week05 阿土 茶壺 燈

1.如何叫出3D茶壺且打燈

#include///打光0:宣告陣列,裡⾯有光的屬性值
const GLfloat light_ambient[] = { 0.0f, 0.0f, 0.0f, 1.0f }; 
const GLfloat light_diffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
 const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
 const GLfloat light_position[] = { 2.0f, 5.0f, 5.0f, 0.0f }; 
const GLfloat mat_ambient[] = { 0.7f, 0.7f, 0.7f, 1.0f }; 
const GLfloat mat_diffuse[] = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f }; 
const GLfloat high_shininess[] = { 100.0f }; 
void display()///茶壺程式碼 
{ 
         glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
         glutSolidTeapot(0.3);
         glutSwapBuffers();
}
 int main(int argc, char *argv[]) 
{
         glutInit(&argc, argv); 
         glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); 
         glutCreateWindow("GLUT Shapes");
         glutDisplayFunc(display); 
         
          ///打光需要的3D depth test
         glEnable(GL_DEPTH_TEST);
         glDepthFunc(GL_LESS);
        
         ///打光1:開啟光線 
         glEnable(GL_LIGHT0); 
         glEnable(GL_NORMALIZE); 
         glEnable(GL_COLOR_MATERIAL); 
         glEnable(GL_LIGHTING);
       
         ///打光2:設定light的設定值
        glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient); 
        glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse); 
        glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
        glLightfv(GL_LIGHT0, GL_POSITION, light_position);
      
        ///打光2.2:要把物體也設定好她的material 
       glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
       glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
       glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
       glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess); 
       glutMainLoop();
       return EXIT_SUCCESS;

2.用滑鼠改變光線位置
void motion(int x,int y)
{
    GLfloat light_position[] = { 2.0f, -5.0f, -5.0f, 0.0f };
    light_position[0] = (x-150)/150.0*10;
    light_position[1] = -(y-150)/150.0*10;
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glutPostRedisplay();

}

glutMotionFunc(motion);

3.原尺寸放大縮小

static void resize(int width,int height)
{
    const float ar = (float)width / (float) height;

    glViewport(0,0,width,height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    glOrtho(-ar,ar,-1,+1,-1,+1);///保持物體的aspect ratio 長寬比,要是正確的
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

}