Lesson One, ported to Kotlin

android/AndroidOpenGLESLessons/app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion 25
@@ -23,8 +24,33 @@ android {
 
     buildTypes {
         release {
-            minifyEnabled true
-            signingConfig signingConfigs.release
+            //minifyEnabled true
+            //signingConfig signingConfigs.release
         }
     }
+
+    packagingOptions {
+        exclude 'META-INF/build_main.kotlin_module' // will not include NOTICE file
+//    exclude 'META-INF/NOTICE' // will not include NOTICE file
+//    exclude 'META-INF/LICENSE' // will not include LICENSE file
+//    // as noted by @Vishnuvathsan you may also need to include
+//    // variations on the file name. It depends on your dependencies.
+//    // Some other common variations on notice and license file names
+//    exclude 'META-INF/notice'
+//    exclude 'META-INF/notice.txt'
+//    exclude 'META-INF/license'
+//    exclude 'META-INF/license.txt'
+    }
+}
+
+allprojects {
+    repositories {
+        mavenCentral()
+        maven { url 'https://jitpack.io' }
+    }
 }
+
+dependencies {
+    compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
+    compile 'com.github.kotlin-graphics:uno-sdk:cd7941c0f7'
+}

android/AndroidOpenGLESLessons/app/src/main/java/com/learnopengles/android/lesson1/LessonOneActivity.java

@@ -7,54 +7,54 @@
 import android.opengl.GLSurfaceView;
 import android.os.Bundle;
 
-public class LessonOneActivity extends Activity 
-{
-	/** Hold a reference to our GLSurfaceView */
-	private GLSurfaceView mGLSurfaceView;
-
-	@Override
-	public void onCreate(Bundle savedInstanceState) 
-	{
-		super.onCreate(savedInstanceState);
-		
-		mGLSurfaceView = new GLSurfaceView(this);
-
-		// Check if the system supports OpenGL ES 2.0.
-		final ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
-		final ConfigurationInfo configurationInfo = activityManager.getDeviceConfigurationInfo();
-		final boolean supportsEs2 = configurationInfo.reqGlEsVersion >= 0x20000;
-
-		if (supportsEs2) 
-		{
-			// Request an OpenGL ES 2.0 compatible context.
-			mGLSurfaceView.setEGLContextClientVersion(2);
-
-			// Set the renderer to our demo renderer, defined below.
-			mGLSurfaceView.setRenderer(new LessonOneRenderer());
-		} 
-		else 
-		{
-			// This is where you could create an OpenGL ES 1.x compatible
-			// renderer if you wanted to support both ES 1 and ES 2.
-			return;
-		}
-
-		setContentView(mGLSurfaceView);
-	}
-
-	@Override
-	protected void onResume() 
-	{
-		// The activity must call the GL surface view's onResume() on activity onResume().
-		super.onResume();
-		mGLSurfaceView.onResume();
-	}
-
-	@Override
-	protected void onPause() 
-	{
-		// The activity must call the GL surface view's onPause() on activity onPause().
-		super.onPause();
-		mGLSurfaceView.onPause();
-	}	
+public class LessonOneActivity extends Activity {
+    /**
+     * Hold a reference to our GLSurfaceView
+     */
+    private GLSurfaceView mGLSurfaceView;
+
+    private final boolean useKotlin = true;
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        mGLSurfaceView = new GLSurfaceView(this);
+
+        // Check if the system supports OpenGL ES 2.0.
+        final ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
+        final ConfigurationInfo configurationInfo = activityManager.getDeviceConfigurationInfo();
+        final boolean supportsEs2 = configurationInfo.reqGlEsVersion >= 0x20000;
+
+        if (supportsEs2) {
+            // Request an OpenGL ES 2.0 compatible context.
+            mGLSurfaceView.setEGLContextClientVersion(2);
+
+            // Set the renderer to our demo renderer, defined below.
+            if (useKotlin)
+                mGLSurfaceView.setRenderer(new LessonOneRendererKt());
+            else
+                mGLSurfaceView.setRenderer(new LessonOneRenderer());
+        } else {
+            // This is where you could create an OpenGL ES 1.x compatible
+            // renderer if you wanted to support both ES 1 and ES 2.
+            return;
+        }
+
+        setContentView(mGLSurfaceView);
+    }
+
+    @Override
+    protected void onResume() {
+        // The activity must call the GL surface view's onResume() on activity onResume().
+        super.onResume();
+        mGLSurfaceView.onResume();
+    }
+
+    @Override
+    protected void onPause() {
+        // The activity must call the GL surface view's onPause() on activity onPause().
+        super.onPause();
+        mGLSurfaceView.onPause();
+    }
 }