OpenGL超级宝典学习笔记——镜面光与法线平均

GLfloat specref[] = {1.0f, 1.0f, 1.0f, 1.0f};

....//Enable color tracking

glEnable(GL_COLOR_MATERIAL);

//set material properties to follow

glColorglColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);

//使后面的材料具有完全的镜面反射效果以及强光泽

glMaterialfv(GL_FRONT, GL_SPECULAR, specref);

glMateriali(GL_FRONT, GL_SHININESS, 128);

//光源位置 GLfloat lightPos[] = {0.0f, 0.0f, 70.0f, 1.0f};
..
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);

#include "gltools.h"
GLfloat ambientLight[] = {0.5f, 0.5f, 0.5f, 1.0f};
GLfloat specular[] = {1.0f, 1.0f, 1.0f, 1.0f};
GLfloat specref[] = {1.0f, 1.0f, 1.0f, 1.0f};
//光源位置 
GLfloat lightPos[] = {0.0f, 0.0f, 70.0f, 1.0f}; 
//聚光灯光照方向朝z轴负方向
GLfloat spotDir[] = {0.0f, 0.0f, -1.0f}; 
//用于旋转 
static GLfloat xRot = 0.0f; 
static GLfloat yRot = 0.0f; 
#define FLAT_MODE 1 
#define SMOOTH_MODE 2 
#define LOW_LEVEL 3 
#define MEDIUM_LEVEL 4 
#define HIGH_LEVEL 5 
int iShade = FLAT_MODE; 
int iLevel = LOW_LEVEL; 
void SetupRC()
{
  glClearColor(0.0f, 0.0f, 0.0f, 1.0f); 
  //开启深度测试 
  glEnable(GL_DEPTH_TEST); 
  //剔除掉不必要的背面 
  glFrontFace(GL_CCW);
  glEnable(GL_CULL_FACE);
  glCullFace(GL_BACK); 
  //开启光照 
  glEnable(GL_LIGHTING); 
  //设置light0光照参数 
  glLightfv(GL_LIGHT0, GL_AMBIENT_AND_DIFFUSE, ambientLight);
  glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
  //设置光源位置和方向 
  glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
  glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, spotDir);
  glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, 80.0f); 
  //设置全局环境光 
  glLightModelfv(GL_AMBIENT, ambientLight); 
  //开启light0 
  glEnable(GL_LIGHT0); 
  //开启和设置颜色追踪 
  glEnable(GL_COLOR_MATERIAL); 
  //设置多边形正面的材料的环境光和漫反射光属性为颜色追踪 
  glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE); 
  //设置镜面光的反射属性 
  glMaterialfv(GL_FRONT, GL_SPECULAR, specref);
  glMateriali(GL_FRONT, GL_SHININESS, 128);

  glEnable(GL_NORMALIZE);
} 

void RenderScene()
{ if (iShade == FLAT_MODE)
  {
    glShadeModel(GL_FLAT);
  } else {
    glShadeModel(GL_SMOOTH);
  }
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
  //矩阵压栈 
  glPushMatrix();

    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
    glRotatef(yRot, 0.0f, 1.0f, 0.0f); 
   //旋转后重新设置光源位置
   glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
    glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, spotDir);

    glTranslatef(lightPos[0], lightPos[1], lightPos[2]);
    glColor3ub(255, 0, 0);
    glutSolidCone(4.0, 6.0, 15, 15);

    glPushAttrib(GL_LIGHTING_BIT); 
   //关闭光照画小黄球 
      glDisable(GL_LIGHTING);
      glColor3ub(255, 255, 0);
      glutSolidSphere(3.0, 15, 15);
    glPopAttrib(); 
	//矩阵出栈
	glPopMatrix();
  glColor3ub(0, 0, 255); 
  if (iLevel == LOW_LEVEL)
  {
    glutSolidSphere(30.0f, 8, 8);
  } else if (iLevel == MEDIUM_LEVEL)
  {
    glutSolidSphere(30.0f, 10, 10);
  } else {
    glutSolidSphere(30.0f, 15, 15);
  }

  glutSwapBuffers();
}

 void ChangeSize(int w, int h)
{ 
if (h == 0)
  {
    h = 1;
  } 
  //设置视口 
  glViewport(0, 0, w, h);
  GLfloat faspect = (GLfloat)w/(GLfloat)h; 
  //透视投影变换 
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(35.0, faspect, 1.0, 350.0); 
  //模型视图矩阵 
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity(); 
  //先往显示器里平移 
  glTranslatef(0.0f, 0.0f, -250.0f);

  glutPostRedisplay();
} 

void SpecialKeys(int keys, int x, int y)
{ 
//改变旋转角度 
  if (keys == GLUT_KEY_UP)
  {
    xRot -= 5.0f;
  } if (keys == GLUT_KEY_DOWN)
  {
    xRot += 5.0f;
  } if (keys == GLUT_KEY_LEFT)
  {
    yRot += 5.0f;
  } if (keys == GLUT_KEY_RIGHT)
  {
    yRot -= 5.0f;
  } if (xRot > 356.0f)
  {
    xRot = 0.0f;
  } else if (xRot < -1.0f)
  {
    xRot = 355.0f;
  } if (yRot > 356.0f)
  {
    yRot = 0.0f;
  } else if (yRot < -1.0f)
  {
    yRot = 355.0f;
  }

  glutPostRedisplay();
} 

void ProcessMenu(int key)
{ 
switch(key)
  { case 1:
    iShade = FLAT_MODE; break; case 2:
    iShade = SMOOTH_MODE; break; case 3:
    iLevel = LOW_LEVEL; break; case 4:
    iLevel = MEDIUM_LEVEL; break; case 5:
    iLevel = HIGH_LEVEL; break; default: break;
  }
  glutPostRedisplay();
} 

int main(int args, char *arv[])
{
  glutInit(&args, arv);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutInitWindowSize(800, 600);
  glutCreateWindow("spot light");
  glutDisplayFunc(RenderScene);
  glutReshapeFunc(ChangeSize);
  glutSpecialFunc(SpecialKeys); 
  //创建菜单
  int menuID = glutCreateMenu(ProcessMenu);
  glutAddMenuEntry("Flag Mode", 1);
  glutAddMenuEntry("SMOOTH Mode", 2);
  glutAddMenuEntry("Low Level", 3);
  glutAddMenuEntry("Midum Level", 4);
  glutAddMenuEntry("High Level", 5);
  glutAttachMenu(GLUT_RIGHT_BUTTON);
  SetupRC();
  glutMainLoop(); 
  return 0;
}