PlaySound: Support OGG fallback over MP3

pkg/sound/sound_sdl.go

@@ -4,7 +4,10 @@
 package sound
 
 import (
+	"errors"
+	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 
 	"git.kirsle.net/SketchyMaze/doodle/pkg/log"
@@ -21,6 +24,13 @@ var (
 	music  = map[string]*sdl.Track{}
 	sounds = map[string]*sdl.Track{}
 	mu     sync.RWMutex
+
+	// Supported file extensions, in preference order.
+	SupportedSoundExtensions = []string{
+		".wav",
+		".ogg",
+		".mp3",
+	}
 )
 
 // Initialize SDL2 Audio at startup.
@@ -85,9 +95,16 @@ func LoadSound(filename string) audio.Playable {
 		return sfx
 	}
 
+	// Resolve the filepath on disk to this sound.
+	fullpath, err := ResolveFilename(filename)
+	if err != nil {
+		log.Error("Loading sound: %s: %s", filename, err)
+		return nil
+	}
+
 	// Load the sound in.
 	log.Info("Loading sound: %s", filename)
-	track, err := engine.LoadSound(filepath.Join(SoundRoot, filename))
+	track, err := engine.LoadSound(fullpath)
 	if err != nil {
 		log.Error("sound.LoadSound: failed to load file %s: %s", filename, err)
 		return nil
@@ -108,3 +125,40 @@ func PlaySound(filename string) {
 		sound.Play(1)
 	}
 }
+
+// ResolveFilename resolves the filename to a sound file on disk.
+//
+// Ogg has been found more reliable than MP3 for cross-platform distribution. A doodad might
+// request a "sound.mp3" but the filename on disk is actually "sound.ogg" and this function
+// will return the latter, if "sound.mp3" does not exist.
+//
+// If the exact filename does exist, it is returned; otherwise a preference order of
+// WAV > OGG > MP3 will be tried and returned if those versions exist.
+//
+// Returns the full path on disk (e.g. "rtp/sfx/sound.ogg")
+func ResolveFilename(filename string) (string, error) {
+	// Does the exact file exist?
+	if _, err := os.Stat(filepath.Join(SoundRoot, filename)); !os.IsNotExist(err) {
+		return filepath.Join(SoundRoot, filename), nil
+	}
+
+	// If the filename ends with a supported extension, trim it to the basename.
+	var basename = filename
+	for _, ext := range SupportedSoundExtensions {
+		if filepath.Ext(filename) == ext {
+			basename = strings.TrimSuffix(filename, ext)
+		}
+	}
+
+	// Try the basename + suffixes.
+	for _, ext := range SupportedSoundExtensions {
+		check := filepath.Join(SoundRoot, basename+ext)
+		if _, err := os.Stat(check); !os.IsNotExist(err) {
+			log.Info("Sound(%s): resolved to nearest match %s", filename, check)
+			return check, nil
+		}
+	}
+
+	// No luck.
+	return "", errors.New("no suitable sound file found")
+}