CGAL & opengl 绘制voronoi图

各种配环境是真滴难受，，
一晚上终于搞好了，
cgal 4.12
boost 1.68.0
opengl
freeglut-MSVC 3.0.0
包含目录：

库目录：

链接器->输入->附加依赖项

代码：

//

#include "stdafx.h"
#include 
#include 
#include 
#include 
#include 
#include 

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Delaunay_triangulation_2 Delaunay;
typedef Delaunay::Vertex_handle Vertex_handle;

typedef K::Point_2 Point;

std::vector vertices;

int global_w, global_h;
int tri_state = 0;

void points_draw()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glPushMatrix();

	std::vector ::iterator iter;
	glColor3f(1.0, 1.0, 1.0);
	glPointSize(5);
	glBegin(GL_POINTS);
	for (iter = vertices.begin(); iter != vertices.end(); iter++)
		glVertex2i(iter->hx(), iter->hy());
	glEnd();

	glPopMatrix();
	glutSwapBuffers();
}

void points_add_point(int x, int y)
{
	vertices.push_back(Point(x, global_h - y));
}


void points_clear()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glPushMatrix();
	glPopMatrix();
	glutSwapBuffers();

	vertices.clear();
	tri_state = 0;
}

void read_file()//从文件中读入点集数据，调试时所使用
{
	FILE* f;
	f = freopen("data.txt", "r", stdin);

	int a, b;
	while (std::cin >> a >> b)
	{
		vertices.push_back(Point(a, b));
	}

	fclose(f);
}

void points_triangulation()
{
	Delaunay dt;//Delaunay数据结构，代表当前数据的一个且仅有一个的三角剖分，详情请参考CGAL_manual

	dt.insert(vertices.begin(), vertices.end());//输入数据

	points_draw();//points_draw()函数中已经调用一次glutSwapBuffers()，本函数再一次调用glutSwapBuffers()
				  //在一帧的绘制中两次调用glutSwapBuffers()，虽对本例无影响，但存在一些问题，这不是本文的重点，可暂且忽略之

	glPushMatrix();

	Delaunay::Finite_faces_iterator fit;//遍历Delaunay的所有面（有限面），将每个面的边画出来
	glColor3f(0.0, 0.0, 1.0);
	for (fit = dt.finite_faces_begin(); fit != dt.finite_faces_end(); fit++)
	{
		glBegin(GL_LINE_LOOP);
		glVertex2i(fit->vertex(0)->point().hx(), fit->vertex(0)->point().hy());
		glVertex2i(fit->vertex(1)->point().hx(), fit->vertex(1)->point().hy());
		glVertex2i(fit->vertex(2)->point().hx(), fit->vertex(2)->point().hy());
		glEnd();
	}//完成Delaunay三角剖分的绘制，Delaunay图

	Delaunay::Edge_iterator eit;//遍历Delaunay的所有边，绘制Delaunay图的对偶图，即Voronoi图

	glEnable(GL_LINE_STIPPLE);//使用点画模式，即使用虚线来绘制Voronoi图
	glLineStipple(1, 0x3333);
	glColor3f(0.0, 1.0, 0.0);

	for (eit = dt.edges_begin(); eit != dt.edges_end(); eit++)
	{
		CGAL::Object o = dt.dual(eit);//边eit在其对偶图中所对应的边

		if (CGAL::object_cast(&o)) //如果这条边是线段，则绘制线段
		{
			glBegin(GL_LINES);
			glVertex2i(CGAL::object_cast(&o)->source().hx(), CGAL::object_cast(&o)->source().hy());
			glVertex2i(CGAL::object_cast(&o)->target().hx(), CGAL::object_cast(&o)->target().hy());
			glEnd();
		}
		else if (CGAL::object_cast(&o))//如果这条边是射线，则绘制射线
		{
			glBegin(GL_LINES);
			glVertex2i(CGAL::object_cast(&o)->source().hx(), CGAL::object_cast(&o)->source().hy());
			glVertex2i(CGAL::object_cast(&o)->point(1).hx(), CGAL::object_cast(&o)->point(1).hy());
			glEnd();
		}
	}
	glDisable(GL_LINE_STIPPLE);//关闭点画模式

	glPopMatrix();
	glutSwapBuffers();

	tri_state = 1;//完成三角剖分，置状态为1
}

void display(void)
{
}

void init(void)
{
	glClearColor(0.0, 0.0, 0.0, 0.0);
	glShadeModel(GL_FLAT);

}

void reshape(int w, int h)
{
	global_w = w;
	global_h = h;
	points_clear();

	glViewport(0, 0, w, h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	glOrtho(0, w, 0, h, -1.0, 1.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

void mouse(int button, int state, int x, int y)
{
	if (button == GLUT_LEFT_BUTTON && state == GLUT_UP)
	{
		if (tri_state == 1) points_clear();
		else
		{
			points_add_point(x, y);
			//read_file();
			points_draw();
		}
	}
	if (button == GLUT_RIGHT_BUTTON && state == GLUT_UP)
	{
		if (tri_state == 1) points_clear();
		else points_triangulation();
	}
}

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_DOUBLE | GLUT_RGB);
	glutInitWindowSize(800, 600);
	glutInitWindowPosition(100, 100);
	glutCreateWindow(argv[0]);
	init();
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	glutMouseFunc(mouse);
	glutKeyboardFunc(keyboard);
	glutMainLoop();
	return 0;
}