计算机图形学——直线扫描转换基本增量法

void dda(HDC hdc)
{

    float dx,dy;
    int k;
    float x;
    float y;
    HPEN       pen=NULL;
    pen = CreatePen(PS_SOLID,5,RGB(255,0,0));
    SelectObject(hdc,pen);


    k=_abs(x2-x1);
    if(_abs(y2-y1)>k)
        k=_abs(y2-y1);
    dx=(x2-x1)/k;
    dy=(y2-y1)/k;
    x=x1;
    y=y1;
    

    for(int i=0;i<=k;i++)
    {
        MoveToEx(hdc, (int)(x+0.5f)*20,(int)(y+0.5f)*20, NULL);
        LineTo(hdc,(int)(x+0.5f)*20,(int)(y+0.5f)*20);
        x=x+dx;
        y=y+dy;

    }
}