老哥们为什么我用mfc画线的时候最新的那个端点一直链接原点是怎么回事，感觉主要问题是在那一串星号下面的代码，因为那个点的颜色会随那个rgb一起改变
那个原点会一直连接我最新的控制点和绘制出来的曲线的点
void CbView::DoubleBuffer(CDC* pDC) {
CRect rect;
GetClientRect(&rect);
nClientWidth = rect.Width();
nClientHeight = rect.Height();
pDC->SetMapMode(MM_ANISOTROPIC);
pDC->SetWindowExt(rect.Width(), rect.Height());
pDC->SetViewportExt(rect.Width(), -rect.Height());
pDC->SetViewportOrg(rect.Width() / 2, rect.Height() / 2);
CDC memDC;//内存DC
memDC.CreateCompatibleDC(pDC);//创建一个与显示pDC兼容的内存memDC
CBitmap NewBitmap, * pOldBitmap;//内存中承载的临时位图
NewBitmap.CreateCompatibleBitmap(pDC, rect.Width(), rect.Height());//创建兼容位图
pOldBitmap = memDC.SelectObject(&NewBitmap);//将兼容位图选入memDC
memDC.FillSolidRect(rect, pDC->GetBkColor());
rect.OffsetRect(-rect.Width() / 2, -rect.Height() / 2);
memDC.SetMapMode(MM_ANISOTROPIC);//内存自定义DC坐标系
memDC.SetWindowExt(rect.Width(), rect.Height());
memDC.SetViewportExt(rect.Width(), -rect.Height());
memDC.SetViewportOrg(rect.Width() / 2, rect.Height() / 2);
*************************
CPen NewPen, * pOldPen;
NewPen.CreatePen(PS_SOLID, 3, RGB(255, 0, 0));
pOldPen = memDC.SelectObject(&NewPen);
CBrush NewBrush, * pOldBrush;
pOldBrush = (CBrush*)memDC.SelectStockObject(BLACK_BRUSH);
for (int i = 0; i < max; i++) {
if (i == 0) {
memDC.MoveTo(P[i].x,P[i].y);
memDC.Ellipse(Round(P[i].x) - 5, Round(P[i].y) - 5, Round(P[i].x) + 5, Round(P[i].y) + 5);
}
else{
memDC.LineTo(Round(P[i].x), Round(P[i].y));
memDC.Ellipse(Round(P[i].x) - 5, Round(P[i].y) - 5, Round(P[i].x) + 5, Round(P[i].y) + 5);
}
}
if (CtrlPtNum != -1) {
CString str;
str.Format(_T(" x=%.0f,y=%.0f"), P[CtrlPtNum].x, P[CtrlPtNum].y);
memDC.TextOut(Round(P[CtrlPtNum].x) + 5, Round(P[CtrlPtNum].y) + 5, str);
}
pDC->SelectObject(pOldBrush);
memDC.SelectObject(pOldPen);
DrawBSplineCurve(&memDC);//绘制曲线
pDC->BitBlt(rect.left, rect.top, rect.Width(), rect.Height(), &memDC, -rect.Width() / 2, -rect.Height() / 2, SRCCOPY);
//pDC->BitBlt(rect.left, rect.top, rect.Width(), rect.Height(), &memDC, NULL, NULL, SRCCOPY);
memDC.SelectObject(pOldBitmap);
NewBitmap.DeleteObject();
memDC.DeleteDC();}
void CbView::OnMouseMove(UINT nFlags, CPoint point)
{
//TODO: 在此添加消息处理程序代码和/或调用默认值
CString str;
str.Format(_T("[%d,%d] "), point.x - nClientWidth / 2, nClientHeight / 2 - point.y); //引号中的两个空格是为了消除重叠现象
CDC* pDC = GetDC();
pDC->TextOut(0, 0, str); //窗口左上角坐标为（0，0），修改可改变鼠标坐标的显示位置
