Mercurial > sdl-ios-xcode

comparison README.RISCOS @ 1035:974ba6ae0fa3

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Date: Wed, 26 Jan 2005 13:37:09 GMT From: Peter Naulls Subject: RISC OS SDL Patches Sam, I've attached a diff of the latest changes to libSDL for RISC OS support. These changes are by Alan Buckley and myself. The most significant of these are: Optimised assembler blit rountines - I've attached the file src/video/riscos/SDL_riscosASM.s which is needed for this. Move to using /dev/dsp instead of its own audio implementation. This means that src/audio/riscos/SDL_drenderer.c should be removed Typo fixes. Mainly correct spelling of "RISC OS", but some from elsewhere too.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 12 Feb 2005 18:01:31 +0000
parents d74fbf56f2f6
children de3d552b59b2
comparison
equal deleted inserted replaced
1034:2eca15c3f609 1035:974ba6ae0fa3
1 Readme for RISC OS port of SDL 1 Readme for RISC OS port of SDL
2 ============================== 2 ==============================
3 3
4 This document last updated on 25th June 2004 4 This document last updated on 26th January 2005
5 5
6 This is a RISC OS port of the Simple Direct Media Layer (SDL) by Alan Buckley. 6 This is a RISC OS port of the Simple Direct Media Layer (SDL) by Alan Buckley with contributions from Peter Naulls.
7 7
8 Details of the SDL can be found at http://www.libsdl.org. 8 Details of the SDL can be found at http://www.libsdl.org.
9 9
10 The source code including the RISC OS version can be obtained from http://www.libsdl.org. 10 The source code including the RISC OS version can be obtained from
11 http://www.libsdl.org.
11 12
12 RISC OS makefiles, pre built libraries and many games and applications compiled for RISC OS using this library can be downloaded from The Unix Porting Project at http://www.chocky.org/unix/index.html. 13 RISC OS makefiles, pre built libraries and many games and applications compiled for RISC OS using this library can be downloaded from The Unix Porting Project at http://www.chocky.org/unix/index.html.
13 14
14 This is released under the LGPL see the file COPYING for details. 15 This is released under the LGPL see the file COPYING for details.
15 16
16 17
17 RISCOS port of SDL runtime information 18 RISC OS port of SDL runtime information
18 ====================================== 19 ======================================
19 20
20 Runtime requirements 21 Runtime requirements
21 -------------------- 22 --------------------
22 23
23 This library currently needs a minimum of RISCOS 3.6. The source code for the library (and a lot of the programs built with it) also need long file names. 24 This library currently needs a minimum of RISC OS 3.6. The source code for the library (and a lot of the programs built with it) also need long file names.
24 25
25 To use the audio you also need 16 bit sound and to have installed the Digital Render module by Andreas Dehmel version 0.51 available from his web site: 26 To use the audio you also need 16 bit sound and to have installed the DigitalRender module by Andreas Dehmel version 0.51 available from his
26 http://home.t-online.de/~zarquon 27 web site: http://home.t-online.de/~zarquon
28 This is loaded when needed by UnixLib.
27 29
28 Note: As most programs ported from other OS's use high resolution graphics and a memory back buffer a machine with a StrongARM processor and 1 or 2MB of VRAM (or a better machine) is recomended. 30 Note: As most programs ported from other OSes use high resolution graphics and a memory back buffer a machine with a StrongARM processor and 1 or 2MB of VRAM (or a better machine) is recomended.
29 31
30 32
31 RISCOS runtime parameters 33 RISC OS runtime parameters
32 ------------------------- 34 -------------------------
33 35
34 Several environmental variables have been defined to make porting programs easier (i.e. By setting these variable you do not need to have source code differences between OS's). 36 Several environmental variables have been defined to make porting programs easier (i.e. By setting these variable you do not need to have source code differences between OSes).
35 37
36 They are all defined on an application basis. 38 They are all defined on an application basis.
37 39
38 The <appname> used below is found as follows: 40 The <appname> used below is found as follows:
39 1. Use the name of the program unless it is !RunImage 41 1. Use the name of the program unless it is !RunImage
40 2. Check the folder specification for the folder !RunImage is run from. If it is a folder name use that name, otherwise if it is an environmental variable of the form <XXX$Dir> use the value of XXX. 42 2. Check the folder specification for the folder !RunImage is run from. If it is a folder name use that name, otherwise if it is an environmental variable of the form <XXX$Dir> use the value of XXX.
41 43
42 The variables are: 44 The variables are:
43 45
44 SDL$<appname>$TaskName - The name of the task for RISCOS. If omitted then <appname> is used for the task name, 46 SDL$<appname>$TaskName - The name of the task for RISC OS. If omitted then <appname> is used for the task name,
45 47
46 SDL$<appname>$BackBuffer - set to 1 to use a system memory back buffer for the screen in full screen mode. Some programs on other systems assume their is always a back buffer even though the SDL specification specifies this is not the case. The current RISCOS implementation uses direct writes to the screen if a hardware fullscreen is requested. 48 SDL$<appname>$BackBuffer - set to 1 to use a system memory back buffer for the screen in full screen mode. Some programs on other systems assume their is always a back buffer even though the SDL specification specifies this is not the case. The current RISC OS implementation uses direct writes to the screen if a hardware fullscreen is requested.
