In a previous article, I showed how to trim a text which overflows the layout box. In the example presented there, the ellipsis is added at the end of truncated text. But if, let’s say, we have to show a long path and file name, it is not meaningful if the file name is not […]
In a previous article, I showed the basics of custom text rendering with DirectWrite (see MFC Support for DirectWrite – Part 7: A Step to Custom Rendering). So far so good but it just mimics the default text rendering. Let’s now modify the overridden IDWriteTextRenderer::DrawGlyphRun in order to draw outlined text. Overridden IDWriteTextRenderer::DrawGlyphRun implementation
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 |
STDMETHODIMP CCustomTextRenderer::XCustomTextRenderer::DrawGlyphRun( void* pClientDrawingContext, FLOAT fBaselineOriginX, FLOAT fBaselineOriginY, DWRITE_MEASURING_MODE measuringMode, const DWRITE_GLYPH_RUN* pGlyphRun, const DWRITE_GLYPH_RUN_DESCRIPTION* pGlyphRunDescription, IUnknown* pClientDrawingEffect) { METHOD_PROLOGUE(CCustomTextRenderer, CustomTextRenderer); CRenderTarget* pRenderTarget = pThis->GetRenderTarget(); ASSERT(pRenderTarget && pRenderTarget->IsValid()); CD2DPointF point(fBaselineOriginX, fBaselineOriginY); CCustomEffect* pCustomEffect = static_cast<CCustomEffect*>(pClientDrawingContext); if (NULL == pCustomEffect) { return _DrawDefaultGlyphRun(pRenderTarget, point, pGlyphRun, measuringMode); } HRESULT hr = E_FAIL; switch (pCustomEffect->GetType()) { case CustomEffectType::outlined_text: hr = _DrawOutlinedGlyphRun(pRenderTarget, dynamic_cast<COutlinedTextEffect*>(pCustomEffect), point, pGlyphRun, measuringMode); // ... // may add other types of custom effects here } return hr; } |
[…]
DirectWrite has hit-testing support that can be useful for showing a caret, making a selection, doing some action if the user chicks in a given text range, and so on. The hit-test methods of IDWriteTextLayout interface are HitTestPoint, HitTestTextPosition and HitTestTextRange. Let me show a simple example for each one. Hit-testing a point This example calls IDWriteTextLayout::HitTestPoint […]
When using “classic” GDI functions i.e. CDC::DrawText, it’s no sweat to trim with ellipsis a single-line text when that text does not fit in the drawing rectangle width, by specifying DT_WORDBREAK flag. We cannot find a similar flag for CRenderTarget::DrawText or CRenderTarget::DrawTextLayout. However, trimming a text is also possible with DirectDraw. All we have to […]
The previous articles from this series show how to format the text layout using built-in DirectWrite methods. However, as said earlier, we can do more custom formatting (e.g. draw double/triple underline/strikethrough, highlight text and so on). How can be done? First, let’s note that ID2D1RenderTarget::DrawTextLayout internally calls IDWriteTextLayout::Draw which has the following prototype:
|
1 2 3 4 5 |
HRESULT Draw( void* clientDrawingContext, IDWriteTextRenderer* renderer, FLOAT originX, FLOAT originY) |
We […]
We can change the color of a text range by passing a brush object to IDWriteTextLayout::SetDrawingEffect. Here is a simple example. An example of using IDWriteTextLayout::SetDrawingEffect
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
LRESULT CDirectWriteDemoView::OnDraw2D(WPARAM wParam, LPARAM lParam) { CHwndRenderTarget* pRenderTarget = (CHwndRenderTarget*)lParam; // Please, see the demo application for more details. // ... // init color effects _InitColorEffects(pRenderTarget, spTextLayout); // Draw the text in the render target. pRenderTarget->DrawTextLayout(CD2DPointF(), // upper-left corner of the text spTextLayout.get(), // text layout object &CD2DSolidColorBrush // default brush used for text (pRenderTarget, D2D1::ColorF(D2D1::ColorF::Black))); return 0; } |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
void CDirectWriteDemoView::_InitColorEffects(CHwndRenderTarget* pRenderTarget, std::shared_ptr<CD2DTextLayout> spTextLayout) { CDirectWriteDemoDoc* pDoc = _GetDocument(); DWRITE_TEXT_RANGE textRange; if(pDoc->FindTextRange(_T("BLUE"), textRange)) _SetTextLayoutDrawingEffect(pRenderTarget, spTextLayout, D2D1::ColorF(D2D1::ColorF::Blue), textRange); if(pDoc->FindTextRange(_T("YELLOW"), textRange)) _SetTextLayoutDrawingEffect(pRenderTarget, spTextLayout, D2D1::ColorF(D2D1::ColorF::Yellow), textRange); if(pDoc->FindTextRange(_T("RED"), textRange)) _SetTextLayoutDrawingEffect(pRenderTarget, spTextLayout, D2D1::ColorF(D2D1::ColorF::Red), textRange); } |
|
1 2 3 4 5 6 7 8 |
void CDirectWriteDemoView::_SetTextLayoutDrawingEffect(CHwndRenderTarget* pRenderTarget, std::shared_ptr<CD2DTextLayout> spTextLpayout, D2D1_COLOR_F color, DWRITE_TEXT_RANGE textRange) { CD2DSolidColorBrush* pBrush = new CD2DSolidColorBrush(pRenderTarget, color); pBrush->Create(pRenderTarget); spTextLayout->Get()->SetDrawingEffect(static_cast<IUnknown*>(pBrush->Get()), textRange); } |
So far, there’s no much “special effects” in the above example. Although a little bit more difficult, it is possible to make more customized rendering like […]
Some fonts like Microsoft’s Gabriola support a number of typographic features which allow users to control how they look, e.g by enabling some fancy stylistic text rendering. With DirectWrite we can do that by passing a IDWriteTypography object to IDWriteTextLayout::SetTypography method. Set text layout typography with DirectWrite in an MFC application We have not an MFC class which […]