From 4ede5b1b4cc302494ed78211a3b11c0fa3606ffd Mon Sep 17 00:00:00 2001
From: kichikuou <KichikuouChrome@gmail.com>
Date: Sun, 16 Feb 2020 10:28:29 +0900
Subject: [PATCH] Android: Play MIDI via temporary file

MediaPlayer in old versions of Android does not accept data: URL.
---
 .../github/kichikuou/system3/GameActivity.kt  |  8 +++----
 src/android/mako.cpp                          | 24 ++++++++++++-------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/android/app/src/main/java/io/github/kichikuou/system3/GameActivity.kt b/android/app/src/main/java/io/github/kichikuou/system3/GameActivity.kt
index 27cdd1d..ba0d742 100644
--- a/android/app/src/main/java/io/github/kichikuou/system3/GameActivity.kt
+++ b/android/app/src/main/java/io/github/kichikuou/system3/GameActivity.kt
@@ -19,7 +19,6 @@ package io.github.kichikuou.system3
 
 import android.media.MediaPlayer
 import android.os.Bundle
-import android.util.Base64
 import android.util.Log
 import org.libsdl.app.SDLActivity
 import java.io.File
@@ -79,7 +78,7 @@ class GameActivity : SDLActivity() {
     @Suppress("unused") fun cddaStart(track: Int, loop: Boolean) = cdda.start(track, loop)
     @Suppress("unused") fun cddaStop() = cdda.stop()
     @Suppress("unused") fun cddaCurrentPosition() = cdda.currentPosition()
-    @Suppress("unused") fun midiStart(buf: ByteArray, loop: Boolean) = midi.start(buf, loop)
+    @Suppress("unused") fun midiStart(path: String, loop: Boolean) = midi.start(path, loop)
     @Suppress("unused") fun midiStop() = midi.stop()
     @Suppress("unused") fun midiCurrentPosition() = midi.currentPosition()
 }
@@ -152,12 +151,11 @@ private class MidiPlayer {
     private var playing = false
     private var playerPaused = false
 
-    fun start(buf: ByteArray, loop: Boolean) {
-        val url = "data:audio/midi;base64," + Base64.encodeToString(buf, Base64.DEFAULT)
+    fun start(path: String, loop: Boolean) {
         try {
             player.apply {
                 reset()
-                setDataSource(url)
+                setDataSource(path)
                 isLooping = loop
                 prepare()
                 start()
diff --git a/src/android/mako.cpp b/src/android/mako.cpp
index a995e58..ab90e9c 100644
--- a/src/android/mako.cpp
+++ b/src/android/mako.cpp
@@ -62,16 +62,24 @@ void MAKO::play_music(int page)
 		}
 		midi->load_mda(page);
 		std::vector<uint8_t> smf = midi->generate_smf(next_loop);
-		jbyteArray array = jni.env()->NewByteArray(smf.size());
-		if (!array) {
-			WARNING("Failed to allocate an array");
+
+		char path[PATH_MAX];
+		snprintf(path, PATH_MAX, "%s/tmp.mid", SDL_AndroidGetInternalStoragePath());
+		FILE* fp = fopen(path, "w");
+		if (!fp) {
+			WARNING("Failed to create temporary file");
 			return;
 		}
-		jbyte *buf = jni.env()->GetByteArrayElements(array, NULL);
-		memcpy(buf, smf.data(), smf.size());
-		jni.env()->ReleaseByteArrayElements(array, buf, 0);
-		jmethodID mid = jni.GetMethodID("midiStart", "([BZ)V");
-		jni.env()->CallVoidMethod(jni.context(), mid, array, next_loop ? 0 : 1);
+		fwrite(smf.data(), smf.size(), 1, fp);
+		fclose(fp);
+
+		jstring path_str = jni.env()->NewStringUTF(path);
+		if (!path_str) {
+			WARNING("Failed to allocate a string");
+			return;
+		}
+		jmethodID mid = jni.GetMethodID("midiStart", "(Ljava/lang/String;Z)V");
+		jni.env()->CallVoidMethod(jni.context(), mid, path_str, next_loop ? 0 : 1);
 	}
 
 	current_music = page;