Refactoring: Project structure, sprite stairs & fog masks rendering fix

src/sound.h

@@ -0,0 +1,23 @@
+#ifndef SOUND_H
+#define SOUND_H
+
+#include <stdint.h>
+
+/**
+ * ==========================================
+ * AUDIO SYNTHESIS & SEQUENCING
+ * ==========================================
+ * This module manages all sound generation via the Game Boy APU registers.
+ */
+
+// Resets internal music state variables
+void sound_reset_music_state(void);
+
+// Callbacks to be hooked into the Game Boy VBL (Vertical Blanking) interrupt
+void play_music_tick(void);
+
+// Call to manually play a note from the game over / victory sequences 
+void play_gameover_step(uint8_t step);
+void play_victory_step(uint8_t step);
+
+#endif