Re: dlls/winmm/winealsa/midi.c: Bug in MIDI_CMD_BENDER fixed

[Marcus Meissner]

On Tue, Jul 26, 2005 at 11:52:55PM +0200, Johannes Koch wrote:
> The pitch value was wrongly converted and has to be centered around zero.
>
> Changelog
>    Fixed pitch bending in the alsa midi driver.

> ? patch.diff
> Index: dlls/winmm/winealsa/midi.c
> ===================================================================
> RCS file: /home/wine/wine/dlls/winmm/winealsa/midi.c,v
> retrieving revision 1.16
> diff -u -p -r1.16 midi.c
> --- dlls/winmm/winealsa/midi.c	27 Apr 2005 09:39:56 -0000	1.16
> +++ dlls/winmm/winealsa/midi.c	26 Jul 2005 21:31:05 -0000
> @@ -833,7 +833,7 @@ static DWORD modData(WORD wDevID, DWORD 
>       snd_seq_ev_set_controller(&event, evt&0x0F, d1, d2);
>       break;
>       case MIDI_CMD_BENDER:
> -		snd_seq_ev_set_pitchbend(&event, evt&0x0F, ((WORD)d1 << 7) | (WORD)d2);
> +		snd_seq_ev_set_pitchbend(&event, evt&0x0F, ((WORD)d2 << 7 | (WORD)d1) - 0x2000);

This is not correct, you need extra ( ) around the << 7, like this perhaps:
> +		snd_seq_ev_set_pitchbend(&event, evt&0x0F, (((WORD)d2 << 7) | (WORD)d1) - 0x2000);

Ciao, Marcus

dlls/winmm/winealsa/midi.c: Bug in MIDI_CMD_BENDER fixed

[Johannes Koch]

No, you don't. The bitwise shifting operator has a higher precedence
than the bitwise or does.
You may test it with this programm:

#include <stdio.h>

int main(int agrc, char** argv)
{
   int iTest = 0x42 << 7 | 0x02;
   int iTest1 = (0x42 << 7) | 0x02;
   int iTest2 = 0x42 << (7 | 0x02);

   printf("iTest: %d; iTest1: %d, iTest2: %d\n", iTest, iTest1, iTest2);

   return 0;
}

I get the following output(compiled with gcc 3.3.5):
iTest: 8450; iTest1: 8450, iTest2: 8448

Greetings,
Johannes

dlls/winmm/winealsa/midi.c: Bug in MIDI_CMD_BENDER fixed

[Felix Nawothnig]

Johannes Koch wrote:
> No, you don't. The bitwise shifting operator has a higher precedence
> than the bitwise or does.

In case you didn't know...

$ man 7 operator

is your friend. :-)

Felix