Initial commit

backends/platform/wii/osystem_sfx.cpp

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#define FORBIDDEN_SYMBOL_EXCEPTION_printf
+
+#include <malloc.h>
+
+#include "osystem.h"
+
+#define SFX_THREAD_STACKSIZE (1024 * 128)
+#define SFX_THREAD_PRIO 80
+#define SFX_THREAD_FRAG_SIZE (1024 * 8)
+#define SFX_BUFFERS 3
+
+static lwpq_t sfx_queue;
+static lwp_t sfx_thread;
+static u8 *sfx_stack;
+static bool sfx_thread_running = false;
+static bool sfx_thread_quit = false;
+
+static u32 sb_hw;
+static u8 *sound_buffer[SFX_BUFFERS];
+
+static void audio_switch_buffers() {
+	sb_hw = (sb_hw + 1) % SFX_BUFFERS;
+	AUDIO_InitDMA((u32) sound_buffer[sb_hw], SFX_THREAD_FRAG_SIZE);
+	LWP_ThreadSignal(sfx_queue);
+}
+
+static void * sfx_thread_func(void *arg) {
+	Audio::MixerImpl *mixer = (Audio::MixerImpl *) arg;
+	u8 sb_sw;
+
+	while (true) {
+		LWP_ThreadSleep(sfx_queue);
+
+		if (sfx_thread_quit)
+			break;
+
+		// the hardware uses two buffers: a front and a back buffer
+		// we use 3 buffers here: two are being pushed to the DSP,
+		// and the free one is where our mixer writes to
+		// thus the latency of our stream is:
+		// 8192 [frag size] / 48000 / 2 [16bit] / 2 [stereo] * 2 [hw buffers]
+		// -> 85.3ms
+		sb_sw = (sb_hw + 1) % SFX_BUFFERS;
+		mixer->mixCallback(sound_buffer[sb_sw], SFX_THREAD_FRAG_SIZE);
+		DCFlushRange(sound_buffer[sb_sw], SFX_THREAD_FRAG_SIZE);
+	}
+
+	return NULL;
+}
+
+void OSystem_Wii::initSfx() {
+	_mixer = new Audio::MixerImpl(48000);
+
+	sfx_thread_running = false;
+	sfx_thread_quit = false;
+
+	sfx_stack = (u8 *) memalign(32, SFX_THREAD_STACKSIZE);
+
+	if (sfx_stack) {
+		memset(sfx_stack, 0, SFX_THREAD_STACKSIZE);
+
+		LWP_InitQueue(&sfx_queue);
+
+		s32 res = LWP_CreateThread(&sfx_thread, sfx_thread_func, _mixer, sfx_stack,
+									SFX_THREAD_STACKSIZE, SFX_THREAD_PRIO);
+
+		if (res) {
+			printf("ERROR creating sfx thread: %d\n", res);
+			LWP_CloseQueue(sfx_queue);
+			return;
+		}
+
+		sfx_thread_running = true;
+	}
+
+	for (u32 i = 0; i < SFX_BUFFERS; ++i) {
+		sound_buffer[i] = (u8 *) memalign(32, SFX_THREAD_FRAG_SIZE);
+		memset(sound_buffer[i], 0, SFX_THREAD_FRAG_SIZE);
+		DCFlushRange(sound_buffer[i], SFX_THREAD_FRAG_SIZE);
+	}
+
+	_mixer->setReady(true);
+
+	sb_hw = 0;
+
+	AUDIO_SetDSPSampleRate(AI_SAMPLERATE_48KHZ);
+	AUDIO_RegisterDMACallback(audio_switch_buffers);
+	AUDIO_InitDMA((u32) sound_buffer[sb_hw], SFX_THREAD_FRAG_SIZE);
+	AUDIO_StartDMA();
+}
+
+void OSystem_Wii::deinitSfx() {
+	if (_mixer)
+		_mixer->setReady(false);
+
+	AUDIO_StopDMA();
+	AUDIO_RegisterDMACallback(NULL);
+
+	if (sfx_thread_running) {
+		sfx_thread_quit = true;
+		LWP_ThreadBroadcast(sfx_queue);
+
+		LWP_JoinThread(sfx_thread, NULL);
+		LWP_CloseQueue(sfx_queue);
+
+		free(sfx_stack);
+		sfx_thread_running = false;
+
+		for (u32 i = 0; i < SFX_BUFFERS; ++i)
+			free(sound_buffer[i]);
+	}
+}