C++ IDWriteFactory::CreateTextLayout方法代码示例

    bool setupLayout (const AttributedString& text, const float maxWidth, const float maxHeight,
                      ID2D1RenderTarget& renderTarget, IDWriteFactory& directWriteFactory,
                      IDWriteFontCollection& fontCollection, ComSmartPtr<IDWriteTextLayout>& textLayout)
    {
        // To add color to text, we need to create a D2D render target
        // Since we are not actually rendering to a D2D context we create a temporary GDI render target

        Font defaultFont;
        BOOL fontFound = false;
        uint32 fontIndex;
        fontCollection.FindFamilyName (defaultFont.getTypeface()->getName().toWideCharPointer(), &fontIndex, &fontFound);

        if (! fontFound)
            fontIndex = 0;

        ComSmartPtr<IDWriteFontFamily> dwFontFamily;
        HRESULT hr = fontCollection.GetFontFamily (fontIndex, dwFontFamily.resetAndGetPointerAddress());

        ComSmartPtr<IDWriteFont> dwFont;
        hr = dwFontFamily->GetFirstMatchingFont (DWRITE_FONT_WEIGHT_NORMAL, DWRITE_FONT_STRETCH_NORMAL, DWRITE_FONT_STYLE_NORMAL,
                                                 dwFont.resetAndGetPointerAddress());
        jassert (dwFont != nullptr);

        const float defaultFontHeightToEmSizeFactor = getFontHeightToEmSizeFactor (*dwFont);

        ComSmartPtr<IDWriteTextFormat> dwTextFormat;
        hr = directWriteFactory.CreateTextFormat (defaultFont.getTypefaceName().toWideCharPointer(), &fontCollection,
                                                  DWRITE_FONT_WEIGHT_REGULAR, DWRITE_FONT_STYLE_NORMAL, DWRITE_FONT_STRETCH_NORMAL,
                                                  defaultFont.getHeight() * defaultFontHeightToEmSizeFactor,
                                                  L"en-us", dwTextFormat.resetAndGetPointerAddress());

        setTextFormatProperties (text, *dwTextFormat);

        {
            DWRITE_TRIMMING trimming = { DWRITE_TRIMMING_GRANULARITY_CHARACTER, 0, 0 };
            ComSmartPtr<IDWriteInlineObject> trimmingSign;
            hr = directWriteFactory.CreateEllipsisTrimmingSign (dwTextFormat, trimmingSign.resetAndGetPointerAddress());
            hr = dwTextFormat->SetTrimming (&trimming, trimmingSign);
        }

        const int textLen = text.getText().length();

        hr = directWriteFactory.CreateTextLayout (text.getText().toWideCharPointer(), textLen, dwTextFormat,
                                                  maxWidth, maxHeight, textLayout.resetAndGetPointerAddress());

        if (FAILED (hr) || textLayout == nullptr)
            return false;

        const int numAttributes = text.getNumAttributes();

        for (int i = 0; i < numAttributes; ++i)
            addAttributedRange (*text.getAttribute (i), *textLayout, textLen, renderTarget, fontCollection);

        return true;
    }

int CDirectWriteRenderer::GetFitCharCount(LPCWSTR pText, int Length, int Width, CDirectWriteFont &Font)
{
	if (pText == nullptr || Length == 0)
		return 0;
	if (m_pRenderTarget == nullptr)
		return 0;

	int FitCharCount = 0;

	IDWriteFactory *pFactory = m_System.GetDWriteFactory();

	if (pFactory != nullptr) {
		IDWriteTextFormat *pTextFormat = Font.GetTextFormat();

		if (pTextFormat != nullptr) {
			IDWriteTextLayout *pTextLayout;

			pTextFormat->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_LEADING);
			pTextFormat->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP);
			if (Length < 0)
				Length = ::lstrlenW(pText);
			HRESULT hr = pFactory->CreateTextLayout(
				pText,
				Length,
				pTextFormat,
				static_cast<float>(Width),
				m_pRenderTarget->GetSize().height,
				&pTextLayout);
			if (SUCCEEDED(hr)) {
				Util::CTempBuffer<DWRITE_CLUSTER_METRICS, 256> ClusterMetrics(Length);
				UINT32 ClusterCount;

