feat(audio): add audio module and audio/audio.h

Signed-off-by: Lorenzo Torres <lorenzo@sagittarius-a.org>

audio/audio.h

@@ -0,0 +1,87 @@
+#ifndef AUDIO_H
+#define AUDIO_H
+
+#include "../core/linear.h"
+
+enum audio_filetype {
+    AUDIO_FILETYPE_WAV,
+    AUDIO_FILETYPE_MP3,
+};
+
+/*
+ * The context object stores data related to audio, implementation 
+ * depends on backend.
+ */
+struct audio_context;
+
+/*
+ * The resource object stores the read sound data 
+ * loaded from a file and extra options.
+ */
+struct audio_resource;
+
+/*
+ * The source object represents an audio producing
+ * object with a position, an orientation and a velocity.
+ * A source must have a resource or multiple
+ * resources attached to it to be usable. (see audio_source_attach_resource)
+ */
+struct audio_source;
+
+/*
+ * The listener object represents the client's camera(i.e. ears),
+ * also having a position, an orientation and a velocity.
+ */
+struct audio_listener;
+
+/*
+ * This struct contains the flags with which 
+ * audio files will be loaded.
+ */
+struct audio_resource_opts {
+    enum audio_filetype type;
+};
+
+struct audio_source_play_opts { int dummy; };
+
+struct audio_listener_opts { int dummy; };
+
+struct audio_context *audio_context_init(void);
+void audio_context_deinit(struct audio_context *context);
+
+/*
+ * Creates a resource object from 'path' using specified options
+ */
+struct audio_resource *audio_resource_load(const char *path, struct audio_resource_opts opts);
+void audio_resource_free(struct audio_resource *resource);
+
+struct audio_source *audio_source_init(vec3 pos, vec3 vel, vec3 ori);
+void audio_source_deinit(struct audio_source *source);
+/*
+ * Attaches 'resource' to 'source'.
+ * Returns a source-specific index which is used to play the resource via 'source'.
+ */
+u16 audio_source_attach_resource(struct audio_source *source, struct audio_resource *resource);
+/*
+ * Plays 'index'th audio resource via 'source' using 'opts'.
+ * Will use default options if 'opts' is NULL.
+ * defaults:
+ * TODO
+ */
+void audio_source_play(struct audio_source *source, struct audio_source_play_opts *opts, u16 index);
+/*
+ * Attaches 'resource' to 'source' at given 'index' overwriting whatever was there first.
+ */
+void audio_source_attach_resource_index(struct audio_source *source, struct audio_resource *resource, u16 index);
+
+struct audio_listener *audio_listener_init(vec3 pos, vec3 vel, vec3 ori);
+void audio_listener_deinit(struct audio_listener *listener);
+/*
+ * Applies 'opts' to 'listener'.
+ * Will use defaults if 'opts' was NULL.
+ * defaults:
+ * TODO
+ */
+void audio_listener_apply_opts(struct audio_listener *listener, struct audio_listener_opts *opts);
+
+#endif