To: sdl@libsdl.org From: Christian Walther <cwalther@gmx.ch> Date: Thu, 15 Dec 2005 21:19:53 +0100 Subject: [SDL] More mouse enhancements for Mac OS X The attached patch brings two more enhancements to mouse handling on Mac OS X (Quartz): 1. Currently, after launching an SDL application, SDL's notion of the mouse position is stuck in the top left corner (0,0) until the first time the mouse is moved. That's because the UpdateMouse() function isn't implemented in the Quartz driver. This patch adds it. 2. When grabbing input while the mouse cursor is hidden, the function CGAssociateMouseAndMouseCursorPosition(0) is called, which prevents the system's notion of the mouse location from moving (and therefore leaving the SDL window) even when the mouse is moved. However, apparently the Wacom tablet driver (and maybe other special pointing device drivers) doesn't care about that setting and still allows the mouse location to go outside of the window. Interestingly, the system cursor, which is made visible by the existing code in SDL in that case, does not follow the mouse location, but appears in the middle of the SDL window. The mouse location being outside of the window however means that mouse button events go to background applications (or the dock or whatever is there), which is very confusing to the user who sees no cursor outside of the SDL window. I have not found any way of intercepting these events (and that's probably by design, as "normal" applications shouldn't prevent the user from bringing other applications' windows to the front by clicking on them). An idea would be placing a fully transparent, screen-filling window in front of everything, but I fear that this might affect rendering performance (by doing unnecessary compositing, using up memory, or whatever). The deluxe solution to the problem would be talking to the tablet driver using AppleEvents to tell it to constrain its mapped area to the window (see Wacom's "TabletEventDemo" sample app, http://www.wacomeng.com/devsupport/mac/downloads.html), but I think that the bloat that solution would add to SDL would outweigh its usefulness. What I did instead in my patch is reassociating mouse and cursor when the mouse leaves the window while an invisible grab is in effect, and restoring the grab when the window is entered. That way, the grab can still be effectively broken by a tablet, but at least it's obvious to the user that it is broken. That change is minimal - it doesn't affect operation with a mouse (or a trackpad), and the code that it adds is not executed on every PumpEvents() call, only when entering and leaving the window. Unless there are any concerns about the patch, please apply. Feel free to shorten the lengthy comment in SDL_QuartzEvents.m if you think it's too verbose. Thanks -Christian

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Using the Simple DirectMedia Layer with EPOC/SymbianOS 6.0
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I.  Building the Simple DirectMedia Layer libraries:

  You can get Symbian SDK from: 
    http://www.symbian.com.
 
  First create "Epoc" directory under SDL main directory and unpack 
  EpocBuildFiles.zip in it.
   
  To build the librarys goto "epoc" directory and type:
    bldmake bldfiles
    abld makefile vc6 (for creating Microsoft Visual C++ makefiles)
    abld build wins udeb (building for wins emulator)
    abld build armi urel (building for real device)

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II. Building the Simple DirectMedia Layer programs:

  Building SDL test programs is easy once you have built the libraries:
    abld test build wins udeb
    abld test build armi urel

  Supported real screen resolutions
    320 x 200 x  8 bit
    320 x 200 x 12 bit
    640 x 200 x  8 bit
    640 x 200 x 12 bit
  Supported "emulated" screen resolutions 
    640 x 400 x  8 bit
    640 x 400 x 12 bit
    640 x 480 x  8 bit
    640 x 480 x 12 bit
  "Emulated" resolutions are implemented by by shrinking the screen vertically 
  i.e. only every second scanline is drawn. This is mainly ment to be used for 
  testing quick ports of programs. Using faked resolutions is a waste of memory 
  and cpu power!

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III. Running test programs

  Copy executable to the device and run it from the File manager.   The Esc 
  key quits demo programs. In Crystal, Exe programs do not appear in task list 
  nor in Extras :-(. Test programs are tested in Nokia 9210 Communicator.

  Special keys used in SDL:
    The Caps lock key enables or disables the virtual cursor. 
    Function keys are mapped as follows: 
    F1=chr+q, F2=chr+w,..., F8=chr+i, 
    F9=chr+a,..., F12=chr+d.

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IV.  Enjoy! :)

  If you have a project you'd like me to know about, or want to ask questions,
  go ahead and join the SDL developer's mailing list by sending e-mail to:

	sdl-request@libsdl.org

  and put "subscribe" into the subject of the message. Or alternatively you
  can use the web interface:

	http://www.libsdl.org/mailman/listinfo/sdl

  You can find more info about Epoc version of SDL from Hannu Viitala's 
  homepage
    http://www.mbnet.fi/~haviital
  
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