				hr = pTextLayout->GetClusterMetrics(ClusterMetrics.GetBuffer(), Length, &ClusterCount);
				if (SUCCEEDED(hr)) {
					float Pos = 0.0f;

					for (UINT32 i = 0; i < ClusterCount; i++) {
						Pos += ClusterMetrics[i].width;
						if (static_cast<int>(std::ceil(Pos)) > Width)
							break;
						FitCharCount += ClusterMetrics[i].length;
					}
				}

				pTextLayout->Release();
			}

			pTextFormat->Release();
		}

		pFactory->Release();
	}

	return FitCharCount;
}

 virtual HRESULT STDMETHODCALLTYPE CreateTextLayout(
     WCHAR const* string,
     UINT32 stringLength,
     IDWriteTextFormat* textFormat,
     FLOAT maxWidth,
     FLOAT maxHeight,
     IDWriteTextLayout** textLayout
     )
 {
     return orig_this->CreateTextLayout(string, stringLength, textFormat, maxWidth, maxHeight, textLayout);
 }

bool CDirectWriteRenderer::GetTextMetrics(
	LPCWSTR pText, int Length, CDirectWriteFont &Font, TextMetrics *pMetrics)
{
	if (pText == nullptr || pMetrics == nullptr)
		return false;
	if (m_pRenderTarget == nullptr)
		return false;

	HRESULT hr = E_UNEXPECTED;
	IDWriteFactory *pFactory = m_System.GetDWriteFactory();

	if (pFactory != nullptr) {
		IDWriteTextFormat *pTextFormat = Font.GetTextFormat();

		if (pTextFormat != nullptr) {
			D2D1_SIZE_F Size;
			IDWriteTextLayout *pTextLayout;

			pTextFormat->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_LEADING);
			pTextFormat->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP);
			if (Length < 0)
				Length = ::lstrlenW(pText);
			Size = m_pRenderTarget->GetSize();
			hr = pFactory->CreateTextLayout(
				pText,
				Length,
				pTextFormat,
				Size.width,
				Size.height,
				&pTextLayout);
			if (SUCCEEDED(hr)) {
				DWRITE_TEXT_METRICS Metrics;

				hr = pTextLayout->GetMetrics(&Metrics);
				if (SUCCEEDED(hr)) {
					pMetrics->Width = Metrics.width;
					pMetrics->WidthIncludingTrailingWhitespace = Metrics.widthIncludingTrailingWhitespace;
					pMetrics->Height = Metrics.height;
				}

				pTextLayout->Release();
			}

			pTextFormat->Release();
		}

		pFactory->Release();
	}

	return SUCCEEDED(hr);
}

void MWinDeviceImpl::SetText(
	const string&		inText)
{
	if (mTextLayout != nil)
		mTextLayout->Release();

	wstring s(c2w(inText));

	THROW_IF_HRESULT_ERROR(
		sDWFactory->CreateTextLayout(
			s.c_str(),
			s.length(),
			GetTextFormat(),
			99999.0f,
			99999.0f,
			&mTextLayout
		));
}

    // This method takes an attributed string and outputs a GlyphLayout data
    // structure that contains the glyph number and location of each inidividual glyph
    void getGlyphLayout (const AttributedString& text, GlyphLayout& glyphLayout)
    {
        // For now we are creating the DirectWrite Factory, System Font Collection,
        // D2D Factory and GDI Render target every time we layout text.
        // This is inefficient and we may be loading and unloading libraries each layout.
        // These four things should be created once at application startup and be destroyed
        // when the application exits. I'm not sure where the best place to do this so
        // for now I will just use the inefficient method.

        IDWriteFactory* dwFactory = nullptr;
        HRESULT hr = DWriteCreateFactory (DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory),
            reinterpret_cast<IUnknown**>(&dwFactory));

        IDWriteFontCollection* dwFontCollection = nullptr;
        hr = dwFactory->GetSystemFontCollection (&dwFontCollection);

