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.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401036

README.RISCOS

 Readme for RISC OS port of SDL
 ==============================
 
-This document last updated on 25th June 2004
+This document last updated on 26th January 2005
 
-This is a RISC OS port of the Simple Direct Media Layer (SDL) by Alan Buckley.
+This is a RISC OS port of the Simple Direct Media Layer (SDL) by Alan Buckley with contributions from Peter Naulls.
 
 Details of the SDL can be found at http://www.libsdl.org.
 
-The source code including the RISC OS version can be obtained from http://www.libsdl.org.
+The source code including the RISC OS version can be obtained from
+http://www.libsdl.org.
 
 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.
 
 This is released under the LGPL see the file COPYING for details.
 
 
-RISCOS port of SDL runtime information
+RISC OS port of SDL runtime information
 ======================================
 
 Runtime requirements
 --------------------
 
-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.
+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.
 
-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:
-  http://home.t-online.de/~zarquon
+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
+web site: http://home.t-online.de/~zarquon
+This is loaded when needed by UnixLib.
 
-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.
+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.
 
 
-RISCOS runtime parameters
+RISC OS runtime parameters
 -------------------------
 
-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).
+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).
 
 They are all defined on an application basis.
 
@@ -41,9 +43,9 @@ The <appname> used below is found as follows:
 
 The variables are:
 
-SDL$<appname>$TaskName - The name of the task for RISCOS. If omitted then <appname> is used for the task name,
+SDL$<appname>$TaskName - The name of the task for RISC OS. If omitted then <appname> is used for the task name,
 
-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.
+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.
 
 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.
 
@@ -51,7 +53,7 @@ SDL$<appname>$AudioBuffer - set the minimum size of the audio buffer in samples
 
 
 
-RISCOS SDL port API notes
+RISC OS SDL port API notes
 =========================
 
 Current level of implementation
@@ -59,11 +61,11 @@ Current level of implementation
 
 The following list is an overview of how much of the SDL is implemented. The areas match the main areas of the SDL.
 
-video - Mostly done. Doesn't cover gamma, YUV-overlay or open gl.
+video - Mostly done. Doesn't cover gamma, YUV-overlay or OpenGL.
 Window Manager - Mostly done. SetIcon/IconifyWindow not implemented.
 Events - Mostly done. Resize and some joystick events missing.
 Joystick - Currently assumes a single joystick with 4 buttons.
-Audio - Requires Digital Renderer module.
+Audio - Done
 CDROM - Not implemented.
 Threads - Done
 Timers - Done
@@ -76,12 +78,12 @@ SDL API notes
 This section contains additional notes on some specific commands.
 
 SDL_SetVideoMode
-  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.
+  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.
   Open GL is not supported so SDL_OPENGL and SDL_OPENGLBLIT flags fail.
   SDL_RESIZEABLE and SDL_NOFRAME flags are not supported.
 
 SDL_SetColors
-  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.
+  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.
 
 SDL_CreateCursor
    Inverted colour is not supported.
@@ -107,6 +109,3 @@ Notes on current implementation
 -------------------------------
 
 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.
-
-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.
-

configure.in

@@ -2644,7 +2644,7 @@ case "$target" in
         # MiNT does not define "unix"
         CFLAGS="$CFLAGS -Dunix"
         ;;
-    *-*-riscos)
+    *-riscos)
         ARCH=riscos
         # Set up files for the video library
         if test x$enable_video = xyes; then
@@ -2653,8 +2653,11 @@ case "$target" in
         fi
         # Set up files for the audio library
         if test x$enable_audio = xyes; then
-            AUDIO_SUBDIRS="$AUDIO_SUBDIRS riscos"
-            AUDIO_DRIVERS="$AUDIO_DRIVERS riscos/libaudio_riscos.la"
+            CFLAGS="$CFLAGS -DOSS_SUPPORT"
+            AUDIO_SUBDIRS="$AUDIO_SUBDIRS dsp"
+            AUDIO_DRIVERS="$AUDIO_DRIVERS dsp/libaudio_dsp.la"
+            AUDIO_SUBDIRS="$AUDIO_SUBDIRS dma"
+            AUDIO_DRIVERS="$AUDIO_DRIVERS dma/libaudio_dma.la"
         fi
         # Set up files for the joystick library
         if test x$enable_joystick = xyes; then
@@ -2684,7 +2687,7 @@ case "$target" in
             COPY_ARCH_SRC(src/timer, riscos, SDL_systimer.c)
         fi
 
