more vks, stupid mutlistep build, and imgui

8 files changed, 570 insertions, 0 deletions

diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/CMakeLists.txt b/lib/imgui-1.90.7/examples/example_android_opengl3/CMakeLists.txt
new file mode 100644
index 0000000..63531f4
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/CMakeLists.txt
@@ -0,0 +1,40 @@
+cmake_minimum_required(VERSION 3.6)
+
+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
+)
diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/android/.gitignore b/lib/imgui-1.90.7/examples/example_android_opengl3/android/.gitignore
new file mode 100644
index 0000000..3c7a619
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/android/.gitignore
@@ -0,0 +1,12 @@
+.cxx
+.externalNativeBuild
+build/
+*.iml
+
+.idea
+.gradle
+local.properties
+
+# Android Studio puts a Gradle wrapper here, that we don't want:
+gradle/
+gradlew*
diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/build.gradle b/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/build.gradle
new file mode 100644
index 0000000..53181ba
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/build.gradle
@@ -0,0 +1,46 @@
+apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+
+android {
+    compileSdkVersion 33
+    buildToolsVersion "33.0.2"
+    ndkVersion "25.2.9519653"
+
+    defaultConfig {
+        applicationId "imgui.example.android"
+        namespace "imgui.example.android"
+        minSdkVersion 24
+        targetSdkVersion 33
+        versionCode 1
+        versionName "1.0"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt')
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
+    }
+
+    kotlinOptions {
+        jvmTarget="11"
+    }
+
+    externalNativeBuild {
+        cmake {
+            path "../../CMakeLists.txt"
+            version '3.22.1'
+        }
+    }
+}
+repositories {
+    mavenCentral()
+}
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+}
diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/src/main/AndroidManifest.xml b/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..a87b95b
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/src/main/AndroidManifest.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <application
+        android:label="ImGuiExample"
+        android:allowBackup="false"
+        android:fullBackupContent="false"
+        android:hasCode="true">
+
+        <activity
+            android:name="imgui.example.android.MainActivity"
+            android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
+            android:configChanges="orientation|keyboardHidden|screenSize"
+            android:exported="false">
+            <meta-data android:name="android.app.lib_name"
+                android:value="ImGuiExample" />
+
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>
diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/src/main/java/MainActivity.kt b/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/src/main/java/MainActivity.kt
new file mode 100644
index 0000000..896a88c
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/android/app/src/main/java/MainActivity.kt
@@ -0,0 +1,40 @@
+package imgui.example.android
+
+import android.app.NativeActivity
+import android.os.Bundle
+import android.content.Context
+import android.view.inputmethod.InputMethodManager
+import android.view.KeyEvent
+import java.util.concurrent.LinkedBlockingQueue
+
+class MainActivity : NativeActivity() {
+    public override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+    }
+
+    fun showSoftInput() {
+        val inputMethodManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
+        inputMethodManager.showSoftInput(this.window.decorView, 0)
+    }
+
+    fun hideSoftInput() {
+        val inputMethodManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
+        inputMethodManager.hideSoftInputFromWindow(this.window.decorView.windowToken, 0)
+    }
+
+    // Queue for the Unicode characters to be polled from native code (via pollUnicodeChar())
+    private var unicodeCharacterQueue: LinkedBlockingQueue<Int> = LinkedBlockingQueue()
+
+    // We assume dispatchKeyEvent() of the NativeActivity is actually called for every
+    // KeyEvent and not consumed by any View before it reaches here
+    override fun dispatchKeyEvent(event: KeyEvent): Boolean {
+        if (event.action == KeyEvent.ACTION_DOWN) {
