Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_SetColors.3 @ 765:4c2ba6161939
Editors Note: The original patch was modified to use SDL_Delay() instead of
nanosleep because nanosleep may not be portable to all systems
using SDL with the ALSA backend. This may be a moot point with
the switch to blocking writes anyway...
Date: Sat, 27 Dec 2003 21:47:36 +0100
From: Michel Daenzer
To: Debian Bug Tracking System
Subject: [SDL] Bug#225252: [PATCH] ALSA fixes
Package: libsdl1.2debian-all
Version: 1.2.6-2
Severity: normal
Tags: patch
For SDL 1.2.6, the ALSA backend was changed to call snd_pcm_open() with
SND_PCM_NONBLOCK. That's a good idea per se, however, it causes high CPU
usage, interrupted sound and stuttering in some games here. Taking a nanosleep
whenever snd_pcm_writei() returns -EAGAIN fixes this, but I think it's more
efficient to use blocking mode for the actual sound playback. Feedback from the
SDL and ALSA lists appreciated.
The patch also fixes the default ALSA device to be used.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 04 Jan 2004 15:40:50 +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_SetColors" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
| 3 SDL_SetColors\- Sets a portion of the colormap for the given 8-bit surface\&. | |
| 4 .SH "SYNOPSIS" | |
| 5 .PP | |
| 6 \fB#include "SDL\&.h" | |
| 7 .sp | |
| 8 \fBint \fBSDL_SetColors\fP\fR(\fBSDL_Surface *surface, SDL_Color *colors, int firstcolor, int ncolors\fR); | |
| 9 .SH "DESCRIPTION" | |
| 10 .PP | |
| 11 Sets a portion of the colormap for the given 8-bit surface\&. | |
| 12 .PP | |
| 13 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_SetColors\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\&. | |
| 14 .PP | |
| 15 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\&. | |
| 16 .PP | |
| 17 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)\&. \fBSDL_SetColors\fP modifies both palettes (if present), and is equivalent to calling \fISDL_SetPalette\fR with the \fBflags\fR set to \fB(SDL_LOGPAL | SDL_PHYSPAL)\fP\&. | |
| 18 .SH "RETURN VALUE" | |
| 19 .PP | |
| 20 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_SetColors\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\&. | |
| 21 .SH "EXAMPLE" | |
| 22 .PP | |
| 23 .nf | |
| 24 \f(CW/* Create a display surface with a grayscale palette */ | |
| 25 SDL_Surface *screen; | |
| 26 SDL_Color colors[256]; | |
| 27 int i; | |
| 28 \&. | |
| 29 \&. | |
| 30 \&. | |
| 31 /* Fill colors with color information */ | |
| 32 for(i=0;i<256;i++){ | |
| 33 colors[i]\&.r=i; | |
| 34 colors[i]\&.g=i; | |
| 35 colors[i]\&.b=i; | |
| 36 } | |
| 37 | |
| 38 /* Create display */ | |
| 39 screen=SDL_SetVideoMode(640, 480, 8, SDL_HWPALETTE); | |
| 40 if(!screen){ | |
| 41 printf("Couldn\&'t set video mode: %s | |
| 42 ", SDL_GetError()); | |
| 43 exit(-1); | |
| 44 } | |
| 45 | |
| 46 /* Set palette */ | |
| 47 SDL_SetColors(screen, colors, 0, 256); | |
| 48 \&. | |
| 49 \&. | |
| 50 \&. | |
| 51 \&.\fR | |
| 52 .fi | |
| 53 .PP | |
| 54 .SH "SEE ALSO" | |
| 55 .PP | |
| 56 \fI\fBSDL_Color\fR\fR \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_SetPalette\fP\fR, \fI\fBSDL_SetVideoMode\fP\fR | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
57 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01 |