opengl 正方体+模拟视角旋转

  1 // first_3D.cpp : 定义控制台应用程序的入口点。
  2 //
  3 
  4 #include "stdafx.h"
  5 #include <GL/glut.h>
  6 #include <math.h>
  7 
  8 // 将立方体的八个顶点保存到一个数组里面
  9 static const GLfloat vertex_list[8][3] = {
 10     -0.5f, -0.5f, -0.5f,
 11      0.5f, -0.5f, -0.5f,
 12     -0.5f,  0.5f, -0.5f,
 13      0.5f,  0.5f, -0.5f,
 14     -0.5f, -0.5f,  0.5f,
 15      0.5f, -0.5f,  0.5f,
 16     -0.5f,  0.5f,  0.5f,
 17      0.5f,  0.5f,  0.5f,
 18 };
 19 //变换后数组
 20 GLfloat vertex_list_new[8][3] = {
 21     -0.5f, -0.5f, -0.5f,
 22      0.5f, -0.5f, -0.5f,
 23     -0.5f,  0.5f, -0.5f,
 24      0.5f,  0.5f, -0.5f,
 25     -0.5f, -0.5f,  0.5f,
 26      0.5f, -0.5f,  0.5f,
 27     -0.5f,  0.5f,  0.5f,
 28      0.5f,  0.5f,  0.5f,
 29 };
 30 
 31 void work(float T[4][4])
 32 {
 33     GLfloat list_temp[8][3];
 34     for(int i=0;i<8;i++)
 35         for(int j=0;j<3;j++)
 36             list_temp[i][j] = vertex_list_new[i][j];
 37     for(int i=0;i<8;i++)
 38     {
 39         for(int j=0;j<4;j++)
 40         {
 41             float sum = 0;
 42             for(int k=0;k<4;k++)
 43             {
 44                 sum+=list_temp[i][k]*T[k][j];
 45             }
 46             vertex_list_new[i][j] = sum;
 47         }
 48     }
 49     return;
 50 }
 51 // 将要使用的顶点的序号保存到一个数组里面
 52 static const GLint index_list[][4] = {
 53     0, 2, 3, 1,
 54     0, 4, 6, 2,
 55     0, 1, 5, 4,
 56     4, 5, 7, 6,
 57     1, 3, 7, 5,
 58     2, 6, 7, 3,
 59 };
 60 
 61 void display()
 62 {
 63     glClear(GL_COLOR_BUFFER_BIT);
 64     glMatrixMode(GL_MODELVIEW); 
 65     glLoadIdentity(); 
 66     //gluLookAt(1.5,1.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0);//视点
 67 
 68     /* /坐标轴
 69     glLineWidth(1);
 70     glColor3f( 0.0, 0.0, 0.0);     // 黑色
 71     glBegin(GL_LINES);
 72     glVertex3f(-0xFFFFFFF,0,0);
 73     glVertex3f(0xFFFFFFF,0,0);
 74     glVertex3f(0,-0xFFFFFFF,0);
 75     glVertex3f(0,0xFFFFFFF,0);
 76     glVertex3f(0,0,-0xFFFFFFF);
 77     glVertex3f(0,0,0xFFFFFFF);
 78     glEnd();
 79     //坐标轴绘制结束*/
 80 
 81     /* /绘制原立方体
 82     glColor3f( 1.0, 1.0, 0.0);
 83     //glBegin(GL_QUADS);
 84     for(int i=0; i<6; ++i)         // 有六个面，循环六次
 85     {
 86         glBegin( GL_LINE_LOOP);
 87         for(int j=0; j<4; ++j)     // 每个面有四个顶点，循环四次
 88         {
 89             glVertex3fv(vertex_list[index_list[i][j]]);
 90         }
 91         glEnd();
 92     }
 93     //立方体绘制结束*/
 94     
 95     //绘制新立方体
 96     glColor3f( 1.0, 0.0, 0.0);
 97     //glBegin(GL_QUADS);
 98     for(int i=0; i<6; ++i)         // 有六个面，循环六次
 99     {
100         glBegin( GL_LINE_LOOP);
