多边形扫描转换和区域填充

#define MAX_POLYGONS 80

#define MAX_VERTICES 100

typedef int Bool;

#define TRUE 1

#define FALSE 0

#include

#include

#include

#include

#include

#include

#include

using namespace std;

void myMouse(int ,int ,int ,int );

void myMotion(int,int);

void myDisplay();

void myReshape(int ,int);

void color_menu(int);

void main_menu(int);

int pick_polygon(int x,int y);

void save();

void myinit();

typedef struct polygon

{

    int color;

    bool used;

    int xmin,xmax,ymin,ymax;/*包围盒*/

    float xc,yc;/*多边形的中心*/

    int nvertices; /*顶点的数目*/

    int x[MAX_VERTICES];//顶点

    int y[MAX_VERTICES];

}polygon;

bool picking=FALSE;//如果处于拾取状态，则为TRUE

bool moving=FALSE;

int lock;////////////

int in_polygon=-1;

int present_color=0;

GLsizei wh=500,ww=800;//初始窗口大小

int draw_mode=0;

GLfloat colors[8][3]={{0.0,0.0,0.0},{1.0,0.0,0.0},{0.0,1.0,0.0},{0.0,0.0,1.0},{0.0,1.0,1.0},{1.0,0.0,1.0},{1.0,1.0,0.0},{1.0,1.0,1.0}};

polygon polygons[MAX_POLYGONS];

void myReshape(int w,int h)

{

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    gluOrtho2D(0,(GLdouble)w,0,(GLdouble)h);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

    glViewport(0,0,w,h);

    ww=w;

    wh=h;

}

void myinit()

{

    int i;

    //清屏颜色

    glClearColor(1.0,1.0,1.0,1);

    fstream file; 

    file.open("save.txt",ios_base::in|ios_base::out|ios_base::app); 

    try {

     for(i=0;i            file.read((char *)(&polygons[i]),sizeof(polygons[i])); 

        }

    } catch (exception * ex) 

    { // 捕获 exception*;

     for(i=0;i        {

            polygons[i].used=FALSE;

        }

    }

    file.close();    

}

void save(){

    //添加写文件命令

    int i;

    fstream file; 

    file.open("save.txt",ios_base::in|ios_base::out|ios::binary); 

for(i=0;i        file.write((char *)(&polygons[i]),sizeof(polygons[i]));

    }

    file.close(); 

}

void myMouse(int btn,int state,int x,int y)

{

    int i,j;

    y=wh-y;

    if(btn==GLUT_LEFT_BUTTON&&state==GLUT_DOWN&&!picking&&!moving)

    {//增加顶点

        moving=FALSE;

     if(in_polygon>=0){

         if(polygons[in_polygon].nvertices>=MAX_VERTICES)

            {

                printf("超出了最大承受点数，最大承受点数为%d\\n",MAX_VERTICES);

                exit(0);

            }

            i=polygons[in_polygon].nvertices;

            polygons[in_polygon].x[i]=x;

            polygons[in_polygon].y[i]=y;

            polygons[in_polygon].nvertices++;

        }

        glutPostRedisplay();

    }

    if(btn==GLUT_LEFT_BUTTON&&state==GLUT_DOWN&&picking&&!moving)

    {//删除多边形

        picking=FALSE;

        moving=FALSE;

        j=pick_polygon(x,y);

     if(j>=0)

        {

            polygons[j].used=FALSE;

            in_polygon=-1;

            glutPostRedisplay();

        }

    }

    if(btn==GLUT_MIDDLE_BUTTON&&state==GLUT_DOWN){

        moving=FALSE;

     if(in_polygon>=0)

        {

            polygons[in_polygon].xmax=polygons[in_polygon].xmin=polygons[in_polygon].x[0];

            polygons[in_polygon].ymax=polygons[in_polygon].ymin=polygons[in_polygon].y[0];

            polygons[in_polygon].xc=polygons[in_polygon].x[0];

            polygons[in_polygon].yc=polygons[in_polygon].y[0];

         for(i=1;i            {

             if(polygons[in_polygon].x[i]                    polygons[in_polygon].xmin=polygons[in_polygon].x[i];

             else if(polygons[in_polygon].x[i]>polygons[in_polygon].xmax)

                    polygons[in_polygon].xmax=polygons[in_polygon].x[i];

             if(polygons[in_polygon].y[i]                    polygons[in_polygon].ymin=polygons[in_polygon].y[i];

             else if(polygons[in_polygon].y[i]>polygons[in_polygon].ymax)

                    polygons[in_polygon].ymax=polygons[in_polygon].y[i];

                polygons[in_polygon].xc+=polygons[in_polygon].x[i];

                polygons[in_polygon].yc+=polygons[in_polygon].y[i];

