt");
265 // infile.open(av[1]);
266 width = winSizeX;
267 height = winSizeY;
268
269 // initialize OpenGL utility toolkit (glut)
270 glutInit(&ac, av);
271
272 // single disply and RGB color mapping
273 glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); // set display mode
274 glutInitWindowSize(winSizeX, winSizeY); // set window size
275 glutInitWindowPosition(0, 0); // set window position on screen
276 glutCreateWindow("Lab2 Window"); // set window title
277
278 // set up the mouse and keyboard callback functions
279 // register the keyboard action function
280 glutKeyboardFunc(myKeyboard);
281 // displayFunc is called whenever there is a need to redisplay the window,
282 // e.g., when the window is exposed from under another window or when the window is de-iconified
283 glutDisplayFunc(displayFunc); // register the redraw function
284
285 // set background color
286 glClearColor(0.0, 0.0, 0.0, 0.0); // set the background to black
287 glClear(GL_COLOR_BUFFER_BIT); // clear the buffer
288
289 // misc setup
290 glMatrixMode(GL_PROJECTION); // setup coordinate system
291 glLoadIdentity();
292 gluOrtho2D(0, winSizeX, 0, winSizeY);
293 glShadeModel(GL_FLAT);
294 glFlush();
295 glutMainLoop();
296 }
297
298
299 void scale(float sx, float sy, float sz)
300 {
301 S.m[0][0]=sx; S.m[1][1]=sy; S.m[2][2]=sz;
302 TM=S*TM;
303 }
304 void rotate(float rx, float ry, float rz, int i)
305 {
306 if(i == 0)
307 {
308 rx = rx * PI / 180.0; ry = ry * PI / 180.0; rz = rz * PI / 180.0;
309 }
310 Rx.m[1][1]=cos(rx); Rx.m[2][2]=cos(rx); Rx.m[1][2]=-sin(rx); Rx.m[2][1]=sin(rx);
311 Ry.m[0][0]=cos(ry); Ry.m[2][2]=cos(ry); Ry.m[0][2]=sin(ry); Ry.m[2][0]=-sin(ry);
312 Rz.m[0][0]=cos(rz); Rz.m[1][1]=cos(rz); Rz.m[0][1]=-sin(rz); Rz.m[1][0]=sin(rz);
313 R = Rz*Ry*Rz;
314 TM=R*TM;
315 }
316 void translate(float tx, float ty, float tz)
317 {
318 T.m[0][3]=tx; T.m[1][3]=ty; T.m[2][3]=tz;
319 TM=T*TM;
320 }
321 void reset()
322 {
323 /*T.reset_mat(),S.reset_mat(),R.reset_mat(),Rx.reset_mat(),Ry.reset_mat(),Rz.reset_mat(),
324 Sh.reset_mat(),TM.reset_mat(), M.reset_mat(),GRM.reset_mat(),EM.reset_mat(),Mirrorx.reset_mat(),
325 PM.reset_mat(), WTVM.reset_mat();*/
326 for(int j=0; j<num_tm; j++)
327 {
328 for(int i=1; i<=num_vertex; i++)
329 {
330 observe[j][i].x = poly_vertex[j][i].x;
331 observe[j][i].y = poly_vertex[j][i].y;
332 observe[j][i].z = poly_vertex[j][i].z;
333 }
334 }
335
336 }
337 void observer(float PX, float PY, float PZ, float CX, float CY, float CZ, float Tilt, float Near, float Far, float FOV)
338 {
339 //GRM
340 translate(-PX,-PY,-PZ);
341 //print_mat(T);
342 float x = CX-PX;
343 float y = CY-PY;
344 float z = CZ-PZ;
345 //Tilt=Tilt*PI/180.0;
346 float l=sqrt(x*x+y*y+z*z);
347 vec v(x,y,z);
348 vec t(0,1,sin(Tilt*PI/180.0));
349 vec v3;
350 v3.x = v.x/l; v3.y = v.y/l; v3.z = v.z/l;
351 vec v1=cross(v,t);
352 vec v2=cross(v1,v3);
353 GRM.m[0][0]=v1.x; GRM.m[0][1]=v1.y; GRM.m[0][2]=v1.z;
354 GRM.m[1][0]=v2.x; GRM.m[1][1]=v2.y; GRM.m[1][2]=v2.z;
355 GRM.m[2][0]=v3.x; GRM.m[2][1]=v3.y; GRM.m[2][2]=v3.z;
356 //GRM.m[1][2]=-0.71;
357 //float ry = abs(asin(x/sqrt(x*x+y*y+z*z)));
358 /*float ry = abs(asin(x/sqrt(x*x+y*y+z*z)));
359 float rx = atan(y/sqrt(pow(x,2.0)+pow(z,2.0)));
360 float rz = Tilt*PI/180.0;
361
362 rotate(rx,ry,rz,1);
363 print_mat(Ry);
364 print_mat(Rx);
365 print_mat(Rz);
366 Mirrorx.m[0][0]=-1;
367 GRM = Mirrorx*Rz*Rx*Ry;*/
368 //GRM.m[1][1]=0.71;
369 //GRM.m[1][2]=-0.71;
370 //GRM.m[2][1]=-0.71;
