rainmeter-studio/Common/Gfx/Util/DWriteHelpers.cpp

/*
  Copyright (C) 2013 Birunthan Mohanathas

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#include "DWriteHelpers.h"
#include <wrl/client.h>
#include <cmath>

namespace Gfx {
namespace Util {

DWRITE_TEXT_METRICS GetAdjustedDWriteTextLayoutMetrics(
	IDWriteTextLayout* textLayout, bool gdiEmulation, bool containsNewLine)
{
	DWRITE_TEXT_METRICS metrics;
	textLayout->GetMetrics(&metrics);

	if (gdiEmulation)
	{
		float size = 0.0f;
		textLayout->GetFontSize(0, &size);
		metrics.width = floor(metrics.width + ((size / 3.0f) * 2.0f) + ((size * 3.0f / 4.0f) / 17.5f) + 0.255f);
		
		if (containsNewLine)
		{
			metrics.width -= ((size * 3.0f / 4.0f) / 4.0f);
		}

		metrics.height = floor(metrics.height + (size / 9.25f) + 0.3f); 
	}

	return metrics;
}

HRESULT GetDWritePropertiesFromGDIProperties(
	IDWriteFactory* factory, const WCHAR* gdiFamilyName, const bool gdiBold, const bool gdiItalic,
	DWRITE_FONT_WEIGHT& dwriteFontWeight, DWRITE_FONT_STYLE& dwriteFontStyle,
	DWRITE_FONT_STRETCH& dwriteFontStretch, WCHAR* dwriteFamilyName, UINT dwriteFamilyNameSize)
{
	HRESULT hr = E_FAIL;
	IDWriteFont* dwriteFont = CreateDWriteFontFromGDIFamilyName(factory, gdiFamilyName);
	if (dwriteFont)
	{
		hr = GetFamilyNameFromDWriteFont(dwriteFont, dwriteFamilyName, dwriteFamilyNameSize);
		if (SUCCEEDED(hr))
		{
			GetPropertiesFromDWriteFont(
				dwriteFont, gdiBold, gdiItalic, &dwriteFontWeight, &dwriteFontStyle, &dwriteFontStretch);
		}

		dwriteFont->Release();
	}

	return hr;
}

void GetPropertiesFromDWriteFont(
	IDWriteFont* dwriteFont, const bool bold, const bool italic,
	DWRITE_FONT_WEIGHT* dwriteFontWeight, DWRITE_FONT_STYLE* dwriteFontStyle,
	DWRITE_FONT_STRETCH* dwriteFontStretch)
{
	*dwriteFontWeight = dwriteFont->GetWeight();
	if (bold)
	{
		if (*dwriteFontWeight == DWRITE_FONT_WEIGHT_NORMAL)
		{
			*dwriteFontWeight = DWRITE_FONT_WEIGHT_BOLD;
		}
		else if (*dwriteFontWeight < DWRITE_FONT_WEIGHT_ULTRA_BOLD)
		{
			// If 'gdiFamilyName' was e.g. 'Segoe UI Light', |dwFontWeight| wil be equal to
			// DWRITE_FONT_WEIGHT_LIGHT. If |gdiBold| is true in that case, we need to
			// increase the weight a little more for similar results with GDI+.
			// TODO: Is +100 enough?
			*dwriteFontWeight = (DWRITE_FONT_WEIGHT)(*dwriteFontWeight + 100);
		}
	}

	*dwriteFontStyle = dwriteFont->GetStyle();
	if (italic && *dwriteFontStyle == DWRITE_FONT_STYLE_NORMAL)
	{
		*dwriteFontStyle = DWRITE_FONT_STYLE_ITALIC;
	}

	*dwriteFontStretch = dwriteFont->GetStretch();
}

IDWriteFont* CreateDWriteFontFromGDIFamilyName(IDWriteFactory* factory, const WCHAR* gdiFamilyName)
{
	Microsoft::WRL::ComPtr<IDWriteGdiInterop> dwGdiInterop;
	HRESULT hr = factory->GetGdiInterop(dwGdiInterop.GetAddressOf());
	if (SUCCEEDED(hr))
	{
		LOGFONT lf = {};
		wcscpy_s(lf.lfFaceName, gdiFamilyName);
		lf.lfHeight = -12;
		lf.lfWeight = FW_DONTCARE;
		lf.lfCharSet = DEFAULT_CHARSET;
		lf.lfOutPrecision = OUT_DEFAULT_PRECIS;
		lf.lfClipPrecision = CLIP_DEFAULT_PRECIS;
		lf.lfQuality = ANTIALIASED_QUALITY;
		lf.lfPitchAndFamily = VARIABLE_PITCH;