+            unicodeCharacterQueue.offer(event.getUnicodeChar(event.metaState))
+        }
+        return super.dispatchKeyEvent(event)
+    }
+
+    fun pollUnicodeChar(): Int {
+        return unicodeCharacterQueue.poll() ?: 0
+    }
+}
diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/android/build.gradle b/lib/imgui-1.90.7/examples/example_android_opengl3/android/build.gradle
new file mode 100644
index 0000000..ccd2185
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/android/build.gradle
@@ -0,0 +1,24 @@
+buildscript {
+    ext.kotlin_version = '1.8.0'
+    repositories {
+        google()
+        mavenCentral()
+
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:7.4.1'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}
diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/android/settings.gradle b/lib/imgui-1.90.7/examples/example_android_opengl3/android/settings.gradle
new file mode 100644
index 0000000..e7b4def
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/android/settings.gradle
@@ -0,0 +1 @@
+include ':app'
diff --git a/lib/imgui-1.90.7/examples/example_android_opengl3/main.cpp b/lib/imgui-1.90.7/examples/example_android_opengl3/main.cpp
new file mode 100644
index 0000000..e0ad5f9
--- /dev/null
+++ b/lib/imgui-1.90.7/examples/example_android_opengl3/main.cpp
@@ -0,0 +1,383 @@
+// dear imgui: standalone example application for Android + OpenGL ES 3
+
+// Learn about Dear ImGui:
+// - FAQ                  https://dearimgui.com/faq
+// - Getting Started      https://dearimgui.com/getting-started
+// - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
+// - Introduction, links and more at the top of imgui.cpp
+
+#include "imgui.h"
+#include "imgui_impl_android.h"
+#include "imgui_impl_opengl3.h"
+#include <android/log.h>
+#include <android_native_app_glue.h>
+#include <android/asset_manager.h>
+#include <EGL/egl.h>
+#include <GLES3/gl3.h>
+#include <string>
+
+// Data
+static EGLDisplay           g_EglDisplay = EGL_NO_DISPLAY;
+static EGLSurface           g_EglSurface = EGL_NO_SURFACE;
+static EGLContext           g_EglContext = EGL_NO_CONTEXT;
+static struct android_app*  g_App = nullptr;
+static bool                 g_Initialized = false;
+static char                 g_LogTag[] = "ImGuiExample";
+static std::string          g_IniFilename = "";
+
+// Forward declarations of helper functions
+static void Init(struct android_app* app);
+static void Shutdown();
+static void MainLoopStep();
+static int ShowSoftKeyboardInput();
+static int PollUnicodeChars();
+static int GetAssetData(const char* filename, void** out_data);
+
+// Main code
+static void handleAppCmd(struct android_app* app, int32_t appCmd)
+{
+    switch (appCmd)
+    {
+    case APP_CMD_SAVE_STATE:
+        break;
+    case APP_CMD_INIT_WINDOW:
+        Init(app);
+        break;
+    case APP_CMD_TERM_WINDOW:
+        Shutdown();
+        break;
+    case APP_CMD_GAINED_FOCUS:
+    case APP_CMD_LOST_FOCUS:
+        break;
+    }
+}
+
+static int32_t handleInputEvent(struct android_app* app, AInputEvent* inputEvent)
+{
+    return ImGui_ImplAndroid_HandleInputEvent(inputEvent);
+}
+
+void android_main(struct android_app* app)
+{
+    app->onAppCmd = handleAppCmd;
+    app->onInputEvent = handleInputEvent;
+
+    while (true)
+    {
+        int out_events;
+        struct android_poll_source* out_data;
+
+        // Poll all events. If the app is not visible, this loop blocks until g_Initialized == true.
+        while (ALooper_pollAll(g_Initialized ? 0 : -1, nullptr, &out_events, (void**)&out_data) >= 0)
+        {
+            // Process one event
+            if (out_data != nullptr)
+                out_data->process(app, out_data);
+
+            // Exit the app by returning from within the infinite loop
+            if (app->destroyRequested != 0)
+            {
+                // shutdown() should have been called already while processing the
+                // app command APP_CMD_TERM_WINDOW. But we play save here
+                if (!g_Initialized)
+                    Shutdown();
+
+                return;
+            }
+        }
+
+        // Initiate a new frame
+        MainLoopStep();
+    }
+}
+
+void Init(struct android_app* app)
+{
+    if (g_Initialized)
+        return;
+
+    g_App = app;
+    ANativeWindow_acquire(g_App->window);
+
+    // Initialize EGL
+    // This is mostly boilerplate code for EGL...