        // To add color to text, we need to create a D2D render target
        // Since we are not actually rendering to a D2D context we create a temporary GDI render target
        ID2D1Factory *d2dFactory = nullptr;
        hr = D2D1CreateFactory (D2D1_FACTORY_TYPE_SINGLE_THREADED, &d2dFactory);
        D2D1_RENDER_TARGET_PROPERTIES d2dRTProp = D2D1::RenderTargetProperties(
            D2D1_RENDER_TARGET_TYPE_SOFTWARE,
            D2D1::PixelFormat(
            DXGI_FORMAT_B8G8R8A8_UNORM,
            D2D1_ALPHA_MODE_IGNORE),
            0,
            0,
            D2D1_RENDER_TARGET_USAGE_GDI_COMPATIBLE,
            D2D1_FEATURE_LEVEL_DEFAULT
            );
        ID2D1DCRenderTarget* d2dDCRT = nullptr;
        hr = d2dFactory->CreateDCRenderTarget (&d2dRTProp, &d2dDCRT);

        // Initially we set the paragraph up with a default font and then apply the attributed string ranges later
        Font defaultFont;
        const float defaultFontHeightToEmSizeFactor = getFontHeightToEmSizeFactor (defaultFont, *dwFontCollection);
        // We should probably be detecting the locale instead of hard coding it to en-us
        String localeName("en-us");

        // We multiply the font height by the size factor so we layout text at the correct size
        IDWriteTextFormat* dwTextFormat = nullptr;
        hr = dwFactory->CreateTextFormat (
            defaultFont.getTypefaceName().toWideCharPointer(),
            dwFontCollection,
            DWRITE_FONT_WEIGHT_REGULAR,
            DWRITE_FONT_STYLE_NORMAL,
            DWRITE_FONT_STRETCH_NORMAL,
            defaultFont.getHeight() * defaultFontHeightToEmSizeFactor,
            localeName.toWideCharPointer(),
            &dwTextFormat
            );

        // Paragraph Attributes
        // Set Paragraph Alignment
        if (text.getTextAlignment() == AttributedString::left)
            dwTextFormat->SetTextAlignment (DWRITE_TEXT_ALIGNMENT_LEADING);
        if (text.getTextAlignment() == AttributedString::right)
            dwTextFormat->SetTextAlignment (DWRITE_TEXT_ALIGNMENT_TRAILING);
        if (text.getTextAlignment() == AttributedString::center)
            dwTextFormat->SetTextAlignment (DWRITE_TEXT_ALIGNMENT_CENTER);
        // DirectWrite cannot justify text, default to left alignment
        if (text.getTextAlignment() == AttributedString::justified)
            dwTextFormat->SetTextAlignment (DWRITE_TEXT_ALIGNMENT_LEADING);
        // Set Word Wrap
        if (text.getWordWrap() == AttributedString::none)
            dwTextFormat->SetWordWrapping (DWRITE_WORD_WRAPPING_NO_WRAP);
        if (text.getWordWrap() == AttributedString::byWord)
            dwTextFormat->SetWordWrapping (DWRITE_WORD_WRAPPING_WRAP);
        // DirectWrite does not support wrapping by character, default to wrapping by word
        if (text.getWordWrap() == AttributedString::byChar)
            dwTextFormat->SetWordWrapping (DWRITE_WORD_WRAPPING_WRAP);
        // DirectWrite does not automatically set reading direction
        // This must be set correctly and manually when using RTL Scripts (Hebrew, Arabic)
        if (text.getReadingDirection() == AttributedString::rightToLeft)
            dwTextFormat->SetReadingDirection (DWRITE_READING_DIRECTION_RIGHT_TO_LEFT);

        IDWriteTextLayout* dwTextLayout = nullptr;
        hr = dwFactory->CreateTextLayout (
            text.getText().toWideCharPointer(),
            text.getText().length(),
            dwTextFormat,
            glyphLayout.getWidth(),
            glyphLayout.getHeight(),
            &dwTextLayout
            );

        // Character Attributes
        int numCharacterAttributes = text.getCharAttributesSize();
        for (int i = 0; i < numCharacterAttributes; ++i)
        {
            Attr* attr = text.getCharAttribute (i);
            // Character Range Error Checking
            if (attr->range.getStart() > text.getText().length()) continue;
            if (attr->range.getEnd() > text.getText().length()) attr->range.setEnd (text.getText().length());
            if (attr->attribute == Attr::font)
            {
                AttrFont* attrFont = static_cast<AttrFont*>(attr);
                DWRITE_TEXT_RANGE dwRange;
//.........这里部分代码省略.........