C++ IDWriteFont::GetStyle方法代码示例

ULONG GetBestFontAttributes(IDWriteFontCollection* fontCollection, const WCHAR* fontFamilyName, const FontFaceInfo& desiredAttributes)
{
    DWRITE_FONT_WEIGHT  fontWeight  = desiredAttributes.fontWeight;
    DWRITE_FONT_STYLE   fontStyle   = desiredAttributes.fontStyle;
    DWRITE_FONT_STRETCH fontStretch = desiredAttributes.fontStretch;

    IDWriteFontFamily*  fontFamily = NULL;
    IDWriteFont*        font = NULL;

    if (SUCCEEDED(GetFontFamily(fontCollection, fontFamilyName, &fontFamily)))
    {
        if (SUCCEEDED(fontFamily->GetFirstMatchingFont(fontWeight, fontStretch, fontStyle, &font)))
        {
            fontWeight = font->GetWeight();
            fontStyle = font->GetStyle();
            fontStretch = font->GetStretch();
        }
    }

    SafeRelease(&font);
    SafeRelease(&fontFamily);

    FontFaceInfo fontFaceInfo(L"", fontWeight, fontStyle, fontStretch);

    return fontFaceInfo.PackedFontAttributes();
}

bool TextFormatD2D::GetDWPropertiesFromGDIProperties(
	const WCHAR* gdiFamilyName, const bool gdiBold, const bool gdiItalic,
	DWRITE_FONT_WEIGHT& dwFontWeight, DWRITE_FONT_STYLE& dwFontStyle,
	DWRITE_FONT_STRETCH& dwFontStretch, WCHAR* dwFamilyName, UINT dwFamilyNameSize)
{
	bool result = false;
	IDWriteFont* dwFont = CreateDWFontFromGDIFamilyName(gdiFamilyName);
	if (dwFont)
	{
		if (GetFamilyNameFromDWFont(dwFont, dwFamilyName, dwFamilyNameSize))
		{
			dwFontWeight = dwFont->GetWeight();
			if (gdiBold)
			{
				if (dwFontWeight == DWRITE_FONT_WEIGHT_NORMAL)
				{
					dwFontWeight = DWRITE_FONT_WEIGHT_BOLD;
				}
				else if (dwFontWeight < 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?
					dwFontWeight = (DWRITE_FONT_WEIGHT)(dwFontWeight + 100);
				}
			}

			dwFontStyle = dwFont->GetStyle();
			if (gdiItalic && dwFontStyle == DWRITE_FONT_STYLE_NORMAL)
			{
				dwFontStyle = DWRITE_FONT_STYLE_ITALIC;
			}

			dwFontStretch = dwFont->GetStretch();

			result = true;
		}

		dwFont->Release();
	}

	return result;
}

static void styleChanged(struct fontDialog *f)
{
	LRESULT pos;
	BOOL selected;
	IDWriteFont *font;

	selected = cbGetCurSel(f->styleCombobox, &pos);
	if (!selected)		// on deselect, do nothing
		return;
	f->curStyle = pos;

	font = (IDWriteFont *) cbGetItemData(f->styleCombobox, (WPARAM) (f->curStyle));
	// these are for the nearest match when changing the family; see below
	f->weight = font->GetWeight();
	f->style = font->GetStyle();
	f->stretch = font->GetStretch();

	queueRedrawSampleText(f);
}

//.........这里部分代码省略.........

        // Select the first locale.  This is OK, because we are not displaying the family name.
        index = 0;
        
        // Get the length of the family name.
        if (SUCCEEDED(hr))
        {
            hr = pFamilyNames->GetStringLength(index, &length);
        }

        if (SUCCEEDED(hr))
        {
            // Allocate a new string.
            name = new (std::nothrow) wchar_t[length+1];
		    if (name == NULL)
            {
			    hr = E_OUTOFMEMORY;
            }
        }

        // Get the actual family name.
        if (SUCCEEDED(hr))
        {
            hr = pFamilyNames->GetString(index, name, length+1);
        }

        if (SUCCEEDED(hr))
        {
            // Calculate the font size.
            fontSize = (float) -MulDiv(lf.lfHeight, 96, GetDeviceCaps(hdc, LOGPIXELSY));
        }

