OpenGL实现边缘填充算法_C/C++

OpenGL实现边缘填充算法

2021-08-17 14:55BYSora C/C++

这篇文章主要为大家详细介绍了OpenGL实现边缘填充算法，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

边缘填充的思想：枚举每一条边，对这条边右边的像素进行求补操作，就是有填充则去掉，无填充就进行填充

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									#include <GL/gl.h>

									#include <GL/glut.h>

									#include <iostream>

									#include <cmath>

									#include <cstring>

									#include <string>

									using namespace std;

									int x[]= {10,70,70,60,40,30,20};

									int y[]= {10,10,50,40,60,20,30};

									int vis[500][500]; //判断该坐标的点是否存在

									void init()

									{

									 glClearColor (0.0, 0.0, 0.0, 0.0);

									 glMatrixMode (GL_PROJECTION);

									 gluOrtho2D (0.0, 200.0, 0.0, 150.0);

									}

									void MidBresenhamCircle()

									{

									 memset(vis,0,sizeof(vis));

									 glClear(GL_COLOR_BUFFER_BIT);

									 glLineWidth(2);

									 glBegin(GL_LINES); //绘制多边形形状

									 for(int i=0; i<7; ++i)

									 {

									  glVertex2i(x[i],y[i]);

									  glVertex2i(x[(i+1)%7],y[(i+1)%7]);

									 }

									 glEnd();

									 glFlush();

									 glPointSize(2);

									 glBegin(GL_POINTS);

									 for(int i=x[1],j=y[1]; i<300; ++i) //特殊处理k=0的边

									 {

									  if(!vis[i][j])

									  {

									   glColor3f(0.0f,1.0f,0.0f);

									   glVertex2i(i,j);

									   vis[i][j]=1;

									  }

									  else

									  {

									   glColor3f(0.0f,0.0f,0.0f);

									   glVertex2i(i,j);

									   vis[i][j]=1;

									  }

									 }

									 for(int j=y[1]; j<=y[2]; ++j) //特殊处理k不存在的边

									 {

									  for(int i=x[1]; i<300; ++i)

									  {

									   if(!vis[i][j])

									   {

									    glColor3f(0.0f,1.0f,0.0f);

									    glVertex2i(i,j);

									    vis[i][j]=1;

									   }

									   else

									   {

									    glColor3f(0.0f,0.0f,0.0f);

									    glVertex2i(i,j);

									    vis[i][j]=1;

									   }

									  }

									 }

									 for(int p=2; p<7; ++p)

									 {

									  int k=(y[(p+1)%7]-y[p])/(x[(p+1)%7]-x[p]); //求出斜率

									  int x1=x[(p+1)%7],x0=x[p],y1=y[(p+1)%7],y0=y[p]; //根据斜率推导出这条直线的各个点

									  if(y1<y0)

									  {

									   swap(x1,x0);

									   swap(y1,y0);

									  }

									  for(int j=y0; j<=y1; ++j)

									  {

									   int i=(j-y0+k*x0)/k;

									   for(int px=i; px<300; ++px)

									   {

									    if(!vis[px][j])

									    {

									     glColor3f(0.0f,1.0f,0.0f);

									     glVertex2i(px,j);

									     vis[px][j]=1;

									    }

									    else

									    {

									     glColor3f(0.0f,0.0f,0.0f);

									     glVertex2i(px,j);

									     vis[px][j]=0;

									    }

									   }

									  }

									 }

									 glEnd();

									 glFlush();

									}

									int main(int argc, char *argv[])

									{

									 glutInit(&argc, argv);

									 glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);

									 glutInitWindowPosition(100, 100);

									 glutInitWindowSize(500, 500);

									 glutCreateWindow("第一个opengl程序");

									 init();

									 glutDisplayFunc(MidBresenhamCircle);

									 glutMainLoop();

									 return 0;

									}