added android project and linked to engine source with successful compilation

android/src/main/AndroidManifest.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+      package="com.omigamedev"
+      android:versionCode="1"
+      android:versionName="1.0">
+    <application android:label="@string/app_name" android:icon="@drawable/ic_launcher">
+        <activity android:name="android.app.NativeActivity"
+                  android:label="@string/app_name">
+            <meta-data android:name="android.app.lib_name"
+              android:value="native-lib" />
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

android/src/main/cpp/main.cpp

@@ -0,0 +1,338 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+//BEGIN_INCLUDE(all)
+#include <initializer_list>
+#include <memory>
+#include <jni.h>
+#include <errno.h>
+#include <cassert>
+
+#include <EGL/egl.h>
+#include <GLES3/gl3.h>
+
+#include <android/sensor.h>
+#include <android/log.h>
+#include <android_native_app_glue.h>
+
+#define LOGI(...) ((void)__android_log_print(ANDROID_LOG_INFO, "native-activity", __VA_ARGS__))
+#define LOGW(...) ((void)__android_log_print(ANDROID_LOG_WARN, "native-activity", __VA_ARGS__))
+
+/**
+ * Our saved state data.
+ */
+struct saved_state {
+    float angle;
+    int32_t x;
+    int32_t y;
+};
+
+/**
+ * Shared state for our app.
+ */
+struct engine {
+    struct android_app* app;
+
+    ASensorManager* sensorManager;
+    const ASensor* accelerometerSensor;
+    ASensorEventQueue* sensorEventQueue;
+
+    int animating;
+    EGLDisplay display;
+    EGLSurface surface;
+    EGLContext context;
+    int32_t width;
+    int32_t height;
+    struct saved_state state;
+};
+
+/**
+ * Initialize an EGL context for the current display.
+ */
+static int engine_init_display(struct engine* engine) {
+    // initialize OpenGL ES and EGL
+
+    /*
+     * Here specify the attributes of the desired configuration.
+     * Below, we select an EGLConfig with at least 8 bits per color
+     * component compatible with on-screen windows
+     */
+    const EGLint attribs[] = {
+            EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+            EGL_BLUE_SIZE, 8,
+            EGL_GREEN_SIZE, 8,
+            EGL_RED_SIZE, 8,
+            EGL_NONE
+    };
+    EGLint w, h, dummy, format;
+    EGLint numConfigs;
+    EGLConfig config;
+    EGLSurface surface;
+    EGLContext context;
+
+    EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+
+    eglInitialize(display, 0, 0);
+
+    /* Here, the application chooses the configuration it desires.
+     * find the best match if possible, otherwise use the very first one
+     */
+    eglChooseConfig(display, attribs, nullptr,0, &numConfigs);
+    std::unique_ptr<EGLConfig[]> supportedConfigs(new EGLConfig[numConfigs]);
+    assert(supportedConfigs);
+    eglChooseConfig(display, attribs, supportedConfigs.get(), numConfigs, &numConfigs);
+    assert(numConfigs);
+    auto i = 0;
+    for (; i < numConfigs; i++) {
+        auto& cfg = supportedConfigs[i];
+        EGLint r, g, b, d;
+        if (eglGetConfigAttrib(display, cfg, EGL_RED_SIZE, &r)   &&
+            eglGetConfigAttrib(display, cfg, EGL_GREEN_SIZE, &g) &&
+            eglGetConfigAttrib(display, cfg, EGL_BLUE_SIZE, &b)  &&
+            eglGetConfigAttrib(display, cfg, EGL_DEPTH_SIZE, &d) &&
+            r == 8 && g == 8 && b == 8 && d == 0 ) {
+
+            config = supportedConfigs[i];
+            break;
+        }
+    }
+    if (i == numConfigs) {
+        config = supportedConfigs[0];
+    }
+
+    /* EGL_NATIVE_VISUAL_ID is an attribute of the EGLConfig that is
+     * guaranteed to be accepted by ANativeWindow_setBuffersGeometry().
+     * As soon as we picked a EGLConfig, we can safely reconfigure the
+     * ANativeWindow buffers to match, using EGL_NATIVE_VISUAL_ID. */
+    eglGetConfigAttrib(display, config, EGL_NATIVE_VISUAL_ID, &format);
+    surface = eglCreateWindowSurface(display, config, engine->app->window, NULL);
+    context = eglCreateContext(display, config, NULL, NULL);
+
+    if (eglMakeCurrent(display, surface, surface, context) == EGL_FALSE) {
+        LOGW("Unable to eglMakeCurrent");
+        return -1;
+    }
+
+    eglQuerySurface(display, surface, EGL_WIDTH, &w);
