360 degree images now will be displayed somehow (at least they are)

app/src/main/java/de/trac/spherical/MainActivity.java

@@ -1,6 +1,9 @@
 package de.trac.spherical;
 
+import android.content.Context;
 import android.content.Intent;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
 import android.net.Uri;
 import android.opengl.GLSurfaceView;
 import android.support.v7.app.AppCompatActivity;
@@ -17,6 +20,7 @@ import de.trac.spherical.parser.PhotoSphereMetadata;
 import de.trac.spherical.parser.SphereParser;
 
 import de.trac.spherical.rendering.Renderer;
+import de.trac.spherical.rendering.SphereSurfaceView;
 
 public class MainActivity extends AppCompatActivity {
 
@@ -25,18 +29,17 @@ public class MainActivity extends AppCompatActivity {
     public static final String MIME_PHOTO_SPHERE = "application/vnd.google.panorama360+jpg";
     public static final String MIME_IMAGE = "image/*";
 
-    private TextView text;
-    private GLSurfaceView surfaceView;
+    private SphereSurfaceView surfaceView;
+    private Renderer renderer;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
-        //TODO: Remove later
-        text = (TextView) findViewById(R.id.hello_world);
-        surfaceView = (GLSurfaceView) findViewById(R.id.surface_view);
-        surfaceView.setEGLContextClientVersion(2);
-        surfaceView.setRenderer(new Renderer());
+
+        // Initialize renderer and setup surface view.
+        surfaceView = new SphereSurfaceView(this);
+        renderer = new Renderer(surfaceView);
+        setContentView(surfaceView);
 
         Intent intent = getIntent();
         switch (intent.getAction()) {
@@ -129,7 +132,7 @@ public class MainActivity extends AppCompatActivity {
     }
 
     private void displayPhotoSphere(InputStream inputStream, PhotoSphereMetadata metadata) {
-        //Please fill me!
+        renderer.setBitmap(BitmapFactory.decodeStream(inputStream));
     }
 
     /**
@@ -137,6 +140,6 @@ public class MainActivity extends AppCompatActivity {
      * @param inputStream
      */
     private void displayFlatImage(InputStream inputStream) {
-
+        Toast.makeText(this, "Not yet implemented", Toast.LENGTH_SHORT).show();
     }
 }

app/src/main/java/de/trac/spherical/rendering/Renderer.java

@@ -1,8 +1,9 @@
 package de.trac.spherical.rendering;
 
 
-import android.database.MatrixCursor;
+import android.graphics.Bitmap;
 import android.opengl.GLSurfaceView;
+import android.opengl.GLUtils;
 import android.opengl.Matrix;
 import android.util.Log;
 
@@ -10,6 +11,7 @@ import javax.microedition.khronos.egl.EGLConfig;
 import javax.microedition.khronos.opengles.GL10;
 
 import static android.opengl.GLES20.*;
+import static android.opengl.GLUtils.getEGLErrorString;
 
 public class Renderer implements GLSurfaceView.Renderer {
 
@@ -65,6 +67,29 @@ public class Renderer implements GLSurfaceView.Renderer {
     private int positionLocation;
     private int textureCoordinatesLocation;
     private int mvpLocation;
+    private int texLocation;
+
+    // Store texture.
+    private final int textureID [] = new int[1];
+
+    // Store bitmap for lazy loading.
+    private Bitmap bitmap = null;
+
+    // Store input handler instance to determine transformation.
+    private SphereSurfaceView surfaceView;
+
+    /**
+     * Constructor. Will be set as renderer of the specified surface view.
+     * @param surfaceView SurfaceView which will own the renderer
+     */
+    public Renderer(SphereSurfaceView surfaceView) {
+        if(surfaceView == null)
+            throw new NullPointerException("SurfaceView must not be null");
+
+        this.surfaceView = surfaceView;
+        this.surfaceView.setEGLContextClientVersion(2);
+        this.surfaceView.setRenderer(this);
+    }
 
     /**
      * Draws the frame.
@@ -72,8 +97,19 @@ public class Renderer implements GLSurfaceView.Renderer {
      */
     public void onDrawFrame(GL10 unused) {
 
+        // Upload texture, if necessary.
+        if(bitmap != null) {
+            glBindTexture(GL_TEXTURE_2D, textureID[0]);
+            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+            GLUtils.texImage2D(GL_TEXTURE_2D, 0, bitmap, 0);
+
+            // Release bitmap for garbage collection.
+            bitmap = null;
+        }
+
         // Update transformation matrix.
-        Matrix.multiplyMM(mvpMatrix, 0, viewMatrix, 0, modlMatrix, 0);
+        Matrix.multiplyMM(mvpMatrix, 0, surfaceView.getRotationMatrix(), 0, modlMatrix, 0);
         Matrix.multiplyMM(mvpMatrix, 0, projMatrix, 0, mvpMatrix, 0);
 
         // Draw the frame.
@@ -87,12 +123,17 @@ public class Renderer implements GLSurfaceView.Renderer {
         glVertexAttribPointer(textureCoordinatesLocation, 2, GL_FLOAT, false, 2*4, sphere.getTextureCoordinatesBuffer());
 
         glUniformMatrix4fv(mvpLocation, 1, false, mvpMatrix, 0);
+        glUniform1i(texLocation, 0);
         glDrawElements(GL_TRIANGLES, sphere.getIndexBuffer().capacity(), GL_UNSIGNED_SHORT, sphere.getIndexBuffer());
 
         glDisableVertexAttribArray(textureCoordinatesLocation);
         glDisableVertexAttribArray(positionLocation);
 
         glUseProgram(0);
+
+        int error = glGetError();
+        if(error != GL_NO_ERROR)
+            Log.e("Renderer", "Error: " + getEGLErrorString(error));
     }
 
