partially done work on total source tree rework, separation of engine context and game context, generalization of renderer for different backends as well as web platform target

src/twn_audio_c.h

@@ -0,0 +1,55 @@
+#ifndef TWN_AUDIO_C_H
+#define TWN_AUDIO_C_H
+
+#include "twn_audio.h"
+
+#include <SDL2/SDL_audio.h>
+
+#define STB_VORBIS_HEADER_ONLY
+#include <stb_vorbis.c>
+#include <xm.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+
+
+typedef enum audio_file_type {
+    audio_file_type_ogg,
+    audio_file_type_xm,
+    audio_file_type_count,
+    audio_file_type_unknown,
+} t_audio_file_type;
+
+
+union audio_context {
+    struct {
+        stb_vorbis *handle;
+        unsigned char *data;
+        int frequency;
+        uint8_t channel_count;
+    } vorbis;
+
+    struct {
+        xm_context_t *handle;
+    } xm;
+};
+
+
+struct audio_channel {
+    t_play_audio_args args;
+    enum audio_file_type file_type;
+    union audio_context context; /* interpreted by `file_type` value */
+    const char *path;
+    const char *name;
+};
+
+
+struct audio_channel_item {
+    char *key;
+    struct audio_channel value;
+};
+
+
+void audio_callback(void *userdata, uint8_t *stream, int len);
+
+#endif