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view docs/man3/SDL_SetPalette.3 @ 1748:5e86e34453d4
------- Comment #1 From Max Horn 2006-04-17 03:08 [reply] -------
Created an attachment (id=106) [edit]
Patch for src/joystick/win32/SDL_mmjoystick.c
I am not even a Windows user, so take the following with a grain of salt:
SDL_mmjoystick.c has a function GetJoystickName which obtains the joystick
name by looking at the registry. The way it does that seems very fishy to me.
Namely, it uses the parameter "index" to construct a registry value name (BTW,
those variables used in the code are really badly named). The value of "index"
in turn equals the current value of "numdevs", as called from
SDL_SYS_JoystickInit.
I read through the MSDN docs at
<http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/dnarinput/html/msdn_extdirect.asp>,
and I believe the simple fix is to replace line 183 of said file
SYS_JoystickName[numdevs] = GetJoystickName(numdevs, joycaps.szRegKey);
by the following:
SYS_JoystickName[numdevs] = GetJoystickName(SYS_JoystickID[i],
joycaps.szRegKey);
However, that is only *hiding* the real issue. Problem is, the list of
joysticks as returned by windows may contains "gaps", and the code deals
incorrectly with that. Namely those gaps occur if joysticks are
removed/(re)added, as the reporter observed.
The attached patch fixes this and another (off-by-one) issue in the code. But
since I have no Windows machine, I can't even test-compile it, so use with
caution.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 29 Apr 2006 20:22:31 +0000 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
line wrap: on
line source
.TH "SDL_SetPalette" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_SetPalette\- Sets the colors in the palette of an 8-bit surface\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_SetPalette\fP\fR(\fBSDL_Surface *surface, int flags, SDL_Color *colors, int firstcolor, int ncolors\fR); .SH "DESCRIPTION" .PP Sets a portion of the palette for the given 8-bit surface\&. .PP Palettized (8-bit) screen surfaces with the \fBSDL_HWPALETTE\fP flag have two palettes, a logical palette that is used for mapping blits to/from the surface and a physical palette (that determines how the hardware will map the colors to the display)\&. \fISDL_BlitSurface\fR always uses the logical palette when blitting surfaces (if it has to convert between surface pixel formats)\&. Because of this, it is often useful to modify only one or the other palette to achieve various special color effects (e\&.g\&., screen fading, color flashes, screen dimming)\&. .PP This function can modify either the logical or physical palette by specifing \fBSDL_LOGPAL\fP or \fBSDL_PHYSPAL\fPthe in the \fBflags\fR parameter\&. .PP When \fBsurface\fR is the surface associated with the current display, the display colormap will be updated with the requested colors\&. If \fBSDL_HWPALETTE\fP was set in \fISDL_SetVideoMode\fR flags, \fBSDL_SetPalette\fP will always return \fB1\fR, and the palette is guaranteed to be set the way you desire, even if the window colormap has to be warped or run under emulation\&. .PP The color components of a \fI\fBSDL_Color\fR\fR structure are 8-bits in size, giving you a total of 256^3=16777216 colors\&. .SH "RETURN VALUE" .PP If \fBsurface\fR is not a palettized surface, this function does nothing, returning \fB0\fR\&. If all of the colors were set as passed to \fBSDL_SetPalette\fP, it will return \fB1\fR\&. If not all the color entries were set exactly as given, it will return \fB0\fR, and you should look at the surface palette to determine the actual color palette\&. .SH "EXAMPLE" .PP .nf \f(CW /* Create a display surface with a grayscale palette */ SDL_Surface *screen; SDL_Color colors[256]; int i; \&. \&. \&. /* Fill colors with color information */ for(i=0;i<256;i++){ colors[i]\&.r=i; colors[i]\&.g=i; colors[i]\&.b=i; } /* Create display */ screen=SDL_SetVideoMode(640, 480, 8, SDL_HWPALETTE); if(!screen){ printf("Couldn\&'t set video mode: %s ", SDL_GetError()); exit(-1); } /* Set palette */ SDL_SetPalette(screen, SDL_LOGPAL|SDL_PHYSPAL, colors, 0, 256); \&. \&. \&. \&.\fR .fi .PP .SH "SEE ALSO" .PP \fISDL_SetColors\fR, \fISDL_SetVideoMode\fR, \fISDL_Surface\fR, \fISDL_Color\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01