Android Support

.github/workflows/cmake-multi-platform.yml

@@ -1,10 +1,6 @@
 name: CMake on multiple platforms
 
-on:
-  push:
-    branches: [ "main" ]
-  pull_request:
-    branches: [ "main" ]
+on: [push, pull_request]
 
 jobs:
   build-all:
@@ -74,3 +70,28 @@ jobs:
     - name: Test
       working-directory: ./build/tests
       run: ctest --build-config ${{ matrix.build_type }} --output-on-failure
+
+  build-android:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v6
+
+    - name: Setup JDK 17
+      uses: actions/setup-java@v5
+      with:
+        java-version: '17'
+        distribution: 'temurin'
+        cache: 'gradle'
+
+    - name: Setup Android SDK
+      uses: android-actions/setup-android@v4
+
+    - name: Grant execute permission for gradlew
+      run: chmod +x android/gradlew
+
+    - name: Buld APK with Gradle
+      run: ./gradlew assembleRelease
+      working-directory: android
+      env:
+        ANDROID_NDK_HOME: ${{ env.ANDROID_NDK_HOME }}

.gitignore

@@ -1055,4 +1055,9 @@ dkms.conf
 # Raspberry Pi Pico Object file
 *.uf2
 # Raspberry Pi Pico disassembler file
-*.dis
+*.dis
+
+# Android / CLion / IntelliJ
+.idea
+android/local.properties
+android/.gradle/

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required (VERSION 3.28)
 
-project ("GadgetCore" LANGUAGES CXX)
+project ("GadgetCore" LANGUAGES C CXX)
 
 # --------------------------------------- #
 # ----- Fetch External Dependencies ----- #
@@ -74,6 +74,10 @@ set(ASSIMP_BUILD_RAW_IMPORTER ON)
 set(ASSIMP_BUILD_STL_IMPORTER ON)
 set(ASSIMP_BUILD_USD_IMPORTER OFF) # I would like to support this but build fails on Linux
 
+if (ANDROID)
+	add_compile_definitions(USE_FILE32API) # Forces minizip to use standard fopen instead of missing fopen64
+endif()
+
 FetchContent_MakeAvailable(Assimp)
 
 FetchContent_Declare(
@@ -100,17 +104,20 @@ else()
     set(EXCEPTION_FLAG "")
 endif()
 
-find_program(CLANG_TIDY_EXE NAMES clang-tidy)
-
-if (CLANG_TIDY_EXE)
-	message(STATUS "clang-tidy checks enabled")
-	set(CMAKE_CXX_CLANG_TIDY
-		clang-tidy
-		"-extra-arg=${EXCEPTION_FLAG}"
-		"--header-filter=.*[/\\]include[/\\]GCore[/\\]"
-	)
-else()
-	message(STATUS "clang-tidy not found, will not run checks")
+# TODO - See if we get clang-tidy to work reliably with Android Studio
+if (NOT ANDROID)
+	find_program(CLANG_TIDY_EXE NAMES clang-tidy)
+
+	if (CLANG_TIDY_EXE)
+		message(STATUS "clang-tidy checks enabled")
+		set(CMAKE_CXX_CLANG_TIDY
+			clang-tidy
+			"-extra-arg=${EXCEPTION_FLAG}"
+			"--header-filter=.*[/\\]include[/\\]GCore[/\\]"
+		)
+	else()
+		message(STATUS "clang-tidy not found, will not run checks")
+	endif()
 endif()
 
 # --------------------------------------- #
@@ -178,11 +185,29 @@ endif()
 # --------------------------------------- #
 
 if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
-	target_compile_definitions(GadgetCore PUBLIC GADGET_PLATFORM_WINDOWS)
+	target_compile_definitions(GadgetCore
+		PUBLIC
+			GADGET_PLATFORM_TYPE_PC
+			GADGET_PLATFORM_WINDOWS
+	)
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
-	target_compile_definitions(GadgetCore PUBLIC GADGET_PLATFORM_MACOS)
+	target_compile_definitions(GadgetCore
+		PUBLIC
+			GADGET_PLATFORM_TYPE_PC
+			GADGET_PLATFORM_MACOS
+	)
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-	target_compile_definitions(GadgetCore PUBLIC GADGET_PLATFORM_LINUX)
+	target_compile_definitions(GadgetCore
+		PUBLIC
+			GADGET_PLATFORM_TYPE_PC
+			GADGET_PLATFORM_LINUX
+	)
+elseif(ANDROID)
+	target_compile_definitions(GadgetCore
+		PUBLIC
+			GADGET_PLATFORM_TYPE_MOBILE
+			GADGET_PLATFORM_ANDROID
+	)
 endif()
 
 # --------------------------- #

README.md

@@ -7,9 +7,9 @@ GadgetCore spawned out of work on [GadgetEngine](https://github.com/ShikenNugget
 - **Platform Abstraction**: You should never need to directly call a platform-specific function or an underlying system API.
 
 ## Platform Support
-GadgetCore officially supports Windows, Mac, and Linux.
+GadgetCore officially supports Windows, Mac, Linux, and Android.
 
-Official platform support will be expanded to include mobile, game consoles, and WASM some time in the future. Android is the next highest priority. That said, I expect most features to work on most platforms regardless.
+This will be expanded to include WebAssembly, game consoles, and iOS some time in the future. Most features should work on most platforms regardless of official support status. Bug reports for unsupported platforms are welcome.
 
