Breaseman算法绘制圆形|中点算法绘制圆形_程序片段

Breaseman算法绘制圆形|中点算法绘制圆形_程序片段

1. Breaseman算法绘制圆形程序

　　由于算法的特殊性，限制绘制第一象限部分，其他部分通过旋转绘制。

 void CCGProjectWorkView::bresenHam_1P4Circle(int radium, const float lineColor[])
 {
     int pointX, pointY, deltD, deltHD, deltDV, direction;
     pointX = ;
     pointY = radium;
     deltD = *(-radium);

     glColor3f(lineColor[], lineColor[], lineColor[]);
     glBegin(GL_POINTS);
     while (pointY >= )
     {
         glVertex3f(pointX, pointY, );
         if (deltD < )//D点在圆内
         {
             deltHD = *(deltD+pointY)-;
             if (deltHD <= )
                 direction = ;// H 点距离最近
             else
                 direction = ;// D 点距离最近
         }
         else if (deltD > )//D点在圆外
         {
             deltDV = *(deltD -pointX)-;
             if(deltDV <= )// D点里的最贱
                 direction = ;
             else
                 direction = ;//V点距离最近
         }
         else
             direction = ;//D在圆上
         switch(direction)
         {
         case :
             //H点位置
             pointX++;
             deltD += *pointX+;
             break;
         case :
             //D点位置
             pointX++;
             pointY--;
             deltD += *(pointX-pointY+);
             break;
         case :
             //V点位置
             pointY--;
             deltD += (-*pointY+);
             break;
         default :
             break;
         }
     }
     glEnd();

 }

2. 中点算法绘制圆形

　　由于算法的特殊性，程序限制第一象限的1/8部分。

 //之画出正上方位于第一象限的左边的1/8园
 void CCGProjectWorkView::midPoint_1P8Circle(int radium, const float lineColor[])
 {
     int pointX, pointY, r;
     float distJugeFactor;
     r = radium;
     int deltX, deltY;//评判因子中x与y的个分量的递推分量
     deltX = ;
     deltY =  - r - r;
     distJugeFactor =  - r;

     pointX = ;
     pointY = radium;
     glColor3f(lineColor[], lineColor[], lineColor[]);
     glBegin(GL_POINTS);
         glVertex3f(pointX, pointY, );
         while (pointX < pointY)
         {
             if (distJugeFactor < )//中点位于圆内
             {
                 distJugeFactor += deltX;
                 deltX += ;
                 pointX++;
             }
             else
             {
                 distJugeFactor += deltX + deltY;
                 deltX += ;
                 deltY += ;
                 pointX++;
                 pointY--;
             }
             glVertex3f(pointX, pointY, );
         }
     glEnd();

 }