371 //GRM.m[2][2]=-0.71;
372 //Mirrorx.m[0][0]=-1;
373 printf("GRM\n");
374 print_mat(GRM);
375 EM = Mirrorx*GRM*T;
376 //print_mat(EM);
377 transform_observe(EM);
378 //print();
379
380 //projection(1.33,Near,Far,FOV);
381 }
382 void view(float VL, float VR, float VB, float VT)
383 {
384 DrawWindow();
385 float WL=-1, WR=1, WB=-1, WT=1;
386 translate(-WL, -WB, 0);
387 WTVM = T * WTVM;
388 scale((VR-VL)/(WR-WL), (VT-VB)/(WT-WB), 1);
389 WTVM = S * WTVM;
390 translate(VL, VB, 0);
391 WTVM = T * WTVM;
392 printf("WTVM\n");
393 print_mat(WTVM);
394 //transform_observe(WTVM);
395
396 }
397 void display()
398 {
399 projection((VR-VL)/(VT-VB),Near,Far,FOV);
400 transform_observe(WTVM);
401 cout << "num_tm: " << num_tm << endl;
402 //cout << num_vertex << " " << num_face << endl;
403 //print();
404 for(int k=0; k<num_tm; k++)
405 {
406 for(int i=0; i<num_face; i++)
407 {
408 for(int j=0; j<n-1; j++)
409 DrawLines_4(observe[k][poly_face[i][j]].x, observe[k][poly_face[i][j]].y, observe[k][poly_face[i][j+1]].x, observe[k][poly_face[i][j+1]].y);
410 DrawLines_4(observe[k][poly_face[i][n-1]].x, observe[k][poly_face[i][n-1]].y, observe[k][poly_face[i][0]].x, observe[k][poly_face[i][0]].y);
411 }
412 }
413 reset();
414 EM.reset_mat();
415 PM.reset_mat();
416 WTVM.reset_mat();
417 }
418 void read_asc_file()
419 {
420 num_tm++;
421 cout << file_name << endl;
422 ifstream fin(file_name);
423 fin >> num_vertex >> num_face;
424 cout << num_vertex << " " << num_face << endl;
425 // read vertex one by one
426 for(int i=1; i<=num_vertex; i++)
427 {
428 fin >> poly_vertex[num_tm-1][i].x >> poly_vertex[num_tm-1][i].y >> poly_vertex[num_tm-1][i].z;
429 }
430 // read face one by one
431 for(int i=0; i<num_face; i++)
432 {
433 fin >> n;
434 for(int j=0; j<n; j++)
435 fin >> poly_face[i][j];
436 }
437
438 transform(TM);//
439 reset();
440 TM.reset_mat();
441
442 //print();
443 }
444
445 void transform(mat t)
446 {
447 for(int i=1; i<=num_vertex; i++)
448 poly_vertex[num_tm-1][i] = mat_mul_vec(t, poly_vertex[num_tm-1][i]);
449 }
450 void transform_observe(mat t)
451 {
452 for(int j=0; j<num_tm; j++)
453 {
454 for(int i=1; i<=num_vertex; i++)
455 observe[j][i] = mat_mul_vec(t, observe[j][i]);
456 }
457 }
458
459 void projection(float AR, float Near, float Far, float FOV)
460 {
461 //PM
462 FOV=FOV*PI/180.0;
463 float Y=Far*tan(FOV);
464 float H=Near*tan(FOV);
465 PM.m[1][1]=AR;
466 PM.m[2][2]=Y/(Y-H)*tan(FOV);
467 PM.m[2][3]=Y*H/(H-Y)*tan(FOV);
468 PM.m[3][2]=tan(FOV);
469 PM.m[3][3]=0;
470 /*PM.m[1][1]=AR;
471 PM.m[2][2]=0.58;
472 PM.m[3][2]=0.58;
473 PM.m[3][3]=0;*
474 PM.m[2][3]=-0.58;*/
475 print_mat(PM);
476 transform_observe(PM);
477
478 per_div(); //
479 }
480
481 void per_div()
482 {
483 for(int j=0; j<num_tm; j++)
484 {
485 for(int i=1; i<=num_vertex; i++)
486 {
487 observe[j][i].x /= observe[j][i].w;
488 observe[j][i].y /= observe[j][i].w;
489 observe[j][i].z /= observe[j][i].w;
490 observe[j][i].w /= observe[j][i].w;
491 }
492 }
493
494 }
495
496 void DrawWindow()
497 {
498 DrawLines_4(VL, VB, VR, VB);
499 DrawLines_4(VR, VB, VR, VT);
500 DrawLines_4(VR, VT, VL, VT);
501 DrawLines_4(VL, VT, VL, VB);
502 }
503
504 void print()
505 {
506 for(int j=0; j<num_tm; j++)
507 {
508 for(int i=1; i<=num_vertex; i++)
509 cout << poly_vertex[j][i].x << " " << poly_vertex[j][i].y << " " << poly_vertex[j][i].z << endl;
510 }
511 }
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547