        // Create a text format using the converted font information.
        if (SUCCEEDED(hr))
        {
            hr = g_pDWriteFactory->CreateTextFormat(
                name,                // Font family name.
                NULL,                        
                pFont->GetWeight(),
                pFont->GetStyle(),
                pFont->GetStretch(),
                fontSize,
                L"en-us",
                &g_pTextFormat
                );
        }

        // Create a text layout.
        if (SUCCEEDED(hr))
        {
            hr = g_pDWriteFactory->CreateTextLayout(
                text,
                textLength,
                g_pTextFormat,
                1024.0f,
                480.0f,
                &g_pTextLayout
                );
        }

        // Underline and strikethrough are part of a LOGFONT structure, but are not
        // part of a DWrite font object so we must set them using the text layout.
        if(lf.lfUnderline)
        {
            DWRITE_TEXT_RANGE textRange = {0, textLength};
            g_pTextLayout->SetUnderline(true, textRange);
        }

        if(lf.lfStrikeOut)
        {
            DWRITE_TEXT_RANGE textRange = {0, textLength};
            g_pTextLayout->SetStrikethrough(true, textRange);
        }
        
        // Create a bitmap render target for our custom renderer.
        if (SUCCEEDED(hr))
        {
            hr = g_pGdiInterop->CreateBitmapRenderTarget(hdc, r.right, r.bottom, &g_pBitmapRenderTarget);
        }
        
        // Create default rendering params for our custom renderer.
        if (SUCCEEDED(hr))
        {
            hr = g_pDWriteFactory->CreateRenderingParams(&g_pRenderingParams);
        }

        if (SUCCEEDED(hr))
        {
            // Initialize the custom renderer class.
		    g_pGdiTextRenderer = new (std::nothrow) GdiTextRenderer(g_pBitmapRenderTarget, g_pRenderingParams);
        }

        // Clean up local interfaces.
        SafeRelease(&pFontFamily);
        SafeRelease(&pFont);
        SafeRelease(&pFamilyNames);
    }

    return hr;
}

    HRESULT
DWriteContext::SetLOGFONT(const LOGFONTW &logFont, float fontSize)
{
    // Most of this function is copy from: http://msdn.microsoft.com/en-us/library/windows/desktop/dd941783(v=vs.85).aspx
    HRESULT hr = S_OK;

    IDWriteFont *font = NULL;
    IDWriteFontFamily *fontFamily = NULL;
    IDWriteLocalizedStrings *localizedFamilyNames = NULL;

    if (SUCCEEDED(hr))
    {
	hr = mGdiInterop->CreateFontFromLOGFONT(&logFont, &font);
    }

    // Get the font family to which this font belongs.
    if (SUCCEEDED(hr))
    {
	hr = font->GetFontFamily(&fontFamily);
    }

    // Get the family names. This returns an object that encapsulates one or
    // more names with the same meaning but in different languages.
    if (SUCCEEDED(hr))
    {
	hr = fontFamily->GetFamilyNames(&localizedFamilyNames);
    }

    // Get the family name at index zero. If we were going to display the name
    // we'd want to try to find one that matched the use locale, but for
    // purposes of creating a text format object any language will do.

    wchar_t familyName[100];
    if (SUCCEEDED(hr))
    {
	hr = localizedFamilyNames->GetString(0, familyName,
		ARRAYSIZE(familyName));
    }

    if (SUCCEEDED(hr))
    {
	// If no font size was passed in use the lfHeight of the LOGFONT.
	if (fontSize == 0)
	{
	    // Convert from pixels to DIPs.
	    fontSize = PixelsToDipsY(logFont.lfHeight);
	    if (fontSize < 0)
	    {
		// Negative lfHeight represents the size of the em unit.
		fontSize = -fontSize;
	    }
	    else
	    {
		// Positive lfHeight represents the cell height (ascent +
		// descent).
		DWRITE_FONT_METRICS fontMetrics;
		font->GetMetrics(&fontMetrics);

		// Convert the cell height (ascent + descent) from design units
		// to ems.
		float cellHeight = static_cast<float>(
			fontMetrics.ascent + fontMetrics.descent)
					       / fontMetrics.designUnitsPerEm;