            }

            polygons[in_polygon].xc=polygons[in_polygon].xc/polygons[in_polygon].nvertices;

            polygons[in_polygon].yc=polygons[in_polygon].yc/polygons[in_polygon].nvertices;

        }

        in_polygon=-1;

        glutPostRedisplay();

    }

    if(btn==GLUT_LEFT_BUTTON&&state==GLUT_DOWN&&moving){

        moving=false;

     if(in_polygon>=0)

        {

            polygons[in_polygon].xmax=polygons[in_polygon].xmin=polygons[in_polygon].x[0];

            polygons[in_polygon].ymax=polygons[in_polygon].ymin=polygons[in_polygon].y[0];

            polygons[in_polygon].xc=polygons[in_polygon].x[0];

            polygons[in_polygon].yc=polygons[in_polygon].y[0];

         for(i=1;i            {

             if(polygons[in_polygon].x[i]                    polygons[in_polygon].xmin=polygons[in_polygon].x[i];

             else if(polygons[in_polygon].x[i]>polygons[in_polygon].xmax)

                    polygons[in_polygon].xmax=polygons[in_polygon].x[i];

             if(polygons[in_polygon].y[i]                    polygons[in_polygon].ymin=polygons[in_polygon].y[i];

             else if(polygons[in_polygon].y[i]>polygons[in_polygon].ymax)

                    polygons[in_polygon].ymax=polygons[in_polygon].y[i];

                polygons[in_polygon].xc+=polygons[in_polygon].x[i];

                polygons[in_polygon].yc+=polygons[in_polygon].y[i];

            }

            polygons[in_polygon].xc=polygons[in_polygon].xc/polygons[in_polygon].nvertices;

            polygons[in_polygon].yc=polygons[in_polygon].yc/polygons[in_polygon].nvertices;

        }

        in_polygon=-1;

        glutPostRedisplay();

        moving=true;

        glutPostRedisplay();

        int j=pick_polygon(x,y);

     if(j>=0)

        {

            lock=j;

        }

    }

}

int pick_polygon(int x,int y)

{//根据每个多边形的包围盒寻找第一个包含拾取位置的多边形

    int i;

for(i=0;i    {

        if(polygons[i].used)

        {

         if((x>=polygons[i].xmin)&&(x<=polygons[i].xmax)&&

             (y>=polygons[i].ymin)&&(y            {

                in_polygon=i;

                moving=TRUE;

                return(i);

            }

        }

    }

    printf("not in a polygon\\n");

    return(-1);

}

void myMotion(int x,int y)

{//判断是否位于多边形内部

    float dx,dy;

    int i,j;

    if(moving)

    {

        y=wh-y;

        j=pick_polygon(x,y);

     if(j<0)

        {

            printf("not in a polygon\\n");

            return;

        }

        if(lock==j){

        //如果位于多边形内部，则移动多边形

        dx=x-polygons[j].xc;

        dy=y-polygons[j].yc;

     for(i=0;i            polygons[j].x[i]+=dx;

            polygons[j].y[i]+=dy;

        }

        polygons[j].xc+=dx;

        polygons[j].yc+=dy;

     if(dx>0) polygons[j].xmax+=dx;

        else polygons[j].xmin+=dx;

     if(dy>0) polygons[j].ymax+=dy;

        else polygons[j].ymin+=dy;

        glutPostRedisplay();

        }

    }

}

void color_menu(int index)

{

    present_color=index;

if(in_polygon>=0) polygons[in_polygon].color=index;

}

void main_menu(int index){

    int i;

    switch(index)

    {

        case(1)://建立一个新的多边形

        {

            moving=FALSE;

         for(i=0;i            if(i==MAX_POLYGONS)

            {

                printf("exceeeded maximum number of polygons\\n");

                exit(0);

