[实例]OpenGL绘制茶壶（光照、三维变换）

这里仅仅提供一个实例程序，如果对opengl的相关知识了解不多，可以看看我的其他博客专题 (ฅ• . •ฅ)。

程序目标：

绘制一个茶壶，用“+、-”键来旋转茶壶，同时实现光照。

#include <windows.h>
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>

double angle = 0.0;

void initialize()
{
    glClearColor(1.0,1.0,1.0,0.0);
    //设置光照
    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 };

    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);

    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);

    glEnable(GL_LIGHT0);
    glEnable(GL_NORMALIZE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHTING);

    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);

    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);

}

static void resize(int width, int height)
{
    //指定视口
    glViewport(0, 0, width, height);

    //投影变换---平截头体
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(40.0,(GLdouble)width/(GLdouble)height,0.1,10000.0);
}

static void display(void)
{
    //视图变换，指定相机
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0.0,0.0,5.0, 0.0,0.0,0.0, 0.0,1.0,0.0);

    //模型变换
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glColor3f(1.0,0.0,0.0);

    glPushMatrix();
    glRotatef(angle,0.0,1.0,0.0);
    glutSolidTeapot(1.0);
    glPopMatrix();

    glutSwapBuffers();
}


static void key(unsigned char key, int x, int y)
{
    switch (key)
    {
    case 27 :
    case 'q':
        exit(0);
        break;

    case '+':
        angle++;
        break;

    case '-':
        angle--;
        break;
    }

    glutPostRedisplay();
}



/* Program entry point */

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitWindowSize(640,480);
    glutInitWindowPosition(10,10);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    initialize();

    glutReshapeFunc(resize);
    glutDisplayFunc(display);
    glutKeyboardFunc(key);

    glutMainLoop();

    return EXIT_SUCCESS;
}

程序的执行结果如下：