-        CFLAGS="$CFLAGS -DENABLE_RISCOS -DDRENDERER_SUPPORT"
+        CFLAGS="$CFLAGS -DENABLE_RISCOS"
 
         SYSTEM_LIBS="$SYSTEM_LIBS -ljpeg -ltiff -lpng -lz"
         ;;
@@ -2859,7 +2862,6 @@ src/audio/nas/Makefile
 src/audio/nto/Makefile
 src/audio/openbsd/Makefile
 src/audio/paudio/Makefile
-src/audio/riscos/Makefile
 src/audio/sun/Makefile
 src/audio/ums/Makefile
 src/audio/windib/Makefile

include/SDL_syswm.h

@@ -140,12 +140,12 @@ struct SDL_SysWMmsg {
 	int pollBlock[64];
 };
 
-/* The RISCOS custom window manager information structure */
+/* The RISC OS custom window manager information structure */
 typedef struct SDL_SysWMinfo {
 	SDL_version version;
 	int wimpVersion;    /* Wimp version running under */
-	int taskHandle;     /* The RISCOS task handle */
-	int window;			/* The RISCOS display window */
+	int taskHandle;     /* The RISC OS task handle */
+	int window;		/* The RISC OS display window */
 } SDL_SysWMinfo;
 
 #elif defined(__QNXNTO__)

src/audio/SDL_audiodev.c

@@ -27,7 +27,7 @@ static char rcsid =
 
 /* Get the name of the audio device we use for output */
 
-#if defined(unix) || defined(__unix__)
+#if defined(unix) || defined(__unix__) || defined(__riscos__)
 
 #include <stdlib.h>
 #include <stdio.h>

src/audio/riscos/.cvsignore

-Makefile.in
-Makefile
-.libs
-*.o
-*.lo
-*.la

src/audio/riscos/Makefile.am

-
-## Makefile.am for SDL using the RISC OS audio system
-
-noinst_LTLIBRARIES = libaudio_riscos.la
-libaudio_riscos_la_SOURCES = $(SRCS)
-
-# The SDL audio driver sources
-SRCS =	SDL_drenderer.c	\
-	SDL_drenderer.h

src/audio/riscos/SDL_drenderer.h

-/*
-    SDL - Simple DirectMedia Layer
-    Copyright (C) 1997-2004 Sam Lantinga
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Library General Public
-    License as published by the Free Software Foundation; either
-    version 2 of the License, or (at your option) any later version.
-
-    This library is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Library General Public License for more details.
-
-    You should have received a copy of the GNU Library General Public
-    License along with this library; if not, write to the Free
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    Sam Lantinga
-    slouken@devolution.com
-*/
-
-
-#ifndef _SDL_drenderer_h
-#define _SDL_drenderer_h
-
-#include "SDL_sysaudio.h"
-
-/* Hidden "this" pointer for the video functions */
-#define _THIS	SDL_AudioDevice *this
-
-struct SDL_PrivateAudioData {
-	unsigned char *audio_buf;
-};
-
-#endif /* _SDL_drenderer_h */

src/joystick/riscos/SDL_sysjoystick.c

@@ -21,7 +21,7 @@
 */
 
 /*
-   RISCOS - Joystick support by Alan Buckley (alan_baa@hotmail.com) - 10 April 2003
+   RISC OS - Joystick support by Alan Buckley (alan_baa@hotmail.com) - 10 April 2003
 
    Note: Currently assumes joystick is present if joystick module is loaded
    and that there is one joystick with four buttons.
@@ -78,7 +78,7 @@ const char *SDL_SYS_JoystickName(int index)
 {
 	if (index == 0)
 	{
-		return "RISCOS Joystick 0";
+		return "RISC OS Joystick 0";
 	}
 
 	SDL_SetError("No joystick available with that index");

src/thread/linux/clone.S

 
 /* Taken with thanks from LinuxThreads 0.6 */
 
-/* This is no longer necessary with glibc-2.1, which has it's own clone() */
+/* This is no longer necessary with glibc-2.1, which has its own clone() */
 #ifdef linux
 /* Look to see if glibc is available, and if so, what version */
 #include <features.h>

src/timer/riscos/SDL_systimer.c

@@ -99,8 +99,8 @@ void SDL_Delay (Uint32 ms)
     } else is_event_thread = 1;
 #endif
 
-/*TODO: Next version of unixlib may allow us to use usleep here */
-/*      for non event threads */
+        /*TODO: Next version of Unixlib may allow us to use usleep here */
+        /*      for non event threads */
 
