OpenGL实现贝塞尔曲线或曲面

#include "GLTools.h"

#ifdef __APPLE__
#include 
#else
#define FREEGLUT_STATIC
#include 
#endif

//控制点
GLfloat ctrlpoints[4][3] = {
 { -4.0, -4.0, 0.0}, { -2.0, 4.0, 0.0},
 {2.0, -4.0, 0.0}, {4.0, 4.0, 0.0}};

void init(void)
{
 glClearColor(0.0, 0.0, 0.0, 0.0);
 glShadeModel(GL_FLAT);
 //定义一维求值器
 glMap1f(GL_MAP1_VERTEX_3, 0.0, 1.0, 3, 4, &ctrlpoints[0][0]);
 //启动求职器
 glEnable(GL_MAP1_VERTEX_3);
}

void display(void)
{
 int i;

 glClear(GL_COLOR_BUFFER_BIT);
 glColor3f(1.0, 1.0, 1.0);
 glBegin(GL_LINE_STRIP);
 for (i = 0; i <= 30; i++)
  glEvalCoord1f((GLfloat) i/30.0);//执行求值器，每执行一次产生一个坐标
 glEnd();

 //绘制4个控制点
 glPointSize(5.0);
 glColor3f(1.0, 1.0, 0.0);
 glBegin(GL_POINTS);
 for (i = 0; i <4; i++)
  glVertex3fv(&ctrlpoints[i][0]);
 glEnd();
 glFlush();
}

void reshape(int w, int h)
{
 glViewport(0, 0, (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();
}

void keyboard(unsigned char key, int x, int y)
{
 switch (key) {
  case 27:
   exit(0);
   break;
 }
}

int main(int argc, char** argv)
{
 glutInit(&argc, argv);
 glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
 glutInitWindowSize (500, 500);
 glutInitWindowPosition (100, 100);
 glutCreateWindow (argv[0]);
 init ();
 glutDisplayFunc(display);
 glutReshapeFunc(reshape);
 glutKeyboardFunc (keyboard);
 glutMainLoop();
 return 0;
}

#include "GLTools.h"

#ifdef __APPLE__
#include 
#else
#define FREEGLUT_STATIC
#include 
#endif

GLfloat ctrlpoints[4][4][3] = {
 {{ -1.5, -1.5, 4.0}, { -0.5, -1.5, 2.0},
  {0.5, -1.5, -1.0}, {1.5, -1.5, 2.0}},
 {{ -1.5, -0.5, 1.0}, { -0.5, -0.5, 3.0},
  {0.5, -0.5, 0.0}, {1.5, -0.5, -1.0}},
 {{ -1.5, 0.5, 4.0}, { -0.5, 0.5, 0.0},
  {0.5, 0.5, 3.0}, {1.5, 0.5, 4.0}},
 {{ -1.5, 1.5, -2.0}, { -0.5, 1.5, -2.0},
  {0.5, 1.5, 0.0}, {1.5, 1.5, -1.0}}
};

GLfloat texpts[2][2][2] = {{{0.0, 0.0}, {0.0, 1.0}},
 {{1.0, 0.0}, {1.0, 1.0}}};

void display(void)
{
 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 glColor3f(1.0, 1.0, 1.0);
 glEvalMesh2(GL_FILL, 0, 20, 0, 20);//glMapGrid2f()均匀产生坐标值，这里执行绘制
 glFlush();
}

#define imageWidth 64
#define imageHeight 64
GLubyte image[3*imageWidth*imageHeight];
//纹理数据
void makeImage(void)
{
 int i, j;
 float ti, tj;

 for (i = 0; i