Update Android example to use SDL3

examples/example_android_opengl3/CMakeLists.txt

@@ -1,40 +1,232 @@
-cmake_minimum_required(VERSION 3.6)
+cmake_minimum_required(VERSION 3.2)
 
 project(ImGuiExample)
 
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
-add_library(${CMAKE_PROJECT_NAME} SHARED
-  ${CMAKE_CURRENT_SOURCE_DIR}/main.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_demo.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_draw.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_tables.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_widgets.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../backends/imgui_impl_android.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../backends/imgui_impl_opengl3.cpp
-  ${ANDROID_NDK}/sources/android/native_app_glue/android_native_app_glue.c
-)
-
-set(CMAKE_SHARED_LINKER_FLAGS
-  "${CMAKE_SHARED_LINKER_FLAGS} -u ANativeActivity_onCreate"
-)
-
-target_compile_definitions(${CMAKE_PROJECT_NAME} PRIVATE
-  IMGUI_IMPL_OPENGL_ES3
-)
-
-target_include_directories(${CMAKE_PROJECT_NAME} PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}/../..
-  ${CMAKE_CURRENT_SOURCE_DIR}/../../backends
-  ${ANDROID_NDK}/sources/android/native_app_glue
-)
-
-target_link_libraries(${CMAKE_PROJECT_NAME} PRIVATE
-  android
-  EGL
-  GLESv3
-  log
-)
+option(CONFIGURE_WITH_SDL3 "Configure with SDL3: ON/OFF" OFF)
+
+# Android Project
+if(CONFIGURE_WITH_SDL3)
+  message(INFO ": Configuring Android example with SDL3")
+  if(NOT DEFINED ENV{ANDROID_HOME})
+      message(FATAL_ERROR "Set ANDROID_HOME to path of Android Sdk.")
+  endif()
+
+  if(NOT DEFINED ENV{ANDROID_NDK_HOME})
+      message(FATAL_ERROR "Set ANDROID_NDK_HOME to path of Android Ndk.")
+  endif()
+
+  # Download SDL3
+  set(SDL_DIR_NAME "SDL-main")
+  set(DOWNLOADED_SDL_DIR "${CMAKE_BINARY_DIR}/${SDL_DIR_NAME}")
+  set(SDL_MAIN_BRANCH_ZIP_URL "https://github.com/libsdl-org/SDL/archive/main.zip")
+  # Package name should match the same in Gradle build files
+  set(IMGUI_PKG_NAME "imgui.example.android")
+  set(IMGUI_ACTIVITY "ImguiActivity")
+
+  file(DOWNLOAD ${SDL_MAIN_BRANCH_ZIP_URL} SHOW_PROGRESS ${DOWNLOADED_SDL_DIR}.zip STATUS DOWNLOAD_STATUS)
+  file(ARCHIVE_EXTRACT INPUT "${DOWNLOADED_SDL_DIR}.zip")
+
+  list(GET DOWNLOAD_STATUS 0 STATUS_CODE)
+  list(GET DOWNLOAD_STATUS 1 ERROR_MESSAGE)  
+
+  # Check if download was successful.
+  if(${STATUS_CODE} EQUAL 0)
+      message(INFO ": ${SDL_DIR_NAME}.zip download completed successfully!")
+  else()
+      message(FATAL_ERROR "Error occurred during download: ${ERROR_MESSAGE}")
+  endif()
+
+  set(IMGUI_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../..)
+  set(SDL3_OPENGL3_DIR "${IMGUI_DIR}/examples/example_sdl3_opengl3")
+  set(ANDROID_OPENGL3_DIR "${IMGUI_DIR}/examples/example_android_opengl3")
+  set(IMGUI_BACKENDS_DIR "${IMGUI_DIR}/backends")
+  set(SDL3_MAIN_CPP "main_sdl3.cpp")
+
+  # Copy Gradle files
+  set(GRADLE_WRAPPER_DOWNLOAD "${DOWNLOADED_SDL_DIR}/android-project/gradlew")
+  set(GRADLE_BATCH_DOWNLOAD "${DOWNLOADED_SDL_DIR}/android-project/gradlew.bat")
