Develop Reference

Exit to a different Activity when game loop ends?

I want my game to exit and go to a separate Activity when the user collides. For example, I want it to go back to my main menu. I've tried adding a Button, new intent method etc and these don't work. I can't find the answer anywhere and i'm not knowledgeable enough to do this as I'm learning. I've trawled the internet but nothing has really helped. Any advice would be awesome. My idea was to change the newgame() method to exit the game?
import android.content.Context;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.util.ArrayList;
import java.util.Random;
public class GamePanel extends SurfaceView implements SurfaceHolder.Callback {
private Threading threading;
private BackgroundImage bg;
public static final int WIDTH = 856;
public static final int HEIGHT = 480;
public static final int MovementSpeed = -8;
private Player player;
private ArrayList<BorderTop> borderTop;
private ArrayList<BorderBottom> borderBottom;
private ArrayList<Smokepuff> smoke;
private ArrayList<Missile> missiles;
private int MaximumBorderHeight;
private int MinimumBorderHeight;
private boolean topDown = true;
private boolean botDown = true;
private int progressDifficulty = 20;
private Random rand = new Random();
private boolean newGameCreated;
private long smokeStartTime;
private long missileStartTime;
public GamePanel(Context context) {
super(context);
getHolder().addCallback(this);
setFocusable(true);
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
bg = new BackgroundImage(BitmapFactory.decodeResource(getResources(), R.drawable.grassbg1));
player = new Player(BitmapFactory.decodeResource(getResources(), R.drawable.smallcatfinal), 40, 44, 1);
borderTop = new ArrayList<BorderTop>();
borderBottom = new ArrayList<BorderBottom>();
smoke = new ArrayList<Smokepuff>();
missiles = new ArrayList<Missile>();
smokeStartTime= System.nanoTime();
missileStartTime = System.nanoTime();
threading = new Threading(getHolder(), this);
threading.setRunning(true);
threading.start();
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
int counter = 0;
while (retry && counter < 1000) {
counter++;
try {
threading.setRunning(false);
threading.join();
retry = false;
threading = null;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
if (!player.getPlaying()) {
player.setPlaying(true);
player.setUp(true);
}else{
player.setUp(true);
}
return true;
}
if (event.getAction() == MotionEvent.ACTION_UP) {
player.setUp(false);
return true;
}
return super.onTouchEvent(event);
}
public void update() {
if (player.getPlaying()) {
bg.update();
player.update();
MaximumBorderHeight = 30 + player.getScore() / progressDifficulty;
if (MaximumBorderHeight > HEIGHT / 4) MaximumBorderHeight = HEIGHT / 4;
MinimumBorderHeight = 5 + player.getScore() / progressDifficulty;
//check bottom border collision
for (int i = 0; i < borderBottom.size(); i++) {
if (collision(borderBottom.get(i), player))
player.setPlaying(false);
}
//check top border collision
for (int i = 0; i < borderTop.size(); i++) {
if (collision(borderTop.get(i), player))
player.setPlaying(false);
}
this.updateTop();
this.updateBottom();
long missileElapsed = (System.nanoTime() - missileStartTime) / 1000000;
if (missileElapsed > (2000 - player.getScore() / 4)) {
//first missile always goes down the middle
if (missiles.size() == 0) {
missiles.add(new Missile(BitmapFactory.decodeResource(getResources(), R.drawable.