 	/* Set the timeout interval - Linux only needs to do this once */
 	then = SDL_GetTicks();
@@ -222,7 +222,7 @@ void SDL_SYS_TimerQuit(void)
 
 int SDL_SYS_StartTimer(void)
 {
-	SDL_SetError("Internal logic error: RISCOS uses threaded timer");
+	SDL_SetError("Internal logic error: RISC OS uses threaded timer");
 	return(-1);
 }
 

src/video/riscos/Makefile.am

@@ -6,6 +6,7 @@ libvideo_riscos_la_SOURCES = $(CGX_SRCS)
 
 # The SDL RISC OS video driver sources
 CGX_SRCS = 				\
+	SDL_riscosASM.s			\
 	SDL_riscosevents.c		\
 	SDL_riscosevents_c.h		\
 	SDL_riscosFullScreenVideo.c	\

src/video/riscos/SDL_riscosASM.s

+Date: Wed, 26 Jan 2005 13:37:09 GMT
+From: Peter Naulls <peter@chocky.org>
+To: slouken@libsdl.org
+Subject: RISC OS SDL Patches
+
+;
+;    SDL - Simple DirectMedia Layer
+;    Copyright (C) 1997-2004 Sam Lantinga
+;
+;    This library is free software; you can redistribute it and/or
+;    modify it under the terms of the GNU Library General Public
+;    License as published by the Free Software Foundation; either
+;    version 2 of the License, or (at your option) any later version.
+;
+;    This library is distributed in the hope that it will be useful,
+;    but WITHOUT ANY WARRANTY; without even the implied warranty of
+;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;    Library General Public License for more details.
+;
+;    You should have received a copy of the GNU Library General Public
+;    License along with this library; if not, write to the Free
+;    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+;
+;    Sam Lantinga
+;    slouken@devolution.com
+;
+; Assembler routines for RISC OS display
+;
+
+	AREA |C$$CODE|
+
+	EXPORT |RISCOS_Put32|
+
+; Display 32bpp to 32bpp, 1:1
+;
+; Code provided by Adrain Lees
+;
+; entry a1 -> destination
+;       a2 =  dest width in pixels
+;       a3 =  dest line length in bytes
+;       a4 =  dest height in scanlines
+;       arg5 -> source
+;       arg6 =  byte offset from end of source line to start of next
+
+Arg5    *       10*4
+Arg6    *       Arg5+4
+
+RISCOS_Put32    ROUT
+                STMFD   sp!,{a2,v1-v6,sl,fp,lr}
+                LDR     ip,[sp,#Arg5]
+                MOV     lr,a1
+                B       ucp64lp
+
+00              ;tail strip of 1-15 pixels
+
+                LDR     v1,[ip],#4
+01              SUBS    a2,a2,#1
+                STR     v1,[lr],#4
+                LDRHI   v1,[ip],#4
+                BHI     %01
+                B       %02
+
+ucp64end        ADDS    a2,a2,#16
+                BNE     %00
+
+02              SUBS    a4,a4,#1                ;height--
+                LDRHI   v1,[sp,#Arg6]
+                LDRHI   a2,[sp]                 ;reload width
+                BLS     %03
+
+                ;move to start of next scanline
+
+                ADD     lr,a1,a3
+                ADD     a1,a1,a3
+                ADD     ip,ip,v1
+
+ucp64lp         SUBS    a2,a2,#16
+                BLO     ucp64end
+
+                PLD     [ip,#64]
+
+                LDR     v1,[ip],#4
+                LDR     v2,[ip],#4
+                LDR     v3,[ip],#4
+                LDR     v4,[ip],#4
+                LDR     v5,[ip],#4
+                LDR     v6,[ip],#4
+                LDR     sl,[ip],#4
+                LDR     fp,[ip],#4
+                STR     v1,[lr],#4
+                STR     v2,[lr],#4
+                STR     v3,[lr],#4
+                STR     v4,[lr],#4
+                STR     v5,[lr],#4
+                STR     v6,[lr],#4
+                STR     sl,[lr],#4
+                STR     fp,[lr],#4
+
+                PLD     [ip,#64]
+
+                LDR     v1,[ip],#4
+                LDR     v2,[ip],#4
+                LDR     v3,[ip],#4
+                LDR     v4,[ip],#4
+                LDR     v5,[ip],#4
+                LDR     v6,[ip],#4
+                LDR     sl,[ip],#4
+                LDR     fp,[ip],#4
+                STR     v1,[lr],#4
+                STR     v2,[lr],#4
+                STR     v3,[lr],#4
+                STR     v4,[lr],#4
+                STR     v5,[lr],#4
+                STR     v6,[lr],#4
+                STR     sl,[lr],#4
+                STR     fp,[lr],#4
+
+                B       ucp64lp
+
+03              LDMFD   sp!,{a2,v1-v6,sl,fp,pc}
+

src/video/riscos/SDL_riscosevents.c

@@ -21,7 +21,7 @@
 */
 
 /*
-     File added by Alan Buckley (alan_baa@hotmail.com) for RISCOS compatability
+     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
 	 27 March 2003
 
