Skip to content
Permalink
Browse files

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

  • Loading branch information
slouken committed May 29, 2003
1 parent 7eadf52 commit 6e7ff9d084001b673414a1dc2352c913c88b455b
2 README
@@ -19,7 +19,7 @@ Objective C, Perl, PHP, Pike, Python, and Ruby.
The current version supports Linux, Windows, BeOS, MacOS, MacOS X,
FreeBSD, OpenBSD, BSD/OS, Solaris, and IRIX. The code contains support
for Windows CE, AmigaOS, Dreamcast, Atari, QNX, NetBSD, AIX, OSF/Tru64,
and SymbianOS, but these are not officially supported.
RISC OS, and SymbianOS, but these are not officially supported.

This library is distributed under GNU LGPL version 2, which can be
found in the file "COPYING". This license allows you to use SDL
@@ -130,6 +130,23 @@ typedef struct {
HGLRC hglrc; /* The OpenGL context, if any */
} SDL_SysWMinfo;

#elif defined(__riscos__)

/* RISC OS custom event structure */
struct SDL_SysWMmsg {
SDL_version version;
int eventCode; /* The window for the message */
int pollBlock[64];
};

/* The RISCOS custom window manager information structure */
typedef struct {
SDL_version version;
int wimpVersion; /* Wimp version running under */
int taskHandle; /* The RISCOS task handle */
int window; /* The RISCOS display window */
} SDL_SysWMinfo;

#else

/* The generic custom event structure */
@@ -6,7 +6,7 @@ noinst_LTLIBRARIES = libaudio.la
# Define which subdirectories need to be built
SUBDIRS = @AUDIO_SUBDIRS@
DIST_SUBDIRS = alsa arts baudio dma dmedia dsp esd macrom nas nto openbsd \
paudio sun ums windib windx5 disk mint dc
paudio riscos sun ums windib windx5 disk mint dc

DRIVERS = @AUDIO_DRIVERS@

@@ -91,6 +91,9 @@ static AudioBootStrap *bootstrap[] = {
#endif
#ifdef ENABLE_DC
&DCAUD_bootstrap,
#endif
#ifdef DRENDERER_SUPPORT
&DRENDERER_bootstrap,
#endif
NULL
};
@@ -381,7 +384,7 @@ int SDL_OpenAudio(SDL_AudioSpec *desired, SDL_AudioSpec *obtained)
return(-1);
}

#ifdef macintosh
#if defined(macintosh) || defined(__riscos__)
/* FIXME: Need to implement PPC interrupt asm for SDL_LockAudio() */
#else
#if defined(__MINT__) && !defined(ENABLE_THREADS)
@@ -156,6 +156,9 @@ extern AudioBootStrap DISKAUD_bootstrap;
#ifdef ENABLE_DC
extern AudioBootStrap DCAUD_bootstrap;
#endif
#ifdef DRENDERER_SUPPORT
extern AudioBootStrap DRENDERER_bootstrap;
#endif

/* This is the current audio device */
extern SDL_AudioDevice *current_audio;
@@ -0,0 +1,9 @@

## 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
@@ -0,0 +1,293 @@
/*
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
*/


#include <stdlib.h>
#include <stdio.h>
#include <memory.h>

#include <kernel.h>
#include "swis.h"

#include "SDL_endian.h"
#include "SDL_audio.h"
#include "SDL_audio_c.h"
#include "SDL_audiomem.h"
#include "SDL_sysaudio.h"
#include "SDL_drenderer.h"

