Advanced MFC Programming

Chapter 10. Bitmap
Draw this
portion with
shadowed color
Draw this
portion with
highlighted color
Figure 10-3. Implement chiseled effect
The highlighted outline can be obtained in the same way, but we need to combine the original bitmap
and the inverted bitmap differently here:
1) Draw the original bitmap at position (1, 1).
1) Invert the bitmap image.
1) Combine the inverted image with the original image with bit-wise OR operation, with the inverted
image be put at position (0, 0) (Figure 10-5).
If we combine the two outlines and paint them with highlighted and shadowed colors respectively, then
fill the rest part with a normal color (A color between the highlighted and shadowed color), we will have a
3D effect. For example, we can use white as the highlighted color, dark gray as the shadowed color, and
light gray as the normal color.
Draw original
image at (0, 0)
Resulted outline
Combine them
using bit-wise OR
operation
Draw inverted
image at (1, 1)
Figure 10-4. Generate the outline that should be drawn with shadowed color
Creating Binary Bitmap Image
So we need to generate monochrome black/white binary image from the original color bitmap. Of
course we can examine every pixel one by one and compare its brightness with a threshold (Usually the
threshold value is set to the middle between the brightest and darkest color, which are white and black
respectively). If the brightness of a pixel is greater than the threshold, its color is set to white, otherwise it
will be set to black.
However, we can implement this conversion in an easier way. Remember, when creating the bitmap by
calling function CBitmap::CreateBitmap(…), we are allowed to specify the bitmap’s attributes, which
includes the dimension of the image, number of bytes in each raster line, and bit count per pixel. Here, the
bit count per pixel indicates how many bits will be used for representing a single pixel. If we set it to 1, the
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