+  set(GRADLE_WRAPPER_JAR "gradle-wrapper.jar")
+  set(GRADLE_WRAPPER_DIR "${ANDROID_OPENGL3_DIR}/android/gradle/wrapper")
+  set(GRADLE_WRAPPER_PROPS_FILENAME "${GRADLE_WRAPPER_DIR}/gradle-wrapper.properties")
+  set(GRADLE_WRAPPER_PROPS_CONTENT "distributionBase=GRADLE_USER_HOME\n"
+  "distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-bin.zip\n"
+  "distributionPath=wrapper/dists\n"
+  "zipStorePath=wrapper/dists\n"
+  "zipStoreBase=GRADLE_USER_HOME\n")
+  # Check if Gradle Wrapper directory is present in repo
+  if(NOT EXISTS ${GRADLE_WRAPPER_DIR})
+    add_custom_command(OUTPUT CMD PRE_BUILD COMMAND ${CMAKE_COMMAND} -E make_directory ${GRADLE_WRAPPER_DIR})
+    message(INFO ": Made Gradle Wrapper dir")
+  else()
+    message(INFO ": Found Gradle Wrapper dir")
+  endif()
+  file(WRITE ${GRADLE_WRAPPER_PROPS_FILENAME} ${GRADLE_WRAPPER_PROPS_CONTENT})
+
+  message(INFO ": Copying Gradle wrapper files to Android project")
+  execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${GRADLE_WRAPPER_DOWNLOAD}" "${ANDROID_OPENGL3_DIR}/android")
+  execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${GRADLE_BATCH_DOWNLOAD}" "${ANDROID_OPENGL3_DIR}/android")
+  execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${DOWNLOADED_SDL_DIR}/android-project/gradle/wrapper/${GRADLE_WRAPPER_JAR}" "${GRADLE_WRAPPER_DIR}")
+
+  # Copy SDL3 Java files
+  set(SDL_JAVA_SRC_MAIN "${DOWNLOADED_SDL_DIR}/android-project/app/src/main/java")
+  set(SDL_JAVA_PKG_PATH "org/libsdl/app")
+  set(ANDROID_JAVA_PATH "${ANDROID_OPENGL3_DIR}/android/app/src/main/java")
+  set(ANDROID_SDL_JAVA_FILES "${ANDROID_JAVA_PATH}/${SDL_JAVA_PKG}")
+  if(NOT EXISTS ${ANDROID_SDL_JAVA_FILES})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${ANDROID_SDL_JAVA_FILES})
+    message(INFO ": Made dir ${ANDROID_SDL_JAVA_FILES}")
+  else()
+    message(INFO ": Found dir ${ANDROID_SDL_JAVA_FILES}")
+  endif()
+  message(INFO ": Copying SDL3 Java files to Android project")
+  list(APPEND SDL_JAVA_FILES HIDDevice HIDDeviceBLESteamController HIDDeviceManager HIDDeviceUSB SDL SDLActivity SDLAudioManager SDLControllerManager SDLDummyEdit SDLInputConnection SDLSurface)
+  foreach(JAVA_FILE ${SDL_JAVA_FILES})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${SDL_JAVA_SRC_MAIN}/${SDL_JAVA_PKG_PATH}/${JAVA_FILE}.java" "${ANDROID_SDL_JAVA_FILES}/${SDL_JAVA_PKG_PATH}/${JAVA_FILE}.java")
+  endforeach()
+
+  # Copy SDL's AndroidManifest.xml over to the repo, rewriting the previous example's manifest
+  set(SDL_MANIFEST_FILE ${DOWNLOADED_SDL_DIR}/android-project/app/src/main/AndroidManifest.xml)
+  set(ANDROID_MANIFEST_PATH ${ANDROID_JAVA_PATH}/..)
+  message(INFO ": Writing ${ANDROID_MANIFEST_PATH}/AndroidManifest.xml")
+  file(COPY ${SDL_MANIFEST_FILE} DESTINATION ${ANDROID_MANIFEST_PATH})
+  execute_process(COMMAND sed -i -e "s|name=\"SDLActivity\"|name=\"${IMGUI_ACTIVITY}\"|g" "${ANDROID_MANIFEST_PATH}/AndroidManifest.xml")
+  # Copy Android resource files
+  set(SDL_ANDROID_RES "${DOWNLOADED_SDL_DIR}/android-project/app/src/main/res")
