maskedbitmap.cpp

The Lite Evaluation/Demonstration Kit is intended to illustrate use of the AN3042. The AN3042 is c

//
// maskedBitmap.cpp
//

#include "stdafx.h"
#include "maskedBitmap.h"


/////////////////////////////////////////////////////////////////////////
// CMaskedBitmap member functions

void CMaskedBitmap::Draw (CDC* pDC, int x, int y)
{
    BITMAP bm;								// Allocate a bitmap (descriptor) structure on the stack
    GetObject (sizeof (BITMAP), &bm);		// ...and fill it in.

    CPoint size (bm.bmWidth, bm.bmHeight);  // Init a CPoint object to the size (width/height) of bm
    pDC->DPtoLP (&size);					// ...and convert to logical units (because that's what BitBlt takes).

    CPoint org (0, 0);						// Do the same for a point that's at the origin.
    pDC->DPtoLP (&org);

    CDC dcMem;								// Construct a memory-based device context object.

    dcMem.CreateCompatibleDC (pDC);			// 

    CBitmap* pOldBitmap = dcMem.SelectObject (this);	// "Selects the MaskedBitmap that we're drawing (this) into the device context."
														//   which means that SelectObject returns a pointer to the bitmap.

    dcMem.SetMapMode (pDC->GetMapMode ());				// Copy pDC's MapMode into dcMem.

    pDC->BitBlt						// Dest: display context object
				(x, y,				// Dest: location of upper left corner in destination DC (in Logical units).
				 size.x, size.y,	// Dest: size of the destination rectangle and source bitmap (in Logical units).
				 &dcMem,			// Source bitmap - a pointer to a CDC object that identifies the device context of the source.
									//   It must be NULL if dwRop specifies a raster operation that does not include a source.
				 org.x, org.y,		// Source: upper-left corner of the source bitmap (in Logical units).					
				 SRCCOPY);			// dwRop

	// m_bitmapBackColor = pDC->GetPixel( x + 2, y + 2 );	// Get the background color (not quite at the edge of the bitmap).

    dcMem.SelectObject (pOldBitmap);
}