Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_PollEvent.3 @ 1259:36f24cdfcda7
te: Thu, 17 Apr 2003 11:25:26 -0700
From: "Jim"
Subject: [SDL] Frame buffer patches...
Would seem that GCC 3.2.2 promotes all signed values to unsigned if any single vlaue is unsigned in an expression...
for instance when calculating an elo touch position....evertyhign is an (int) except for cach_vinfo.xres which is unsigned. THerefore if y
ou reverse the SDL_ELO_MIN_X and SDL_ELO_MAX_X values the resulging negative value pegs the expression to it's max. Attached it the accumu
lated patch to typecast the unsigned values to (int)
- *dx = (cache_vinfo.xres - (cache_vinfo.xres * (input_x - ELO_MIN_X)) / width);
+ *dx = ((int)cache_vinfo.xres - ((int)cache_vinfo.xres * (input_x - ELO_MIN_X)) / width);
and also to provide quite failure to operations which have the screen currently locked...
The touch screen I'm using the original values were exactly opposite of any position I touched on the screen - evaluating the math the expr
ession SHOULD have handled reversing the min and max values - and after casting the unsigned .xres and .yres to a signed int - worked well.
..
Jim
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Tue, 24 Jan 2006 06:36:43 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
| rev | line source |
|---|---|
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
1 .TH "SDL_PollEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
| 3 SDL_PollEvent\- Polls for currently pending events\&. | |
| 4 .SH "SYNOPSIS" | |
| 5 .PP | |
| 6 \fB#include "SDL\&.h" | |
| 7 .sp | |
| 8 \fBint \fBSDL_PollEvent\fP\fR(\fBSDL_Event *event\fR); | |
| 9 .SH "DESCRIPTION" | |
| 10 .PP | |
| 11 Polls for currently pending events, and returns \fB1\fR if there are any pending events, or \fB0\fR if there are none available\&. | |
| 12 .PP | |
| 13 If \fBevent\fR is not \fBNULL\fP, the next event is removed from the queue and stored in that area\&. | |
| 14 .SH "EXAMPLES" | |
| 15 .PP | |
| 16 .PP | |
| 17 .nf | |
| 18 \f(CWSDL_Event event; /* Event structure */ | |
| 19 | |
| 20 \&. | |
| 21 \&. | |
| 22 \&. | |
| 23 /* Check for events */ | |
| 24 while(SDL_PollEvent(&event)){ /* Loop until there are no events left on the queue */ | |
| 25 switch(event\&.type){ /* Process the appropiate event type */ | |
| 26 case SDL_KEYDOWN: /* Handle a KEYDOWN event */ | |
| 27 printf("Oh! Key press | |
| 28 "); | |
| 29 break; | |
| 30 case SDL_MOUSEMOTION: | |
| 31 \&. | |
| 32 \&. | |
| 33 \&. | |
| 34 default: /* Report an unhandled event */ | |
| 35 printf("I don\&'t know what this event is! | |
| 36 "); | |
| 37 } | |
| 38 }\fR | |
| 39 .fi | |
| 40 .PP | |
| 41 .SH "SEE ALSO" | |
| 42 .PP | |
| 43 \fI\fBSDL_Event\fR\fR, \fI\fBSDL_WaitEvent\fP\fR, \fI\fBSDL_PeepEvents\fP\fR | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
44 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59 |