8连通、4连通的洪泛填充以及边界填…

 运用八连通边界填充算法进行多边形的填充

（1）首先通过颜色混合的方式形成一个图形包中函数的对多边形的填充，如下图所示：

【注】主要代码如下：//实现多边形的简单填充
#include

#ifdef __APPLE__
#include
#else
#include
#endif

#include

void init (void)
{
    glClearColor (1.0, 1.0, 1.0, 0.0);  // Set display-window color to white.
    glMatrixMode (GL_PROJECTION);       // Set projection parameters.
    gluOrtho2D (0.0, 200.0, 0.0, 150.0);
}
void lineSegment (void)
{
    glClear (GL_COLOR_BUFFER_BIT);  // Clear display window.
    glColor3f (0.0, 0.0, 1.0);      // Set line segment color to red.
   // glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
    glBegin (GL_POLYGON);
    glShadeModel(GL_TRIANGLES);
        glVertex2i(20,40);
        glVertex2i(25,60);
        glVertex2i(30,70);
        glVertex2i(40,80);
        glColor3f(1.0,0.0,0.0);
        glVertex2i(30,90);
        glVertex2i(20,75);
    glEnd ( );
    glFlush ( );     // Process all OpenGL routines as quickly as possible.
}
int main (int argc, char** argv)
{
    glutInit (&argc, argv);                         // Initialize GLUT.
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);   // Set display mode.
    glutInitWindowPosition (50, 100);   // Set top-left display-window position.
    glutInitWindowSize (400, 300);      // Set display-window width and height.
    glutCreateWindow ("An Example OpenGL Program"); // Create display window.
    init ( );                            // Execute initialization procedure.
    glutDisplayFunc (lineSegment);       // Send graphics to display window.
    glutMainLoop ( );                    // Display everything and wait.
    return 0;
}

 

（2）通过8连通边界填充算法进行填充多边形，多边形边界使用4倍线宽。

【注】主要代码如下：

void BoundaryFill8(int x, int y,Color fillColor,Color borderColor)

{

//在此添加4连通或8连通代码

    Color interColor;

 

    //glReadPixels(x,y,1,1,GL_RGB,GL_UNSIGNED_INT,color);

    getPixel(x,y,interColor);

    if (!rgbColorEqual(interColor,borderColor) && !rgbColorEqual(interColor,fillColor)){

        setPixel(x,y);

        BoundaryFill8(x+1,y,fillColor,borderColor);

        BoundaryFill8(x-1,y,fillColor,borderColor);

        BoundaryFill8(x,y+1,fillColor,borderColor);

        BoundaryFill8(x,y-1,fillColor,borderColor);

        BoundaryFill8(x+1,y+1,fillColor,borderColor);

        BoundaryFill8(x-1,y-1,fillColor,borderColor);

        BoundaryFill8(x-1,y+1,fillColor,borderColor);

        BoundaryFill8(x-1,y-1,fillColor,borderColor);

    }

}

（3）通过4连通洪泛填充算法进行填充多边形，多边形边界使用4倍线宽。

【注】主要代码如下：

//实现多边形的简单填充
#include

#ifdef __APPLE__
#include
#else
#include
#endif

#include
#include
typedef  float Color[3];
bool rgbColorEqual(Color c1,Color c2)
{
 if(fabs(c1[1]-c2[1])<0.001 && fabs(c1[2]-c2[2])<0.001 && fabs(c1[0]-c2[0])<0.001)
  return true;
 else
  return false;
}
void setPixel(GLint x,  GLint y)
{
 glBegin(GL_POINTS);
 glVertex2i(x, y);
 glEnd();
}
void getPixel(GLint x, GLint y, Color c)
{
 glReadPixels(x,y,1,1,GL_RGB,GL_FLOAT,c);
}

void BoundaryFill4(int x, int y,Color fillColor,Color borderColor)
{
 //在此添加4连通或8连通代码
    Color interColor;

    //glReadPixels(x,y,1,1,GL_RGB,GL_UNSIGNED_INT,color);
    getPixel(x,y,interColor);
    if (!rgbColorEqual(interColor,borderColor) && !rgbColorEqual(interColor,fillColor)){
        setPixel(x,y);
        BoundaryFill4(x+1,y,fillColor,borderColor);
        BoundaryFill4(x-1,y,fillColor,borderColor);
        BoundaryFill4(x,y+1,fillColor,borderColor);
        BoundaryFill4(x,y-1,fillColor,borderColor);
    }
}

void FloudFill4(int x, int y,Color fillColor,Color initColor)
{
 //在此添加4连通或8连通代码
    Color interColor;

    //glReadPixels(x,y,1,1,GL_RGB,GL_UNSIGNED_INT,color);
    getPixel(x,y,interColor);
    if (rgbColorEqual(interColor,initColor) && !rgbColorEqual(interColor,fillColor)){
        setPixel(x,y);
        FloudFill4(x+1,y,fillColor,initColor);
        FloudFill4(x-1,y,fillColor,initColor);
        FloudFill4(x,y+1,fillColor,initColor);
        FloudFill4(x,y-1,fillColor,initColor);
    }
}

void BoundaryFill8(int x, int y,Color fillColor,Color borderColor)
{
 //在此添加4连通或8连通代码
    Color interColor;

    //glReadPixels(x,y,1,1,GL_RGB,GL_UNSIGNED_INT,color);
    getPixel(x,y,interColor);
    if (!rgbColorEqual(interColor,borderColor) && !rgbColorEqual(interColor,fillColor)){
        setPixel(x,y);
        BoundaryFill8(x+1,y,fillColor,borderColor);
        BoundaryFill8(x-1,y,fillColor,borderColor);
        BoundaryFill8(x,y+1,fillColor,borderColor);
        BoundaryFill8(x,y-1,fillColor,borderColor);
        BoundaryFill8(x+1,y+1,fillColor,borderColor);
        BoundaryFill8(x-1,y-1,fillColor,borderColor);
        BoundaryFill8(x-1,y+1,fillColor,borderColor);
        BoundaryFill8(x-1,y-1,fillColor,borderColor);
    }
}

void init(void)
{
 glClearColor(1.0,1.0,1.0,0.0);
 glMatrixMode (GL_PROJECTION);
 gluOrtho2D (0.0, 200.0, 0.0, 200.0);

}
void Draw(void)
{
 Color a={1.0,1.0,0.0},b={0.0,1.0,1.0};

 glClear(GL_COLOR_BUFFER_BIT);
    glLineWidth(4.0);
    glViewport(0,0,200,200);
    glColor3fv(b);
 glBegin(GL_LINE_LOOP);
     glVertex2i(90, 40);
     glVertex2i(120, 100);
     glVertex2i(90, 160);
  glVertex2i(60, 160);
  glVertex2i(60, 40);
 glEnd();
 glColor3fv(a);
 BoundaryFill4(70,60,a,b);

 glViewport(200,0,200,200);
    glColor3fv(b);
 glBegin(GL_POLYGON);
     glVertex2i(90, 40);
     glVertex2i(120, 100);
     glVertex2i(90, 160);
  glVertex2i(60, 160);
  glVertex2i(60, 40);
 glEnd();
 glColor3fv(a);
 FloudFill4(70,60,a,b);
    glFlush();
}
int main(int argc, char *argv[])
{
 glutInit(&argc, argv);
 glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
 glutInitWindowPosition(100, 100);
 glutInitWindowSize(400, 200);
 glutCreateWindow("4连通边界和洪泛填充算法！");
 init();
 glutDisplayFunc(Draw);
 glutMainLoop();
 return 0;
}