		// Divide the font size by the cell height to get the font em
		// size.
		fontSize /= cellHeight;
	    }
	}
    }

    // The text format includes a locale name. Ideally, this would be the
    // language of the text, which may or may not be the same as the primary
    // language of the user. However, for our purposes the user locale will do.
    wchar_t localeName[LOCALE_NAME_MAX_LENGTH];
    if (SUCCEEDED(hr))
    {
	if (GetUserDefaultLocaleName(localeName, LOCALE_NAME_MAX_LENGTH) == 0)
	    hr = HRESULT_FROM_WIN32(GetLastError());
    }

    if (SUCCEEDED(hr))
    {
	// Create the text format object.
	hr = mDWriteFactory->CreateTextFormat(
		familyName,
		NULL, // no custom font collection
		font->GetWeight(),
		font->GetStyle(),
		font->GetStretch(),
		fontSize,
		localeName,
		&mTextFormat);
    }

    if (SUCCEEDED(hr))
    {
	mFontWeight = static_cast<DWRITE_FONT_WEIGHT>(logFont.lfWeight);
	mFontStyle = logFont.lfItalic ? DWRITE_FONT_STYLE_ITALIC
	    : DWRITE_FONT_STYLE_NORMAL;
//.........这里部分代码省略.........

static void fontDialogDrawSampleText(struct fontDialog *f, ID2D1RenderTarget *rt)
{
	D2D1_COLOR_F color;
	D2D1_BRUSH_PROPERTIES props;
	ID2D1SolidColorBrush *black;
	IDWriteFont *font;
	IDWriteLocalizedStrings *sampleStrings;
	BOOL exists;
	WCHAR *sample;
	WCHAR *family;
	IDWriteTextFormat *format;
	D2D1_RECT_F rect;
	HRESULT hr;

	color.r = 0.0;
	color.g = 0.0;
	color.b = 0.0;
	color.a = 1.0;
	ZeroMemory(&props, sizeof (D2D1_BRUSH_PROPERTIES));
	props.opacity = 1.0;
	// identity matrix
	props.transform._11 = 1;
	props.transform._22 = 1;
	hr = rt->CreateSolidColorBrush(
		&color,
		&props,
		&black);
	if (hr != S_OK)
		logHRESULT(L"error creating solid brush", hr);

	font = (IDWriteFont *) cbGetItemData(f->styleCombobox, (WPARAM) f->curStyle);
	hr = font->GetInformationalStrings(DWRITE_INFORMATIONAL_STRING_SAMPLE_TEXT, &sampleStrings, &exists);
	if (hr != S_OK)
		exists = FALSE;
	if (exists) {
		sample = fontCollectionCorrectString(f->fc, sampleStrings);
		sampleStrings->Release();
	} else
		sample = L"The quick brown fox jumps over the lazy dog.";

	// DirectWrite doesn't allow creating a text format from a font; we need to get this ourselves
	family = cbGetItemText(f->familyCombobox, f->curFamily);
	hr = dwfactory->CreateTextFormat(family,
		NULL,
		font->GetWeight(),
		font->GetStyle(),
		font->GetStretch(),
		// typographic points are 1/72 inch; this parameter is 1/96 inch
		// fortunately Microsoft does this too, in https://msdn.microsoft.com/en-us/library/windows/desktop/dd371554%28v=vs.85%29.aspx
		f->curSize * (96.0 / 72.0),
		// see http://stackoverflow.com/questions/28397971/idwritefactorycreatetextformat-failing and https://msdn.microsoft.com/en-us/library/windows/desktop/dd368203.aspx
		// TODO use the current locale again?
		L"",
		&format);
	if (hr != S_OK)
		logHRESULT(L"error creating IDWriteTextFormat", hr);
	uiFree(family);

	rect.left = 0;
	rect.top = 0;
	rect.right = realGetSize(rt).width;
	rect.bottom = realGetSize(rt).height;
	rt->DrawText(sample, wcslen(sample),
		format,
		&rect,
		black,
		// TODO really?
		D2D1_DRAW_TEXT_OPTIONS_NONE,
		DWRITE_MEASURING_MODE_NATURAL);

	format->Release();
	if (exists)
		uiFree(sample);
	black->Release();
}