missile), WIDTH + 10, HEIGHT / 2, 45, 15, player.getScore(), 13));
} else {
missiles.add(new Missile(BitmapFactory.decodeResource(getResources(), R.drawable.missile),
WIDTH + 10, (int) (rand.nextDouble() * (HEIGHT - (MaximumBorderHeight * 2)) + MaximumBorderHeight), 45, 15, player.getScore(), 13));
}
//reset timer
missileStartTime = System.nanoTime();
}
//loop through every missile and check collision and remove
for (int i = 0; i < missiles.size(); i++) {
//update missile
missiles.get(i).update();
if (collision(missiles.get(i), player)) {
missiles.remove(i);
player.setPlaying(false);
break;
}
//remove missile if it is way off the screen
if (missiles.get(i).getX() < -100) {
missiles.remove(i);
break;
}
}
long elapsed = (System.nanoTime() - smokeStartTime) / 1000000;
if (elapsed > 120) {
smoke.add(new Smokepuff(player.getX(), player.getY() + 10));
smokeStartTime = System.nanoTime();
}
for (int i = 0; i < smoke.size(); i++) {
smoke.get(i).update();
if (smoke.get(i).getX() < -10) {
smoke.remove(i);
}
}
} else {
newGameCreated = false;
if (!newGameCreated) {
newGame();
}
}
public boolean collision (GameObject a, GameObject b)
{
if (Rect.intersects(a.getRectangle(), b.getRectangle())) {
return true;
}
return false;
}
#Override
public void draw(Canvas canvas) {
super.draw(canvas);
final float ScaleX = (float) getWidth() / WIDTH*1.f;
final float ScaleY = (float) getHeight() / HEIGHT*1.f;
if (canvas != null) {
final int savedState = canvas.save();
canvas.scale(ScaleX, ScaleY);
bg.draw(canvas);
player.draw(canvas);
for(Smokepuff sp: smoke)
{
sp.draw(canvas);
}
//draw missiles
for(Missile m: missiles)
{
m.draw(canvas);
}
for(BorderTop bt: borderTop)
{
bt.draw(canvas);
}
for(BorderBottom bb: borderBottom)
{
bb.draw(canvas);
}
canvas.restoreToCount(savedState);
}
}
public void updateBottom() {
if (player.getScore() % 40 == 0) {
borderBottom.add(new BorderBottom(BitmapFactory.decodeResource(getResources(), R.drawable.brick),
borderBottom.get(borderBottom.size() - 1).getX() + 20, (int) ((rand.nextDouble()
* MaximumBorderHeight) + (HEIGHT - MaximumBorderHeight))));
}
//update bottom border
for (int i = 0; i < borderBottom.size(); i++) {
borderBottom.get(i).update();
//if border is moving off screen, remove it and add a corresponding new one
if (borderBottom.get(i).getX() < -20) {
borderBottom.remove(i);
//determine if border will be moving up or down
if (borderBottom.get(borderBottom.size() - 1).getY() <= HEIGHT - MaximumBorderHeight) {
botDown = true;
}
if (borderBottom.get(borderBottom.size() - 1).getY() >= HEIGHT - MinimumBorderHeight) {
botDown = false;
}
if (botDown) {
borderBottom.add(new BorderBottom(BitmapFactory.decodeResource(getResources(),R.drawable.brick
), borderBottom.get(borderBottom.size() - 1).getX() + 20, borderBottom.get(borderBottom.size() - 1
).getY() + 1));
} else {
borderBottom.add(new BorderBottom(BitmapFactory.decodeResource(getResources(), R.drawable.brick
), borderBottom.get(borderBottom.size() - 1).getX() + 20, borderBottom.get(borderBottom.size() - 1
).getY() - 1));
}
}
}
}
public void updateTop()
{
if (player.getScore() % 50 == 0) {
borderTop.add(new BorderTop(BitmapFactory.decodeResource(getResources(), R.drawable.brick), borderTop.get(borderTop.size() - 1).getX() + 20, 0, (int) ((rand.nextDouble() * (MaximumBorderHeight)) + 1)));
}
for (int i = 0; i < borderTop.size(); i++) {
borderTop.get(i).update();
if (borderTop.get(i).getX() < -20) {
borderTop.remove(i);
if (borderTop.get(borderTop.size() - 1).getHeight() >= MaximumBorderHeight) {
topDown = false;
}
if (borderTop.get(borderTop.size() - 1).getHeight() <= MinimumBorderHeight) {
topDown = true;
}
if (topDown) {
borderTop.add(new BorderTop(BitmapFactory.decodeResource(getResources(), R.drawable.brick), borderTop.get(borderTop.size() - 1).getX() + 20, 0, borderTop.get(borderTop.size() - 1).getHeight() + 1));
} else {
borderTop.add(new BorderTop(BitmapFactory.decodeResource(getResources(), R.drawable.brick), borderTop.get(borderTop.size() - 1).getX() + 20, 0, borderTop.get(borderTop.size() - 1).getHeight() - 1));
}
}
}
}
public void newGame() {
borderBottom.clear();
borderTop.clear();
missiles.clear();
smoke.clear();
MinimumBorderHeight = 5;
MaximumBorderHeight = 30;
player.resetDY();
player.resetScore();
player.setY(HEIGHT/2);
//create initial borders
//initial top border
for(int i = 0; i*20<WIDTH+40;i++)
{
// first top border create
if(i==0)
{borderTop.add(new BorderTop(BitmapFactory.decodeResource(getResources(),R.drawable.brick
),i*20,0, 10));
}
else
{
borderTop.add(new BorderTop(BitmapFactory.decodeResource(getResources(),R.drawable.brick
),i*20,0, borderTop.get(i-1).getHeight()+1));
}
}
//initial bottom border
for(int i = 0; i*20<WIDTH+40; i++)
{
//first border ever created
if(i==0)
{
borderBottom.add(new BorderBottom(BitmapFactory.decodeResource(getResources(),R.drawable.brick)
,i*20,HEIGHT - MinimumBorderHeight));
}
//adding borders until the initial screen is filed
else
{
borderBottom.add(new BorderBottom(BitmapFactory.decodeResource(getResources(), R.drawable.brick),
i * 20, borderBottom.get(i - 1).getY() - 1));
}
}
newGameCreated = true;
}
}

Android calculating Velocity wtih Accelerometer data

Due to the power consuming GPS data, I would like to calculate the device speed with only the accelerometer x,y and z data. I have read a lot of questions about this topic and I tried many set-ups to find a satisfactory solution to calculate the speed when my device is in my car.
