opengl 正方体+模拟视角旋转

// first_3D.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <GL/glut.h>
#include <math.h>

// 将立方体的八个顶点保存到一个数组里面
static const GLfloat vertex_list[8][3] = {
    -0.5f, -0.5f, -0.5f,
     0.5f, -0.5f, -0.5f,
    -0.5f,  0.5f, -0.5f,
     0.5f,  0.5f, -0.5f,
    -0.5f, -0.5f,  0.5f,
     0.5f, -0.5f,  0.5f,
    -0.5f,  0.5f,  0.5f,
     0.5f,  0.5f,  0.5f,
};
//变换后数组
GLfloat vertex_list_new[8][3] = {
    -0.5f, -0.5f, -0.5f,
     0.5f, -0.5f, -0.5f,
    -0.5f,  0.5f, -0.5f,
     0.5f,  0.5f, -0.5f,
    -0.5f, -0.5f,  0.5f,
     0.5f, -0.5f,  0.5f,
    -0.5f,  0.5f,  0.5f,
     0.5f,  0.5f,  0.5f,
};

void work(float T[4][4])
{
    GLfloat list_temp[8][3];
    for(int i=0;i<8;i++)
        for(int j=0;j<3;j++)
            list_temp[i][j] = vertex_list_new[i][j];
    for(int i=0;i<8;i++)
    {
        for(int j=0;j<4;j++)
        {
            float sum = 0;
            for(int k=0;k<4;k++)
            {
                sum+=list_temp[i][k]*T[k][j];
            }
            vertex_list_new[i][j] = sum;
        }
    }
    return;
}
// 将要使用的顶点的序号保存到一个数组里面
static const GLint index_list[][4] = {
    0, 2, 3, 1,
    0, 4, 6, 2,
    0, 1, 5, 4,
    4, 5, 7, 6,
    1, 3, 7, 5,
    2, 6, 7, 3,
};

void display()
{
    glClear(GL_COLOR_BUFFER_BIT);
    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 
    //gluLookAt(1.5,1.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0);//视点

    /* /坐标轴
    glLineWidth(1);
    glColor3f( 0.0, 0.0, 0.0);     // 黑色
    glBegin(GL_LINES);
    glVertex3f(-0xFFFFFFF,0,0);
    glVertex3f(0xFFFFFFF,0,0);
    glVertex3f(0,-0xFFFFFFF,0);
    glVertex3f(0,0xFFFFFFF,0);
    glVertex3f(0,0,-0xFFFFFFF);
    glVertex3f(0,0,0xFFFFFFF);
    glEnd();
    //坐标轴绘制结束*/

    /* /绘制原立方体
    glColor3f( 1.0, 1.0, 0.0);
    //glBegin(GL_QUADS);
    for(int i=0; i<6; ++i)         // 有六个面，循环六次
    {
        glBegin( GL_LINE_LOOP);
        for(int j=0; j<4; ++j)     // 每个面有四个顶点，循环四次
        {
            glVertex3fv(vertex_list[index_list[i][j]]);
        }
        glEnd();
    }
    //立方体绘制结束*/
    
    //绘制新立方体
    glColor3f( 1.0, 0.0, 0.0);
    //glBegin(GL_QUADS);
    for(int i=0; i<6; ++i)         // 有六个面，循环六次
    {
        glBegin( GL_LINE_LOOP);
        for(int j=0; j<4; ++j)     // 每个面有四个顶点，循环四次
        {
            glVertex3fv(vertex_list_new[index_list[i][j]]);
        }
        glEnd();
    }
    //立方体绘制结束
    glFlush();
    glutSwapBuffers();
}

void reshape(int w,int h) 
{ 
    glViewport(0,0,w,h); 
    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    glOrtho(-1.0,1.0,-1.0,1.0,-1.0,1.0); 
} 

void init()
{
    glClearColor( 255, 255, 255, 0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    //glOrtho(-4.0,4.0,-4.0,4.0,-4.0,4.0);
    glMatrixMode(GL_MODELVIEW);
}

int main(int argc,char** argv)
{
    //计算部分
    float a,b,c;//Ov
    a = 0;
    b = 0;
    c = 10;
    float R = sqrt(a*a+b*b+c*c);
    float d = 1.0;
    float costh = c/sqrt(a*a+c*c);
    float sinth = a/sqrt(a*a+c*c);
    float cosfy = b/R;
    float sinfy = sqrt(a*a+c*c)/R;

    
    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
    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
    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
    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
    //work(T1);work(T2);work(T3);work(T4);
    
    //世界--观察坐标系 合成矩阵
    float Tv[4][4] = {{cosfy,-cosfy*sinth,-sinfy*sinth,0},{0,sinfy,-cosfy,0},{-sinth,-cosfy*costh,-sinfy*costh,0},{0,0,R,1}};
    //work(Tv);

    
    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
    float Tproj[4][4] = {{-1,0,0,0},{0,1,0,0},{0,0,0,0},{0,0,0,1}};   //投影矩阵
    //work(Tpersp);work(Tproj);
    float Ts[4][4] = {{1,0,0,0},{0,1,0,0},{0,0,0,1/d},{0,0,0,0}};     //合成
    //work(Ts);

    //总合成
    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}};
    work(T);

    float T_1[4][4] = {{1,0,0,0},{0,1,0,0},{0,0,0,-1/d},{0,0,0,R/d}};
    //work(T_1);


    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowSize(500,500);
    glutInitWindowPosition(100,100);
    glutCreateWindow("立方体");
    glutReshapeFunc(reshape); 
    glutDisplayFunc(display);
    init();
    glutMainLoop();
    return 0;
}