Week11

寫法１：

#include <GL/glut.h>
float angleX=0;
void display()
{
 glEnable(GL_DEPTH_TEST);
 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 glPushMatrix();

  glRotatef(angleX, 0,1,0);
  glutSolidTeapot(0.3);

  glTranslatef(0.4,0,0);
  glutSolidSphere(0.2,30,30);

  glTranslatef(-0.8,0,0);
  glutSolidSphere(0.2,30,30);

  glTranslatef(0.4,0.4,0);
  glutSolidSphere(0.2,30,30);


 glPopMatrix();
 glutSwapBuffers();
}
void keyboard(unsigned char key, int x, int y)
{
     if(key=='a') angleX+=3;
     if(key=='b') angleX-=3;
     glutPostRedisplay();
     
}
void myLight()
{
 const GLfloat light_position[] = { 2.0f, 5.0f, -5.0f, 0.0f };
 glEnable(GL_LIGHT0);
 glEnable(GL_NORMALIZE);
 glEnable(GL_COLOR_MATERIAL);
 glEnable(GL_LIGHTING);
 glLightfv(GL_LIGHT0, GL_POSITION, light_position);
}
int main()
{
 glutInitDisplayMode(GLUT_DOUBLE |GLUT_DEPTH);
 glutCreateWindow("week11");
 glutDisplayFunc(display);
 glutKeyboardFunc(keyboard);
 myLight();
 glutMainLoop();
}

寫法２：

加上glPushMatrix(); 和 glPopMatrix()  這個大括號!!!

這樣就不會導致座標很亂

#include <GL/glut.h>

float angleX=0;

void display()

{

 glEnable(GL_DEPTH_TEST);

 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

 glPushMatrix();

  glRotatef(angleX, 0,1,0);

  glutSolidTeapot(0.3);

  

glPushMatrix();

  glTranslatef(0.4,0,0);

  glutSolidSphere(0.2,30,30);

glPopMatrix();

glPushMatrix();  

  glTranslatef(-0.4,0,0);

  glutSolidSphere(0.2,30,30);

glPopMatrix();

glPushMatrix();

  glTranslatef(0,0.4,0);

  glutSolidSphere(0.2,30,30);

glPopMatrix();

  

 glPopMatrix();

 glutSwapBuffers();

}

void keyboard(unsigned char key, int x, int y)

{

     if(key=='a') angleX+=3;

     if(key=='b') angleX-=3;

     glutPostRedisplay();

        

}

void myLight()

{

 const GLfloat light_position[] = { 2.0f, 5.0f, -5.0f, 0.0f };

 glEnable(GL_LIGHT0);

 glEnable(GL_NORMALIZE);

 glEnable(GL_COLOR_MATERIAL);

 glEnable(GL_LIGHTING);  

 glLightfv(GL_LIGHT0, GL_POSITION, light_position); 

}

int main()

{

 glutInitDisplayMode(GLUT_DOUBLE |GLUT_DEPTH);

 glutCreateWindow("week11");

 glutDisplayFunc(display);

 glutKeyboardFunc(keyboard);

 myLight();

 glutMainLoop();

}