+  set(ANDROID_RES_PATH "${ANDROID_OPENGL3_DIR}/android/app/src/main/res")
+  message(INFO ": Copying Android resources files")
+  if(NOT EXISTS ${ANDROID_RES_PATH})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${ANDROID_RES_PATH})
+    file(COPY ${SDL_ANDROID_RES} DESTINATION ${ANDROID_RES_PATH}/..)
+    message(INFO ": Made dir ${ANDROID_RES_PATH}")
+  else()
+    message(INFO ": Found dir ${ANDROID_RES_PATH}")
+  endif()
+  execute_process(COMMAND sed -i -e "s|Game|${PROJECT_NAME}|g" "${ANDROID_RES_PATH}/values/strings.xml")
+
+  # Create the Android Activity which extends SDLActivity
+  set(IMGUI_ACTIVITY_PATH ${ANDROID_JAVA_PATH}/com/example/imgui)
+  if(NOT EXISTS ${IMGUI_ACTIVITY_PATH})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${IMGUI_ACTIVITY_PATH})
+    message(INFO ": Made ${IMGUI_ACTIVITY_PATH}")
+  else()
+    message(INFO ": Found ${IMGUI_ACTIVITY_PATH}")
+  endif()
+  message(INFO ": Writing ${IMGUI_ACTIVITY_PATH}/${IMGUI_ACTIVITY}.java")
+  set(ACTIVITY_CONTENT "package ${IMGUI_PKG_NAME}\;\n"
+    "import org.libsdl.app.SDLActivity\;\n"
+    "public class ${IMGUI_ACTIVITY} extends SDLActivity {}\n")
+  file(WRITE ${IMGUI_ACTIVITY_PATH}/${IMGUI_ACTIVITY}.java ${ACTIVITY_CONTENT})
+
+  # Copy/Link SDL3 source files
+  option(LINK_SDL_FILES "Link SDL Files" OFF)
+  set(ANDROID_JNI_SDL_DIR "${ANDROID_OPENGL3_DIR}/android/app/jni/SDL")
+  if(NOT EXISTS ${ANDROID_JNI_SDL_DIR})
+    if(LINK_SDL_FILES)
+        message(INFO ": Using symbolic links for SDL dir")
+        file(CREATE_LINK "${DOWNLOADED_SDL_DIR}" ${ANDROID_JNI_SDL_DIR} SYMBOLIC)
+    else()
+        message(INFO ": Copying SDL source files to Android JNI dir")
+        file(COPY "${DOWNLOADED_SDL_DIR}/include" DESTINATION "${ANDROID_JNI_SDL_DIR}")
+        file(COPY "${DOWNLOADED_SDL_DIR}/src" DESTINATION "${ANDROID_JNI_SDL_DIR}")
+        file(COPY "${DOWNLOADED_SDL_DIR}/Android.mk" DESTINATION "${ANDROID_JNI_SDL_DIR}")
+    endif()
+  else()
+    message(INFO ": Found SDL sources in Android JNI dir")
+  endif()
+
+  # Copy Imgui files and backends
+  set(ANDROID_JNI_SRC_DIR "${ANDROID_OPENGL3_DIR}/android/app/jni/src")
+  list(APPEND IMGUI_FILES imgui.cpp imgui_demo.cpp imgui_draw.cpp imgui_tables.cpp imgui_widgets.cpp imconfig.h imgui_internal.h imgui.h imstb_rectpack.h imstb_textedit.h imstb_truetype.h)
+  list(APPEND IMGUI_BACKENDS imgui_impl_opengl3.cpp imgui_impl_sdl3.cpp imgui_impl_opengl3_loader.h imgui_impl_opengl3.h imgui_impl_sdl3.h)
+  if(NOT EXISTS ${ANDROID_JNI_SRC_DIR})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${ANDROID_JNI_SRC_DIR})
+    message(INFO ": Made Android JNI dir")
+  else()
+    message(INFO ": Found Android JNI dir")
+  endif()
+  foreach(IMGUI_FILE ${IMGUI_FILES})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${IMGUI_DIR}/${IMGUI_FILE}" "${ANDROID_JNI_SRC_DIR}/${IMGUI_FILE}")
+  endforeach()
+  foreach(IMGUI_BACKEND ${IMGUI_BACKENDS})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${IMGUI_BACKENDS_DIR}/${IMGUI_BACKEND}" "${ANDROID_JNI_SRC_DIR}/${IMGUI_BACKEND}")