            }

            polygons[i].color=present_color;

            polygons[i].used=TRUE;

            polygons[i].nvertices=0;

            in_polygon=i;

            picking=FALSE;

            glutPostRedisplay();

            break;

        }

        case(2)://结束多边形的定义并计算多边形包围盒和它的中心位置

        {

            moving=FALSE;

         if(in_polygon>=0)

            {

                polygons[in_polygon].xmax=polygons[in_polygon].xmin=polygons[in_polygon].x[0];

                polygons[in_polygon].ymax=polygons[in_polygon].ymin=polygons[in_polygon].y[0];

                polygons[in_polygon].xc=polygons[in_polygon].x[0];

                polygons[in_polygon].yc=polygons[in_polygon].y[0];

             for(i=1;i                {

                 if(polygons[in_polygon].x[i]                        polygons[in_polygon].xmin=polygons[in_polygon].x[i];

                 else if(polygons[in_polygon].x[i]>polygons[in_polygon].xmax)

                        polygons[in_polygon].xmax=polygons[in_polygon].x[i];

                 if(polygons[in_polygon].y[i]                        polygons[in_polygon].ymin=polygons[in_polygon].y[i];

                 else if(polygons[in_polygon].y[i]>polygons[in_polygon].ymax)

                        polygons[in_polygon].ymax=polygons[in_polygon].y[i];

                    polygons[in_polygon].xc+=polygons[in_polygon].x[i];

                    polygons[in_polygon].yc+=polygons[in_polygon].y[i];

                }

                polygons[in_polygon].xc=polygons[in_polygon].xc/polygons[in_polygon].nvertices;

                polygons[in_polygon].yc=polygons[in_polygon].yc/polygons[in_polygon].nvertices;

            }

            in_polygon=-1;

            glutPostRedisplay();

            break;

        }

    case(3)://设置拾取模式

        {

            picking=TRUE;

            moving=FALSE;

            break;

        }

    case(4)://设置移动模式

        {

            moving=TRUE;

            glutPostRedisplay();

            break;

        }

    case(5)://退出

        {

            exit(0);

            break;

        }

    case(6)://保存

        {

            save();

            break;

        }

    }

}

void myDisplay()

{//显示所有的活动多边形

    int i,j;

    glClear(GL_COLOR_BUFFER_BIT);

for(i=0;i    {

        if(polygons[i].used)

        {

            glColor3fv(colors[polygons[i].color]);

            glBegin(GL_POLYGON);

         for(j=0;j                glVertex2i(polygons[i].x[j],polygons[i].y[j]);

            glEnd();

        }

    }

/*    printf("%d\\n",in_polygon);

if(in_polygon>=0){

        int k=in_polygon;

        glColor3fv(colors[polygons[k].color]);

        glBegin(GL_LINE_STRIP);

        int s;

     for(s=0;s            printf("haha%d\\n",s);

            glVertex2i(polygons[k].x[s],polygons[k].y[s]);

        }

        glEnd();

    }*/

    glFlush();

}

void main(int argc,char ** argv)

{    

    int c_menu;

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);

    glutInitWindowSize(500,500);

    glutCreateWindow("polygon modeler");

    glutDisplayFunc(myDisplay);

    myinit();

    c_menu=glutCreateMenu(color_menu);

    glutAddMenuEntry("Black",0);

    glutAddMenuEntry("Red",1);

    glutAddMenuEntry("Green",2);

    glutAddMenuEntry("Blue",3);

    glutAddMenuEntry("Cyan",4);

    glutAddMenuEntry("Magenta",5);

    glutAddMenuEntry("Yellow",6);

    glutAddMenuEntry("White",7);

    glutCreateMenu(main_menu);

    glutAddMenuEntry("new polygon",1);

    glutAddMenuEntry("end polygon",2);

    glutAddMenuEntry("delete polygon",3);

    glutAddMenuEntry("move polygon",4);

    glutAddMenuEntry("quit",5);

    glutAddMenuEntry("save",6);

    glutAddSubMenu("Colors",c_menu);

    glutAttachMenu(GLUT_RIGHT_BUTTON);

    glutReshapeFunc(myReshape);

    glutMouseFunc(myMouse);

    glutMotionFunc(myMotion);

    glutMainLoop();

}