pDC->MoveTo(nClientWidth / 2, nClientHeight / 2);
pDC->LineTo(nClientWidth / 2, nClientHeight / 2);
if (TRUE == bMove)
{
if (CtrlPtNum == -1) { CtrlPtNum = 0; }
else {
P[CtrlPtNum] =Convert( point);
}
}
CtrlPtNum = -1;
int i;
for (i = 0; i < max; i++) {
CP2 CursorPt = Convert (point);//得到鼠标当前位置并且将点存在变量中
CString str1;
if ((CursorPt.x - P[i].x) * (CursorPt.x - P[i].x) + (CursorPt.y - P[i].y) * (CursorPt.y - P[i].y) < 25) //如果鼠标与某个控制点的距离不超过5个像素点认为当前鼠标指向点
{
CtrlPtNum = i;
bLBtnDown = TRUE;
SetCursor(LoadCursor(NULL, IDC_SIZEALL));//鼠标改
break;
}
}
if (max == i)
{
CtrlPtNum = -1;
}
ReleaseDC(pDC);
Invalidate(FALSE);
CView::OnMouseMove(nFlags, point);
}
void CbView::DrawBSplineCurve(CDC * pDC)//绘制曲线
{
// TODO: 在此处添加实现代码.
CPen redPen, greenPen, * pOldPen;
redPen.CreatePen(PS_SOLID, 2, RGB(255, 0, 0));
greenPen.CreatePen(PS_SOLID, 2, RGB(0, 255, 0));
CP2 pt;//曲线上的当前点
pt.x = Round((P[0].x + 4.0 * P[1].x + P[2].x) / 6);
pt.y = Round((P[0].y + 4.0 * P[1].y + P[2].y) / 6);
pOldPen = pDC->SelectObject(&greenPen);
pDC->Ellipse(Round(pt.x) - 5, Round(pt.y) - 5, Round(pt.x) + 5, Round(pt.y) + 5);
pDC->SelectObject(pOldPen);
pDC->MoveTo(Round(pt.x), Round(pt.y));
for (int i = 3; i < max; i++) {
for (double t = 0.0; t <= 1; t += 0.01) {
double F03 = (-t * t * t + 3 * t * t - 3 * t + 1) / 6;
double F13 = (3 * t * t * t - 6 * t * t + 4) / 6;
double F23 = (-3 * t * t * t + 3 * t * t + 3 * t + 1) / 6;
double F33 = t * t * t / 6;
pt.x = P[i - 3].x* F03 + P[i-2].x * F13 + P[i - 1].x * F23 +P[i].x* F33;
pt.y = P[i - 3].y * F03 + P[i - 2].y * F13 + P[i - 1].y * F23 + P[i].y * F33;
pDC->LineTo(Round(pt.x),Round(pt.y));//绘制曲线
}
pOldPen = pDC->SelectObject(&greenPen);
pDC->Ellipse(Round(pt.x) - 5, Round(pt.y) - 5, Round(pt.x) + 5, Round(pt.y) + 5);
pDC->SelectObject(pOldPen);
}
pDC->SelectObject(pOldPen);
}
CP2 CbView::Convert(CPoint point) {
CP2 pt;
pt.x = point.x - nClientWidth / 2;
pt.y = nClientHeight / 2 - point.y;
return pt;
}
void CbView::OnLButtonDown(UINT nFlags, CPoint point)
{
// TODO: 在此添加消息处理程序代码和/或调用默认值
if (Brd)
{
P[j] = Convert(point);
if (j < max - 1) j++;
else Brd = FALSE;
}
if (bLBtnDown == TRUE)
{
bMove = TRUE;
}
CView::OnLButtonDown(nFlags, point);
}
void CbView::OnLButtonUp(UINT nFlags, CPoint point)
{
// TODO: 在此添加消息处理程序代码和/或调用默认值
bLBtnDown = FALSE;
bMove = FALSE;
//CtrlPtNum = 0;
CView::OnLButtonUp(nFlags, point);
}
