[comp.windows.ms] Bitmaps under Windows

eskin@btree.uucp (Michael Eskin) (02/28/90)

We are in the process of porting some Macintosh code to Windows and are
having some trouble with bitmaps.  On the Macintosh, I an able to setup
a bitmap that points to a particular address in memory and then BLT to
or from that bitmap.  In the application we are writing, a buffer
containing bitmap data, and the organization of that data are being
passed to a routine that wants to BLT that data either to another
location in memory or to a window.  Is it possible to create a device
context for the source bitmap and then associate the buffer memory with
that context without having Windows allocate the bits when the device
context is created?  The application that we are writing is designed to
be platform independent until the BLT, so there really isn't a concept
of a device context for Windows until the BLT routine is called.

We have been fighting with this problem for a few months without much
luck so any help would be greatly appreciated!

Michael Eskin
Brooktree Imaging SBU
(619) 535-3476

bturner@hpcvlx.cv.hp.com (Bill Turner) (03/01/90)

> We are in the process of porting some Macintosh code to Windows and are
> having some trouble with bitmaps.  On the Macintosh, I an able to setup
> a bitmap that points to a particular address in memory and then BLT to
> or from that bitmap.  In the application we are writing, a buffer
> containing bitmap data, and the organization of that data are being
> passed to a routine that wants to BLT that data either to another
> location in memory or to a window.  Is it possible to create a device
> context for the source bitmap and then associate the buffer memory with
> that context without having Windows allocate the bits when the device
> context is created?

Once the memory DC has been created, you can use SelectObject(hMemDC, hBitmap)
to change the bitmap used, just as you would with any other drawing object.

--Bill Turner (bturner@hp-pcd.hp.com)
HP Interface Technology Operation