Fix random flickering

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

@@ -173,7 +173,7 @@ public class Renderer implements GLSurfaceView.Renderer {
         glGenTextures(1, textureID, 0);
 
         // Initialize matrices.
-        Matrix.setIdentityM(modlMatrix, 0);
+        Matrix.setRotateM(modlMatrix, 0, 90, 1.0f, 0.0f, 0.0f);
         Matrix.setLookAtM(viewMatrix, 0, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f);
     }
 

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

@@ -23,14 +23,10 @@ public class SphereSurfaceView extends GLSurfaceView implements SensorEventListe
     // The actual rotation matrix determined by user input.
     private final float rotationMatrix [] = new float[16];
 
-    // This matrix is used to compensate sensor coordinate system rotation.
-    private final float offsetMatrix [] = new float[16];
-
     public SphereSurfaceView(Context context) {
         super(context);
 
         Matrix.setIdentityM(rotationMatrix, 0);
-        Matrix.setRotateM(offsetMatrix, 0, 90.0f, 1.0f, 0.0f, 0.0f);
 
         SensorManager manager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
         Sensor accelerometer = manager.getSensorList(Sensor.TYPE_ROTATION_VECTOR).get(0);
@@ -83,7 +79,6 @@ public class SphereSurfaceView extends GLSurfaceView implements SensorEventListe
 
         synchronized (rotationMatrix) {
             SensorManager.getRotationMatrixFromVector(rotationMatrix, event.values);
-            Matrix.multiplyMM(rotationMatrix, 0, rotationMatrix, 0, offsetMatrix, 0);
         }
     }