Advanced MFC Programming

Chapter 10. Bitmap
COLOR_3DHILIGHT
COLOR_3DHIGHLIGHT
COLOR_BTNHILIGHT
COLOR_BTNHIGHLIGHT
COLOR_3DLIGHT
COLOR_3DSHADOW
COLOR_BTNSHADOW
Highlight color of three-dimensional display elements, this
color is used for drawing edges facing the light source.
Light color of three-dimensional display elements, this color is
used for drawing edges facing the light source.
Shadow color for three-dimensional display elements, this
color is used for drawing edges facing away from the light
source.
In the sample, we choose COLOR_BTNHIGHLIGHT as the highlighted color, and COLOR_BTNSHADOW as the
shadowed color.
New Function
In the sample, a new function CreateGrayedBitmap(…) is declared in class CGDIView to create grayed
image from a nomal bimap:
……
……
……
class CGDIView : public CScrollView
{
public:
}
HBITMAP CreateGrayedBitmap(CBitmap *);
The only parameter to this function is a CBitmap type pointer. The function will return an HBITMAP
handle, which is the grayed bitmap. Within the function, we must prepare three bitmaps: the bitmap that
will be used to store the final grayed image, the mask image that stores the shadowed outline, and the mask
image that stores the highlighted outline. The function starts with creating these bitmaps:
HBITMAP CGDIView::CreateGrayedBitmap(CBitmap *pBmp)
{
BITMAP bm;
CClientDC dc(this);
CDC dcMono;
CDC dcColor;
CBitmap bmpShadow;
CBitmap bmpHilight;
CBitmap bmpGray;
CBitmap *pBmpShadowOld;
CBitmap *pBmpHilightOld;
CBitmap *pBmpOld;
CBrush brush;
CBrush *pBrOld;
……
dcMono.CreateCompatibleDC(&dc);
dcColor.CreateCompatibleDC(&dc);
ASSERT(dcMono.GetSafeHdc());
ASSERT(dcColor.GetSafeHdc());
pBmp->GetBitmap(&bm);
bmpShadow.CreateBitmap(bm.bmWidth, bm.bmHeight, 1, 1, NULL);
bmpHilight.CreateBitmap(bm.bmWidth, bm.bmHeight, 1, 1, NULL);
bmpGray.CreateCompatibleBitmap(&dc, bm.bmWidth, bm.bmHeight);
pBmpOld=dcColor.SelectObject(pBmp);
The final grayed image will be stored in variable bmpGray. We will refer image created by this variable
as “grayed image”, although the image may not be grayed in the interim.
The other two CBitmap type variables, bmpHilight and bmpShadow will be used to store the outline
mask images. We need two memory DCs, one used to select the color bitmap (normal image passed
through pointer pBmp, and grayed image bmpGray) and one for binary bitmaps (the outline mask bitmaps).
Note that binary bitmaps are created with bit count per pixel set to 1 and the grayed bitmap (actually it is a
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