Added initial support for RISC OS (thanks Peter Naulls!)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40631

src/timer/Makefile.am

@@ -10,6 +10,7 @@ ARCH_SUBDIRS = $(srcdir)/amigaos \
                $(srcdir)/linux \
                $(srcdir)/macos \
                $(srcdir)/mint \
+               $(srcdir)/riscos \
                $(srcdir)/win32
 
 # Include the architecture-independent sources

src/timer/riscos/SDL_systimer.c

@@ -0,0 +1,146 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001  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
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+#include <stdio.h>
+#include <time.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include "SDL_error.h"
+#include "SDL_timer.h"
+#include "SDL_timer_c.h"
+
+/* Timer start/reset time */
+static Uint32 timerStart;
+/* Timer running function */
+void RISCOS_CheckTimer();
+
+extern void RISCOS_BackgroundTasks(void);
+
+/* The first ticks value of the application */
+clock_t start;
+
+void SDL_StartTicks(void)
+{
+	/* Set first ticks value */
+	start = clock();
+}
+
+Uint32 SDL_GetTicks (void)
+{
+	clock_t ticks;
+
+	ticks=clock()-start;
+
+
+#if CLOCKS_PER_SEC == 1000
+
+	return(ticks);
+
+#elif CLOCKS_PER_SEC == 100
+
+	return (ticks * 10);
+
+#else
+
+	return ticks*(1000/CLOCKS_PER_SEC);
+
+#endif
+
+}
+
+extern void DRenderer_FillBuffers();
+
+void SDL_Delay (Uint32 ms)
+{
+    Uint32 now,then,elapsed;
+
+	/* Set the timeout interval - Linux only needs to do this once */
+	then = SDL_GetTicks();
+
+	do {
+		/* Do background tasks required while sleeping as we are not multithreaded */
+		RISCOS_BackgroundTasks();
+		/* Calculate the time interval left (in case of interrupt) */
+		now = SDL_GetTicks();
+		elapsed = (now-then);
+		then = now;
+		if ( elapsed >= ms ) {
+			break;
+		}
+		ms -= elapsed;
+
+	} while ( 1 );
+}
+
+int SDL_SYS_TimerInit(void)
+{
+	return(0);
+}
+
+void SDL_SYS_TimerQuit(void)
+{
+	SDL_SetTimer(0, NULL);
+}
+
+int SDL_SYS_StartTimer(void)
+{
+	timerStart = SDL_GetTicks();
+
+	return(0);
+}
+
+void SDL_SYS_StopTimer(void)
+{
+	/* Don't need to do anything as we use SDL_timer_running
+	   to detect if we need to check the timer */
+}
+
+
+void RISCOS_CheckTimer()
+{
+	if (SDL_timer_running && SDL_GetTicks() - timerStart >= SDL_alarm_interval)
+	{
+		Uint32 ms;
+
+		ms = SDL_alarm_callback(SDL_alarm_interval);
+		if ( ms != SDL_alarm_interval )
+		{
+			if ( ms )
+			{
+				SDL_alarm_interval = ROUND_RESOLUTION(ms);
+			} else
+			{
+				SDL_alarm_interval = 0;
+				SDL_timer_running = 0;
+			}
+		}
+		if (SDL_alarm_interval) timerStart = SDL_GetTicks();
+	}
+}