// 范例P257.cpp : Defines the entry point for the console application.// #include "stdafx.h"#include <gl/glut.h> #define checkImageWidth 64#define checkImageHeight 64#define subImageWidth 16#define subImageHeight 16 static GLubyte subImage[subImageWidth][subImageHeight][4];static GLubyte checkImage[checkImageWidth][checkImageHeight][4]; static GLuint texName; static GLuint CoordX,CoordY; void makeCheckImage(void){ int i,j,k,c;  for(i=0;i<checkImageWidth;i++)  for(j=0;j<checkImageHeight;j++)  {   c=(((i&0x8)==0)^((j&0x8)==0))*255;   for(k=0;k<3;k++)    checkImage[i][j][k]=(GLubyte)c;   checkImage[i][j][3]=(GLubyte)255;  }  for(i=0;i<subImageWidth;i++)  for(j=0;j<subImageHeight;j++)  {   c=(((i&0x4)==0)^((j&0x4)==0))*255;   //for(k=0;k<3;k++)    subImage[i][j][0]=(GLubyte)c;    subImage[i][j][1]=(GLubyte)0;    subImage[i][j][2]=(GLubyte)0;   subImage[i][j][3]=255;  }} void display(){ glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); glColor3f(1.0,1.0,1.0);       //设置画笔白色  glEnable(GL_TEXTURE_2D); glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL); glBindTexture(GL_TEXTURE_2D,texName);  glBegin(GL_QUADS); glTexCoord2f(0.0,0.0);glVertex3f(-2.0,-1.0,0.0); glTexCoord2f(0.0,1.0);glVertex3f(-2.0,1.0,0.0); glTexCoord2f(1.0,1.0);glVertex3f(0.0,1.0,0.0); glTexCoord2f(1.0,0.0);glVertex3f(0.0,-1.0,0.0);  glTexCoord2f(0.0,0.0);glVertex3f(1.0,-1.0,0.0); glTexCoord2f(0.0,1.0);glVertex3f(1.0,1.0,0.0); glTexCoord2f(1.0,1.0);glVertex3f(2.41421,1.0,-1.41421); glTexCoord2f(1.0,0.0);glVertex3f(2.41421,-1.0,-1.41421); glEnd(); glFlush(); glDisable(GL_TEXTURE_2D);  glFlush();          //立即显示出来} void init(){ glClearColor(0.0,0.0,0.0,0.0);     //用黑色清除背景 glShadeModel(GL_FLAT); glEnable(GL_DEPTH_TEST); makeCheckImage(); glPixelStorei(GL_UNPACK_ALIGNMENT,1);  glGenTextures(1,&texName); glBindTexture(GL_TEXTURE_2D,texName);  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);  glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,checkImageWidth,checkImageHeight,0,GL_RGBA,  GL_UNSIGNED_BYTE,checkImage);} void reshape(int w,int h){ glViewport(0,0,(GLsizei)w,(GLsizei)h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(60.0,(GLfloat)w/(GLfloat)h,1.0,30.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0,0.0,-3.6);}   // s向后，w向前，a向左，d向右 void keyboard(unsigned char key,int x,int y){ switch(key){ case 'w': case 'W':  CoordY+=4;  break; case 's': case 'S':  CoordY-=4;  break; case 'A': case 'a':  CoordX-=4;  break; case 'd': case 'D':  CoordX+=4;  break; case 'r': case 'R':  glBindTexture(GL_TEXTURE_2D,texName);  glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,checkImageWidth,checkImageHeight,0,GL_RGBA,   GL_UNSIGNED_BYTE,checkImage);  glutPostRedisplay();  return; } glBindTexture(GL_TEXTURE_2D,texName); glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,checkImageWidth,checkImageHeight,0,GL_RGBA,   GL_UNSIGNED_BYTE,checkImage); glBindTexture(GL_TEXTURE_2D,texName); glTexSubImage2D(GL_TEXTURE_2D,0,CoordX,CoordY,subImageWidth,subImageHeight,GL_RGBA,  GL_UNSIGNED_BYTE,subImage); glutPostRedisplay();} int main(int argc,char ** argv){ glutInit(&argc,argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowSize(250,250);     //初始化窗口大小 glutInitWindowPosition(0,0);    //初始化窗口位置 glutCreateWindow("hello");      //创建标题为“hello”的窗口 init();           //调用初始化函数 glutDisplayFunc(display);      //注册回调函数 glutReshapeFunc(reshape); glutKeyboardFunc(keyboard); glutMainLoop();         //进入主循环处理事件 return 0;}

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