Visual C++ and MFC Programming 2nd Edition

Chapter 9 Strings Visual C++ and MFC Fundamentals

pDC->SelectObject(brOld);

}

This would produce:

As you can see, we get only the the lower-right 3/4 portion of the square and the line is

pointing in the 3 to 6 quadrant of a clock.

Imagine that you want the origin (0, 0) to be positioned at the (220, 150) point. We saw

already that you can use the CDC::SetViewportOrg() (keep in mind that this member

function only changes the origin of the coordinate system; it does not influence the

orientation of the axes nor does it control the units or dimensions) method to specify the

origin. Here is an example (we are not specifying the mapping mode because MM_TEXT

can be used as the default):

void CExoView::OnDraw(CDC* pDC)

{

CExoDoc* pDoc = GetDocument();

ASSERT_VALID(pDoc);

CPen PenRed(PS_SOLID, 1, RGB(255, 0, 0));

CBrush BrushAqua(RGB(0, 255, 255));

CBrush *brOld;

CPen *pnOld;

pnOld = pDC->SelectObject(&PenRed);

brOld = pDC->SelectObject(&BrushAqua);

pDC->SetViewportOrg(220, 150);

// Draw a square with a red border and an aqua background

pDC->Rectangle(-100, -100, 100, 100);

CPen BluePen(PS_SOLID, 1, RGB(0, 0, 255));

pnOld = pDC->SelectObject(&BluePen);

// Diagonal line at 45 degrees starting at the origin (0, 0)

pDC->MoveTo(0, 0);

pDC->LineTo(120, 120);