Don't create new cpu_thread on app resume

Android/jni/jnihooks.c

@@ -21,6 +21,9 @@ void Java_org_deadc0de_apple2ix_Apple2Activity_nativeOnCreate(JNIEnv *env, jobje
     data_dir = strdup(dataDir);
     (*env)->ReleaseStringUTFChars(env, j_dataDir, dataDir);
     LOG("nativeOnCreate(%s)...", data_dir);
+
+    c_initialize_firsttime();
+    pthread_create(&cpu_thread_id, NULL, (void *) &cpu_thread, (void *)NULL);
 }
 
 void Java_org_deadc0de_apple2ix_Apple2Activity_nativeGraphicsChanged(JNIEnv *env, jobject obj, jint width, jint height) {
@@ -31,9 +34,15 @@ void Java_org_deadc0de_apple2ix_Apple2Activity_nativeGraphicsChanged(JNIEnv *env
 void Java_org_deadc0de_apple2ix_Apple2Activity_nativeGraphicsInitialized(JNIEnv *env, jobject obj, jint width, jint height) {
     LOG("%s", "native graphicsInitialized...");
     video_driver_reshape(width, height);
+
 #if !TESTING
-    c_initialize_firsttime();
-    pthread_create(&cpu_thread_id, NULL, (void *) &cpu_thread, (void *)NULL);
+    static bool graphicsPreviouslyInitialized = false;
+    if (graphicsPreviouslyInitialized) {
+        video_driver_shutdown();
+    }
+    graphicsPreviouslyInitialized = true;
+    video_driver_init((void *)0);
+
 #else
     char *local_argv[] = {
         "-f",

src/display.c

@@ -604,11 +604,13 @@ void video_init(void) {
     video_initialize_color();
 #if !HEADLESS
 #if !defined(__APPLE__)
+#if !defined(ANDROID)
     if (!is_headless) {
         video_driver_init((void *)0);
     }
 #endif
 #endif
+#endif
 }
 
 void video_main_loop(void) {

src/video/glvideo.c

@@ -616,10 +616,13 @@ static void gldriver_init_common(void) {
 static void gldriver_shutdown(void) {
     // Cleanup all OpenGL objects
     glDeleteTextures(1, &a2TextureName);
+    a2TextureName = 0;
     _destroy_VAO(crtVAOName);
+    crtVAOName = 0;
     mdlDestroyModel(crtModel);
     crtModel = NULL;
     glDeleteProgram(program);
+    program = 0;
 }
 
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