利用de Casteljau算法绘制Bezier曲面

上次的博客中我利用de Casteljau绘制了Bezier曲线，那么为了之后绘制Bezier的三角曲面片，还是先铺垫一下，绘制双三次的Bezier曲面

先上代码

#include<GL/GLUT.H>
#include <windows.h>
#include <math.h>
#include <gl/GL.h>

GLfloat ctrlPoints[4][4][3] =
{
{
{ -0.8f, -0.7f, 0.2f }, { -0.3f, -0.6f, 0.2f }, { 0.2f, -0.65f, 0.3f }, { 0.7f, -0.7f, 0.2f }
},
{
{ -0.9f, -0.2f, 0.3f }, { -0.3f, 0.2f, 0.5f }, { 0.3f, -0.2f, 0.4f }, { 0.75f, -0.2f, 0.3f },
},
{
{ -0.9f, 0.3f, 0.3f }, { -0.3f, 0.2f, 0.5f }, { 0.25f, 0.25f, 0.6f }, { 0.8f, 0.3f, 0.3f },
},
{
{ -0.8f, 0.8f, 0.1f }, { -0.3f, 0.8f, 0.2f }, { 0.2f, 0.85f, 0.1f }, { 0.7f, 0.8f, 0.1f },
}
};

void myDisplay(void){
glClear(GL_COLOR_BUFFER_BIT);
glRotatef(-65.0, 1.0, 0.3, 0.2);

/* The following code displays the control points as dots. */
glPointSize(5.0);
glColor3f(1.0, 1.0, 0.0);

for (int i = 0; i < 4; i++){
glBegin(GL_POINTS);
for (int j = 0; j < 4; j++)
glVertex3fv(&ctrlPoints[i][j][0]);
glEnd();
}

glColor3f(0.0, 1.0, 1.0);
for (int i = 0; i < 4; i++){
glBegin(GL_LINE_STRIP);
for (int j = 0; j < 4; j++)
glVertex3fv(&ctrlPoints[i][j][0]);
glEnd();
glBegin(GL_LINE_STRIP);
for (int j = 0; j < 4; j++)
glVertex3fv(&ctrlPoints[j][i][0]);
glEnd();
}

int n = 4;//number
float xarray[4];
float yarray[4];
float zarray[4];
GLfloat ps[11][4][3];
for (int v = 0; v < 4;v++)
{
int u = 0;
for(double t = 0.0;t<=1;t+=0.1)
{
for (int i = 1; i < n; ++i)
{
for (int j = 0; j < n - i; ++j)
{
if (i == 1) // i==1时,第一次迭代,由已知控制点计算
{
xarray[j] = ctrlPoints[j][v][0] * (1 - t) + ctrlPoints[j+1][v][0] * t;
yarray[j] = ctrlPoints[j][v][1] * (1 - t) + ctrlPoints[j+1][v][1] * t;
zarray[j] = ctrlPoints[j][v][2] * (1 - t) + ctrlPoints[j+1][v][2] * t;
continue;
}
// i != 1时,通过上一次迭代的结果计算
xarray[j] = xarray[j] * (1 - t) + xarray[j + 1] * t;
yarray[j] = yarray[j] * (1 - t) + yarray[j + 1] * t;
zarray[j] = zarray[j] * (1 - t) + zarray[j + 1] * t;
}

}
ps[u][v][0] = xarray[0];
ps[u][v][1] = yarray[0];
ps[u][v][2] = zarray[0];
u++;
}

}

GLfloat ps1[11][11][3];
for (int v = 0; v < 11; v++){
int u = 0;
for (double t = 0.0; t <= 1; t += 0.1)
{
for (int i = 1; i < n; ++i)
{
for (int j = 0; j < n - i; ++j)
{
if (i == 1) // i==1时,第一次迭代,由已知控制点计算
{
xarray[j] = ps[v][j][0] * (1 - t) + ps[v][j + 1][0] * t;
yarray[j] = ps[v][j][1] * (1 - t) + ps[v][j + 1][1] * t;
zarray[j] = ps[v][j][2] * (1 - t) + ps[v][j + 1][2] * t;
continue;
}
// i != 1时,通过上一次迭代的结果计算
xarray[j] = xarray[j] * (1 - t) + xarray[j + 1] * t;
yarray[j] = yarray[j] * (1 - t) + yarray[j + 1] * t;
zarray[j] = zarray[j] * (1 - t) + zarray[j + 1] * t;
}

}
ps1[v][u][0] = xarray[0];
ps1[v][u][1] = yarray[0];
ps1[v][u][2] = zarray[0];
u++;
}
}

glColor3f(1.0, 1.0, 1.0);
for (int i = 0; i < 11; i++){
glBegin(GL_LINE_STRIP);
for (int j = 0; j < 11; j++)
glVertex3fv(&ps1[i][j][0]);
glEnd();

glBegin(GL_LINE_STRIP);
for (int j = 0; j < 11; j++)
glVertex3fv(&ps1[j][i][0]);
glEnd();
}

glFlush();
}

int main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
glutInitWindowPosition(100, 100);
glutInitWindowSize(400, 400);
glutCreateWindow("opengl1");
glutDisplayFunc(&myDisplay);
glutMainLoop();
return 0;
}
其实后来才发现这是我两篇博客http://blog.csdn.net/lafengxiaoyu/article/details/51295464和利用de算法求曲线的合体篇

。。。。

效果是酱的



O了，下一步的工作就要开始绘制三角面片了哦也