To: sdl@libsdl.org From: Christian Walther <cwalther@gmx.ch> Date: Fri, 18 Nov 2005 23:39:02 +0100 Subject: [SDL] Mouse position bugs on Mac OS X The attached patch fixes a few bugs in SDL related to the mouse position in windowed mode on Mac OS X, reproduced using the attached minimal test program - at least here on 10.3.9, with SDL CVS from today. Could anyone test whether the bugs exist and are fixed by the patch on 10.2 and 10.4? 1. When using OpenGL, the vertical mouse positions obtained through events or SDL_GetMouseState() are off by one. 2. When using OpenGL, SDL_WarpMouse() inverts the y coordinate. 3. Clicks on the topmost pixel row of the window are not recognized. 1 and 2 do not occur in non-OpenGL mode, while 3 does. All three only occur in windowed mode, not in fullscreen. The cause for 1 and 3 is that in Cocoa, "the location of the mouse" seems to be defined as "the location of the top left corner of the mouse pointer's hot pixel" (this is not documented, it's just what I found out here), which together with the fact that Cocoa's usual y coordinates start at the bottom and increase upwards means that the y coordinate of the mouse runs from 1 to h, not from 0 to h-1, in a window of height h. If it does work on 10.2 and 10.4 (I'll try to test it as soon as I can, but at the moment all I have at hand is 10.3.9), can this be applied to the CVS? -Christian To: sdl@libsdl.org From: Christian Walther <cwalther@gmx.ch> Date: Mon, 28 Nov 2005 10:41:51 +0100 Subject: [SDL] Re: Mouse position bugs on Mac OS X I wrote: > I'll try to test it as soon as I can, but at the moment all I have at hand is 10.3.9 So, here are the results of my tests (with patched and unpatched frameworks compiled with Xcode 1.5 (gcc 3.3) on 10.3.9): On 10.1.5, my test program doesn't run because of "Undefined symbols: SDL undefined reference to _CGMainDisplayID expected to be defined in Carbon". I guess not supporting 10.1 was a deliberate decision then and that's OK with me. On 10.2.8, 10.3.9, and 10.4.0, the bugs exist as described in my original post and are fixed by my patch. That is, there is no difference between pre/post 10.3 and the patched version works correctly in all combinations of GL/non-GL and windowed/fullscreen. I therefore recommend the patch for inclusion. -Christian

.TH "SDL_keysym" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_keysym\- Keysym structure
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  Uint8 scancode;
  SDLKey sym;
  SDLMod mod;
  Uint16 unicode;
} SDL_keysym;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBscancode\fR
Hardware specific scancode
.TP 20
\fBsym\fR
SDL virtual keysym
.TP 20
\fBmod\fR
Current key modifiers
.TP 20
\fBunicode\fR
Translated character
.SH "DESCRIPTION"
.PP
The \fBSDL_keysym\fR structure is used by reporting key presses and releases since it is a part of the \fI\fBSDL_KeyboardEvent\fR\fR\&.
.PP
The \fBscancode\fR field should generally be left alone, it is the hardware dependent scancode returned by the keyboard\&. The \fBsym\fR field is extremely useful\&. It is the SDL-defined value of the key (see \fISDL Key Syms\fR\&. This field is very useful when you are checking for certain key presses, like so: 
.PP
.nf
\f(CW\&.
\&.
while(SDL_PollEvent(&event)){
  switch(event\&.type){
    case SDL_KEYDOWN:
      if(event\&.key\&.keysym\&.sym==SDLK_LEFT)
        move_left();
      break;
    \&.
    \&.
    \&.
  }
}
\&.
\&.\fR
.fi
.PP
 \fBmod\fR stores the current state of the keyboard modifiers as explained in \fI\fBSDL_GetModState\fP\fR\&. The \fBunicode\fR is only used when UNICODE translation is enabled with \fI\fBSDL_EnableUNICODE\fP\fR\&. If \fBunicode\fR is non-zero then this a the UNICODE character corresponding to the keypress\&. If the high 9 bits of the character are 0, then this maps to the equivalent ASCII character: 
.PP
.nf
\f(CWchar ch;
if ( (keysym\&.unicode & 0xFF80) == 0 ) {
  ch = keysym\&.unicode & 0x7F;
}
else {
  printf("An International Character\&.
");
}\fR
.fi
.PP
 UNICODE translation does have a slight overhead so don\&'t enable it unless its needed\&.
.SH "SEE ALSO"
.PP
\fI\fBSDLKey\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00