DOO-SABIN 细分曲面（编辑中）

之前实现了简单的细分曲线，即Chaikin细分算法，现在准备实现DooSabine细分曲面

我这里借助http://www.idav.ucdavis.edu/education/CAGDNotes/CAGDNotes/Doo-Sabin/Doo-Sabin.html

这篇文章中的例子，首先需要先绘制出实例中的这个图

两个小时过去了。。我终于画出这幅图来了。。给跪，其中一定要用到这里面的关于polygon模式的语句

void glPolygonMode(

GLenum face, GLenum mode

)

;

其中GL_FRONT for front-facing polygons, GL_BACK for back-facing polygons, or GL_FRONT_AND_BACK for front- and back-facing polygons

mode有

GL_POINT

, 

GL_LINE

, and 

GL_FILL三种，其中初始状态是GL_FILL，正反两面都是

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

static const GLfloat vertex_list[2][8][3] = {
{{ -0.1f, 0.5f, 0.3f }, { -0.1f, 0, 0.3f }, { -0.6f, 0, 0.3f }, { -0.6f, -0.5f, 0.3f }, { 0.6f, -0.5f, 0.3f }, { 0.6f, 0, 0.3f }, { 0.1f, 0, 0.3f }, { 0.1f, 0.5f, 0.3f } },
{ { -0.1f, 0.5f, -0.3f }, { -0.1f, 0, -0.3f }, { -0.6f, 0, -0.3f }, { -0.6f, -0.5f, -0.3f }, { 0.6f, -0.5f, -0.3f }, { 0.6f, 0, -0.3f }, { 0.1f, 0, -0.3f }, { 0.1f, 0.5f, -0.3f } }
};

void myDisplay(void) {

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
glRotatef(60, 1, 1, 1);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(100.0f, 1.0f, 1.0f, 10.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0.0, -0.8, 1.5, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

/*glRotatef(-60, -1, 1, 1);*/
glColor3f(0, 0, 1);

glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

glBegin(GL_POLYGON);
for (int j = 0; j < 8; ++j)     // 每个面有八个顶点，循环八次
glVertex3fv(vertex_list[0][j]);
glEnd();

glBegin(GL_POLYGON);
for (int j = 0; j < 8; ++j)     // 每个面有八个顶点，循环八次
glVertex3fv(vertex_list[1][j]);
glEnd();

//绘制侧面的面
glColor3f(0, 0, 1);
for (int i = 0; i < 8; i++)      // 有八个面，循环八次
{
if (i == 7)
{
glBegin(GL_QUADS);
glVertex3fv(vertex_list[0][i]);
glVertex3fv(vertex_list[0][0]);
glVertex3fv(vertex_list[1][0]);
glVertex3fv(vertex_list[1][i]);
glEnd();
}
else
{
glBegin(GL_QUADS);
glVertex3fv(vertex_list[0][i]);
glVertex3fv(vertex_list[0][i + 1]);
glVertex3fv(vertex_list[1][i + 1]);
glVertex3fv(vertex_list[1][i]);

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;
}

学到这里突然要发现需要学习好多数据结构的东西。。我觉得有必要专门写一篇关于数据结构和图形表示的博客。。那这一块的东西还是暂时放一放。马上搞定了回来补

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

static const GLfloat vertex_list[2][8][3] = {
{{ -0.1f, 0.5f, 0.3f }, { -0.1f, 0, 0.3f }, { -0.6f, 0, 0.3f }, { -0.6f, -0.5f, 0.3f }, { 0.6f, -0.5f, 0.3f }, { 0.6f, 0, 0.3f }, { 0.1f, 0, 0.3f }, { 0.1f, 0.5f, 0.3f } },
{ { -0.1f, 0.5f, -0.3f }, { -0.1f, 0, -0.3f }, { -0.6f, 0, -0.3f }, { -0.6f, -0.5f, -0.3f }, { 0.6f, -0.5f, -0.3f }, { 0.6f, 0, -0.3f }, { 0.1f, 0, -0.3f }, { 0.1f, 0.5f, -0.3f } }
};

void myDisplay(void) {

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
glRotatef(60, 1, 1, 1);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(100.0f, 1.0f, 1.0f, 10.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0.0, -0.8, 1.5, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

/*glRotatef(-60, -1, 1, 1);*/
glColor3f(0, 0, 1);

glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

glBegin(GL_POLYGON);
for (int j = 0; j < 8; ++j)     // 每个面有八个顶点，循环八次
glVertex3fv(vertex_list[0][j]);
glEnd();

glBegin(GL_POLYGON);
for (int j = 0; j < 8; ++j)     // 每个面有八个顶点，循环八次
glVertex3fv(vertex_list[1][j]);
glEnd();

//绘制侧面的面
glColor3f(0, 0, 1);
for (int i = 0; i < 8; i++)      // 有八个面，循环八次
{
if (i == 7)
{
glBegin(GL_QUADS);
glVertex3fv(vertex_list[0][i]);
glVertex3fv(vertex_list[0][0]);
glVertex3fv(vertex_list[1][0]);
glVertex3fv(vertex_list[1][i]);
glEnd();
}
else
{
glBegin(GL_QUADS);
glVertex3fv(vertex_list[0][i]);
glVertex3fv(vertex_list[0][i + 1]);
glVertex3fv(vertex_list[1][i + 1]);
glVertex3fv(vertex_list[1][i]);

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;
}

这篇博文没有写完。。突然发现要去补数据结构的课。。，好了不多说了，去补课了