DPtoLP.md

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Function name : DPtoLP

Group: Coordinate Space and Transformation - Library: gdi32

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Converts device coordinates into logical coordinates.

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Declaration:

BOOL DPtoLP(
	HDC hdc,           // handle to device context
	LPPOINT lpPoints,  // array of points
	int nCount         // count of points in array
);  

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FoxPro declaration:

DECLARE INTEGER DPtoLP IN gdi32;
	INTEGER hdc,;
	STRING @lpPoints,;
	INTEGER nCount  

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Parameters:

hdc [in] Handle to the device context.

lpPoints [in/out] Pointer to an array of POINT structures. The x- and y-coordinates contained in each POINT structure will be transformed.

nCount [in] Specifies the number of points in the array.

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Return value:

If the function succeeds, the return value is nonzero.

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Comments:

The conversion depends on the mapping mode of the device context, the settings of the origins and extents for the window and viewport, and the world transformation.

LOCAL hWindow, hDC, cBuffer  
hWindow = _screen.HWnd  
hDC = GetWindowDC(hWindow)  
  
cBuffer = num2dword(100) + num2dword(100)  
? DPtoLP(hDC, @cBuffer, 1)  
  
? buf2dword(SUBSTR(cBuffer,1,4)),;  
	buf2dword(SUBSTR(cBuffer,5,4))  
  
= ReleaseDC(hWindow, hDC)

See also: LPtoDP.

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