// XFontSize.cpp  Version 1.0
//
// Author:  Hans Dietrich
//          hdietrich@gmail.com
//
// License:
//     This software is released into the public domain.  You are free to use
//     it in any way you like, except that you may not sell this source code.
//
//     This software is provided "as is" with no expressed or implied warranty.
//     I accept no liability for any damage or loss of business that this 
//     software may cause.
//
///////////////////////////////////////////////////////////////////////////////

#include "stdafx.h"
//#include "windows.h"
#define XFONTSIZE_CPP
#include "XFontSize.h"
#include "tchar.h"

int CXFontSize::m_cyPixelsPerInch = 0;

//=============================================================================
CXFontSize::CXFontSize()
//=============================================================================
{
	Init();
}

//=============================================================================
void CXFontSize::Init()
//=============================================================================
{
	if (m_cyPixelsPerInch == 0)
	{
		HDC hdc = ::CreateDC(_T("DISPLAY"), NULL, NULL, NULL);
		if (hdc)
		{
			m_cyPixelsPerInch = ::GetDeviceCaps(hdc, LOGPIXELSY);
			::DeleteDC(hdc);
		}
	}
}

//=============================================================================
CXFontSize::~CXFontSize()
//=============================================================================
{
}

//=============================================================================
int CXFontSize::GetFontPointSize(int nHeight)
//=============================================================================
{
	Init();
	int nPointSize = 0;
	if (m_cyPixelsPerInch)
	{
		nPointSize = MulDiv(nHeight, 72, m_cyPixelsPerInch);
		if (nPointSize < 0)
			nPointSize = -nPointSize;
	}
	return nPointSize;
}

//=============================================================================
int CXFontSize::GetFontHeight(int nPointSize)
//=============================================================================
{
	Init();
	int nHeight = 0;
	if (m_cyPixelsPerInch)
	{
		nHeight = -MulDiv(nPointSize, m_cyPixelsPerInch, 72);
	}
	return nHeight;
}