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：


计算机图形学 Opengl" TITLE="8连通、4连通的洪泛填充以及边界填充 计算机图形学 Opengl" />

【注】主要代码如下：//实现多边形的简单填充

#include<windows.h>
#ifdef
__APPLE__

#include <GLUT/glut.h>

#else

#include <GL/glut.h>

#endif
#include
<stdlib.h>
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。


计算机图形学 Opengl" TITLE="8连通、4连通的洪泛填充以及边界填充 计算机图形学 Opengl" />
【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。


计算机图形学 Opengl" TITLE="8连通、4连通的洪泛填充以及边界填充 计算机图形学 Opengl" />
【注】主要代码如下：

//实现多边形的简单填充

#include<windows.h>
#ifdef
__APPLE__

#include <GLUT/glut.h>

#else

#include <GL/glut.h>

#endif
#include
<stdlib.h>

#include <math.h>

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;

}