Wrong result with SDLK_SCANCODE_MASK
Closed this issue · 8 comments
In a C program this statement
printf("%d %d\n",SDLK_SCANCODE_MASK,SDLK_LEFT);
prints
1073741824 1073741904
In Fortran, using SDL2.f90:
print *, SDLK_SCANCODE_MASK,SDLK_LEFT, ' --- pressing LEFT: ',event%key%key_sym%sym
prints
0 81 --- pressing LEFT: 1073741903
This causes
select case (event%key%key_sym%sym)
case (SDLK_LEFT)
to fail: in Fortran, not only the above SDLK... constants values are wrong, but also what reports event%key%key_sym%sym (1073741903 instead of 1073741904) for LEFT arrow pressed is wrong..
BTW, maybe we need also SDL_GetMouseState...
In the C headers for SDL2, I find:
SDL_keycode.h:#define SDLK_SCANCODE_MASK (1<<30)
which corresponds to use a `left shift'.
In Fortran the left shift operator is ishft(i,shift) with shift > 0; shift < 0 is for the right shift operator.
See: ISHFT
So you should use
integer(kind=c_int), parameter :: SDLK_SCANCODE_MASK = ishft(1, 30)
But this does not fix completely the issue. Now one gets:
print *, SDLK_SCANCODE_MASK,SDLK_LEFT, ' --- pressing LEFT: ',event%key%key_sym%sym
[...]
1073741824 1073741905 --- pressing LEFT: 1073741903
SDLK_SCANCODE_MASK is the same both for C and Fortran but not `SDLK_LEFT'... and 'event%key%key_sym%sym'..
Maybe we need to go to sleep..... (just the 03:17!)
Thank you for pointing this out. The reason why SDLK_LEFT does not match your C example is that the SDL_SCANCODE_* parameters are all increased by one, to be able to check the array returned by sdl_get_keyboard_state(). Fortran arrays start with index 1, whereas C arrays start with 0. For compatibility, I will decrease the SDL_SCANCODE_* by one to the original values, but this will make the use of sdl_get_keyboard_state() a little ugly.
@interkosmos wrote:
The reason why SDLK_LEFT does not match your C example..
No, you can leave things as now then if all is coherent. Thanks.
....Oops, I see you have already done the change..
How it works sdl_get_keyboard_state() now? OK this seems to work:
integer(C_UINT8_T), pointer :: keys(:) => null()
[...]
r%keys(0:) => sdl_get_keyboard_state()
Oops.. maybe we need SetWindowIcon and an example how to add an icon to our apps...
SDL_SetWindowIcon() has been added with commit 12a0879.
Maybe we need the SDL_WINDOWEVENT_XXXXX (SHOWN, HIDDEN, etc,) constants...
Enum has been added with commit ea9180c.