diff src/audio/dummy/SDL_dummyaudio.c @ 1532:30f189cdd82b

Implemented dummy audio driver. Fixes Bugzilla #161.
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 14 Mar 2006 08:53:33 +0000
parents
children 38c1eb6b0083
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/audio/dummy/SDL_dummyaudio.c	Tue Mar 14 08:53:33 2006 +0000
@@ -0,0 +1,154 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2006 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 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
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+
+    This file hacked^H^H^H^H^H^Hwritten by Ryan C. Gordon
+        (icculus@icculus.org)
+*/
+#include "SDL_config.h"
+
+/* Output raw audio data to a file. */
+
+#if HAVE_STDIO_H
+#include <stdio.h>
+#endif
+
+#include "SDL_rwops.h"
+#include "SDL_timer.h"
+#include "SDL_audio.h"
+#include "../SDL_audiomem.h"
+#include "../SDL_audio_c.h"
+#include "../SDL_audiodev_c.h"
+#include "SDL_dummyaudio.h"
+
+/* The tag name used by DUMMY audio */
+#define DUMMYAUD_DRIVER_NAME         "dummy"
+
+/* environment variables and defaults. */
+#define DUMMYENVR_WRITEDELAY      "SDL_DUMMYAUDIODELAY"
+#define DUMMYDEFAULT_WRITEDELAY   150
+
+/* Audio driver functions */
+static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec);
+static void DUMMYAUD_WaitAudio(_THIS);
+static void DUMMYAUD_PlayAudio(_THIS);
+static Uint8 *DUMMYAUD_GetAudioBuf(_THIS);
+static void DUMMYAUD_CloseAudio(_THIS);
+
+/* Audio driver bootstrap functions */
+static int DUMMYAUD_Available(void)
+{
+	const char *envr = SDL_getenv("SDL_AUDIODRIVER");
+	if (envr && (SDL_strcmp(envr, DUMMYAUD_DRIVER_NAME) == 0)) {
+		return(1);
+	}
+	return(0);
+}
+
+static void DUMMYAUD_DeleteDevice(SDL_AudioDevice *device)
+{
+	SDL_free(device->hidden);
+	SDL_free(device);
+}
+
+static SDL_AudioDevice *DUMMYAUD_CreateDevice(int devindex)
+{
+	SDL_AudioDevice *this;
+	const char *envr;
+
+	/* Initialize all variables that we clean on shutdown */
+	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
+	if ( this ) {
+		SDL_memset(this, 0, (sizeof *this));
+		this->hidden = (struct SDL_PrivateAudioData *)
+				SDL_malloc((sizeof *this->hidden));
+	}
+	if ( (this == NULL) || (this->hidden == NULL) ) {
+		SDL_OutOfMemory();
+		if ( this ) {
+			SDL_free(this);
+		}
+		return(0);
+	}
+	SDL_memset(this->hidden, 0, (sizeof *this->hidden));
+
+	envr = SDL_getenv(DUMMYENVR_WRITEDELAY);
+	this->hidden->write_delay = (envr) ? SDL_atoi(envr) : DUMMYDEFAULT_WRITEDELAY;
+
+	/* Set the function pointers */
+	this->OpenAudio = DUMMYAUD_OpenAudio;
+	this->WaitAudio = DUMMYAUD_WaitAudio;
+	this->PlayAudio = DUMMYAUD_PlayAudio;
+	this->GetAudioBuf = DUMMYAUD_GetAudioBuf;
+	this->CloseAudio = DUMMYAUD_CloseAudio;
+
+	this->free = DUMMYAUD_DeleteDevice;
+
+	return this;
+}
+
+AudioBootStrap DUMMYAUD_bootstrap = {
+	DUMMYAUD_DRIVER_NAME, "SDL dummy audio driver",
+	DUMMYAUD_Available, DUMMYAUD_CreateDevice
+};
+
+/* This function waits until it is possible to write a full sound buffer */
+static void DUMMYAUD_WaitAudio(_THIS)
+{
+	SDL_Delay(this->hidden->write_delay);
+}
+
+static void DUMMYAUD_PlayAudio(_THIS)
+{
+    /* no-op...this is a null driver. */
+}
+
+static Uint8 *DUMMYAUD_GetAudioBuf(_THIS)
+{
+	return(this->hidden->mixbuf);
+}
+
+static void DUMMYAUD_CloseAudio(_THIS)
+{
+	if ( this->hidden->mixbuf != NULL ) {
+		SDL_FreeAudioMem(this->hidden->mixbuf);
+		this->hidden->mixbuf = NULL;
+	}
+}
+
+static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)
+{
+#if HAVE_STDIO_H
+	fprintf(stderr, "\nWARNING: You are using the SDL dummy audio driver!"
+                    " No sound will be output!\n\n");
+#endif
+
+	/* Allocate mixing buffer */
+	this->hidden->mixlen = spec->size;
+	this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
+	if ( this->hidden->mixbuf == NULL ) {
+		return(-1);
+	}
+	SDL_memset(this->hidden->mixbuf, spec->silence, spec->size);
+
+	/* We're ready to rock and roll. :-) */
+	return(0);
+}
+