548 //////////////////////////////////////////////////////////////////////////////////////hw1///////////////////////////////////////////////////////////
549 void DrawLines_4(int x1, int y1, int x2, int y2) //判断画哪一种线
550 {
551 if(x1 >= x2)
552 {
553 if(y1 >= y2)
554 {
555 swap(x1, x2);
556 swap(y1, y2);
557 if((y2-y1) >= (x2-x1))
558 drawLine2(x1, y1, x2, y2, 1);
559 else
560 drawLine1(x1, y1, x2, y2, 1);
561 }
562 else
563 {
564 if((y2-y1) >= (x1-x2))
565 drawLine3(x1, y1, x2, y2, 1);
566 else
567 drawLine4(x2, y2, x1, y1, 1);
568 }
569 }
570 else
571 {
572 if(y2 >= y1)
573 {
574 if((y2-y1) <= (x2-x1))
575 drawLine1(x1, y1, x2, y2, 1);
576 else
577 drawLine2(x1, y1, x2, y2, 1);
578 }
579 else
580 {
581 if((y1-y2) <= (x2-x1))
582 drawLine4(x1, y1, x2, y2, 1);
583 else
584 drawLine3(x2, y2, x1, y1, 1);
585 }
586 }
587
588 glFlush();
589 }
590
591 // draw a dot at location with integer coordinates (x,y), and with color (r,g,b)
592 void drawDot(int x, int y, float r, float g, float b)
593 {
594 glBegin(GL_POINTS);
595
596 // set the color of dot
597 glColor3f(r, g, b);
598
599 // invert height because the opengl origin is at top-left instead of bottom-left
600 glVertex2i(x , height-y);
601
602 glEnd();
603 }
604
605 // Draw line for dx>0 and dy>0
606 void drawLine1(int x1, int y1, int x2, int y2, bool xy_interchange) //0-45度
607 {
608 //cout << "Drawing Line1!" << endl;
609 int x = x1;
610 int y = y1;
611
612 int a = y2 - y1;
613 int b = x1 - x2;
614 int d = 2 * a + b;
615 int IncE = 2 * a;
616 int IncNE = 2 * (a + b);
617
618 while(x <= x2)
619 {
620 if(d <= 0)
621 {
622 x++;
623 d += IncE;
624 }
625 else
626 {
627 x++;
628 y++;
629 d += IncNE;
630 }
631 drawDot(x, height-y, 0.0, 0.0, 10.0);
632
633 }
634 }
635
636 // Draw line for dx>0 and dy<0
637 void drawLine2(int x1, int y1, int x2, int y2, bool xy_interchange) //45-90度
638 {
639 //cout << "Drawing Line2!" << endl;
640 //转换为0-45度的情况
641 swap(x2, y2);
642 swap(x1, y1);
643
644 int x = x1;
645 int y = y1;
646
647 int a = y2 - y1;
648 int b = x1 - x2;
649 int d = 2 * a + b;
650 int IncE = 2 * a;
651 int IncNE = 2 * (a + b);
652
653 while(x <= x2)
654 {
655 if(d <= 0)
656 {
657 x++;
658 d += IncE;
659 }
660 else
661 {
662 x++;
663 y++;
664 d += IncNE;
665 }
666 drawDot(y, height-x, 0.0, 0.0, 10.0);
667
668 }
669 }
670
671 // Draw line for dx<0 and dy>0
672 void drawLine3(int x1, int y1, int x2, int y2, bool xy_interchange) //90-135度
673 {
674 //cout << "Drawing Line3!" << endl;
675 swap(x2, y2);
676 swap(x1, y1);
677 y1 = -y1;
678 y2 = -y2;
679 int x = x1;
680 int y = y1;
681
682 int a = y2 - y1;
683 int b = x1 - x2;
684 int d = 2 * a + b;
685 int IncE = 2 * a;
686 int IncNE = 2 * (a + b);
687
688 while(x <= x2)
689 {
690 if(d <= 0)
691 {
692 x++;
693 d += IncE;
694 }
695 else
696 {
697 x++;
698 y++;
699 d += IncNE;
700 }
701 drawDot(-y, height-x, 0.0, 0.0, 10.0);
702
703 }
704 }
705
706 // Draw line for dx<0 and dy>0
707 void drawLine4(int x1, int y1, int x2, int y2, bool xy_interchange) //135-180度
708 {
709 //cout << "Drawing Line4!" << endl;
710 y1 = -y1;
711 y2 = -y2;
712 int x = x1;
713 int y = y1;
714
715 int a = y2 - y1;
716 int b = x1 - x2;
717 int d = 2 * a + b;
718 int IncE = 2 * a;
719 int IncNE = 2 * (a + b);
720
721 while(x <= x2)
722 {
723 if(d <= 0)
724 {
725 x++;
726 d += IncE;
727 }
728 else
729 {
730 x++;
731 y++;
732 d += IncNE;
733 }
734 drawDot(x, height+y, 0.0, 0.0, 10.0);
735
736 }
737 }
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