101         for(int j=0; j<4; ++j)     // 每个面有四个顶点，循环四次
102         {
103             glVertex3fv(vertex_list_new[index_list[i][j]]);
104         }
105         glEnd();
106     }
107     //立方体绘制结束
108     glFlush();
109     glutSwapBuffers();
110 }
111 
112 void reshape(int w,int h) 
113 { 
114     glViewport(0,0,w,h); 
115     glMatrixMode(GL_PROJECTION); 
116     glLoadIdentity(); 
117     glOrtho(-1.0,1.0,-1.0,1.0,-1.0,1.0); 
118 } 
119 
120 void init()
121 {
122     glClearColor( 255, 255, 255, 0.0);
123     glMatrixMode(GL_PROJECTION);
124     glLoadIdentity();
125     //glOrtho(-4.0,4.0,-4.0,4.0,-4.0,4.0);
126     glMatrixMode(GL_MODELVIEW);
127 }
128 
129 int main(int argc,char** argv)
130 {
131     //计算部分
132     float a,b,c;//Ov
133     a = 0;
134     b = 0;
135     c = 10;
136     float R = sqrt(a*a+b*b+c*c);
137     float d = 1.0;
138     float costh = c/sqrt(a*a+c*c);
139     float sinth = a/sqrt(a*a+c*c);
140     float cosfy = b/R;
141     float sinfy = sqrt(a*a+c*c)/R;
142 
143     
144     float T1[4][4] = {{1,0,0,0},{0,1,0,0},{0,0,1,0},{-a,-b,-c,1}};                    //原点到视点平移变换矩阵
145     float T2[4][4] = {{-costh,0,-sinth,0},{0,1,0,0},{sinth,0,-costh,0},{0,0,0,1}};    //绕y1轴旋转变换
146     float T3[4][4] = {{1,0,0,0},{0,sinfy,-cosfy,0},{0,cosfy,sinfy,0},{0,0,0,1}};      //绕x2轴旋转变换
147     float T4[4][4] = {{-1,0,0,0},{0,1,0,0},{0,0,1,0},{0,0,0,1}};                      //关于y3Ovz3面的反射变换
148     //work(T1);work(T2);work(T3);work(T4);
149     
150     //世界--观察坐标系 合成矩阵
151     float Tv[4][4] = {{cosfy,-cosfy*sinth,-sinfy*sinth,0},{0,sinfy,-cosfy,0},{-sinth,-cosfy*costh,-sinfy*costh,0},{0,0,R,1}};
152     //work(Tv);
153 
154     
155     float Tpersp[4][4] = {{1,0,0,0},{0,1,0,0},{0,0,1,1/d},{0,0,0,0}}; //透视矩阵
156     float Tproj[4][4] = {{-1,0,0,0},{0,1,0,0},{0,0,0,0},{0,0,0,1}};   //投影矩阵
157     //work(Tpersp);work(Tproj);
158     float Ts[4][4] = {{1,0,0,0},{0,1,0,0},{0,0,0,1/d},{0,0,0,0}};     //合成
159     //work(Ts);
160 
161     //总合成
162     float T[4][4] = {{costh,-costh*sinth,0,-sinfy*sinth/d},{0,sinfy,0,-cosfy/d},{-sinth,-cosfy*costh,0,-sinfy*costh/d},{0,0,0,R/d}};
163     work(T);
164 
165     float T_1[4][4] = {{1,0,0,0},{0,1,0,0},{0,0,0,-1/d},{0,0,0,R/d}};
166     //work(T_1);
167 
168 
169     glutInit(&argc,argv);
170     glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
171     glutInitWindowSize(500,500);
172     glutInitWindowPosition(100,100);
173     glutCreateWindow("立方体");
174     glutReshapeFunc(reshape); 
175     glutDisplayFunc(display);
176     init();
177     glutMainLoop();
178     return 0;
179 }