47 49
48 SDL$<appname>$CloseAction - set the action for the close icon. Again as programs don't match the specification you can set this to 0 to remove the close icon from the main window for applications where this does not affect the program. 50 SDL$<appname>$CloseAction - set the action for the close icon. Again as programs don't match the specification you can set this to 0 to remove the close icon from the main window for applications where this does not affect the program.
49 51
50 SDL$<appname>$AudioBuffer - set the minimum size of the audio buffer in samples in steps of 512. If this is less than the minimum calculated from the parameters requested in the program by SDL_OpenAudio these will be used instead. If this parameter is not used or set to 0 the buffer size will be calculated to buffer 10 centisecond of sound. The time buffered can be calculated as specified size/frequency in seconds. The larger the buffer the more audio data that will be buffered, but this can lead to a lag between a sound being requested and it being heard, so the size should be kept to a minimum. You should only set this parameter if the sound is being missed out. 52 SDL$<appname>$AudioBuffer - set the minimum size of the audio buffer in samples in steps of 512. If this is less than the minimum calculated from the parameters requested in the program by SDL_OpenAudio these will be used instead. If this parameter is not used or set to 0 the buffer size will be calculated to buffer 10 centisecond of sound. The time buffered can be calculated as specified size/frequency in seconds. The larger the buffer the more audio data that will be buffered, but this can lead to a lag between a sound being requested and it being heard, so the size should be kept to a minimum. You should only set this parameter if the sound is being missed out.
51 53
52 54
53 55
54 RISCOS SDL port API notes 56 RISC OS SDL port API notes
55 ========================= 57 =========================
56 58
57 Current level of implementation 59 Current level of implementation
58 ------------------------------- 60 -------------------------------
59 61
60 The following list is an overview of how much of the SDL is implemented. The areas match the main areas of the SDL. 62 The following list is an overview of how much of the SDL is implemented. The areas match the main areas of the SDL.
61 63
62 video - Mostly done. Doesn't cover gamma, YUV-overlay or open gl. 64 video - Mostly done. Doesn't cover gamma, YUV-overlay or OpenGL.
63 Window Manager - Mostly done. SetIcon/IconifyWindow not implemented. 65 Window Manager - Mostly done. SetIcon/IconifyWindow not implemented.
64 Events - Mostly done. Resize and some joystick events missing. 66 Events - Mostly done. Resize and some joystick events missing.
65 Joystick - Currently assumes a single joystick with 4 buttons. 67 Joystick - Currently assumes a single joystick with 4 buttons.
66 Audio - Requires Digital Renderer module. 68 Audio - Done
67 CDROM - Not implemented. 69 CDROM - Not implemented.
68 Threads - Done 70 Threads - Done
69 Timers - Done 71 Timers - Done
70 72
71 Thread support can be removed by defining DISABLE_THREADS and recompiling the library. 73 Thread support can be removed by defining DISABLE_THREADS and recompiling the library.
74 ------------- 76 -------------
75 77
76 This section contains additional notes on some specific commands. 78 This section contains additional notes on some specific commands.
77 79
78 SDL_SetVideoMode 80 SDL_SetVideoMode
79 On RISCOS a fullscreen mode directly accesses the screen. This can be modified by the environmental variable (SDL$<appname>$BackBuffer) or by using the SDL_SWSURFACE flag to write to an offscreen buffer that is updated using SDL_UpdateRects. 81 On RISC OS a fullscreen mode directly accesses the screen. This can be modified by the environmental variable (SDL$<appname>$BackBuffer) or by using the SDL_SWSURFACE flag to write to an offscreen buffer that is updated using SDL_UpdateRects.
80 Open GL is not supported so SDL_OPENGL and SDL_OPENGLBLIT flags fail. 82 Open GL is not supported so SDL_OPENGL and SDL_OPENGLBLIT flags fail.
81 SDL_RESIZEABLE and SDL_NOFRAME flags are not supported. 83 SDL_RESIZEABLE and SDL_NOFRAME flags are not supported.
82 84
83 SDL_SetColors 85 SDL_SetColors
84 In a wimp mode the screen colours are not changed for a hardware palette instead the RISCOS sprite colour mapping is used to get the best matching colours. 86 In a wimp mode the screen colours are not changed for a hardware palette instead the RISC OS sprite colour mapping is used to get the best matching colours.
85 87
86 SDL_CreateCursor 88 SDL_CreateCursor
87 Inverted colour is not supported. 89 Inverted colour is not supported.
88 90
89 SDL_WM_ToggleFullScreen 91 SDL_WM_ToggleFullScreen
105 107
106 Notes on current implementation 108 Notes on current implementation
107 ------------------------------- 109 -------------------------------
108 110
109 Keyboard and mouse are polled so if too long a time is spent between a call to SDL_PumpEvents, functions that use it, or SDL_Delay events can be missed. 111 Keyboard and mouse are polled so if too long a time is spent between a call to SDL_PumpEvents, functions that use it, or SDL_Delay events can be missed.
110
111 The sound is sent to the digital renderer player in a seperate thread. If there is too long a delay between this thread being processed (possibly if a lot else is running in the Wimp) the sound may sound incorrect or dissappear.
112