StackOverflow2013

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POWallpaperService and Accelerometer
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copied!<p>After trying everything I thought I will try to see if someone here knows what is my problem, before I give up completely. So what I am trying to do is to make my image slide behind this "rotating cube". For example if I tilt my phone to right it starts to slide right and vice versa.</p> <p>Here is the code. It is very long and got much meaningless code for this question, but I thought to give it full, ignore the parts that arent importand. It is CubeWallpaper1 sample provided in sdk. I have just modified it and tried to add accelerometer to it and make it work.</p> <p>So if you could take a look and tell me what is wrong with it.</p> <pre><code>public class LiveWall extends WallpaperService implements SensorEventListener { float xAxis,yAxis,zAxis; private SensorManager mSensorManager; private Sensor mAccelerometer; Bitmap drawable; private final Handler mHandler = new Handler(); @Override public void onCreate() { super.onCreate(); mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE); mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); drawable = BitmapFactory.decodeResource(getResources(),R.drawable.bg); mSensorManager.registerListener(this, mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL); } public void onAccuracyChanged(Sensor arg0, int arg1) { // TODO Auto-generated method stub } public void onSensorChanged(SensorEvent event) { xAxis = event.values[0]; yAxis = event.values[1]; zAxis = event.values[2]; } @Override public void onDestroy() { super.onDestroy(); } @Override public Engine onCreateEngine() { return new CubeEngine(); } class CubeEngine extends Engine { private final Paint mPaint = new Paint(); private float mOffset; private float mTouchX = -1; private float mTouchY = -1; private long mStartTime; private float mCenterX; private float mCenterY; private final Runnable mDrawCube = new Runnable() { public void run() { drawFrame(); } }; private boolean mVisible; CubeEngine() { // Create a Paint to draw the lines for our cube final Paint paint = mPaint; paint.setColor(Color.GREEN); paint.setAntiAlias(true); paint.setStrokeWidth(15); paint.setStrokeCap(Paint.Cap.ROUND); paint.setStyle(Paint.Style.STROKE); mStartTime = SystemClock.elapsedRealtime(); } @Override public void onCreate(SurfaceHolder surfaceHolder) { super.onCreate(surfaceHolder); // By default we don't get touch events, so enable them. setTouchEventsEnabled(true); } @Override public void onDestroy() { super.onDestroy(); mHandler.removeCallbacks(mDrawCube); } @Override public void onVisibilityChanged(boolean visible) { mVisible = visible; if (visible) { drawFrame(); } else { mHandler.removeCallbacks(mDrawCube); } } @Override public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) { super.onSurfaceChanged(holder, format, width, height); // store the center of the surface, so we can draw the cube in the right spot mCenterX = width/2.0f; mCenterY = height/2.0f; drawFrame(); } @Override public void onSurfaceCreated(SurfaceHolder holder) { super.onSurfaceCreated(holder); } @Override public void onSurfaceDestroyed(SurfaceHolder holder) { super.onSurfaceDestroyed(holder); mVisible = false; mHandler.removeCallbacks(mDrawCube); } @Override public void onOffsetsChanged(float xOffset, float yOffset, float xStep, float yStep, int xPixels, int yPixels) { mOffset = xOffset; drawFrame(); } /* * Store the position of the touch event so we can use it for drawing later */ @Override public void onTouchEvent(MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_MOVE) { mTouchX = event.getX(); mTouchY = event.getY(); } else { mTouchX = -1; mTouchY = -1; } super.onTouchEvent(event); } /* * Draw one frame of the animation. This method gets called repeatedly * by posting a delayed Runnable. You can do any drawing you want in * here. This example draws a wireframe cube. */ void drawFrame() { final SurfaceHolder holder = getSurfaceHolder(); Canvas c = null; try { c = holder.lockCanvas(); if (c != null) { // draw something drawCube(c); drawTouchPoint(c); } } finally { if (c != null) holder.unlockCanvasAndPost(c); } // Reschedule the next redraw mHandler.removeCallbacks(mDrawCube); if (mVisible) { mHandler.postDelayed(mDrawCube, 1000 / 25); } } /* * Draw a wireframe cube by drawing 12 3 dimensional lines between * adjacent corners of the cube */ void drawCube(Canvas c) { c.save(); c.translate(mCenterX, mCenterY); c.drawColor(0xff000000); c.drawBitmap(drawable, 0+xAxis,0+yAxis, mPaint); drawLine(c, -400, -400, -400, 400, -400, -400); drawLine(c, 400, -400, -400, 400, 400, -400); drawLine(c, 400, 400, -400, -400, 400, -400); drawLine(c, -400, 400, -400, -400, -400, -400); drawLine(c, -400, -400, 400, 400, -400, 400); drawLine(c, 400, -400, 400, 400, 400, 400); drawLine(c, 400, 400, 400, -400, 400, 400); drawLine(c, -400, 400, 400, -400, -400, 400); drawLine(c, -400, -400, 400, -400, -400, -400); drawLine(c, 400, -400, 400, 400, -400, -400); drawLine(c, 400, 400, 400, 400, 400, -400); drawLine(c, -400, 400, 400, -400, 400, -400); c.restore(); } /* * Draw a 3 dimensional line on to the screen */ void drawLine(Canvas c, int x1, int y1, int z1, int x2, int y2, int z2) { long now = SystemClock.elapsedRealtime(); float xrot = ((float)(now - mStartTime)) / 1000; float yrot = (0.5f - mOffset) * 2.0f; float zrot = 0; // 3D transformations // rotation around X-axis float newy1 = (float)(Math.sin(xrot) * z1 + Math.cos(xrot) * y1); float newy2 = (float)(Math.sin(xrot) * z2 + Math.cos(xrot) * y2); float newz1 = (float)(Math.cos(xrot) * z1 - Math.sin(xrot) * y1); float newz2 = (float)(Math.cos(xrot) * z2 - Math.sin(xrot) * y2); // rotation around Y-axis float newx1 = (float)(Math.sin(yrot) * newz1 + Math.cos(yrot) * x1); float newx2 = (float)(Math.sin(yrot) * newz2 + Math.cos(yrot) * x2); newz1 = (float)(Math.cos(yrot) * newz1 - Math.sin(yrot) * x1); newz2 = (float)(Math.cos(yrot) * newz2 - Math.sin(yrot) * x2); // 3D-to-2D projection float startX = newx1 / (4 - newz1 / 400); float startY = newy1 / (4 - newz1 / 400); float stopX = newx2 / (4 - newz2 / 400); float stopY = newy2 / (4 - newz2 / 400); c.drawLine(startX, startY, stopX, stopY, mPaint); } /* * Draw a circle around the current touch point, if any. */ void drawTouchPoint(Canvas c) { if (mTouchX >=0 && mTouchY >= 0) { c.drawCircle(mTouchX, mTouchY, 80, mPaint); } } } } </code></pre>

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