+    {
+        g_EglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+        if (g_EglDisplay == EGL_NO_DISPLAY)
+            __android_log_print(ANDROID_LOG_ERROR, g_LogTag, "%s", "eglGetDisplay(EGL_DEFAULT_DISPLAY) returned EGL_NO_DISPLAY");
+
+        if (eglInitialize(g_EglDisplay, 0, 0) != EGL_TRUE)
+            __android_log_print(ANDROID_LOG_ERROR, g_LogTag, "%s", "eglInitialize() returned with an error");
+
+        const EGLint egl_attributes[] = { EGL_BLUE_SIZE, 8, EGL_GREEN_SIZE, 8, EGL_RED_SIZE, 8, EGL_DEPTH_SIZE, 24, EGL_SURFACE_TYPE, EGL_WINDOW_BIT, EGL_NONE };
+        EGLint num_configs = 0;
+        if (eglChooseConfig(g_EglDisplay, egl_attributes, nullptr, 0, &num_configs) != EGL_TRUE)
+            __android_log_print(ANDROID_LOG_ERROR, g_LogTag, "%s", "eglChooseConfig() returned with an error");
+        if (num_configs == 0)
+            __android_log_print(ANDROID_LOG_ERROR, g_LogTag, "%s", "eglChooseConfig() returned 0 matching config");
+
+        // Get the first matching config
+        EGLConfig egl_config;
+        eglChooseConfig(g_EglDisplay, egl_attributes, &egl_config, 1, &num_configs);
+        EGLint egl_format;
+        eglGetConfigAttrib(g_EglDisplay, egl_config, EGL_NATIVE_VISUAL_ID, &egl_format);
+        ANativeWindow_setBuffersGeometry(g_App->window, 0, 0, egl_format);
+
+        const EGLint egl_context_attributes[] = { EGL_CONTEXT_CLIENT_VERSION, 3, EGL_NONE };
+        g_EglContext = eglCreateContext(g_EglDisplay, egl_config, EGL_NO_CONTEXT, egl_context_attributes);
+
+        if (g_EglContext == EGL_NO_CONTEXT)
+            __android_log_print(ANDROID_LOG_ERROR, g_LogTag, "%s", "eglCreateContext() returned EGL_NO_CONTEXT");
+
+        g_EglSurface = eglCreateWindowSurface(g_EglDisplay, egl_config, g_App->window, nullptr);
+        eglMakeCurrent(g_EglDisplay, g_EglSurface, g_EglSurface, g_EglContext);
+    }
+
+    // Setup Dear ImGui context
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    ImGuiIO& io = ImGui::GetIO();
+
+    // Redirect loading/saving of .ini file to our location.
+    // Make sure 'g_IniFilename' persists while we use Dear ImGui.
+    g_IniFilename = std::string(app->activity->internalDataPath) + "/imgui.ini";
+    io.IniFilename = g_IniFilename.c_str();;
+
+    // Setup Dear ImGui style
+    ImGui::StyleColorsDark();
+    //ImGui::StyleColorsLight();
+
+    // Setup Platform/Renderer backends
+    ImGui_ImplAndroid_Init(g_App->window);
+    ImGui_ImplOpenGL3_Init("#version 300 es");
+
+    // Load Fonts
+    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
+    // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
+    // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
+    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
+    // - Android: The TTF files have to be placed into the assets/ directory (android/app/src/main/assets), we use our GetAssetData() helper to retrieve them.
+
+    // We load the default font with increased size to improve readability on many devices with "high" DPI.
+    // FIXME: Put some effort into DPI awareness.