#define DigitalRenderer_Activate 0x4F700
#define DigitalRenderer_Deactivate 0x4F701
#define DigitalRenderer_ReadState 0x4F705
#define DigitalRenderer_NewSample 0x4F706
#define DigitalRenderer_NumBuffers 0x4F709
#define DigitalRenderer_StreamSamples 0x4F70A
#define DigitalRenderer_Stream16BitSamples 0x4F70B
#define DigitalRenderer_StreamStatistics 0x4F70C
#define DigitalRenderer_StreamFlags 0x4F70D
#define DigitalRenderer_Activate16 0x4F70F
#define DigitalRenderer_GetFrequency 0x4F710

static int FillBuffer;
extern SDL_AudioDevice *current_audio;

extern int riscos_audiobuffer; /* Override for audio buffer size */

/* Audio driver functions */

static void DRenderer_CloseAudio(_THIS);
static int DRenderer_OpenAudio(_THIS, SDL_AudioSpec *spec);

/* Audio driver bootstrap functions */

/* Define following to dump stats to stdout */
/* #define DUMP_AUDIO */


static int Audio_Available(void)
{
_kernel_swi_regs regs;
int available = 0;

/* Use call to set buffers to also check if Module is loaded */
regs.r[0] = 0;
if (_kernel_swi(DigitalRenderer_NumBuffers, &regs, &regs) == 0) available = 1;

return(available);
}

static void Audio_DeleteDevice(SDL_AudioDevice *device)
{
free(device->hidden);
free(device);
}

static SDL_AudioDevice *Audio_CreateDevice(int devindex)
{
SDL_AudioDevice *this;

/* Initialize all variables that we clean on shutdown */
this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
if ( this ) {
memset(this, 0, (sizeof *this));
this->hidden = (struct SDL_PrivateAudioData *)
malloc((sizeof *this->hidden));
}
if ( (this == NULL) || (this->hidden == NULL) ) {
SDL_OutOfMemory();
if ( this ) {
free(this);
}
return(0);
}
memset(this->hidden, 0, (sizeof *this->hidden));

/* Set the function pointers */
this->OpenAudio = DRenderer_OpenAudio;
this->CloseAudio = DRenderer_CloseAudio;
this->free = Audio_DeleteDevice;

return this;
}

AudioBootStrap DRENDERER_bootstrap = {
"drenderer", "RiscOS Digital Renderer Module",
Audio_Available, Audio_CreateDevice
};

/* Routine called to check and fill audio buffers if necessary */
static Uint8 *buffer = NULL;

void DRenderer_FillBuffers()
{
SDL_AudioDevice *audio = current_audio;

if ( !audio || ! audio->enabled )
{
return;
}

if ( ! audio->paused )
{
_kernel_swi_regs regs;
/* Check filled buffers count */
_kernel_swi(DigitalRenderer_StreamStatistics, &regs, &regs);

#ifdef DUMP_AUDIO
if (regs.r[0] <= FillBuffer)
{
printf("Buffers in use %d\n", regs.r[0]);
}
#endif

while (regs.r[0] <= FillBuffer && !audio->paused)
{
if ( audio->convert.needed )
{
int silence;
if ( audio->convert.src_format == AUDIO_U8 )
{
silence = 0x80;
} else {
silence = 0;
}
memset(audio->convert.buf, silence, audio->convert.len);
audio->spec.callback(audio->spec.userdata,
(Uint8 *)audio->convert.buf,audio->convert.len);
SDL_ConvertAudio(&audio->convert);
#if 0
if ( audio->convert.len_cvt != audio->spec.size ) {
/* Uh oh... probably crashes here; */
}
#endif
regs.r[0] = (int)audio->convert.buf;
regs.r[1] = audio->spec.samples * audio->spec.channels;
_kernel_swi(DigitalRenderer_Stream16BitSamples, &regs, &regs);

} else
{
/* Fill buffer with silence */
memset (buffer, 0, audio->spec.size);

audio->spec.callback(audio->spec.userdata,
(Uint8 *)buffer, audio->spec.size);

regs.r[0] = (int)buffer;
regs.r[1] = audio->spec.samples * audio->spec.channels;
_kernel_swi(DigitalRenderer_Stream16BitSamples, &regs, &regs);
}
/* Check if we have enough buffers yet */
_kernel_swi(DigitalRenderer_StreamStatistics, &regs, &regs);
}

