opengl 光照

1. 绘制带有光照效果的场景；
2. 场景包含3个茶壶，通过键盘1,2,3可以分别选中三个茶壶，然后用鼠标对每个茶壶进行分别的旋转；
3. 使用点光源，点光源为白色，以白色的球体表示；
4. 使用3个不同的点光源

           i.      光源1的坐标设置在世界坐标系中，并围绕着三个茶壶的中心进行圆周运动；

           ii.     光源2 的坐标 设置在观察坐标系，不发生变化；

           iii.    光源3的坐标设置在茶壶1的物体坐标系中，当茶壶1被选中进行旋转时，光源3要跟随茶壶1 做相同的旋转；

#include <windows.h>
#include <GL/glut.h>
#include <GL/glext.h>
#include <GL/SOIL.h>
#include <cstdio>
GLfloat r1 = 0.0f;
GLfloat r2 = 0.0f;
GLfloat r3 = 0.0f;
GLfloat rlight1 = 0.0f;

GLfloat mat_specular[] = {1.0f,1.0f,1.0f,1.0f};
GLfloat low_shiniess[] = {5.0};      // 镜面反射

GLfloat material1[] = {1.0f,0.0f,0.0f,1.0f};
GLfloat material2[] = {0.0f,1.0f,0.0f,1.0f};
GLfloat material3[] = {0.0f,0.0f,1.0f,1.0f};


GLfloat light_position1[] = {0.0f,0.0f,4.0f,1.0f};
GLfloat light_diffuse1[] = {1.0f,1.0f,1.0f,1.0f};   //白光

GLfloat light_position2[] = {1.0f,-2.0f,1.0f,1.0f}; //红光
GLfloat light_diffuse2[] = {1.0f,0.0f,0.0f,1.0f};

GLfloat light_position3[] = {0.0f,0.0f,2.0f,1.0f};
GLfloat light_diffuse3[] = {0.0f,0.0f,1.0f,1.0f};// 蓝光
GLfloat light_specular3[] = {1.0f,1.0f,1.0f,1.0f};
//漫射光
void  init ()
{
    glShadeModel(GL_SMOOTH);
    glClearColor(0.0,0.0,0.0,0.0);
    glClearDepth(1.0);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);
    glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
    glEnable(GL_LIGHTING);
    //glMaterialfv(GL_FRONT,GL_SPECULAR,mat_specular);
    //glMaterialfv(GL_FRONT,GL_SHININESS,low_shiniess);
}

void reshape(int w,int h)
{
    glViewport(0,0,(GLsizei)w,(GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0,(GLfloat)w/(GLfloat)h,0.1,100.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0.0f,0.0f,10.0f,
              0.0f,0.0f,0.0f,
              0.0f,1.0f,0.0f);


}
void display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glPushMatrix();
        glRotated(rlight1,0.0f,1.0f,0.0f);
        glLightfv(GL_LIGHT0,GL_POSITION,light_position1);
        glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse1);  //世界坐标系光源
    glPopMatrix();

    glPushMatrix();
        glDisable(GL_LIGHTING);
        glRotated(rlight1,0.0f,1.0f,0.0f);
        glTranslatef(0.0f,0.0f,4.0f);
        glColor3f(1.0f,1.0f,1.0f);         //光源1 白光 的小球
        glutSolidSphere(0.05,10,10);
        glEnable(GL_LIGHTING);
    glPopMatrix();

    glLightfv(GL_LIGHT1,GL_POSITION,light_position2);
    glLightfv(GL_LIGHT1,GL_DIFFUSE,light_diffuse2);    //观察坐标系光源

    glPushMatrix();
        glDisable(GL_LIGHTING);
        glTranslatef(1.0f,-2.0f,1.0f);   //光源2  红光的小球
        glColor3f(1.0f,0.0f,0.0f);
        glutSolidSphere(0.05,10,10);
        glEnable(GL_LIGHTING);
    glPopMatrix();