 ## Stability
 This library is in early development and is considered **unstable**. Expect frequent and unceremonious API breaks at this stage. I also do not plan to guarantee ABI stability for the foreseeable future. This will be updated as we approach a stable release.

android/app/build.gradle

@@ -0,0 +1,68 @@
+plugins {
+     id 'com.android.application'
+}
+
+def buildWithCMake = true;
+
+android {
+    namespace = "org.libsdl.app"
+    compileSdkVersion 35
+    ndkVersion = "28.2.13676358"
+    defaultConfig {
+        minSdkVersion 21
+        targetSdkVersion 35
+        versionCode 1
+        versionName "1.0"
+        externalNativeBuild {
+            ndkBuild {
+                arguments "APP_PLATFORM=android-21"
+                // abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
+                abiFilters 'arm64-v8a', 'x86_64'
+            }
+            cmake {
+                arguments "-DANDROID_PLATFORM=android-21", "-DANDROID_STL=c++_static"
+                // abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
+                abiFilters 'arm64-v8a', 'x86_64'
+            }
+        }
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+    applicationVariants.all { variant ->
+        tasks["merge${variant.name.capitalize()}Assets"]
+            .dependsOn("externalNativeBuild${variant.name.capitalize()}")
+    }
+    if (!project.hasProperty('EXCLUDE_NATIVE_LIBS')) {
+        //sourceSets.main {
+        //    jniLibs.srcDir 'libs'
+        //}
+        externalNativeBuild {
+            if (buildWithCMake) {
+                cmake {
+                    path '../../CMakeLists.txt'
+                    version "3.28.0+"
+                }
+            } else {
+                ndkBuild {
+                    path 'jni/Android.mk'
+                }
+            }
+        }
+
+    }
+    lint {
+        abortOnError = false
+    }
+
+    packagingOptions {
+        doNotStrip "*/libSDL3.so"
+    }
+}
+
+dependencies {
+    implementation fileTree(include: ['*.jar'], dir: 'libs')
+}

android/app/proguard-rules.pro

@@ -0,0 +1,76 @@
+# Add project specific ProGuard rules here.
+# By default, the flags in this file are appended to flags specified
+# in [sdk]/tools/proguard/proguard-android.txt
+# You can edit the include path and order by changing the proguardFiles
+# directive in build.gradle.
+#
+# For more details, see
+#   https://developer.android.com/build/shrink-code
+
+# Add any project specific keep options here:
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+-keep,includedescriptorclasses,allowoptimization class org.libsdl.app.SDLActivity {
+    java.lang.String nativeGetHint(java.lang.String); # Java-side doesn't use this, so it gets minified, but C-side still tries to register it
+    java.lang.String clipboardGetText();
+    boolean clipboardHasText();
+    void clipboardSetText(java.lang.String);
+    int createCustomCursor(int[], int, int, int, int);
+    void destroyCustomCursor(int);
+    android.app.Activity getContext();
+    boolean getManifestEnvironmentVariables();
+    android.view.Surface getNativeSurface();
+    void initTouch();
+    boolean isAndroidTV();
+    boolean isChromebook();
+    boolean isDeXMode();
+    boolean isTablet();
+    void manualBackButton();
+    int messageboxShowMessageBox(int, java.lang.String, java.lang.String, int[], int[], java.lang.String[], int[]);
+    void minimizeWindow();
+    boolean openURL(java.lang.String);
+    void requestPermission(java.lang.String, int);
+    boolean showToast(java.lang.String, int, int, int, int);
+    boolean sendMessage(int, int);
+    boolean setActivityTitle(java.lang.String);
+    boolean setCustomCursor(int);
+    void setOrientation(int, int, boolean, java.lang.String);
+    boolean setRelativeMouseEnabled(boolean);
+    boolean setSystemCursor(int);
+    void setWindowStyle(boolean);
+    boolean shouldMinimizeOnFocusLoss();
+    boolean showTextInput(int, int, int, int, int);
+    boolean supportsRelativeMouse();
+    int openFileDescriptor(java.lang.String, java.lang.String);
+    boolean showFileDialog(java.lang.String[], boolean, boolean, int);
+    java.lang.String getPreferredLocales();
+    java.lang.String formatLocale(java.util.Locale);
+}
+
+-keep,includedescriptorclasses,allowoptimization class org.libsdl.app.HIDDeviceManager {
+    void closeDevice(int);
+    boolean initialize(boolean, boolean);
+    boolean openDevice(int);
+    boolean readReport(int, byte[], boolean);
+    int writeReport(int, byte[], boolean);
+}
+
+-keep,includedescriptorclasses,allowoptimization class org.libsdl.app.SDLAudioManager {
+    void registerAudioDeviceCallback();
+    void unregisterAudioDeviceCallback();
+    void audioSetThreadPriority(boolean, int);
+}
+
+-keep,includedescriptorclasses,allowoptimization class org.libsdl.app.SDLControllerManager {
+    void pollInputDevices();
+    void pollHapticDevices();
+    void hapticRun(int, float, int);
+    void hapticRumble(int, float, float, int);
+    void hapticStop(int);
+}