Mercurial > sdl-ios-xcode
view docs/man3/SDL_keysym.3 @ 717:42ed44b2c8b6
Date: Sun, 14 Sep 2003 17:04:55 -0400
From: Philip D.S. Thoren <pthoren@cs.uml.edu>
Reply-To: "sdl@libsdl.org" <sdl@libsdl.org>
To: "sdl@libsdl.org" <sdl@libsdl.org>
Subject: [SDL] BUG in src/video/windx5/SDL_dx5events.c
I tracked down a bug that crashed my program on Windows *all* the
time.
FILE: src/video/windx5/SDL_dx5events.c
FUNCTION: handle_mouse
BUG:
SDL_PublicSurface is being dereferenced when it is NULL.
I added the following to the very begining of handle_mouse
and it solved my crashing problems:
if (SDL_PublicSurface == NULL) return;
~ Philip D.S. Thoren
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Mon, 15 Sep 2003 13:51:25 +0000 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
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.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