Fix issue #2525: Diff renders incorrectly with "Cascadia Mono" variant

Externals/crystaledit/editlib/renderers/ccrystalrendererdirectwrite.cpp

@@ -297,17 +297,74 @@ static D2D1_SIZE_F GetCharWidthHeight(IDWriteTextFormat *pTextFormat)
 	return {textMetrics.width, textMetrics.height};
 }
 
+static CComPtr<IDWriteFont> CreateFontFromLOGFONT(const LOGFONT& logFont)
+{
+	IDWriteFactory *pDWriteFactory = AfxGetD2DState()->GetWriteFactory();
+	CComPtr<IDWriteGdiInterop> gdiInterop;
+	HRESULT hr = pDWriteFactory->GetGdiInterop(&gdiInterop);
+	if (FAILED(hr))
+		return nullptr;
+	CComPtr<IDWriteFont> dwriteFont;
+	hr = gdiInterop->CreateFontFromLOGFONT(&logFont, &dwriteFont);
+	if (FAILED(hr))
+		return nullptr;
+	return dwriteFont;
+}
+
+static void GetFontFamilyNameFromFont(IDWriteFont* pFont, wchar_t* fontFamilyName, size_t bufsize)
+{
+	if (!pFont)
+		return;
+	CComPtr<IDWriteFontFamily> pFontFamily;
+	HRESULT hr = pFont->GetFontFamily(&pFontFamily);
+	if (FAILED(hr))
+		return;
+	CComPtr<IDWriteLocalizedStrings> pLocalizedStrings;
+	hr = pFontFamily->GetFamilyNames(&pLocalizedStrings);
+	if (FAILED(hr))
+		return;
+	UINT32 index = 0;
+	BOOL exists = FALSE;
+	hr = pLocalizedStrings->FindLocaleName(L"en-us", &index, &exists);
+	if (FAILED(hr) || !exists)
+		index = 0;
+	UINT32 length = 0;
+	pLocalizedStrings->GetStringLength(index, &length);
+	pLocalizedStrings->GetString(index, fontFamilyName, (std::max)(length + 1, static_cast<UINT32>(bufsize)));
+}
+
+static DWRITE_FONT_WEIGHT GetDWriteFontWeight(const LOGFONT& lf, bool bold)
+{
+	DWRITE_FONT_WEIGHT result;
+	const long weight = bold ? (lf.lfWeight + 300) : lf.lfWeight;
+	if (weight <= 100) return DWRITE_FONT_WEIGHT_THIN;
+	else if (weight <= 200) return DWRITE_FONT_WEIGHT_EXTRA_LIGHT;
+	else if (weight <= 300) return DWRITE_FONT_WEIGHT_LIGHT;
+	else if (weight <= 350) return DWRITE_FONT_WEIGHT_SEMI_LIGHT;
+	else if (weight <= 400) return DWRITE_FONT_WEIGHT_NORMAL;
+	else if (weight <= 500) return DWRITE_FONT_WEIGHT_MEDIUM;
+	else if (weight <= 600) return DWRITE_FONT_WEIGHT_SEMI_BOLD;
+	else if (weight <= 700) return DWRITE_FONT_WEIGHT_BOLD;
+	else if (weight <= 800) return DWRITE_FONT_WEIGHT_EXTRA_BOLD;
+	else if (weight <= 900) return DWRITE_FONT_WEIGHT_BLACK;
+	else return DWRITE_FONT_WEIGHT_EXTRA_BLACK;
+}
+
 void CCrystalRendererDirectWrite::SetFont(const LOGFONT &lf)
 {
+	CComPtr<IDWriteFont> pFont = CreateFontFromLOGFONT(lf);
+	wchar_t fontFamilyName[256]{};
+	GetFontFamilyNameFromFont(pFont, fontFamilyName, std::size(fontFamilyName));
+
 	m_lfBaseFont = lf;
 	for (int nIndex = 0; nIndex < 4; ++nIndex)
 	{
 		bool bold = (nIndex & 1) != 0;
 		bool italic = (nIndex & 2) != 0;
 		m_pTextFormat[nIndex].reset(new CD2DTextFormat(&m_renderTarget,
-			lf.lfFaceName[0] ? lf.lfFaceName : _T("Courier New"),
+			fontFamilyName[0] ? fontFamilyName : _T("Courier New"),
 			static_cast<FLOAT>(abs(lf.lfHeight == 0 ? 11 : lf.lfHeight)),
-			bold ? DWRITE_FONT_WEIGHT_BOLD : DWRITE_FONT_WEIGHT_NORMAL,
+			GetDWriteFontWeight(lf, bold),
 			italic ? DWRITE_FONT_STYLE_ITALIC : DWRITE_FONT_STYLE_NORMAL));
 		IDWriteTextFormat *pTextFormat = m_pTextFormat[nIndex]->Get();
 		pTextFormat->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_LEADING);
@@ -316,7 +373,7 @@ void CCrystalRendererDirectWrite::SetFont(const LOGFONT &lf)
 	}
 	m_pCurrentTextFormat = m_pTextFormat[0].get();
 	m_pFont.reset();
-	m_charSize = ::GetCharWidthHeight(m_pTextFormat[3]->Get());
+	m_charSize = ::GetCharWidthHeight(m_pTextFormat[0]->Get());
 }
 
 void CCrystalRendererDirectWrite::SwitchFont(bool italic, bool bold)