		IDWriteFont* dwFont;
		hr = dwGdiInterop->CreateFontFromLOGFONT(&lf, &dwFont);
		if (SUCCEEDED(hr))
		{
			return dwFont;
		}
	}

	return nullptr;
}

HRESULT GetFamilyNameFromDWriteFont(IDWriteFont* font, WCHAR* buffer, const UINT bufferSize)
{
	IDWriteFontFamily* dwriteFontFamily;
	HRESULT hr = font->GetFontFamily(&dwriteFontFamily);
	if (SUCCEEDED(hr))
	{
		hr = GetFamilyNameFromDWriteFontFamily(dwriteFontFamily, buffer, bufferSize);
		dwriteFontFamily->Release();
	}

	return hr;
}

HRESULT GetFamilyNameFromDWriteFontFamily(
	IDWriteFontFamily* fontFamily, WCHAR* buffer, const UINT bufferSize)
{
	IDWriteLocalizedStrings* dwFamilyNames;
	HRESULT hr = fontFamily->GetFamilyNames(&dwFamilyNames);
	if (SUCCEEDED(hr))
	{
		// TODO: Determine the best index?
		hr = dwFamilyNames->GetString(0, buffer, bufferSize);
		dwFamilyNames->Release();
	}

	return hr;
}

bool IsFamilyInSystemFontCollection(IDWriteFactory* factory, const WCHAR* familyName)
{
	bool result = false;
	IDWriteFontCollection* systemFontCollection;
	HRESULT hr = factory->GetSystemFontCollection(&systemFontCollection);
	if (SUCCEEDED(hr))
	{
		UINT32 familyNameIndex;
		BOOL familyNameFound;
		HRESULT hr = systemFontCollection->FindFamilyName(
			familyName, &familyNameIndex, &familyNameFound);
		if (SUCCEEDED(hr) && familyNameFound)
		{
			result = true;
		}

		systemFontCollection->Release();
	}

	return result;
}

HRESULT GetGDIFamilyNameFromDWriteFont(IDWriteFont* font, WCHAR* buffer, UINT bufferSize)
{
	Microsoft::WRL::ComPtr<IDWriteLocalizedStrings> strings;
	BOOL stringsExist;
	font->GetInformationalStrings(
		DWRITE_INFORMATIONAL_STRING_WIN32_FAMILY_NAMES, strings.GetAddressOf(), &stringsExist);
	if (strings && stringsExist)
	{
		return strings->GetString(0, buffer, bufferSize);
	}

	return E_FAIL;
}

IDWriteFont* FindDWriteFontInFontFamilyByGDIFamilyName(
	IDWriteFontFamily* fontFamily, const WCHAR* gdiFamilyName)
{
	const UINT32 fontFamilyFontCount = fontFamily->GetFontCount();
	for (UINT32 j = 0; j < fontFamilyFontCount; ++j)
	{
		IDWriteFont* font;
		HRESULT hr = fontFamily->GetFont(j, &font);
		if (SUCCEEDED(hr))
		{
			WCHAR buffer[LF_FACESIZE];
			hr = GetGDIFamilyNameFromDWriteFont(font, buffer, _countof(buffer));
			if (SUCCEEDED(hr) && _wcsicmp(gdiFamilyName, buffer) == 0)
			{
				return font;
			}

			font->Release();
		}
	}

	return nullptr;
}

IDWriteFont* FindDWriteFontInFontCollectionByGDIFamilyName(
	IDWriteFontCollection* fontCollection, const WCHAR* gdiFamilyName)
{
	const UINT32 fontCollectionFamilyCount = fontCollection->GetFontFamilyCount();
	for (UINT32 i = 0; i < fontCollectionFamilyCount; ++i)
	{
		IDWriteFontFamily* fontFamily;
		HRESULT hr = fontCollection->GetFontFamily(i, &fontFamily);
		if (SUCCEEDED(hr))
		{
			IDWriteFont* font = FindDWriteFontInFontFamilyByGDIFamilyName(
				fontFamily, gdiFamilyName);
			fontFamily->Release();

			if (font)
			{
				return font;
			}
		}
	}

	return nullptr;
}

}  // namespace Util
}  // namespace Gfx