It seems so simple but nothing works, which drives me crazy.
Been trying the Sensor.TYPE_LINEAR_ACCELERATION and the Sensor.TYPE_ACCELEROMETER with removed gravity. Tried a Low Pass Filter on the Linear acceleration data. Unfortunately all with no succes.
Looks like the calculated speed is correct but testing in my car the calculated speed doesn't get higher then about 2 m/s.
below a code snip
mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);
public void onSensorChanged(SensorEvent event) {
if (event.sensor == mAccelerometer) {
if (timestamp != 0) {
final float dT = (event.timestamp - timestamp) * NS2S;
lax = event.values[0];
lay = event.values[1];
laz = event.values[2];
vx = vxo + lax * dT ;
vy = vyo + lay * dT ;
vz = vzo + laz * dT ;
speed = (float) (Math.sqrt(vx*vx + vy*vy + vz*vz)) ;
if (speed < 0.01) {speed = 0 ; }
tv_speed.setText(String.valueOf(speed));
}
timestamp = event.timestamp;
}
}
Hope someone can help, thanks a lot.

It's possible to compute distance and speed using only accelerometer, but with three conditions:
1. Linear movement - trajectory must be straight.
2. Slope of the road must be constant.
3. You must perform calibration procedure before start.
Where can you use this method with such restrictions - it's up to you... Now, how to do it:
We need something, implementing SensorEventListener interface. For the future use, let's add following abstract class:
public abstract class Accelerometer implements SensorEventListener {
protected float lastX;
protected float lastY;
protected float lastZ;
public abstract Point getPoint();
public void onAccuracyChanged(Sensor arg0, int arg1) {
}
}
and this will be our SensorEventListener:
public class XYZAccelerometer extends Accelerometer {
private static final int BUFFER_SIZE = 500;
// calibration
private float dX = 0;
private float dY = 0;
private float dZ = 0;
// buffer variables
private float X;
private float Y;
private float Z;
private int cnt = 0;
// returns last SenorEvent parameters
public Point getLastPoint(){
return new Point(lastX, lastY, lastZ, 1);
}
// returrns parameters, using buffer: average acceleration
// since last call of getPoint().
public Point getPoint(){
if (cnt == 0){
return new Point(lastX, lastY, lastZ, 1);
}
Point p = new Point(X, Y, Z, cnt);
reset();
return p;
}
// resets buffer
public void reset(){
cnt = 0;
X = 0;
Y = 0;
Z = 0;
}
public void onSensorChanged(SensorEvent se) {
float x = se.values[SensorManager.DATA_X] + dX;
float y = se.values[SensorManager.DATA_Y] + dY;
float z = se.values[SensorManager.DATA_Z] + dZ;
lastX = x;
lastY = y;
lastZ = z;
X+= x;
Y+= y;
Z+= z;
if (cnt < BUFFER_SIZE-1) {
cnt++;
} else
{
reset();
}
}
public int getCnt(){
return cnt;
}
public void setdX(float dX) {
this.dX = dX;
}
public void setdY(float dY) {
this.dY = dY;
}
public void setdZ(float dZ) {
this.dZ = dZ;
}
}
Calibrating accelerometer must be called before each experiment. Phone orientation must not be changed while measuring.
