作业题目：
图形变换：实现一个图形绕任意直线旋转的程序。
要求：把一个三维图形绕任意一条直线旋转，需要有初始图形，和旋转后的图形，最好也可以实时控制旋转。
最少要做出绕z轴旋转。
原理：http://inside.mines.edu/~gmurray/ArbitraryAxisRotation/ArbitraryAxisRotation.html
或参见《计算机图形学》
1: #include "stdafx.h"
2: #include<gl/glut.h>
3: #include<windows.h>
4: #include<gl/GLU.h>
5: #include<gl/GL.h>
6: #include <math.h>
7: GLfloat rtri=45,posX=1,posY=1.0,posZ=1,scale=0.5;
8:
9: void keyboard(unsigned char key,int x,int y){
10: switch (key) {
11: case 'l':
12: rtri=rtri+5;
13: if(rtri>=360)
14: rtri=0.0;
15: glutPostRedisplay();
16: break;
17: case 'r':
18: rtri=rtri-5;
19: if(rtri<=0)
20: rtri=360;
21: glutPostRedisplay();
22: break;
23: case 's':
24: scale=scale+0.1;
25: if(scale>=1.0)
26: scale=0.0;
27: glutPostRedisplay();
28: break;
29: case 'S':
30: scale=scale-0.1;
31: if(scale<=0.0)
32: scale=1.0;
33: glutPostRedisplay();
34: break;
35: case 'x':
36: posX = posX+0.1;
37: if(posX>=1.0)
38: posX=0;
39: glutPostRedisplay();
40: break;
41: case 'X':
42: posX = posX-0.1;
43: if(posX<=0.0)
44: posY=1.0;
45: glutPostRedisplay();
46: break;
47: case 'y':
48: posY = posY+0.1;
49: if(posY>=1.0)
50: posY=0;
51: glutPostRedisplay();
52: break;
53: case 'Y':
54: posY = posY-0.1;
55: if(posY<=0.0)
56: posY=1;
57: glutPostRedisplay();
58: break;
59: case 'z':
60: posZ = posZ+0.1;
61: if(posZ>=1.0)
62: posZ=0;
63: glutPostRedisplay();
64: break;
65: case 'Z':
66: posZ = posZ-0.1;
67: if(posZ<=0.0)
68: posZ=1.0;
69: glutPostRedisplay();
70: break;
71: case 27:
72: exit(0);
73: break;
74: }
75: }
76: void rotate_Matrix(float r,float x,float y,float z){
77: float l=sqrt(x*x+z*z);
78: float v=sqrt(y*y+z*z);
79: float sin_r1=y/v;
80: float cos_r1=z/v;
81: float sin_r2=-x/l;
82: float cos_r2=z/l;
83: GLfloat revTranslateMatrix[]=
84: {
85: 1.0f,0.0f, 0.0f,posX,
86: 0.0f,1.0f, 0.0f,posY,
87: 0.0f,0.0f, 1.0f,posZ,
88: 0.0f,0.0f, 0.0f,1.0f
89: };
90: GLfloat translateMatrix[]=
91: {
92: 1.0f,0.0f, 0.0f,-posX,
93: 0.0f,1.0f, 0.0f,-posY,
94: 0.0f,0.0f, 1.0f,-posZ,
95: 0.0f,0.0f, 0.0f,1.0f
96: };
97:
98: GLfloat scaleMatrix[]=
99: {
100: scale, 0.0f, 0.0f,0.0f,
101: 0.0f,scale, 0.0f, 0.0f,
102: 0.0f, 0.0f, scale, 0.0f,
103: 0.0, 0.0f, 0.0f, 1.0f
104: };
105: GLfloat rotateXMatrix[]=
106: {
107: 1.0f,0.0f ,0.0f ,0.0f,
108: 0.0f,cos_r1,sin_r1,0.0f,
109: 0.0f,-sin_r1,cos_r1,0.0f,
110: 0.0f,0.0f ,0.0f ,1.0f
111: };
112: GLfloat revRotateXMatrix[]=
113: {
114: 1.0f,0.0f ,0.0f ,0.0f,
115: 0.0f,cos_r1,-sin_r1,0.0f,
116: 0.0f,sin_r1,cos_r1,0.0f,
117: 0.0f,0.0f ,0.0f ,1.0f
