As stated in the Direct2D documentation, the graphics device might become unavailable. If the device is lost, the render target also becomes invalid, along with any device-dependent resources that were associated with the device. That happens infrequently (e.g. if the user removes the display adapter), but once something bad can happen, a good programmer must […]
Once have enabled Direct2D support in an MFC application, there is no sweat to load an image from a file, by using one of CD2DBitmap constructors. Unfortunately, we cannot find a CD2DBitmap method to save it into a image file (something similar to CImage::Save or Gdiplus::Image::Save). No problem, we can try to do it ourselves. […]
We can combine two or more images and/or effects by using the composite effect. Here is an example. Drawing shadows using Direct2D composite effects
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void CD2DStaticCtrl::_DrawImageWithShadow(CHwndRenderTarget* pRenderTarget) { ASSERT(pRenderTarget && pRenderTarget->IsValid()); ASSERT(m_pBitmap && m_pBitmap->IsValid()); // get ID2D1DeviceContext interface; note: must include <d2d1_1.h> CComQIPtr<ID2D1DeviceContext> spDeviceContext = pRenderTarget->GetRenderTarget(); // create shadow effect and set the input image CComPtr<ID2D1Effect> spShadowEffect; spDeviceContext->CreateEffect(CLSID_D2D1Shadow, &spShadowEffect); spShadowEffect->SetInput(0, m_pBitmap->Get()); spShadowEffect->SetValue(D2D1_SHADOW_PROP_BLUR_STANDARD_DEVIATION, m_fBlurStandardDeviation); spShadowEffect->SetValue(D2D1_SHADOW_PROP_COLOR, CRenderTarget::COLORREF_TO_D2DCOLOR(m_shadowColor)); // create flood effect CComPtr<ID2D1Effect> spFloodEffect; spDeviceContext->CreateEffect(CLSID_D2D1Flood, &spFloodEffect); // Note: shadow will be composed in the top of a surface having the background color D2D1_COLOR_F color = CRenderTarget::COLORREF_TO_D2DCOLOR(m_backColor); spFloodEffect->SetValue(D2D1_FLOOD_PROP_COLOR, D2D1::Vector4F(color.r, color.g, color.b, color.a)); // create 2D affine transform effect in order to translate the shadow CComPtr<ID2D1Effect> spAffineTransformEffect; spDeviceContext->CreateEffect(CLSID_D2D12DAffineTransform, &spAffineTransformEffect); spAffineTransformEffect->SetInputEffect(0, spShadowEffect); D2D1_MATRIX_3X2_F translation = D2D1::Matrix3x2F::Translation(m_fShadowDistance, m_fShadowDistance); spAffineTransformEffect->SetValue(D2D1_2DAFFINETRANSFORM_PROP_TRANSFORM_MATRIX, translation); // create the composite effect and combine the effects CComPtr<ID2D1Effect> spCompositeEffect; spDeviceContext->CreateEffect(CLSID_D2D1Composite, &spCompositeEffect); // set input effects spCompositeEffect->SetInputEffect(0, spFloodEffect); spCompositeEffect->SetInputEffect(1, spAffineTransformEffect); // set input image; because the default input count is 1, he have to set it to 3 spCompositeEffect->SetInputCount(3); spCompositeEffect->SetInput(2, m_pBitmap->Get()); // finally perform drawing spDeviceContext->DrawImage(spCompositeEffect); } |
Demo project Download: You can set the amount of blur and the color as well as the distance of the shadow. Resources and related articles MSDN: Composite effect MSDN: Shadow […]
There are two ways to combine Direct2D with Windows GDI API in the same application: Drawing Direct2D content to a GDI device context Drawing GDI content to a Direct2D GDI-compatible render target Let’s see each one! Drawing Direct2D content to a GDI device context For this purpose, use ID2D1DCRenderTarget instead of ID2D1HwndRenderTarget interface. If using MFC […]
Direct2D has built-in support for image processing like changing brightness or contrast, blurring, creating drop shadows, and so on. Basically, we can use for this purpose the CreateEffect and DrawImage methods of ID2D1DeviceContext interface. So far, there is no MFC wrapper class for ID2D1DeviceContext but that’s not so big issue. Once having a valid ID2D1RenderTarget […]
As shown in previous articles, we can enable MFC Direct2D support for a window by a call of CWnd::EnableD2DSupport. Example:
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int CSlideShowWnd::OnCreate(LPCREATESTRUCT lpCreateStruct) { if (CWnd::OnCreate(lpCreateStruct) == -1) return -1; // Enable MFC Direct2D support EnableD2DSupport(); // ... return 0; } |
So far so good as long as all windows which use Direct2D are running in the same thread (usually the application main thread). But let’s say we have more than one window with intensive […]
A previous article shows how to use D2D MFC classes for easily make a simple image viewer. As said there, it can be made even easier. Enabling D2D support in MFC In the WM_CREATE message handler call CWnd::EnableD2DSupport.
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int CDemoView::OnCreate(LPCREATESTRUCT lpCreateStruct) { if (CScrollView::OnCreate(lpCreateStruct) == -1) return -1; EnableD2DSupport(); // Enable D2D support for this window: return 0; } |
In the overridden CView::OnUpdate load the bitmap from the current document’s file.
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void CDemoView::OnUpdate(CView* pSender, LPARAM lHint, CObject* pHint) { CDemoDoc* pDoc = GetDocument(); ASSERT_VALID(pDoc); CSize sizeImage(100, 100); delete m_pBitmap; m_pBitmap = NULL; const CString& strFile = pDoc->GetPathName(); if(! strFile.IsEmpty()) { CHwndRenderTarget* pRenderTarget = this->GetRenderTarget(); ASSERT_VALID(pRenderTarget); m_pBitmap = new CD2DBitmap(pRenderTarget, strFile); HRESULT hr = m_pBitmap->Create(pRenderTarget); if(m_pBitmap->IsValid()) { CD2DSizeF size = m_pBitmap->GetSize(); sizeImage.SetSize(static_cast<int>(size.width), static_cast<int>(size.height)); } } SetScrollSizes(MM_TEXT, sizeImage); ScrollToPosition(CPoint(0, 0)); } |
Map AFX_WM_DRAW2D registered message […]