Added audio streaming capabilities (#471)

d2common/d2fileformats/d2mpq/mpq.go

@@ -273,17 +273,37 @@ func (v *MPQ) ReadFile(fileName string) ([]byte, error) {
 	if err != nil {
 		return []byte{}, err
 	}
+
 	fileBlockData.FileName = strings.ToLower(fileName)
+
 	fileBlockData.calculateEncryptionSeed()
 	mpqStream, err := CreateStream(v, fileBlockData, fileName)
+
 	if err != nil {
 		return []byte{}, err
 	}
+
 	buffer := make([]byte, fileBlockData.UncompressedFileSize)
 	mpqStream.Read(buffer, 0, fileBlockData.UncompressedFileSize)
 	return buffer, nil
 }
 
+func (v *MPQ) ReadFileStream(fileName string) (*MpqDataStream, error) {
+	fileBlockData, err := v.getFileBlockData(fileName)
+	if err != nil {
+		return nil, err
+	}
+	fileBlockData.FileName = strings.ToLower(fileName)
+	fileBlockData.calculateEncryptionSeed()
+
+	mpqStream, err := CreateStream(v, fileBlockData, fileName)
+	if err != nil {
+		return nil, err
+	}
+
+	return &MpqDataStream{stream: mpqStream}, nil
+}
+
 // ReadTextFile reads a file and returns it as a string
 func (v *MPQ) ReadTextFile(fileName string) (string, error) {
 	data, err := v.ReadFile(fileName)
@@ -303,7 +323,7 @@ func (v *BlockTableEntry) calculateEncryptionSeed() {
 }
 
 // GetFileList returns the list of files in this MPQ
-func (v * MPQ) GetFileList() ([]string, error) {
+func (v *MPQ) GetFileList() ([]string, error) {
 	data, err := v.ReadFile("(listfile)")
 	if err != nil {
 		return nil, err

d2common/d2fileformats/d2mpq/mpq_data_stream.go

@@ -0,0 +1,20 @@
+package d2mpq
+
+type MpqDataStream struct {
+	stream *Stream
+}
+
+func (m *MpqDataStream) Read(p []byte) (n int, err error) {
+	totalRead := m.stream.Read(p, 0, uint32(len(p)))
+	return int(totalRead), nil
+}
+
+func (m *MpqDataStream) Seek(offset int64, whence int) (int64, error) {
+	m.stream.CurrentPosition = uint32(offset + int64(whence))
+	return int64(m.stream.CurrentPosition), nil
+}
+
+func (m *MpqDataStream) Close() error {
+	m.stream = nil
+	return nil
+}

d2common/d2fileformats/d2mpq/mpq_stream.go

@@ -86,7 +86,7 @@ func (v *Stream) Read(buffer []byte, offset, count uint32) uint32 {
 	toRead := count
 	readTotal := uint32(0)
 	for toRead > 0 {
-		read := v.readInternal(buffer, offset, count)
+		read := v.readInternal(buffer, offset, toRead)
 		if read == 0 {
 			break
 		}

d2core/d2asset/d2asset.go

@@ -80,6 +80,17 @@ func LoadArchive(archivePath string) (*d2mpq.MPQ, error) {
 	return singleton.archiveManager.loadArchive(archivePath)
 }
 
+func LoadFileStream(filePath string) (*d2mpq.MpqDataStream, error) {
+	verifyWasInit()
+
+	data, err := singleton.fileManager.loadFileStream(filePath)
+	if err != nil {
+		log.Printf("error loading file stream %s (%v)", filePath, err.Error())
+	}
+
+	return data, err
+}
+
 func LoadFile(filePath string) ([]byte, error) {
 	verifyWasInit()
 

d2core/d2asset/file_manager.go

@@ -1,6 +1,7 @@
 package d2asset
 
 import (
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2fileformats/d2mpq"
 	"strings"
 
 	"github.com/OpenDiablo2/OpenDiablo2/d2common"
@@ -22,6 +23,18 @@ func createFileManager(config d2config.Configuration, archiveManager *archiveMan
 	return &fileManager{d2common.CreateCache(fileBudget), archiveManager, config}
 }
 
+
+func (fm *fileManager) loadFileStream(filePath string) (*d2mpq.MpqDataStream, error) {
+	filePath = fm.fixupFilePath(filePath)
+
+	archive, err := fm.archiveManager.loadArchiveForFile(filePath)
+	if err != nil {
+		return nil, err
+	}
+
+	return archive.ReadFileStream(filePath)
+}
+
 func (fm *fileManager) loadFile(filePath string) ([]byte, error) {
 	filePath = fm.fixupFilePath(filePath)
 	if value, found := fm.cache.Retrieve(filePath); found {

d2core/d2audio/d2audio.go

@@ -32,9 +32,7 @@ func Initialize(audioProvider AudioProvider) error {
 // PlayBGM plays an infinitely looping background track
 func PlayBGM(song string) error {
 	verifyWasInit()
-	go func() {
-		singleton.PlayBGM(song)
-	}()
+	singleton.PlayBGM(song)
 	return nil
 }
 

d2core/d2audio/ebiten/ebiten_audio_provider.go

@@ -45,11 +45,11 @@ func (eap *AudioProvider) PlayBGM(song string) {
 			log.Panic(err)
 		}
 	}
-	audioData, err := d2asset.LoadFile(song)
+	audioStream, err := d2asset.LoadFileStream(song)
 	if err != nil {
 		panic(err)
 	}
-	d, err := wav.Decode(eap.audioContext, audio.BytesReadSeekCloser(audioData))
+	d, err := wav.Decode(eap.audioContext, audioStream)
 	if err != nil {
 		log.Fatal(err)
 	}