}
}

/* Size of DMA buffer to use */
#define DRENDERER_BUFFER_SIZE 512

/* Number of centiseconds of sound to buffer.
Hopefully more than the maximum time between calls to the
FillBuffers routine above
*/
#define DRENDERER_CSEC_TO_BUFFER 10

static int DRenderer_OpenAudio(_THIS, SDL_AudioSpec *spec)
{
_kernel_swi_regs regs;
int buffers_per_sample;

#ifdef DUMP_AUDIO
printf("Request format %d\n", spec->format);
printf("Request freq %d\n", spec->freq);
printf("Samples %d\n", spec->samples);
#endif

/* Only support signed 16bit format */
spec->format = AUDIO_S16LSB;

if (spec->samples < DRENDERER_BUFFER_SIZE) spec->samples = DRENDERER_BUFFER_SIZE;

SDL_CalculateAudioSpec(spec);


buffers_per_sample = spec->samples / DRENDERER_BUFFER_SIZE;

if ((spec->samples % DRENDERER_BUFFER_SIZE) != 0)
{
buffers_per_sample++;
spec->samples = buffers_per_sample * DRENDERER_BUFFER_SIZE;
}

/* Set number of buffers to use - the following should give enough
data between calls to the sound polling.
*/

if (riscos_audiobuffer == 0)
{
FillBuffer = (int)((double)DRENDERER_CSEC_TO_BUFFER / ((double)DRENDERER_BUFFER_SIZE * 100.0 / (double)spec->freq)) + 1;
} else FillBuffer = riscos_audiobuffer/DRENDERER_BUFFER_SIZE - buffers_per_sample;

if (FillBuffer < buffers_per_sample) FillBuffer = buffers_per_sample;
regs.r[0] = FillBuffer + buffers_per_sample;

#ifdef DUMP_AUDIO
printf("Buffers per sample %d\n", buffers_per_sample);
printf("Fill buffer %d\n", FillBuffer);
printf("Time buffered (ms) %d\n",(int)((1000.0 * regs.r[0] * DRENDERER_BUFFER_SIZE)/(double)spec->freq));
#endif

if (_kernel_swi(DigitalRenderer_NumBuffers, &regs, &regs) != 0)
{
SDL_SetError("Can't set number of streaming sound buffers\n");
return -1;
}

/* Now initialise sound system */
regs.r[0] = spec->channels; /* Number of channels */
regs.r[1] = DRENDERER_BUFFER_SIZE; /* Samples length */
regs.r[2] = spec->freq; /* frequency */
regs.r[3] = 1; /* Restore previous handler on exit */

if (_kernel_swi(DigitalRenderer_Activate16, &regs, &regs) != 0)
{
SDL_SetError("Unable to activate digital renderer in 16 bit mode\n");
return -1;
}

if (_kernel_swi(DigitalRenderer_GetFrequency, &regs, &regs) == 0)
{
spec->freq = regs.r[0];
}

#ifdef DUMP_AUDIO
printf("Got format %d\n", spec->format);
printf("Frequency %d\n", spec->freq);
printf("Samples %d\n", spec->samples);
#endif

/* Set to fill buffer with zero if we don't get data to it fast enough */
regs.r[0] = 1;
regs.r[1] = ~1;
_kernel_swi(DigitalRenderer_StreamFlags, &regs, &regs);

buffer = (Uint8 *)malloc(sizeof(Uint8) * spec->size);
if (buffer == NULL)
{
SDL_OutOfMemory();
return -1;
}

/* Hopefully returning 2 will show success, but not start up an audio thread */
return 2;
}

static void DRenderer_CloseAudio(_THIS)
{
_kernel_swi_regs regs;

/* Close down the digital renderer */
_kernel_swi(DigitalRenderer_Deactivate, &regs, &regs);

if (buffer != NULL) free(buffer);
}

0 comments on commit 6e7ff9d

Please sign in to comment.