#include <GL/glut.h>

 GLfloat ctrlpoints[][] =

 {{ -4.0, -4.0, 0.0}, { -2.0, 3.0, 0.0},

 {2.0, 4.5, 0.0}, {3.0, -3.0, 0.0}};

 void init(void)

 {

     glClearColor(1.0, 1.0, 1.0, 0.0);

     glShadeModel(GL_FLAT);

     //下行用于定义曲线函数

     glMap1f(GL_MAP1_VERTEX_3, 0.0, 1.0, , , &ctrlpoints[][]);

     glEnable(GL_MAP1_VERTEX_3); //将当前曲线函数激活

 }

 void display(void)

 {

     int i;

     glClear(GL_COLOR_BUFFER_BIT);

     //下面用求值器按20等分计算Bezier曲线上的点

     glColor3f(0.0, 0.0, 0.0);

     glLineWidth();

     glBegin(GL_LINE_STRIP);

     for (i = ; i <= ; i++)

         glEvalCoord1f((GLfloat) i/20.0); //相当于调用了glVertex*()

     glEnd();

     //下面绘制控制多边形

     glLineWidth();

     glColor3f(0.0, 0.0, 1.0);

     glBegin(GL_LINE_STRIP);

     for (i = ; i < ; i++)

         glVertex3fv(&ctrlpoints[i][]);

     glEnd();

     glFlush();

 }

 void reshape(int w, int h)

 {

     glViewport(, , (GLsizei) w, (GLsizei) h);

     glMatrixMode(GL_PROJECTION);

     glLoadIdentity();

     if (w <= h)

         glOrtho(-5.0, 5.0, -5.0*(GLfloat)h/(GLfloat)w, 5.0*(GLfloat)h/(GLfloat)w, -5.0, 5.0);

     else

         glOrtho(-5.0*(GLfloat)w/(GLfloat)h, 5.0*(GLfloat)w/(GLfloat)h, -5.0, 5.0, -5.0, 5.0);

     glMatrixMode(GL_MODELVIEW);

     glLoadIdentity();

 }

 int main(int argc, char** argv)

 {

     glutInit(&argc, argv);

     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);

     glutInitWindowSize (, );

     glutInitWindowPosition (, );

     glutCreateWindow (argv[]);

     init ();

     glutDisplayFunc(display);

     glutReshapeFunc(reshape);

     glutMainLoop();

     return ;

 }

 #include <GL/glut.h>

 GLfloat ctrlpoints[][][] = {

 {{-, , 4.0}, {-, , 2.0}, {-, , 0.0}, {, , 2.0}},

 {{-, , 1.0}, {-, , 3.0}, {-, , 6.0}, {, , -1.0}},

 {{-, , 4.0}, {-, , 0.0}, {-, , 3.0}, {, , 4.0}},

 {{-, , 0.0}, {-, , 0.0}, {-, , 0.0}, {, , 0.0}}

 };

 void display(void)

 {

     int i, j;

     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

     glColor3f(0.0, 0.0, 0.0);

     glPushMatrix ();

     glRotatef(85.0, 1.0, 1.0, 1.0);

     for (j = ; j <= ; j++)

     {

         glBegin(GL_LINE_STRIP);

         for (i = ; i <= ; i++)

             glEvalCoord2f((GLfloat)i/20.0, (GLfloat)j/20.0); //调用求值器

         glEnd();

         glBegin(GL_LINE_STRIP);

         for (i = ; i <= ; i++)

             glEvalCoord2f((GLfloat)j/20.0, (GLfloat)i/20.0); //调用求值器

         glEnd();

     }

     glPopMatrix ();

     glFlush();

 }

 void init(void)

 {

     glClearColor (1.0, 1.0, 1.0, 0.0);

     //下行的代码用控制点定义Bezier曲面函数

     glMap2f(GL_MAP2_VERTEX_3, , , , , , , , , &ctrlpoints[][][]);

     glEnable(GL_MAP2_VERTEX_3);   //激活该曲面函数

     glOrtho(-5.0, 5.0, -5.0, 5.0, -5.0, 5.0);   //构造平行投影矩阵

 }

 int main(int argc, char** argv)

 {

 glutInit(&argc, argv);

 glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);

 glutInitWindowSize (, );

 glutInitWindowPosition (, );

 glutCreateWindow (argv[]);

 init ();

 glutDisplayFunc(display);

 glutMainLoop();

 return ;

 }