view docs/html/sdljoystickeventstate.html @ 1544:ab1e4c41ab71

Fixed bug #33 Mike Frysinger wrote: > with libsdl-1.2.9, some games (like bomberclone) started > segfaulting in Gentoo [...snip...] > the last change in the last hunk: [...snip...] > if i change the statement to read: > (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures() > bomberclone no longer segfaults on my box Alex Volkov wrote: > The test "(table[which].blit_features & GetBlitFeatures()) == > table[which].blit_features)" is correct, and the previous > "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken. I think there is potentially a slightly different cause of the above problem. During the introduction of the Altivec code, the blit_table struct field 'alpha' got changed from a straightforward enum to a bitmask, which makes perfect sense by itself. However, now the table driven blitter selection code in SDL_CalculateBlitN() can choose the wrong blitters when searching for a NO_ALPHA blitter because of the following code: int a_need = 0; ... (a_need & table[which].alpha) == a_need && When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing alpha channel bits to appear in a non-alpha destination surface. I suppose this could theoretically be an indirect cause of the segfault mentioned above. I *think* this can be fixed by changing to int a_need = NO_ALPHA;
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:47:49 +0000
parents 355632dca928
children
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>SDL_JoystickEventState</TITLE
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>SDL_JoystickEventState</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN5969"
></A
><H2
>Name</H2
>SDL_JoystickEventState&nbsp;--&nbsp;Enable/disable joystick event polling</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN5972"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
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NAME="AEN5973"
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><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_JoystickEventState</B
></CODE
>(int state);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN5979"
></A
><H2
>Description</H2
><P
>This function is used to enable or disable joystick event processing. With joystick event processing disabled you will have to update joystick states with <A
HREF="sdljoystickupdate.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickUpdate</TT
></A
> and read the joystick information manually. <TT
CLASS="PARAMETER"
><I
>state</I
></TT
> is either <TT
CLASS="LITERAL"
>SDL_QUERY</TT
>, <TT
CLASS="LITERAL"
>SDL_ENABLE</TT
> or <TT
CLASS="LITERAL"
>SDL_IGNORE</TT
>.</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>Joystick event handling is prefered</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN5990"
></A
><H2
>Return Value</H2
><P
>If <TT
CLASS="PARAMETER"
><I
>state</I
></TT
> is <TT
CLASS="LITERAL"
>SDL_QUERY</TT
> then the current state is returned, otherwise the new processing <TT
CLASS="PARAMETER"
><I
>state</I
></TT
> is returned.</P
></DIV
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CLASS="REFSECT1"
><A
NAME="AEN5996"
></A
><H2
>See Also</H2
><P
><A
HREF="joystick.html"
>SDL Joystick Functions</A
>,
<A
HREF="sdljoystickupdate.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickUpdate</TT
></A
>,
<A
HREF="sdljoyaxisevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_JoyAxisEvent</SPAN
></A
>,
<A
HREF="sdljoyballevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_JoyBallEvent</SPAN
></A
>,
<A
HREF="sdljoybuttonevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_JoyButtonEvent</SPAN
></A
>,
<A
HREF="sdljoyhatevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_JoyHatEvent</SPAN
></A
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