118: };
119: GLfloat rotateYMatrix[]=
120: {
121: cos_r2 ,0.0f,-sin_r2,0.0f,
122: 0.0f ,1.0f,0.0f ,0.0f,
123: sin_r2,0.0f,cos_r2,0.0f,
124: 0.0f ,0.0f,0.0f ,1.0f
125: };
126: GLfloat revRotateYMatrix[]=
127: {
128: cos_r2 ,0.0f,sin_r2,0.0f,
129: 0.0f ,1.0f,0.0f ,0.0f,
130: -sin_r2,0.0f,cos_r2,0.0f,
131: 0.0f ,0.0f,0.0f ,1.0f
132: };
133: GLfloat rotateZMatrix[]=
134: {
135: cos(r),-sin(r),0.0f,0.0f,
136: sin(r),cos(r) ,0.0f,0.0f,
137: 0.0f ,0.0f ,1.0f,0.0f,
138: 0.0f ,0.0f ,0.0f,1.0f
139: };
140: //glMultMatrixf(translateMatrix);
141: glMultMatrixf(rotateXMatrix);
142: glMultMatrixf(rotateYMatrix);
143: glMultMatrixf(rotateZMatrix);
144: glMultMatrixf(revRotateYMatrix);
145: glMultMatrixf(revRotateXMatrix);
146: //glMultMatrixf(revTranslateMatrix);
147: }
148: void drawModel(){
149: glLineWidth(1);
150: glColor3f(1,1,1);
151: //glutWireSphere(1,20,16);
152: glutWireTeapot(0.5);
153: glLineWidth(4);
154:
155: }
156: void drawAxis(float size){
157: //draw axis
158: glLineWidth(3);
159: glBegin(GL_LINES);
160: glColor3f(1.0,0,0);
161: glVertex3f(0,0,0);
162: glVertex3f(size,0,0);
163: glColor3f(0,1,0);
164: glVertex3f(0,0,0);
165: glVertex3f(0,size,0);
166: glColor3f(0,0,1);
167: glVertex3f(0,0,0);
168: glVertex3f(0,0,size);
169: glEnd();
170: glLineWidth(1);
171:
172: //draw arrows
173: glPointSize(5);
174: glBegin(GL_POINTS);
175: glColor3f(1,0,0);
176: glVertex3f(size,0,0);
177: glColor3f(0,1,0);
178: glVertex3f(0,size,0);
179: glColor3f(0,0,1);
180: glVertex3f(0,0,size);
181: glEnd();
182: glPointSize(1);
183: }
184:
185: void renderGL()
186: {
187: glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
188: glMatrixMode( GL_MODELVIEW );
189: glLoadIdentity();
190: glBegin(GL_LINES);
191: glColor3f(0.5,0.5,0.5);
192: glVertex3f(0,0,0);
193: glVertex3f(posX,posY,posZ);
194: printf("x:%f y:%f z:%f\n",posX,posY,posZ);
195: glEnd();
196: drawAxis(2.5);
197: rotate_Matrix(rtri,posX,posY,posZ);
198: drawModel();
199: glutSwapBuffers();
200: }
201:
202: int initGL(int argc,char **argv){
203: glutInit(&argc,argv);
204: glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH);
205: glutInitWindowSize(400,400);
206: int handle=glutCreateWindow("rotate my model");
207: glutDisplayFunc(renderGL);
208: glutKeyboardFunc(keyboard);
209: return handle;
210: }
211:
212: int _tmain(int argc, _TCHAR* argv[])
213: {
214: initGL(argc,(char**)argv);
215: glutMainLoop();
216: return 0;
217: }
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