Add basic Android APK integration

CMakeLists.txt

@@ -12,8 +12,12 @@ set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 set(CMAKE_SKIP_RPATH ON)
 
 add_library(${PROJECT_NAME} STATIC)
-add_executable(Gothic2Notr)
-add_executable(Spacer)
+if(ANDROID)
+  add_library(Gothic2Notr SHARED)
+else()
+  add_executable(Gothic2Notr)
+  add_executable(Spacer)
+endif()
 
 if(MSVC)
   add_definitions(-D_USE_MATH_DEFINES)
@@ -77,7 +81,9 @@ add_subdirectory(shader)
 target_link_libraries(${PROJECT_NAME} GothicShaders)
 
 # editor icons and such
-add_subdirectory(spacer/assets)
+if(NOT ANDROID)
+  add_subdirectory(spacer/assets)
+endif()
 
 include_directories("common")
 
@@ -92,6 +98,8 @@ endif()
 
 if(WIN32)
   target_link_libraries(${PROJECT_NAME} shlwapi DbgHelp)
+elseif(ANDROID)
+  target_link_libraries(${PROJECT_NAME} dl)
 elseif(UNIX)
   target_link_libraries(${PROJECT_NAME} -lpthread -ldl)
 endif()
@@ -178,7 +186,7 @@ if(WIN32)
 endif()
 
 # in debug mode, enable sanitizers
-if(${CMAKE_BUILD_TYPE} MATCHES "Debug")
+if(${CMAKE_BUILD_TYPE} MATCHES "Debug" AND NOT ANDROID)
   add_compile_options(-fsanitize=address)
   add_compile_options(-fsanitize=leak)
   add_link_options   (-fsanitize=address)
@@ -197,13 +205,29 @@ if(IOS)
     XCODE_ATTRIBUTE_CODE_SIGN_IDENTITY "iPhone Developer")
 endif()
 
-target_sources(Gothic2Notr PRIVATE game/main.cpp icon.rc)
+target_sources(Gothic2Notr PRIVATE game/main.cpp)
+if(WIN32)
+  target_sources(Gothic2Notr PRIVATE icon.rc)
+endif()
 target_link_libraries(Gothic2Notr PRIVATE OpenGothic)
 
 # editor
-target_sources(Spacer PRIVATE ${SPACER_SOURCES} spacer/main.cpp)
-target_include_directories(Spacer PRIVATE "spacer")
-target_link_libraries(Spacer PRIVATE OpenGothic SpacerAssets)
+if(NOT ANDROID)
+  target_sources(Spacer PRIVATE ${SPACER_SOURCES} spacer/main.cpp)
+  target_include_directories(Spacer PRIVATE "spacer")
+  target_link_libraries(Spacer PRIVATE OpenGothic SpacerAssets)
+endif()
+
+if(ANDROID)
+  add_android_apk(OpenGothic-apk
+    PACKAGE_NAME org.opengothic.app
+    CODE Gothic2Notr
+    MANIFEST android/AndroidManifest.xml
+    JAVA_DIRS android/java)
+endif()
 
 # installation
-install(TARGETS Gothic2Notr Spacer DESTINATION bin)
+install(TARGETS Gothic2Notr DESTINATION bin)
+if(NOT ANDROID)
+  install(TARGETS Spacer DESTINATION bin)
+endif()

README.md

@@ -91,6 +91,10 @@ There are ongoing efforts to support parts of it to make at least some popular m
 - Ninja
 
 ## Build Instructions
+### Android
+
+The basic ARM64 APK build and ADB game-file setup are documented in [android/README.md](android/README.md).
+
 ### Linux
 Install dependencies:
 * Ubuntu 20.04/22.04 and their derived distros

android/AndroidManifest.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-feature android:name="android.hardware.vulkan.level" android:version="0" android:required="true" />
+    <uses-feature android:name="android.hardware.vulkan.version" android:version="0x00401000" android:required="true" />
+    <application android:label="OpenGothic" android:hasCode="true" android:allowBackup="false"
+        android:theme="@android:style/Theme.Material.NoActionBar.Fullscreen">
+        <activity android:name="org.opengothic.app.GothicActivity" android:exported="true"
+            android:screenOrientation="landscape"
+            android:configChanges="keyboard|keyboardHidden|navigation|orientation|screenSize|screenLayout|smallestScreenSize|density|uiMode">
+            <meta-data android:name="android.app.lib_name" android:value="Gothic2Notr" />
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

