CBCGPGraphicsManager

Detailed Description

The CBCGPGraphicsManager class is a base class for GDI and D2D drawing. All graphics primitives like lines, rectangles, ellipses, geometries, arcs, pies, pyramids and texts can be easily drawn using just few lines of code. In addition, developer can use this class as base of the own graphics rendering implementation differ from GDI or D2D (GDI+ for example). Produce the following steps to add Graphics Manager to your CWnd-derived class:

1. Add a new class member: CBCGPGraphicsManager* m_pGM; and set it to NULL in the class constructor.
2. Delete m_pGM in class destructor.
3. Initialize and use the Graphics Manager in WM_PAINT message handler (OnPaint or OnDraw, if your class is derived from CView):
   • Check if m_pGM is NULL and initialize it: m_pGM = CBCGPGraphicsManager::CreateInstance();
   • Call m_pGM->BindDC(pDC); where pDC is a device content.
   • Call m_pGM->BeginDraw();
   • Call required drawing methods such as m_pGM->FillRectangle, m_pGM->DrawText or m_pGM->DrawLine
   • Call m_pGM->EndDraw();

The following code demonstrates how to use CBCGPGraphicsManager in CView-derived class:

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class CMyView : public CView

{

...

CBCGPGraphicsManager* m_pGM;

};

CMyView::CMyView()

{

m_pGM = NULL;

}

CMyView::~CMyView()

{

if (m_pGM != NULL)

{

delete m_pGM;

}

}

void CMyView::OnDraw(CDC* pDC)

{

CGMDemoDoc* pDoc = GetDocument();

ASSERT_VALID(pDoc);

if (m_pGM == NULL)

{

m_pGM = CBCGPGraphicsManager::CreateInstance();

}

if (m_pGM == NULL)

{

return;

}

m_pGM->BindDC(pDC);

if (!m_pGM->BeginDraw())

{

return;

}

m_pGM->Clear();

CBCGPRect rect(50, 50, 300, 200);

// For better performance we recommend to make CBCGPBrush resources as class member variables

// and setup them in the constructor.

CBCGPBrush brFill(CBCGPColor::LightGreen, CBCGPColor::White, CBCGPBrush::BCGP_GRADIENT_RADIAL_TOP_LEFT);

CBCGPBrush brBorder(CBCGPColor::DarkGreen);

CBCGPBrush brText(CBCGPColor::Black);

CBCGPTextFormat tf;

tf.SetTextAlignment(CBCGPTextFormat::BCGP_TEXT_ALIGNMENT_CENTER);

tf.SetTextVerticalAlignment(CBCGPTextFormat::BCGP_TEXT_ALIGNMENT_CENTER);

m_pGM->FillRectangle(rect, brFill);

m_pGM->DrawRectangle(rect, brBorder);

CString strText = _T("Hello, Graphics Manager!");

m_pGM->DrawText(strText, rect, tf, brText);

m_pGM->EndDraw();

}