+  endforeach()
+
+  # Copy the other SDL3/OpenGL3 example into the Android example (It works!)
+  message(INFO ": Copying example_sdl3_opengl3/main.cpp to Android project and renaming to ${SDL3_MAIN_CPP}")
+  file(COPY "${SDL3_OPENGL3_DIR}/main.cpp" DESTINATION "${ANDROID_JNI_SRC_DIR}")
+  file(RENAME ${ANDROID_JNI_SRC_DIR}/main.cpp ${ANDROID_JNI_SRC_DIR}/${SDL3_MAIN_CPP})
+
+  message(INFO ": Writing src/Android.mk")
+  # Create an Android.mk file for the Android SDL3 app
+  set(SRC_ANDROID_MK "LOCAL_PATH := $(call my-dir)\n"
+    "include $(CLEAR_VARS)\n"
+    "LOCAL_MODULE := main\n"
+    "SDL_PATH := ../SDL\n"
+    "LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(SDL_PATH)/include\n"
+    "LOCAL_CXXFLAGS := -std=c++11 -Wall -DIMGUI_IMPL_OPENGL_ES2\n"
+    "LOCAL_SRC_FILES :=  ${SDL3_MAIN_CPP} \\\n"
+    "imgui_demo.cpp \\\n"
+    "imgui_draw.cpp \\\n"
+    "imgui_tables.cpp \\\n"
+    "imgui_widgets.cpp \\\n"
+    "imgui.cpp \\\n"
+    "imgui_impl_sdl3.cpp \\\n"
+    "imgui_impl_opengl3.cpp \\\n"
+    "imgui.h \\\n"
+    "imconfig.h \\\n"
+    "imgui_internal.h \\\n"
+    "imstb_rectpack.h \\\n"
+    "imstb_textedit.h \\\n"
+    "imstb_truetype.h \\\n"
+    "imgui_impl_sdl3.h \\\n"
+    "imgui_impl_opengl3.h \\\n"
+    "imgui_impl_opengl3_loader.h \n"
+    "LOCAL_SHARED_LIBRARIES := SDL3\n"
+    "LOCAL_LDLIBS := -lEGL -lGLESv3 -lOpenSLES -llog -landroid\n"
+    "include $(BUILD_SHARED_LIBRARY)\n")
+    file(WRITE ${ANDROID_JNI_SRC_DIR}/Android.mk ${SRC_ANDROID_MK})
+    message(INFO ": Writing Android.mk")
+    set(ANDROID_MK "include $(call all-subdir-makefiles)\n")
+    file(WRITE ${ANDROID_JNI_SRC_DIR}/../Android.mk ${ANDROID_MK})
+    message(INFO ": Writing Application.mk")
+    set(APPLICATION_MK "APP_ABI := armeabi-v7a arm64-v8a x86 x86_64\nAPP_PLATFORM=android-19\n")
+    file(WRITE ${ANDROID_JNI_SRC_DIR}/../Application.mk ${APPLICATION_MK})
+else()
+    add_library(${CMAKE_PROJECT_NAME} SHARED
+    ${CMAKE_CURRENT_SOURCE_DIR}/main.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_demo.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_draw.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_tables.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../imgui_widgets.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../backends/imgui_impl_android.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../backends/imgui_impl_opengl3.cpp
+    ${ANDROID_NDK}/sources/android/native_app_glue/android_native_app_glue.c
+  )
+
+  set(CMAKE_SHARED_LINKER_FLAGS
+    "${CMAKE_SHARED_LINKER_FLAGS} -u ANativeActivity_onCreate"
+  )
+
+  target_compile_definitions(${CMAKE_PROJECT_NAME} PRIVATE
+    IMGUI_IMPL_OPENGL_ES3
+  )
+
+  target_include_directories(${CMAKE_PROJECT_NAME} PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}/../..
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../backends
+    ${ANDROID_NDK}/sources/android/native_app_glue
+  )
+
+  target_link_libraries(${CMAKE_PROJECT_NAME} PRIVATE
+    android
+    EGL
+    GLESv3
+    log
+  )
+
+endif()