    //teapot1
    glPushMatrix();
        glTranslatef(0.0f,2.0f,0.0f);
        glRotatef(r1,0.0f,1.0f,0.0f);
        //glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,material1);
        glLightfv(GL_LIGHT2,GL_POSITION,light_position3);
        glLightfv(GL_LIGHT2,GL_DIFFUSE,light_diffuse3);
        glLightfv(GL_LIGHT2,GL_SPECULAR,light_specular3);  //
        glLightf(GL_LIGHT2,GL_SPOT_CUTOFF,45.0f);
        glPushMatrix();
            glDisable(GL_LIGHTING);
            glTranslated(0.0f,0.0f,2.0f);
            glRotatef(r1,0.0f,1.0f,0.0f);
            glColor3f(0.0f,0.0f,1.0f);     //蓝色光源的小球
            glutSolidSphere(0.05,10,10);
            glEnable(GL_LIGHTING);
        glPopMatrix();
        glutSolidTeapot(1.0f);
    glPopMatrix();



    //teapot2
    glPushMatrix();
        glTranslatef(-2.5f,-1.0f,0.0f);
        glRotatef(r2,1.0f,0.0f,0.0f);
        //glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,material2);
        //glColor3f(1.0f,0.0f,0.0f);
        glutSolidTeapot(1.0f);
    glPopMatrix();

    //teapot3
    glPushMatrix();
        glTranslatef(2.5f,-1.0f,0.0f);
        glRotatef(r3,0.0f,0.0f,1.0f);
        //glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,material3);
        //glColor3f(1.0f,1.0f,0.0f);
        glutSolidTeapot(1.0f);
    glPopMatrix();

    glFlush();
}
void mouse_move1(int x,int y)
{
    r1+=10.0f;
    glutPostRedisplay();
}
void mouse_move2(int x,int y)
{
    r2+=10.0f;
    glutPostRedisplay();
}
void mouse_move3(int x,int y)
{
    r3+=10.0f;
    glutPostRedisplay();
}
void rotate1()
{
    rlight1+=1.0f;
    if(rlight1>360.0)
        rlight1 = rlight1-360;
    glutPostRedisplay();
}
void keyboard(unsigned char key,int x,int y)
{
    switch(key)
    {
    case '1':
        glutMotionFunc(mouse_move1);
        break;
    case '2':
        glutMotionFunc(mouse_move2);
        break;
    case '3':
        glutMotionFunc(mouse_move3);
        break;
    case 'r':
        glutIdleFunc(rotate1);
        break;
    case 's':
        glutIdleFunc(NULL);
        break;
    case 'a':        // light1
        glDisable(GL_LIGHT1);
        glDisable(GL_LIGHT2);
        glEnable(GL_LIGHT0);
        glutPostRedisplay();
        break;
     case 'b':       //light2
        glDisable(GL_LIGHT0);
        glDisable(GL_LIGHT2);
        glEnable(GL_LIGHT1);
        glutPostRedisplay();
        break;
     case 'c':      //light2
        glDisable(GL_LIGHT1);
        glDisable(GL_LIGHT0);
        glEnable(GL_LIGHT2);
        glutPostRedisplay();
        break;
    }
}

/*void mouse(int button,int state,int x,int y)
{
    switch(button){
    case GLUT_LEFT_BUTTON:
        if(state == GLUT_DOWN)
        break;
    case GLUT_RIGHT_BUTTON:
        if(state == GLUT_DOWN)
        break;
    }
}*/
int main(int argc,char **argv)
{
    printf("keyboard 1,2,3 choose the teapot   mousemove control\n");
    printf("keyboard r light1 rotated, s stop");
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(900,600);
    glutInitWindowPosition(400,100);
    glutCreateWindow("hello world");
    init();
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutKeyboardFunc(keyboard);
    //glutMouseFunc(mouse);
    glutMainLoop();
    return 0;
}