//DDA算法
//直线的端点坐标(x0,y0),(x1,y1)
void CquhongjuanView::draw_line_dda(CDC*& pDC,int x0, int x1, int y0, int y1)
{
//ss.str(L"");
double k;//斜率
if(x1!=x0&&fabs(k=(y1-y0)*1.0/(x1-x0))<=1) //斜率<=1时
{
//交换
if(x0>x1)
{
swap(x0,x1);
swap(y0,y1);
}
double y=y0;
for(int x=x0;x<=x1;x++)
{
pDC->SetPixel(x,int(y+0.5),RGB(255,0,0));//绘制像素点
//ss<<"("<<x<<","<<y<<")"<<((x-x0+1)%15?" ":"\n");
y+=k;
}
}else //斜率>1时
&nb