C++ IDWriteTextLayout::SetTextAlignment方法代码示例

// Create text layout from string
IDWriteTextLayout* CFW1FontWrapper::createTextLayout(
    const WCHAR *pszString,
    const WCHAR *pszFontFamily,
    FLOAT fontSize,
    const FW1_RECTF *pLayoutRect,
    UINT flags
) {
    if(m_defaultTextInited) {
        UINT32 stringLength = 0;
        while(pszString[stringLength] != 0)
            ++stringLength;

        // Create DWrite text layout for the string
        IDWriteTextLayout *pTextLayout;
        HRESULT hResult = m_pDWriteFactory->CreateTextLayout(
                              pszString,
                              stringLength,
                              m_pDefaultTextFormat,
                              pLayoutRect->Right - pLayoutRect->Left,
                              pLayoutRect->Bottom - pLayoutRect->Top,
                              &pTextLayout
                          );
        if(SUCCEEDED(hResult)) {
            // Layout settings
            DWRITE_TEXT_RANGE allText = {0, stringLength};
            pTextLayout->SetFontSize(fontSize, allText);

            if(pszFontFamily != NULL)
                pTextLayout->SetFontFamilyName(pszFontFamily, allText);

            if((flags & FW1_NOWORDWRAP) != 0)
                pTextLayout->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP);

            if(flags & FW1_RIGHT)
                pTextLayout->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_TRAILING);
            else if(flags & FW1_CENTER)
                pTextLayout->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_CENTER);
            if(flags & FW1_BOTTOM)
                pTextLayout->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_FAR);
            else if(flags & FW1_VCENTER)
                pTextLayout->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_CENTER);

            return pTextLayout;
        }
    }

    return NULL;
}

//.........这里部分代码省略.........
			text_alignment = DWRITE_TEXT_ALIGNMENT_JUSTIFIED;
			break;
		case NF_FEATURE_ALIGN_PARAGRAPH_LEFT:
			parg_alignment = DWRITE_PARAGRAPH_ALIGNMENT_NEAR;
			break;
		case NF_FEATURE_ALIGN_PARAGRAPH_CENTER:
			parg_alignment = DWRITE_PARAGRAPH_ALIGNMENT_CENTER;
			break;
		case NF_FEATURE_ALIGN_PARAGRAPH_RIGHT:
			parg_alignment = DWRITE_PARAGRAPH_ALIGNMENT_FAR;
			break;
		case NF_FEATURE_AA_DISABLED:
			text_aa_mode = D2D1_TEXT_ANTIALIAS_MODE_ALIASED;
			break;
		case NF_FEATURE_AA_WIN_CLEARTYPE:
			text_aa_mode = D2D1_TEXT_ANTIALIAS_MODE_CLEARTYPE;
			break;
		case NF_FEATURE_AA_WIN_GREYSCALE:
			text_aa_mode = D2D1_TEXT_ANTIALIAS_MODE_GRAYSCALE;
			break;
		case NF_FEATURE_PPI:
			ppi_x = features[i].ppi.x;
			ppi_y = features[i].ppi.y;
			break;
		case NF_FEATURE_COLOR_BG:
			bg_color = D2D1::ColorF(
				features[i].color.r,
				features[i].color.g,
				features[i].color.b,
				features[i].color.a);
			break;
		case NF_FEATURE_COLOR_TEXT:
			fg_color = D2D1::ColorF(
				features[i].color.r,
				features[i].color.g,
				features[i].color.b,
				features[i].color.a);
			break;
		default:
			break;
		}
	}

	layout->SetWordWrapping(text_wrap);
	layout->SetTextAlignment(text_alignment);
	layout->SetParagraphAlignment(parg_alignment);
	ctx.d2d_rt->SetDpi(ppi_x, ppi_y);
	ctx.d2d_rt->SetTextAntialiasMode(text_aa_mode);
	ctx.d2d_brush->SetColor(fg_color);

	// figure our result metrics
	// TODO does this call actually rasterizes text?
	DWRITE_TEXT_METRICS text_metrics;
	layout->GetMetrics(&text_metrics);
	float clip_x1 = text_metrics.left;
	float clip_y1 = text_metrics.top;
	float clip_x2 = text_metrics.left + text_metrics.width;
	float clip_y2 = text_metrics.top + text_metrics.height;
	clip_x1 = clip_x1 < 0 ? 0 : (clip_x1 >= w ? w - 1 : clip_x1);
	clip_y1 = clip_y1 < 0 ? 0 : (clip_y1 >= h ? h - 1 : clip_y1);
	clip_x2 = clip_x2 < 0 ? 0 : (clip_x2 >= w ? w - 1 : clip_x2);
	clip_y2 = clip_y2 < 0 ? 0 : (clip_y2 >= h ? h - 1 : clip_y2);
	float clip_w = clip_x2 - clip_x1 + 1.0f;
	float clip_h = clip_y2 - clip_y1 + 1.0f;
	nf_aabb_t aabb;
	aabb.x = clip_x1;
	aabb.y = clip_y1;
	aabb.w = clip_w;
	aabb.h = clip_h;
	if(result_rect)
		*result_rect = aabb;

	// render text
	ctx.d2d_rt->BeginDraw();
	ctx.d2d_rt->Clear(bg_color);
	ctx.d2d_rt->DrawTextLayout(D2D1::Point2F(), layout, ctx.d2d_brush);
	ctx.d2d_rt->EndDraw();
	layout->Release();
	layout = NULL;

	// read texture from d3d
	ctx.d3d_device->CopyResource(ctx.d3d_texture2, ctx.d3d_texture1);

	D3D10_MAPPED_TEXTURE2D mapped = {0};
	if(FAILED(hr = ctx.d3d_texture2->Map(0, D3D10_MAP_READ, 0, &mapped)))
	{
		nf_explain_hr(hr, "can't map d3d texture");
		return -1;
	}

	for(size_t j = aabb.y; j < aabb.y + aabb.h; ++j)
		// hardcoded BGRA8 format
		memcpy(
			(uint8_t*)bitmap + (j * w + aabb.x) * 4,
			(uint8_t*)mapped.pData + j * mapped.RowPitch + aabb.x,
			aabb.w * 4);

	ctx.d3d_texture2->Unmap(0);
	return 0;
}