we have audio

SDL.lean

@@ -65,6 +65,9 @@ opaque loadTexture : String → IO UInt32
 @[extern "sdl_load_font"]
 opaque loadFont : String → UInt32 → IO Bool
 
+@[extern "sdl_load_track"]
+opaque loadTrack : String → IO Bool
+
 @[extern "sdl_render_texture"]
 opaque renderTexture (x : Int32) (y : Int32) (w : Int32) (h : Int32) : IO Int32
 

TestApp.lean

@@ -110,6 +110,11 @@ partial def run : IO Unit := do
     SDL.quit
     return
 
+  unless (← SDL.loadTrack "assets/In_The_Dark_Flashes.mp3") do
+    IO.println "Failed to load audio track"
+    SDL.quit
+    return
+
   let initialState : EngineState := {
     deltaTime := 0.0, lastTime := 0, running := true
     playerX := (SCREEN_WIDTH / 2), playerY := (SCREEN_HEIGHT / 2)

assets/LICENSE.md

@@ -1 +1,6 @@
-wall.png texture by [FacadeGaikan](https://opengameart.org/node/31075), licensed under CC0.
+wall.png texture by [FacadeGaikan](https://opengameart.org/node/31075), licensed under CC0.
+
+Jess Stacy "In The Dark-Flashes"
+Written by Bix Beiderbeck (1903-1931)
+From https://www.openmusicarchive.org
+Public Domain

c/sdl.c

@@ -158,6 +158,23 @@ lean_obj_res sdl_load_font(lean_obj_arg fontname, uint32_t font_size, lean_obj_a
     return lean_io_result_mk_ok(lean_box(1));
 }
 
+// TODO: This plays the track immediatly after loading it, which should not be the case
+lean_obj_res sdl_load_track(lean_obj_arg trackname, lean_obj_arg w) {
+    MIX_Track* mixerTrack = MIX_CreateTrack(mixer);
+    const char* trackname_str = lean_string_cstr(trackname);
+    MIX_Audio* track = MIX_LoadAudio(mixer, trackname_str, false);
+    if (!track) {
+        SDL_Log("C: Failed to load track: %s\n", SDL_GetError());
+        return lean_io_result_mk_ok(lean_box(0));
+    }
+
+    // play the track (does not loop)
+    MIX_SetTrackAudio(mixerTrack, track);
+    MIX_PlayTrack(mixerTrack, 0);
+
+    return lean_io_result_mk_ok(lean_box(1));
+}
+
 // TODO: VERY inefficient text rendering, re-renders entire text each time
 lean_obj_res sdl_render_text(lean_obj_arg text, uint32_t dst_x, uint32_t dst_y, uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha, lean_obj_arg w) {
     if (!g_renderer || !font) return lean_io_result_mk_ok(lean_box_uint32(0));