     /**
@@ -119,7 +160,7 @@ public class Renderer implements GLSurfaceView.Renderer {
 
         //TODO: (re)move tmp code
         Matrix.setIdentityM(modlMatrix, 0);
-        Matrix.translateM(modlMatrix, 0, 0, 0, 4.0f);
+        //Matrix.translateM(modlMatrix, 0, 0, 0, 4.0f);
         Matrix.setLookAtM(viewMatrix, 0, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f);
     }
 
@@ -129,16 +170,21 @@ public class Renderer implements GLSurfaceView.Renderer {
     public void initialize() {
 
         // Initialize sphere.
-        sphere = new Sphere(1.0f, 32, 32); // TODO: choose useful parameters.
+        sphere = new Sphere(10.0f, 32, 32); // TODO: choose useful parameters.
 
         // Set OpenGL state.
-        glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
+        glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
         glEnable(GL_DEPTH_TEST);
         glEnable(GL_CULL_FACE);
-        glCullFace(GL_BACK);
+        glCullFace(GL_FRONT);
+        glEnable(GL_TEXTURE_2D);
+        glActiveTexture(GL_TEXTURE0);
 
         // Build shader program.
         programID = buildProgram(DEFAULT_VERTEX_SHADER, DEFAULT_FRAGMENT_SHADER);
+
+        // Generate texture.
+        glGenTextures(1, textureID, 0);
     }
 
     /**
@@ -146,9 +192,18 @@ public class Renderer implements GLSurfaceView.Renderer {
      */
     public void deinitialize() {
         sphere = null;
+        glDeleteTextures(1, textureID, 0);
         glDeleteProgram(programID);
     }
 
+    /**
+     * Uploads the image data of the given bitmap into the internal texture.
+     * @param bitmap Bitmap to be set as texture
+     */
+    public void setBitmap(Bitmap bitmap) {
+        this.bitmap = bitmap;
+    }
+
     /**
      * Builds a shader program given vertex and fragment shader soruce.
      * @param vertexSource The vertex shader source
@@ -194,6 +249,10 @@ public class Renderer implements GLSurfaceView.Renderer {
         if (mvpLocation == -1) {
             throw new RuntimeException("Could not get uniform location for 'mvpMatrix'");
         }
+        texLocation = glGetUniformLocation(program, "tex");
+        if(texLocation == -1) {
+            throw new RuntimeException("Could not get uniform location for 'tex'");
+        }
 
         return program;
     }

app/src/main/java/de/trac/spherical/rendering/SphereSurfaceView.java

@@ -0,0 +1,103 @@
+package de.trac.spherical.rendering;
+
+import android.content.Context;
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
+import android.opengl.GLSurfaceView;
+import android.opengl.Matrix;
+import android.view.MotionEvent;
+
+/**
+ * This SurfaceView implementation is the glue between the Renderer and any input event.
+ */
+public class SphereSurfaceView extends GLSurfaceView implements SensorEventListener {
+
+    public static boolean USE_TOUCH = true; // TODO: determine dynamically
+
+    private final float TOUCH_SCALE_FACTOR = 180.0f / 1080;
+    private float previousX;
+    private float previousY;
+
+    // The actual rotation matrix determined by user input.
+    private final float rotationMatrix [] = new float[16];
+
+    // The following fields are used as cache.
+    private final float tmpMatrix[] = new float[9];
+    private final float tmpVector[] = new float[3];
+
+    public SphereSurfaceView(Context context) {
+        super(context);
+
+        Matrix.setIdentityM(rotationMatrix, 0);
+
+        SensorManager manager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
+        Sensor accelerometer = manager.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
+        manager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_GAME);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+
+        if(!USE_TOUCH)
+            return true;
+
+        float x = event.getX();
+        float y = event.getY();
+
+        switch (event.getAction()) {
+            case MotionEvent.ACTION_MOVE:
+
+                float dx = x - previousX;
+                float dy = y - previousY;
+
+                if (y > getHeight() / 2)
+                    dx = dx * -1 ;
+
+                if (x < getWidth() / 2)
+                    dy = dy * -1 ;
+
+                Matrix.rotateM(rotationMatrix, 0, dy * TOUCH_SCALE_FACTOR, 1.0f, 0.0f, 0.0f);
+                Matrix.rotateM(rotationMatrix, 0, dx * TOUCH_SCALE_FACTOR, 0.0f, 1.0f, 0.0f);
+        }
+
+        previousX = x;
+        previousY = y;
+        return true;
+
+    }
+
+    @Override
+    public void onAccuracyChanged(Sensor s, int arg1) {
+        // unused
+    }
+
+    @Override
+    public void onSensorChanged(SensorEvent event) {
+
+        if(USE_TOUCH)
+            return;
+
+        SensorManager.getRotationMatrixFromVector(tmpMatrix, event.values);
+        SensorManager.getOrientation(tmpMatrix, tmpVector);
+
+        for (int i = 0; i < tmpVector.length; i++)
+            tmpVector[i] = Math.round(Math.toDegrees(tmpVector[i]));
+
+        synchronized (rotationMatrix) {
+            Matrix.setRotateEulerM(rotationMatrix, 0, -tmpVector[0], -tmpVector[1], -tmpVector[2]);
+        }
+    }
+
+    /**
+     * Returns a matrix representing the devices rotation.
+     * This function is thread safe.
+     * @return rotation matrix according to device rotation
+     */
+    public float [] getRotationMatrix() {
+        synchronized (rotationMatrix) {
+            return rotationMatrix;
+        }
+    }
+}