OpenGL: 雾化效果

#include #pragma comment(lib, "glut32.lib")

#define MODE_NONE 0 #define MODE_LINEAR 1 #define MODE_EXP 2 #define MODE_EXP2 3

GLint fogMode;

void Initialization(void) {  GLfloat position[] = {0.5f, 0.5f, 3.0f, 0.0f};  glEnable(GL_DEPTH_TEST);  glLightfv(GL_LIGHT0,GL_POSITION, position); //设置光源位置

 glEnable(GL_LIGHTING);  glEnable(GL_LIGHT0);  {   //为材质指定对光源的反射   GLfloat ambLight[3] = {0.17f, 0.11f, 0.11f};   glMaterialfv(GL_FRONT, GL_AMBIENT, ambLight);   GLfloat difLight[3] = {0.61f, 0.24f, 0.24f};   glMaterialfv(GL_FRONT, GL_DIFFUSE, difLight);   GLfloat speLight[3] = {0.73f, 0.63f, 0.63f};   glMaterialfv(GL_FRONT, GL_SPECULAR, speLight);   //设置反光系数   glMaterialf(GL_FRONT, GL_SHININESS, 100.0f);   }

 glEnable(GL_FOG);//启用雾功能

 GLfloat fogColor[4] = {0.5f, 0.5f, 0.5f, 1.0f};  fogMode = GL_LINEAR;                     glFogi(GL_FOG_MODE, fogMode);  glFogfv(GL_FOG_COLOR, fogColor);  glFogf(GL_FOG_DENSITY, 0.35f);  glHint(GL_FOG_HINT, GL_DONT_CARE);  glFogf(GL_FOG_START, 1.0f);  glFogf(GL_FOG_END, 5.0f);

 glClearColor(fogColor[0], fogColor[1], fogColor[2], fogColor[3]);//背景色 }

void DrawTeapot(GLfloat x, GLfloat y, GLfloat z) {  glPushMatrix();  {   glTranslatef(x, y, z);   glutSolidTeapot(0.8f);  }  glPopMatrix(); }

void OnDisplay(void) {  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

 DrawTeapot(-2.0f, -1.0f, -1.0f);  DrawTeapot(-1.0f, -0.5f, -2.0f);  DrawTeapot(0.0f, 0.0f, -3.0f);  DrawTeapot(1.0f, 0.5f, -4.0f);  DrawTeapot(2.0f, 1.0f, -5.0f);

 glFlush(); }

void OnReShape(int w,int h) {  glViewport(0, 0, (GLsizei)w, (GLsizei)h);

 glMatrixMode(GL_PROJECTION); //将当前矩阵指定为投影模式  glLoadIdentity();

 GLfloat aspect = GLfloat(h) / GLfloat(w);

 if(w <= h)  {   glOrtho(-2.5f, 2.5f, -2.5f * aspect, 2.5f * aspect, -10.0f, 10.0f);//三维正交投影  }  else  {   glOrtho(-2.5f / aspect, 2.5f / aspect, -2.5f, 2.5f, -10.0f, 10.0f);  }  glMatrixMode(GL_MODELVIEW);  glLoadIdentity(); }

void CreateMenu(void) {  glutAddMenuEntry("线性", MODE_LINEAR);  glutAddMenuEntry("指数", MODE_EXP);  glutAddMenuEntry("指数2", MODE_EXP2);  glutAddMenuEntry("无雾", MODE_NONE);

 glutAttachMenu(GLUT_RIGHT_BUTTON); }

void OnMenu(int value) {  switch (value)  {  case MODE_LINEAR:   fogMode = GL_LINEAR;   break;

 case MODE_EXP:   fogMode = GL_EXP;   break;

 case MODE_EXP2:   fogMode = GL_EXP2;  }

 glFogi(GL_FOG_MODE, fogMode);  if (value == MODE_NONE)  {   glDisable(GL_FOG);  }  else  {   glEnable(GL_FOG);  }  glutPostRedisplay(); } void main(int argc,char* argv[]) {  glutInit(&argc, argv);  glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);  glutInitWindowSize(600, 600);  glutCreateWindow("OpenGL雾化");

 glutReshapeFunc(OnReShape);  glutDisplayFunc(OnDisplay);  glutCreateMenu(OnMenu);

 CreateMenu();  Initialization();

 glutMainLoop(); }

运行效果如下: