🚀 go-pugleaf

>
> Create a bitmap compatible with the HDC of the client area on the screen.
> Call GetClientRect to get the dimensions of that client area and use
> CreateCompatibleBitmap to get a bitmap sized for the screen.
>

Ed,

ok, without getting into where its put just yet (right now I have it in my
paint code)....AND....sorry to belabor this in case I'm boring anyone...

Problem:
    I get one of the aircraft bitmap on the screen at 0,0.....  I assume
that all 160 of them are being displayed at 0,0 on-top of each other.

What I'm doing:
    I have a screen DC
    Create a background DC - make it the same size as screen DC
    Create an airplane DC - make it the same size as the airplane bitmap
    160+ times
             Blit the airplane onto the background
    Blit the background onto the screen.

I perform the following
        hbm = LoadBitmap(hInstance,MAKEINTRESOURCE(IDB_BITMAP1));

//create an off screen memory area for the main screen
        hdcMem = CreateCompatibleDC(hDC);
//create a compatible bitmap the size of the screen HDC
        hbmMem = CreateCompatibleBitmap(hdcMem, width, height);
//create a memory for the aircraft bitmap
        hdcbm = CreateCompatibleDC(NULL);
//setup a buffer area for the plane bitmap so we can find its size
        GetObject(hbm,sizeof(bm),&bm);
//size the DC to the size of the plane bitmap
        hbmPlane = CreateCompatibleBitmap(hdcbm,bm.bmWidth,bm.bmHeight);
//Select the compatible Bitmap into background memory
        hbmT = SelectObject(hdcMem,hbmMem);
//Select the airplane Bitmap into airplane memory
        hbmB = SelectObject(hdcbm,hbm);


That being done, now I go through my list...
 now = head
 while now != NULL

BitBlt(hdcMem,tempLonLat.x,tempLonLat.y,bm.bmWidth,
         bm.bmHeight,hdcbm,0,0,SRCCOPY);
                 // VERY confused here.  see below
 now = next

Now blit it onto screen

BitBlt(hDC,0,0,rect.right-rect.left,rect.bottom-rect.top,hdcMem,0,0,SRCCOPY)

end pseudocode


QUESTION...
  I'm REALLY confused about where the destination of the blit is to be on
the screen back-buffer.  I have my map mode set as follows:
          SetMapMode(hDC,MM_ANISOTROPIC);
          SetWindowExtEx(hDC, xwin,ywin,NULL);
//xwin is 360000    ywin is 180000
          SetViewportExtEx(hDC,width,-height,NULL);
//width and height are the client window size

So in my blit to the back buffer above, I've taken the lon/lat of the
aircraft and convert to device coords, using LPtoDP...THEN use that as the
destination of the blit.
I originally used the Logical coordinates (actual lon/lat [*1000]) and that
didn't seem to work either.

So I have made the CreateCompatibleDC for the screen in device coordinates.
I tried making it logical coordinates and get an error creating the
CreateCompatibleBitmap.

OR...
should I create the compatibleDC for the off screen, then set the map mode
and
SetWindowExtEx and SetViewportEx for the off screen DC also?

Whew!!!  I think I've gone off the deep end with this....

Any further help would sure be appreciated....