      Implements keyboard setup, event pump and keyboard and mouse polling
@@ -43,10 +43,10 @@
 #include "kernel.h"
 #include "swis.h"
 
-/* The translation table from a RISCOS internal key numbers to a SDL keysym */
+/* The translation table from a RISC OS internal key numbers to a SDL keysym */
 static SDLKey RO_keymap[SDLK_LAST];
 
-/* RISCOS Key codes */
+/* RISC OS Key codes */
 #define ROKEY_SHIFT 0
 #define ROKEY_CTRL  1
 #define ROKEY_ALT   2
@@ -90,7 +90,7 @@ void FULLSCREEN_PumpEvents(_THIS)
 	RISCOS_PollKeyboard();
 	RISCOS_PollMouse(this);
 #ifdef DISABLE_THREADS
-	DRenderer_FillBuffers();
+//	DRenderer_FillBuffers();
 	if (SDL_timer_running) RISCOS_CheckTimer();
 #endif
 }
@@ -262,9 +262,11 @@ void RISCOS_PollMouseHelper(_THIS, int fullscreen)
        Sint16 new_x = regs.r[0]; /* Initialy get as OS units */
        Sint16 new_y = regs.r[1];
 
-/* Discard mouse events until the let go of the mouse after starting */
-       if (starting && regs.r[2] != 0) return;
-       else starting = 0;
+       /* Discard mouse events until they let go of the mouse after starting */
+       if (starting && regs.r[2] != 0)
+         return;
+       else
+         starting = 0;
 
        if (new_x != last_x || new_y != last_y || last_buttons != regs.r[2])
        {

src/video/riscos/SDL_riscosmouse.c

@@ -21,7 +21,7 @@
 */
 
 /*
-     File added by Alan Buckley (alan_baa@hotmail.com) for RISCOS compatability
+     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
 	 27 March 2003
 
      Implements mouse cursor shape definitions and positioning

src/video/riscos/SDL_riscossprite.c

@@ -21,7 +21,7 @@
 */
 
 /*
-     File added by Alan Buckley (alan_baa@hotmail.com) for RISCOS compatability
+     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
 	 27 March 2003
 
      Implements Sprite plotting code for wimp display.window

src/video/riscos/SDL_riscostask.c

@@ -21,7 +21,7 @@
 */
 
 /*
-    This file added by Alan Buckley (alan_baa@hotmail.com) to support RISCOS 
+    This file added by Alan Buckley (alan_baa@hotmail.com) to support RISC OS 
 	26 March 2003
 
 	File includes routines for:
@@ -44,7 +44,7 @@
 pthread_t main_thread;
 #endif
 
-/* RISCOS variables */
+/* RISC OS variables */
 
 static int task_handle = 0;
 static int wimp_version = 0;
@@ -84,7 +84,7 @@ static void dump_mode()
 
 /******************************************************************
 
- Initialise as RISCOS Wimp task
+ Initialise as RISC OS Wimp task
 
 *******************************************************************/
 
@@ -169,7 +169,7 @@ void RISCOS_ExitTask()
 		   there is a variable set up in the form SDL$<name>$TaskName
 		   in which case the value of this variable will be used.
 
-		   Now also gets other riscos configuration varibles
+		   Now also gets other RISC OS configuration varibles
                 SDL$<name>$BackBuffer - set to 1 to use a system memory backbuffer in fullscreen mode
 						    so updates wait until a call to SDL_UpdateRects. (default 0)
 						    This is required for programmes where they have assumed this is
@@ -226,7 +226,7 @@ int RISCOS_GetTaskName(char *task_name)
 
 	   if (*p)
 	   {
-		   /* Read variables that effect the RISCOS SDL engine for this task */
+		   /* Read variables that effect the RISC OS SDL engine for this task */
 		   env_var = malloc(strlen(p) + 18); /* 18 is larger than the biggest variable name */
 		   if (env_var)
 		   {
@@ -246,7 +246,7 @@ int RISCOS_GetTaskName(char *task_name)
 			   strcat(env_var, "$BackBuffer");
 
 			   env_val = getenv(env_var);
-			   if (env_val && strcmp(env_val,"1") == 0) riscos_backbuffer = 1;
+			   if (env_val) riscos_backbuffer = atoi(env_val);
 