+    eglQuerySurface(display, surface, EGL_HEIGHT, &h);
+
+    engine->display = display;
+    engine->context = context;
+    engine->surface = surface;
+    engine->width = w;
+    engine->height = h;
+    engine->state.angle = 0;
+
+    // Check openGL on the system
+    auto opengl_info = {GL_VENDOR, GL_RENDERER, GL_VERSION, GL_EXTENSIONS};
+    for (auto name : opengl_info) {
+        auto info = glGetString(name);
+        LOGI("OpenGL Info: %s", info);
+    }
+    // Initialize GL state.
+    //glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
+    glEnable(GL_CULL_FACE);
+    //glShadeModel(GL_SMOOTH);
+    glDisable(GL_DEPTH_TEST);
+
+    return 0;
+}
+
+/**
+ * Just the current frame in the display.
+ */
+static void engine_draw_frame(struct engine* engine) {
+    if (engine->display == NULL) {
+        // No display.
+        return;
+    }
+
+    // Just fill the screen with a color.
+    glClearColor(((float)engine->state.x)/engine->width, engine->state.angle,
+                 ((float)engine->state.y)/engine->height, 1);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    eglSwapBuffers(engine->display, engine->surface);
+}
+
+/**
+ * Tear down the EGL context currently associated with the display.
+ */
+static void engine_term_display(struct engine* engine) {
+    if (engine->display != EGL_NO_DISPLAY) {
+        eglMakeCurrent(engine->display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+        if (engine->context != EGL_NO_CONTEXT) {
+            eglDestroyContext(engine->display, engine->context);
+        }
+        if (engine->surface != EGL_NO_SURFACE) {
+            eglDestroySurface(engine->display, engine->surface);
+        }
+        eglTerminate(engine->display);
+    }
+    engine->animating = 0;
+    engine->display = EGL_NO_DISPLAY;
+    engine->context = EGL_NO_CONTEXT;
+    engine->surface = EGL_NO_SURFACE;
+}
+
+/**
+ * Process the next input event.
+ */
+static int32_t engine_handle_input(struct android_app* app, AInputEvent* event) {
+    struct engine* engine = (struct engine*)app->userData;
+    if (AInputEvent_getType(event) == AINPUT_EVENT_TYPE_MOTION) {
+        engine->animating = 1;
+        engine->state.x = AMotionEvent_getX(event, 0);
+        engine->state.y = AMotionEvent_getY(event, 0);
+        return 1;
+    }
+    return 0;
+}
+
+/**
+ * Process the next main command.
+ */
+static void engine_handle_cmd(struct android_app* app, int32_t cmd) {
+    struct engine* engine = (struct engine*)app->userData;
+    switch (cmd) {
+        case APP_CMD_SAVE_STATE:
+            // The system has asked us to save our current state.  Do so.
+            engine->app->savedState = malloc(sizeof(struct saved_state));
+            *((struct saved_state*)engine->app->savedState) = engine->state;
+            engine->app->savedStateSize = sizeof(struct saved_state);
+            break;
+        case APP_CMD_INIT_WINDOW:
+            // The window is being shown, get it ready.
+            if (engine->app->window != NULL) {
+                engine_init_display(engine);
+                engine_draw_frame(engine);
+            }
+            break;
+        case APP_CMD_TERM_WINDOW:
+            // The window is being hidden or closed, clean it up.
+            engine_term_display(engine);
+            break;
+        case APP_CMD_GAINED_FOCUS:
+            // When our app gains focus, we start monitoring the accelerometer.
+            if (engine->accelerometerSensor != NULL) {
+                ASensorEventQueue_enableSensor(engine->sensorEventQueue,
+                                               engine->accelerometerSensor);
+                // We'd like to get 60 events per second (in us).
+                ASensorEventQueue_setEventRate(engine->sensorEventQueue,
+                                               engine->accelerometerSensor,
+                                               (1000L/60)*1000);
+            }
+            break;
+        case APP_CMD_LOST_FOCUS:
+            // When our app loses focus, we stop monitoring the accelerometer.
+            // This is to avoid consuming battery while not being used.
+            if (engine->accelerometerSensor != NULL) {
+                ASensorEventQueue_disableSensor(engine->sensorEventQueue,
