Advanced MFC Programming

Chapter 8. DC, Pen, Brush and Palette
In the constructor, the logical palette is created as follows:
CGDIView::CGDIView()
{
LPLOGPALETTE lpLogPal;
int i;
}
lpLogPal=(LPLOGPALETTE) new BYTE[sizeof(LOGPALETTE)+255*sizeof(PALETTEENTRY)];
lpLogPal->palVersion=0x300;
lpLogPal->palNumEntries=256;
for(i=0; ipalPalEntry[i].peRed)))=(WORD)i;
lpLogPal->palPalEntry[i].peBlue=0;
lpLogPal->palPalEntry[i].peFlags=PC_EXPLICIT;
}
VERIFY(m_palSys.CreatePalette(lpLogPal));
delete [](BYTE *)lpLogPal;
The procedure above is almost the same with creating a normal logical palette. The only difference
here is that when stuffing structure PALETTEENTRY, the low order word of the structure is filled with an
index to the system palette entry (from 0 to 255), and member peFlags is set to PC_EXPLICIT.
Function CGDIView::OnDraw(…) is implemented as follows:
void CGDIView::OnDraw(CDC* pDC)
{
CBrush brush;
CBrush *ptrBrushOld;
CPalette *ptrPalOld;
CRect rect;
int i, j;
CGDIDoc* pDoc=GetDocument();
ASSERT_VALID(pDoc);
ASSERT(m_palSys.GetSafeHandle());
ptrPalOld=pDC->SelectPalette(&m_palSys, FALSE);
pDC->RealizePalette();
GetClientRect(rect);
rect.right/=16;
rect.bottom/=16;
}
for(j=0; jRectangle(rect);
pDC->SelectObject(ptrBrushOld);
brush.DeleteObject();
rect.OffsetRect(rect.Width(), 0);
}
rect.OffsetRect(-16*rect.Width(), rect.Height());
}
pDC->SelectPalette(ptrPalOld, FALSE);
The client area is divided into 256 (16×16) rectangles. For each rectangle, a brush using a specific
logical palette entry is created. Then function CDC::Rectangle(…) is called to draw the rectangle. Because
no pen is selected into the DC, the default pen will be used to draw the border of the rectangles.
The application can be compiled and executed at this point. There are 256 rectangles in the client
window, each represents one color contained in the system palette. By paying attention to the first 10 and
last 10 entries, we will notice that the colors contained in these entries never change (because they are static
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