Code cleanup, return and exit conditions for Android

android/examples/triangle/src/main/java/de/saschawillems/vulkanSample/VulkanActivity.java

@@ -15,8 +15,6 @@ import java.util.concurrent.Semaphore;
 
 public class VulkanActivity extends NativeActivity {
 
-    VulkanActivity _activity;
-
     static {
         // Load native library
         System.loadLibrary("native-lib");
@@ -24,7 +22,6 @@ public class VulkanActivity extends NativeActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        _activity = this;
     }
 
     // Use a semaphore to create a modal dialog
@@ -33,12 +30,14 @@ public class VulkanActivity extends NativeActivity {
 
     public void showAlert(final String message)
     {
-        ApplicationInfo applicationInfo = _activity.getApplicationInfo();
+        final VulkanActivity activity = this;
+
+        ApplicationInfo applicationInfo = activity.getApplicationInfo();
         final String applicationName = applicationInfo.nonLocalizedLabel.toString();
 
         this.runOnUiThread(new Runnable() {
            public void run() {
-               AlertDialog.Builder builder = new AlertDialog.Builder(_activity, AlertDialog.THEME_HOLO_DARK);
+               AlertDialog.Builder builder = new AlertDialog.Builder(activity, AlertDialog.THEME_HOLO_DARK);
                builder.setTitle(applicationName);
                builder.setMessage(message);
                builder.setPositiveButton("Close", new DialogInterface.OnClickListener() {

base/VulkanTools.cpp

@@ -273,7 +273,9 @@ namespace vks
 			vks::android::showAlert(message.c_str());
 #endif
 			std::cerr << message << "\n";
+#if !defined(__ANDROID__)
 			exit(exitCode);
+#endif
 		}
 
 		void exitFatal(std::string message, VkResult resultCode)

base/vulkanexamplebase.cpp

@@ -333,6 +333,7 @@ void VulkanExampleBase::renderLoop()
 		// Exit loop, example will be destroyed in application main
 		if (destroy)
 		{
+            ANativeActivity_finish(androidApp->activity);
 			break;
 		}
 
@@ -556,8 +557,10 @@ void VulkanExampleBase::renderLoop()
 	}
 #endif
 	// Flush device to make sure all resources can be freed
+    if (device != VK_NULL_HANDLE) {
         vkDeviceWaitIdle(device);
     }
+}
 
 void VulkanExampleBase::updateOverlay()
 {
@@ -830,7 +833,7 @@ VulkanExampleBase::~VulkanExampleBase()
 #endif
 }
 
-void VulkanExampleBase::initVulkan()
+bool VulkanExampleBase::initVulkan()
 {
 	VkResult err;
 
@@ -838,6 +841,7 @@ void VulkanExampleBase::initVulkan()
 	err = createInstance(settings.validation);
 	if (err) {
 		vks::tools::exitFatal("Could not create Vulkan instance : \n" + vks::tools::errorString(err), err);
+		return false;
 	}
 
 #if defined(VK_USE_PLATFORM_ANDROID_KHR)
@@ -864,6 +868,7 @@ void VulkanExampleBase::initVulkan()
 	err = vkEnumeratePhysicalDevices(instance, &gpuCount, physicalDevices.data());
 	if (err) {
 		vks::tools::exitFatal("Could not enumerate physical devices : \n" + vks::tools::errorString(err), err);
+		return false;
 	}
 
 	// GPU selection
@@ -939,6 +944,7 @@ void VulkanExampleBase::initVulkan()
 	VkResult res = vulkanDevice->createLogicalDevice(enabledFeatures, enabledDeviceExtensions);
 	if (res != VK_SUCCESS) {
 		vks::tools::exitFatal("Could not create Vulkan device: \n" + vks::tools::errorString(res), res);
+		return false;
 	}
 	device = vulkanDevice->logicalDevice;
 
@@ -988,6 +994,8 @@ void VulkanExampleBase::initVulkan()
 	};
 	LOGD("androidProduct = %s", androidProduct.c_str());
 #endif	
+
+	return true;
 }
 
 #if defined(_WIN32)
@@ -1399,10 +1407,15 @@ void VulkanExampleBase::handleAppCommand(android_app * app, int32_t cmd)
 		LOGD("APP_CMD_INIT_WINDOW");
 		if (androidApp->window != NULL)
 		{
-			vulkanExample->initVulkan();
+			if (vulkanExample->initVulkan()) {
 				vulkanExample->prepare();
 				assert(vulkanExample->prepared);
 			}
+			else {
+				LOGE("Could not initialize Vulkan, exiting!");
+                androidApp->destroyRequested = 1;
+			}
+		}
 		else
 		{
 			LOGE("No window assigned!");
@@ -1419,7 +1432,9 @@ void VulkanExampleBase::handleAppCommand(android_app * app, int32_t cmd)
 	case APP_CMD_TERM_WINDOW:
 		// Window is hidden or closed, clean up resources
 		LOGD("APP_CMD_TERM_WINDOW");
+		if (vulkanExample->prepared) {
 			vulkanExample->swapChain.cleanup();
+		}
 		break;
 	}
 }

base/vulkanexamplebase.h

@@ -250,7 +250,7 @@ public:
 	virtual ~VulkanExampleBase();
 
 	// Setup the vulkan instance, enable required extensions and connect to the physical device (GPU)
-	void initVulkan();
+	bool initVulkan();
 
 #if defined(_WIN32)
 	void setupConsole(std::string title);