Update Files

Kha/Kinc/Backends/System/Emscripten/Sources/kinc/backend/audio.c.h

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+#include <AL/al.h>
+#include <AL/alc.h>
+#include <assert.h>
+#include <emscripten.h>
+#include <kinc/audio2/audio.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static kinc_a2_buffer_t a2_buffer;
+
+static ALCdevice *device = NULL;
+static ALCcontext *context = NULL;
+static unsigned int channels = 0;
+static unsigned int bits = 0;
+static ALenum format = 0;
+static ALuint source = 0;
+
+static bool audioRunning = false;
+#define BUFSIZE 4096
+static short buf[BUFSIZE];
+#define NUM_BUFFERS 3
+
+static uint32_t samples_per_second = 44100;
+
+static void copySample(void *buffer) {
+	float left_value = *(float *)&a2_buffer.channels[0][a2_buffer.read_location];
+	float right_value = *(float *)&a2_buffer.channels[1][a2_buffer.read_location];
+	a2_buffer.read_location += 1;
+	if (a2_buffer.read_location >= a2_buffer.data_size) {
+		a2_buffer.read_location = 0;
+	}
+	((int16_t *)buffer)[0] = (int16_t)(left_value * 32767);
+	((int16_t *)buffer)[1] = (int16_t)(right_value * 32767);
+}
+
+static void streamBuffer(ALuint buffer) {
+	if (kinc_a2_internal_callback(&a2_buffer, BUFSIZE / 2)) {
+		for (int i = 0; i < BUFSIZE; i += 2) {
+			copySample(&buf[i]);
+		}
+	}
+
+	alBufferData(buffer, format, buf, BUFSIZE * 2, samples_per_second);
+}
+
+static void iter() {
+	if (!audioRunning) {
+		return;
+	}
+
+	ALint processed;
+	alGetSourcei(source, AL_BUFFERS_PROCESSED, &processed);
+
+	if (processed <= 0) {
+		return;
+	}
+	while (processed--) {
+		ALuint buffer;
+		alSourceUnqueueBuffers(source, 1, &buffer);
+		streamBuffer(buffer);
+		alSourceQueueBuffers(source, 1, &buffer);
+	}
+
+	ALint playing;
+	alGetSourcei(source, AL_SOURCE_STATE, &playing);
+	if (playing != AL_PLAYING) {
+		alSourcePlay(source);
+	}
+}
+
+static bool a2_initialized = false;
+
+void kinc_a2_init() {
+	if (a2_initialized) {
+		return;
+	}
+
+	kinc_a2_internal_init();
+	a2_initialized = true;
+
+	a2_buffer.read_location = 0;
+	a2_buffer.write_location = 0;
+	a2_buffer.data_size = 128 * 1024;
+	a2_buffer.channel_count = 2;
+	a2_buffer.channels[0] = (float*)malloc(a2_buffer.data_size * sizeof(float));
+	a2_buffer.channels[1] = (float*)malloc(a2_buffer.data_size * sizeof(float));
+
+	audioRunning = true;
+
+	device = alcOpenDevice(NULL);
+	context = alcCreateContext(device, NULL);
+	alcMakeContextCurrent(context);
+	format = AL_FORMAT_STEREO16;
+
+	ALuint buffers[NUM_BUFFERS];
+	alGenBuffers(NUM_BUFFERS, buffers);
+	alGenSources(1, &source);
+
+	streamBuffer(buffers[0]);
+	streamBuffer(buffers[1]);
+	streamBuffer(buffers[2]);
+
+	alSourceQueueBuffers(source, NUM_BUFFERS, buffers);
+
+	alSourcePlay(source);
+}
+
+void kinc_a2_update() {
+	iter();
+}
+
+void kinc_a2_shutdown() {
+	audioRunning = false;
+}
+
+uint32_t kinc_a2_samples_per_second(void) {
+	return samples_per_second;
+}