+    // Important: when calling AddFontFromMemoryTTF(), ownership of font_data is transferred by Dear ImGui by default (deleted is handled by Dear ImGui), unless we set FontDataOwnedByAtlas=false in ImFontConfig
+    ImFontConfig font_cfg;
+    font_cfg.SizePixels = 22.0f;
+    io.Fonts->AddFontDefault(&font_cfg);
+    //void* font_data;
+    //int font_data_size;
+    //ImFont* font;
+    //font_data_size = GetAssetData("segoeui.ttf", &font_data);
+    //font = io.Fonts->AddFontFromMemoryTTF(font_data, font_data_size, 16.0f);
+    //IM_ASSERT(font != nullptr);
+    //font_data_size = GetAssetData("DroidSans.ttf", &font_data);
+    //font = io.Fonts->AddFontFromMemoryTTF(font_data, font_data_size, 16.0f);
+    //IM_ASSERT(font != nullptr);
+    //font_data_size = GetAssetData("Roboto-Medium.ttf", &font_data);
+    //font = io.Fonts->AddFontFromMemoryTTF(font_data, font_data_size, 16.0f);
+    //IM_ASSERT(font != nullptr);
+    //font_data_size = GetAssetData("Cousine-Regular.ttf", &font_data);
+    //font = io.Fonts->AddFontFromMemoryTTF(font_data, font_data_size, 15.0f);
+    //IM_ASSERT(font != nullptr);
+    //font_data_size = GetAssetData("ArialUni.ttf", &font_data);
+    //font = io.Fonts->AddFontFromMemoryTTF(font_data, font_data_size, 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
+    //IM_ASSERT(font != nullptr);
+
+    // Arbitrary scale-up
+    // FIXME: Put some effort into DPI awareness
+    ImGui::GetStyle().ScaleAllSizes(3.0f);
+
+    g_Initialized = true;
+}
+
+void MainLoopStep()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    if (g_EglDisplay == EGL_NO_DISPLAY)
+        return;
+
+    // Our state
+    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
+    static bool show_demo_window = true;
+    static bool show_another_window = false;
+    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
+    // Poll Unicode characters via JNI
+    // FIXME: do not call this every frame because of JNI overhead
+    PollUnicodeChars();
+
+    // Open on-screen (soft) input if requested by Dear ImGui
+    static bool WantTextInputLast = false;
+    if (io.WantTextInput && !WantTextInputLast)
+        ShowSoftKeyboardInput();
+    WantTextInputLast = io.WantTextInput;
+
+    // Start the Dear ImGui frame
+    ImGui_ImplOpenGL3_NewFrame();
+    ImGui_ImplAndroid_NewFrame();
+    ImGui::NewFrame();
+
+    // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
+    if (show_demo_window)
+        ImGui::ShowDemoWindow(&show_demo_window);
+
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
+
+        ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it.
+
+        ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
+        ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
+        ImGui::Checkbox("Another Window", &show_another_window);
+
+        ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+        ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+
+        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+            counter++;
+        ImGui::SameLine();
+        ImGui::Text("counter = %d", counter);
+
+        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+        ImGui::End();
+    }
+
+    // 3. Show another simple window.
+    if (show_another_window)
+    {
+        ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
+        ImGui::Text("Hello from another window!");
+        if (ImGui::Button("Close Me"))
+            show_another_window = false;
+        ImGui::End();
+    }
+
+    // Rendering
+    ImGui::Render();
+    glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
+    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+    eglSwapBuffers(g_EglDisplay, g_EglSurface);
+}
+
+void Shutdown()
+{
+    if (!g_Initialized)
+        return;
+
+    // Cleanup
+    ImGui_ImplOpenGL3_Shutdown();
+    ImGui_ImplAndroid_Shutdown();
+    ImGui::DestroyContext();
+
+    if (g_EglDisplay != EGL_NO_DISPLAY)
+    {
+        eglMakeCurrent(g_EglDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+
+        if (g_EglContext != EGL_NO_CONTEXT)
+            eglDestroyContext(g_EglDisplay, g_EglContext);
+
+        if (g_EglSurface != EGL_NO_SURFACE)
+            eglDestroySurface(g_EglDisplay, g_EglSurface);
+
+        eglTerminate(g_EglDisplay);
+    }
+
+    g_EglDisplay = EGL_NO_DISPLAY;
+    g_EglContext = EGL_NO_CONTEXT;
+    g_EglSurface = EGL_NO_SURFACE;
+    ANativeWindow_release(g_App->window);
+
+    g_Initialized = false;
+}
+
+// Helper functions
+
+// Unfortunately, there is no way to show the on-screen input from native code.