android/README.md

@@ -0,0 +1,32 @@
+# Android
+
+An ARM64 NativeActivity APK using Tempest's Android backend and generated Gradle project. This is the basic platform integration; touch controls, controller input and game-file importing are not included yet. Android window destruction closes the application, including when backgrounding or locking destroys its surface.
+
+## Build
+
+Install JDK 17, Gradle 8.9, CMake 3.22.1 or newer, Ninja and the Android SDK with SDK 35, build-tools 35.0.0, NDK 27.0.12077973 and SDK CMake 3.22.1. Set `JAVA_HOME`, `ANDROID_HOME` and `VULKAN_SDK`. Put Gradle, Ninja and the host Vulkan SDK's `glslangValidator` on `PATH`. Vulkan headers come from the host SDK; Android links the NDK's Vulkan loader.
+
+Clone with `git clone --recursive https://github.com/Try/OpenGothic.git`, or run `git submodule update --init --recursive` in an existing checkout. Replace `/path/to/ndk` below with the NDK installation directory. The same commands work in PowerShell and a Linux shell.
+
+```sh
+cmake -S . -B build/android -G Ninja -DCMAKE_TOOLCHAIN_FILE=/path/to/ndk/build/cmake/android.toolchain.cmake -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=android-24 -DCMAKE_BUILD_TYPE=Release
+cmake --build build/android --target OpenGothic-apk
+```
+
+APK: `build/android/OpenGothic-apk/build/outputs/apk/release/OpenGothic-apk-release.apk`. Use `-DCMAKE_BUILD_TYPE=Debug` for a debuggable APK under `outputs/apk/debug/OpenGothic-apk-debug.apk`. Desktop builds do not invoke the APK helper or require Android tools.
+
+## Install and game files
+
+Use a legally owned Gothic II: Night of the Raven installation. No game files are included in the APK. Copy the installation root, not only its `Data` directory: `Data`, `_work` and `System` must be directly inside `Gothic2`.
+
+```sh
+adb install -r build/android/OpenGothic-apk/build/outputs/apk/release/OpenGothic-apk-release.apk
+adb shell mkdir -p /sdcard/Android/data/org.opengothic.app/files/Gothic2
+adb push "/path/to/Gothic II/." /sdcard/Android/data/org.opengothic.app/files/Gothic2/
+adb shell am start -n org.opengothic.app/.GothicActivity
+adb logcat -s OpenGothic AndroidRuntime DEBUG
+```
+
+Game files use app-specific external storage, without storage permissions. Logs, saves and writable settings use the app's internal files directory. Uninstalling removes both directories. Ray tracing and mesh shading are disabled for this initial Android build.
+
+With a debug APK, read the file log using `adb shell run-as org.opengothic.app cat files/log.txt`.

android/java/org/opengothic/app/GothicActivity.java

@@ -0,0 +1,28 @@
+package org.opengothic.app;
+
+import android.app.NativeActivity;
+import android.os.Bundle;
+
+import java.io.File;
+
+public class GothicActivity extends NativeActivity {
+    static {
+        System.loadLibrary("Gothic2Notr");
+    }
+
+    private static native void prepareStorage(String writablePath, String gamePath);
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        File external = getExternalFilesDir(null);
+        if (external == null) {
+            throw new IllegalStateException("External application storage is unavailable");
+        }
+        File game = new File(external, "Gothic2");
+        if (!game.isDirectory() && !game.mkdirs()) {
+            throw new IllegalStateException("Unable to create the Gothic2 installation directory");
+        }
+        prepareStorage(getFilesDir().getAbsolutePath(), game.getAbsolutePath());
+        super.onCreate(savedInstanceState);
+    }
+}

common/utils/crashlog.cpp

@@ -14,7 +14,7 @@
 #include <stacktrace>
 #endif
 
-#if defined(__LINUX__) || defined(__APPLE__)
+#if (defined(__LINUX__) && !defined(__ANDROID__)) || defined(__APPLE__)
 #include <execinfo.h> // backtrace
 #include <dlfcn.h>    // dladdr
 #include <cxxabi.h>   // __cxa_demangle
@@ -136,7 +136,7 @@ void CrashLog::dumpStack(const char *sig, const char *extGpuLog) {
 #elif defined(__WINDOWS__)
   traceback.collect(0);
   traceback.log(db, std::cout);
-#elif defined(__LINUX__) || defined(__APPLE__)
+#elif (defined(__LINUX__) && !defined(__ANDROID__)) || defined(__APPLE__)
   tracebackLinux(std::cout);
 #endif
   std::cout << std::endl;
@@ -150,7 +150,7 @@ void CrashLog::dumpStack(const char *sig, const char *extGpuLog) {
   tracebackStd(fout);
 #elif defined(__WINDOWS__)
   traceback.log(db, fout);
-#elif defined(__LINUX__) || defined(__APPLE__)
+#elif (defined(__LINUX__) && !defined(__ANDROID__)) || defined(__APPLE__)
   tracebackLinux(fout);
 #endif
   fout.flush();
@@ -169,7 +169,7 @@ void CrashLog::tracebackStd(std::ostream &out) {
   }
 
