Initial commit

backends/platform/3ds/osystem-audio.cpp

@@ -0,0 +1,107 @@
+/* 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/>.
+ *
+ */
+
+#include "backends/platform/3ds/osystem.h"
+#include "audio/mixer.h"
+
+namespace N3DS {
+
+static bool hasAudio = false;
+
+static void audioThreadFunc(void *arg) {
+	Audio::MixerImpl *mixer = (Audio::MixerImpl *)arg;
+	OSystem_3DS *osys = dynamic_cast<OSystem_3DS *>(g_system);
+
+	const int channel = 0;
+	int bufferIndex = 0;
+	const int bufferCount = 2;
+	const int sampleRate = mixer->getOutputRate();
+	const int bufferSamples = 1024;
+	const int bufferSize = bufferSamples * 4;
+
+	ndspWaveBuf buffers[bufferCount];
+
+	for (int i = 0; i < bufferCount; ++i) {
+		memset(&buffers[i], 0, sizeof(ndspWaveBuf));
+		buffers[i].data_vaddr = linearAlloc(bufferSize);
+		buffers[i].looping = false;
+		buffers[i].status = NDSP_WBUF_FREE;
+	}
+
+	ndspChnReset(channel);
+	ndspChnSetInterp(channel, NDSP_INTERP_LINEAR);
+	ndspChnSetRate(channel, sampleRate);
+	ndspChnSetFormat(channel, NDSP_FORMAT_STEREO_PCM16);
+
+	while (!osys->exiting) {
+		svcSleepThread(5000 * 1000); // Wake up the thread every 5 ms
+
+		if (osys->sleeping) {
+			continue;
+		}
+
+		ndspWaveBuf *buf = &buffers[bufferIndex];
+		if (buf->status == NDSP_WBUF_FREE || buf->status == NDSP_WBUF_DONE) {
+			buf->nsamples = mixer->mixCallback(buf->data_adpcm, bufferSize);
+			if (buf->nsamples > 0) {
+				DSP_FlushDataCache(buf->data_vaddr, bufferSize);
+				ndspChnWaveBufAdd(channel, buf);
+			}
+
+			bufferIndex++;
+			bufferIndex %= bufferCount;
+		}
+	}
+
+	for (int i = 0; i < bufferCount; ++i)
+		linearFree(buffers[i].data_pcm16);
+}
+
+void OSystem_3DS::initAudio() {
+	_mixer = new Audio::MixerImpl(22050);
+
+	hasAudio = R_SUCCEEDED(ndspInit());
+	_mixer->setReady(false);
+
+	if (hasAudio) {
+		s32 prio = 0;
+		svcGetThreadPriority(&prio, CUR_THREAD_HANDLE);
+		audioThread = threadCreate(&audioThreadFunc, _mixer, 32 * 1048, prio - 1, -2, false);
+	}
+}
+
+void OSystem_3DS::destroyAudio() {
+	if (hasAudio) {
+		threadJoin(audioThread, U64_MAX);
+		threadFree(audioThread);
+		ndspExit();
+	}
+
+	delete _mixer;
+	_mixer = 0;
+}
+
+Audio::Mixer *OSystem_3DS::getMixer() {
+	assert(_mixer);
+	return _mixer;
+}
+
+} // namespace N3DS