计算机图形学

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
",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:  }