 			   strcpy(env_var, "SDL$");
 			   strcat(env_var, p);

src/video/riscos/SDL_riscostask.h

@@ -21,7 +21,7 @@
 */
 
 /*
-    This file added by Alan Buckley (alan_baa@hotmail.com) to support RISCOS 
+    This file added by Alan Buckley (alan_baa@hotmail.com) to support RISC OS 
 	26 March 2003
 */
 

src/video/riscos/SDL_riscosvideo.c

@@ -21,10 +21,10 @@
 */
 
 /*
-     File added by Alan Buckley (alan_baa@hotmail.com) for RISCOS compatability
+     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
 	 23 March 2003
 
-     Implements RISCOS display device management.
+     Implements RISC OS display device management.
 	 Routines for full screen and wimp modes are split
 	 into other source files.
 */
@@ -83,7 +83,7 @@ static int RISCOS_LockHWSurface(_THIS, SDL_Surface *surface);
 static void RISCOS_UnlockHWSurface(_THIS, SDL_Surface *surface);
 static void RISCOS_FreeHWSurface(_THIS, SDL_Surface *surface);
 
-/* RISCOS driver bootstrap functions */
+/* RISC OS driver bootstrap functions */
 
 static int RISCOS_Available(void)
 {
@@ -150,16 +150,11 @@ static SDL_VideoDevice *RISCOS_CreateDevice(int devindex)
 	/* Set other entries for fullscreen mode */
 	FULLSCREEN_SetDeviceMode(device);
 
-/* Turn off unixlib file name translation - we hope people have initialised
-   the video system before they try to read any files */
-/*        __riscosify_control = __RISCOSIFY_NO_PROCESS;
-*//* We may be able to eventually replace our processing of filenames with the correct flags above*/
-
 	return device;
 }
 
 VideoBootStrap RISCOS_bootstrap = {
-	RISCOSVID_DRIVER_NAME, "RISCOS video driver",
+	RISCOSVID_DRIVER_NAME, "RISC OS video driver",
 	RISCOS_Available, RISCOS_CreateDevice
 };
 

src/video/riscos/SDL_wimppoll.c

@@ -21,7 +21,7 @@
 */
 
 /*
-     File added by Alan Buckley (alan_baa@hotmail.com) for RISCOS compatability
+     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
 	 27 March 2003
 
      Implements Pumping of events and WIMP polling
@@ -33,6 +33,7 @@
 #include "SDL_events_c.h"
 #include "SDL_riscosvideo.h"
 #include "SDL_riscosevents_c.h"
+#include "SDL_riscosmouse_c.h"
 #include "SDL_timer_c.h"
 
 #include "memory.h"
@@ -61,8 +62,6 @@ extern void WIMP_PollMouse(_THIS);
 extern void RISCOS_PollKeyboard();
 
 #ifdef DISABLE_THREADS
-extern void DRenderer_FillBuffers();
-
 /* Timer running function */
 extern void RISCOS_CheckTimer();
 
@@ -85,7 +84,6 @@ void WIMP_PumpEvents(_THIS)
 	if (hasFocus) RISCOS_PollKeyboard();
 	if (mouseInWindow) WIMP_PollMouse(this);
 #ifdef DISABLE_THREADS
-	DRenderer_FillBuffers();
 	if (SDL_timer_running) RISCOS_CheckTimer();
 #endif
 }
@@ -329,8 +327,6 @@ void RISCOS_BackgroundTasks(void)
 		WIMP_Poll(current_video, 0);
 	}
 #ifdef DISABLE_THREADS
-	/* Keep sound buffers running */
-	DRenderer_FillBuffers();
 	if (SDL_timer_running) RISCOS_CheckTimer();
 #endif
 }

src/video/riscos/SDL_wimpvideo.c

@@ -21,10 +21,10 @@
 */
 
 /*
-     File added by Alan Buckley (alan_baa@hotmail.com) for RISCOS compatability
+     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
 	 27 March 2003
 
-     Implements RISCOS wimp display.
+     Implements RISC OS Wimp display.
 */
 
 #include <stdio.h>
@@ -486,7 +486,7 @@ int WIMP_ToggleFromFullScreen(_THIS)
       WIMP_SetDeviceMode(this);
       WIMP_SetupPlotInfo(this);
 
-      riscos_backbuffer = 1;
+      if (riscos_backbuffer == 0) riscos_backbuffer = 1;
 
       if (buffer && old_alloc_bank) free(old_alloc_bank);