+                                                engine->accelerometerSensor);
+            }
+            // Also stop animating.
+            engine->animating = 0;
+            engine_draw_frame(engine);
+            break;
+    }
+}
+
+/**
+ * This is the main entry point of a native application that is using
+ * android_native_app_glue.  It runs in its own thread, with its own
+ * event loop for receiving input events and doing other things.
+ */
+void android_main(struct android_app* state) {
+    struct engine engine;
+
+    // Make sure glue isn't stripped.
+    app_dummy();
+
+    memset(&engine, 0, sizeof(engine));
+    state->userData = &engine;
+    state->onAppCmd = engine_handle_cmd;
+    state->onInputEvent = engine_handle_input;
+    engine.app = state;
+
+    // Prepare to monitor accelerometer
+    engine.sensorManager = ASensorManager_getInstance();
+    engine.accelerometerSensor = ASensorManager_getDefaultSensor(
+                                        engine.sensorManager,
+                                        ASENSOR_TYPE_ACCELEROMETER);
+    engine.sensorEventQueue = ASensorManager_createEventQueue(
+                                    engine.sensorManager,
+                                    state->looper, LOOPER_ID_USER,
+                                    NULL, NULL);
+
+    if (state->savedState != NULL) {
+        // We are starting with a previous saved state; restore from it.
+        engine.state = *(struct saved_state*)state->savedState;
+    }
+
+    // loop waiting for stuff to do.
+
+    while (1) {
+        // Read all pending events.
+        int ident;
+        int events;
+        struct android_poll_source* source;
+
+        // If not animating, we will block forever waiting for events.
+        // If animating, we loop until all events are read, then continue
+        // to draw the next frame of animation.
+        while ((ident=ALooper_pollAll(engine.animating ? 0 : -1, NULL, &events,
+                                      (void**)&source)) >= 0) {
+
+            // Process this event.
+            if (source != NULL) {
+                source->process(state, source);
+            }
+
+            // If a sensor has data, process it now.
+            if (ident == LOOPER_ID_USER) {
+                if (engine.accelerometerSensor != NULL) {
+                    ASensorEvent event;
+                    while (ASensorEventQueue_getEvents(engine.sensorEventQueue,
+                                                       &event, 1) > 0) {
+                        LOGI("accelerometer: x=%f y=%f z=%f",
+                             event.acceleration.x, event.acceleration.y,
+                             event.acceleration.z);
+                    }
+                }
+            }
+
+            // Check if we are exiting.
+            if (state->destroyRequested != 0) {
+                engine_term_display(&engine);
+                return;
+            }
+        }
+
+        if (engine.animating) {
+            // Done with events; draw next animation frame.
+            engine.state.angle += .01f;
+            if (engine.state.angle > 1) {
+                engine.state.angle = 0;
+            }
+
+            // Drawing is throttled to the screen update rate, so there
+            // is no need to do timing here.
+            engine_draw_frame(&engine);
+        }
+    }
+}
+//END_INCLUDE(all)

android/src/main/cpp/native-lib.cpp

@@ -0,0 +1,7 @@
+#include <stdlib.h>
+
+int main()
+{
+	return 0;
+}
+

android/src/main/java/com/omigamedev/DummyActivity.java

@@ -0,0 +1,15 @@
+package com.omigamedev;
+
+import android.app.Activity;
+import android.os.Bundle;
+
+public class DummyActivity extends Activity
+{
+    /** Called when the activity is first created. */
+    @Override
+    public void onCreate(Bundle savedInstanceState)
+    {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.main);
+    }
+}

android/src/main/res/layout/main.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    >
+<TextView
+    android:layout_width="fill_parent"
+    android:layout_height="wrap_content"
+    android:text="Hello World, DummyActivity"
+    />
+</LinearLayout>
+

android/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">DummyActivity</string>
+</resources>