MFC中逻辑坐标与设备坐标的转换关系
在Windows中,逻辑坐标又称为窗口坐标,设备坐标又称为视口坐标,它们之间的转换关系如下:
xWindow=(xViewport-xViewOrg)x xWinExt/xViewExt+xWinOrg
yWindow=(yViewport-yViewOrg)x yWinExt/yViewExt+yWinOrg
xWiewport=(xWindow-xWinOrg)x xViewExt/xWinext+xViewOrg
yViewPort=(yWindow-yWinOrg)x yViewExt/yWinExt+yViewOrg
其中(xWindow,yWindow)为窗口坐标,(xWinOrg,yWinOrg)为窗口原点坐标,( xWinExt,yWinExt)为窗口范围,(xViewport,yViewPort)为视口坐标,(xViewOrg,yViewOrg)为视口原点坐标,(xViewExt,yViewExt)为视口范围。
可以使用函数DpToLp将设备坐标转换为逻辑坐标,函数LpToDp将逻辑坐标转换为设备坐标