examples/example_android_opengl3/README.md

@@ -0,0 +1,16 @@
+# example_android_opengl3
+
+## Build without SDL3 using CMake
+
+## Build with SDL3 using CMake
+
+This example runs Dear ImGui demo windows with SDL3 on modern Android (targeting Android SDK 34).
+
+Before running CMake, ensure the `JAVA_HOME``, `ANDROID_HOME``, and `ANDROID_NDK_HOME`` environment variables are set.
+
+This command will configure the Android files (it doesn't actually build anything): `cmake -S . -B build .. -DCONFIGURE_WITH_SDL3=ON -DLINK_SDL_FILES=OFF`
+  * Using `-DLINK_SDL_FILES=OFF` will not use symbolic links, instead will copy the SDL sources and includes into the Android JNI directory.
+
+Once CMake has finished successfully, change into the `android` directory and run `./gradlew installDebug`. 
+
+This should install the demo app on a connected emulator or physical device.

examples/example_android_opengl3/android/.gitignore

@@ -10,3 +10,11 @@ local.properties
 # Android Studio puts a Gradle wrapper here, that we don't want:
 gradle/
 gradlew*
+
+app/jni/src
+app/jni/SDL*
+app/jni/Android.mk
+app/jni/Application.mk
+app/src/main/res
+app/src/main/java/com
+app/src/main/java/org

examples/example_android_opengl3/android/app/build.gradle

@@ -2,17 +2,27 @@ apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion 33
-    buildToolsVersion "33.0.2"
-    ndkVersion "25.2.9519653"
+    compileSdkVersion 34
+    buildToolsVersion "34.0.0"
 
     defaultConfig {
         applicationId "imgui.example.android"
         namespace "imgui.example.android"
-        minSdkVersion 24
-        targetSdkVersion 33
+        minSdkVersion 19
+        targetSdkVersion 34
         versionCode 1
         versionName "1.0"
+        externalNativeBuild {
+            ndkBuild {
+                arguments "APP_PLATFORM=android-19"
+                abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
+                }
+            // cmake {
+            //     path "../../CMakeLists.txt"
+            //     version '3.22.1'
+            // }
+        }
+        ndkVersion "25.2.9519653"
     }
 
     buildTypes {
@@ -31,11 +41,19 @@ android {
         jvmTarget="11"
     }
 
-    externalNativeBuild {
-        cmake {
-            path "../../CMakeLists.txt"
-            version '3.22.1'
+    if (!project.hasProperty('EXCLUDE_NATIVE_LIBS')) {
+        sourceSets.main {
+            jniLibs.srcDir 'libs'
+        }
+        externalNativeBuild {
+            ndkBuild {
+                path 'jni/Android.mk'
+            }
+            // cmake {
+            //     path 'jni/CMakeLists.txt'
+            // }
         }
+
     }
 }
 repositories {