+// Therefore, we call ShowSoftKeyboardInput() of the main activity implemented in MainActivity.kt via JNI.
+static int ShowSoftKeyboardInput()
+{
+    JavaVM* java_vm = g_App->activity->vm;
+    JNIEnv* java_env = nullptr;
+
+    jint jni_return = java_vm->GetEnv((void**)&java_env, JNI_VERSION_1_6);
+    if (jni_return == JNI_ERR)
+        return -1;
+
+    jni_return = java_vm->AttachCurrentThread(&java_env, nullptr);
+    if (jni_return != JNI_OK)
+        return -2;
+
+    jclass native_activity_clazz = java_env->GetObjectClass(g_App->activity->clazz);
+    if (native_activity_clazz == nullptr)
+        return -3;
+
+    jmethodID method_id = java_env->GetMethodID(native_activity_clazz, "showSoftInput", "()V");
+    if (method_id == nullptr)
+        return -4;
+
+    java_env->CallVoidMethod(g_App->activity->clazz, method_id);
+
+    jni_return = java_vm->DetachCurrentThread();
+    if (jni_return != JNI_OK)
+        return -5;
+
+    return 0;
+}
+
+// Unfortunately, the native KeyEvent implementation has no getUnicodeChar() function.
+// Therefore, we implement the processing of KeyEvents in MainActivity.kt and poll
+// the resulting Unicode characters here via JNI and send them to Dear ImGui.
+static int PollUnicodeChars()
+{
+    JavaVM* java_vm = g_App->activity->vm;
+    JNIEnv* java_env = nullptr;
+
+    jint jni_return = java_vm->GetEnv((void**)&java_env, JNI_VERSION_1_6);
+    if (jni_return == JNI_ERR)
+        return -1;
+
+    jni_return = java_vm->AttachCurrentThread(&java_env, nullptr);
+    if (jni_return != JNI_OK)
+        return -2;
+
+    jclass native_activity_clazz = java_env->GetObjectClass(g_App->activity->clazz);
+    if (native_activity_clazz == nullptr)
+        return -3;
+
+    jmethodID method_id = java_env->GetMethodID(native_activity_clazz, "pollUnicodeChar", "()I");
+    if (method_id == nullptr)
+        return -4;
+
+    // Send the actual characters to Dear ImGui
+    ImGuiIO& io = ImGui::GetIO();
+    jint unicode_character;
+    while ((unicode_character = java_env->CallIntMethod(g_App->activity->clazz, method_id)) != 0)
+        io.AddInputCharacter(unicode_character);
+
+    jni_return = java_vm->DetachCurrentThread();
+    if (jni_return != JNI_OK)
+        return -5;
+
+    return 0;
+}
+
+// Helper to retrieve data placed into the assets/ directory (android/app/src/main/assets)
+static int GetAssetData(const char* filename, void** outData)
+{
+    int num_bytes = 0;
+    AAsset* asset_descriptor = AAssetManager_open(g_App->activity->assetManager, filename, AASSET_MODE_BUFFER);
+    if (asset_descriptor)
+    {
+        num_bytes = AAsset_getLength(asset_descriptor);
+        *outData = IM_ALLOC(num_bytes);
+        int64_t num_bytes_read = AAsset_read(asset_descriptor, *outData, num_bytes);
+        AAsset_close(asset_descriptor);
+        IM_ASSERT(num_bytes_read == num_bytes);
+    }
+    return num_bytes;
+}