 void CrashLog::tracebackLinux(std::ostream &out) {
-#if defined(__LINUX__) || defined(__APPLE__)
+#if (defined(__LINUX__) && !defined(__ANDROID__)) || defined(__APPLE__)
   // inspired by https://gist.github.com/fmela/591333/36faca4c2f68f7483cd0d3a357e8a8dd5f807edf (BSD)
   void *callstack[64] = {};
   char **symbols = nullptr;

game/main.cpp

@@ -18,6 +18,14 @@
 #include "utils/installdetect.h"
 #endif
 
+#if defined(__ANDROID__)
+#include <android/log.h>
+#include <jni.h>
+#include <filesystem>
+#include <stdexcept>
+#include <string>
+#endif
+
 #include "utils/crashlog.h"
 #include "mainwindow.h"
 #include "gothic.h"
@@ -26,6 +34,48 @@
 
 #include <dmusic.h>
 
+#if defined(__ANDROID__)
+static std::string androidGamePath;
+
+static std::string androidPath(JNIEnv* env, jstring path) {
+  if(path==nullptr)
+    throw std::invalid_argument("Missing application storage path");
+  const char* text = env->GetStringUTFChars(path,nullptr);
+  if(text==nullptr)
+    throw std::runtime_error("Unable to read application storage path");
+  try {
+    std::string result(text);
+    env->ReleaseStringUTFChars(path,text);
+    return result;
+    }
+  catch(...) {
+    env->ReleaseStringUTFChars(path,text);
+    throw;
+    }
+  }
+
+static void throwAndroidError(JNIEnv* env, const char* message) {
+  if(env->ExceptionCheck())
+    return;
+  jclass type = env->FindClass("java/lang/IllegalStateException");
+  if(type!=nullptr)
+    env->ThrowNew(type,message);
+  }
+
+extern "C" JNIEXPORT void JNICALL Java_org_opengothic_app_GothicActivity_prepareStorage(JNIEnv* env, jclass, jstring writablePath, jstring gamePath) {
+  try {
+    std::filesystem::current_path(androidPath(env,writablePath));
+    androidGamePath = androidPath(env,gamePath);
+    }
+  catch(const std::exception& e) {
+    throwAndroidError(env,e.what());
+    }
+  catch(...) {
+    throwAndroidError(env,"Unable to initialize application storage");
+    }
+  }
+#endif
+
 std::string_view selectDevice(const Tempest::AbstractGraphicsApi& api) {
   auto d = api.devices();
 
@@ -68,6 +118,11 @@ std::unique_ptr<Tempest::AbstractGraphicsApi> mkApi(const CommandLine& g) {
   }
 
 int main(int argc,const char** argv) {
+#if defined(__ANDROID__)
+  const char* androidArgs[] = {"Gothic2Notr", "-g", androidGamePath.c_str(), "-rt", "0", "-ms", "0"};
+  argc = sizeof(androidArgs)/sizeof(androidArgs[0]);
+  argv = androidArgs;
+#endif
 #if defined(__IOS__)
   {
     auto appdir = InstallDetect::applicationSupportDirectory();
@@ -78,6 +133,10 @@ int main(int argc,const char** argv) {
   try {
     static Tempest::WFile logFile("log.txt");
     Tempest::Log::setOutputCallback([](Tempest::Log::Mode mode, const char* text) {
+#if defined(__ANDROID__)
+      const int priority = mode==Tempest::Log::Error ? ANDROID_LOG_ERROR : mode==Tempest::Log::Debug ? ANDROID_LOG_DEBUG : ANDROID_LOG_INFO;
+      __android_log_write(priority,"OpenGothic",text);
+#endif
       logFile.write(text,std::strlen(text));
       logFile.write("\n",1);
       if(mode==Tempest::Log::Error)

shader/CMakeLists.txt

@@ -20,7 +20,7 @@ file(GLOB_RECURSE GLSL_SOURCES
   "${CMAKE_SOURCE_DIR}/shader/*.glsl")
 
 # GLSL to SPIRV compiler
-find_program(GLSLANGVALIDATOR glslangValidator "/opt/homebrew/bin")
+find_program(GLSLANGVALIDATOR glslangValidator "/opt/homebrew/bin" NO_CMAKE_FIND_ROOT_PATH)
 if(NOT GLSLANGVALIDATOR)
   message(FATAL_ERROR "glslangValidator required")
 endif()