To calibrate accelerometer, i use this class:
public class Calibrator {
final static int UPDATE_INTERVAL = 400;
final static int ITERATIONS = 5;
Handler hRefresh;
XYZAccelerometer acc;
int eventNumber;
private LinkedList calData;
public Calibrator(Handler hRefresh, XYZAccelerometer acc, int eventNumber) {
this.hRefresh = hRefresh;
this.acc = acc;
this.eventNumber = eventNumber;
}
public void calibrate() {
final Timer calTimer = new Timer();
calData = new LinkedList();
acc.setdX(0);
acc.setdY(0);
acc.setdZ(0);
calTimer.scheduleAtFixedRate(
new TimerTask() {
public void run() {
addCalData(calData);
if (calData.size() > ITERATIONS) {
calTimer.cancel();
try {
calSensor(calData);
} catch (Exception ex) {
try {
throw ex;
} catch (Exception ex1) {
hRefresh.sendEmptyMessage(5);
}
}
hRefresh.sendEmptyMessage(eventNumber);
}
}
},
0,
UPDATE_INTERVAL);
}
private void addCalData(LinkedList cD) {
Point p = acc.getPoint();
cD.add(p);
acc.reset();
}
private void calSensor(LinkedList cD) throws Exception {
if (cD.size() < ITERATIONS-1) {
throw new Exception("not enough data to calibrate");
}
float x = 0;
float y = 0;
float z = 0;
// Don't use first measure
for (int i = 1; i < cD.size(); ++i) {
x += cD.get(i).getX();
y += cD.get(i).getY();
z += cD.get(i).getZ();
}
x = x / (cD.size() - 1);
y = y / (cD.size() - 1);
z = z / (cD.size() - 1);
acc.setdX(-x);
acc.setdY(-y);
acc.setdZ(-z);
}
}
maintenance class to keep data of one measure
public class Point {
private float x = 0;
private float y = 0;
private float z = 0;
private int cnt = 1;
public float getX() {
return x/(float)cnt;
}
public float getY() {
return y/(float)cnt;
}
public float getZ() {
return z/(float)cnt;
}
public Point(float x, float y, float z, int cnt) {
this.x = x;
this.y = y;
this.z = z;
this.cnt = cnt;
}
public float getForce(){
return getX()*getX()+getY()*getY()+getZ()*getZ();
}
}
And class to process data of measure
public class MeasurePoint {
private float x;
private float y;
private float z;
private float speedBefore;
private float speedAfter;
private float distance;
private float acceleration;
private long interval;
private Point averagePoint;
public MeasurePoint(float x, float y, float z, float speedBefore, long interval, Point averagePoint) {
this.x = x;
this.y = y;
this.z = z;
this.speedBefore = speedBefore;
this.interval = interval;
this.averagePoint = averagePoint;
speedAfter = 0;
calc();
}
private void calc(){
//Acceleration as projection of current vector on average
acceleration = this.x*averagePoint.getX() +
this.y*averagePoint.getY() +
this.z*averagePoint.getZ();
acceleration = acceleration / ((float)Math.sqrt(averagePoint.getForce()));
float t = ((float)interval / 1000f);
speedAfter = speedBefore + acceleration * t;
distance = speedBefore*t + acceleration*t*t/2;
}
public String getStoreString(){
String s = "write here whatever you want";
return s;
}
// add getters
}
This one - to store and save data array
public class MeasureData {
// points from accelerometr
private LinkedList accData;
private LinkedList data;
// timer interval of generating points
private long interval;
public MeasureData(long interval) {
this.interval = interval;
accData = new LinkedList ();
data = new LinkedList ();
}
public void addPoint(Point p){
accData.add(p);
}
public void process(){
for(int i = 0; i < accData.size(); ++i){
Point p = accData.get(i);
float speed = 0;
if(i > 0){
speed = data.get(i-1).getSpeedAfter();
}
data.add(new MeasurePoint(p.getX(), p.getY(), p.getZ(), speed, interval, getAveragePoint()));
}
}
public boolean saveExt(Context con, String fname) throws Throwable {
try {
File file = new File(con.getExternalFilesDir(null), fname);
FileOutputStream os = new FileOutputStream(file);
OutputStreamWriter out = new OutputStreamWriter(os);
for (int i = 0; i < data.size(); ++i) {
MeasurePoint m = data.get(i);
out.write(m.getStoreString());
}
out.close();
} catch (Throwable t) {
throw (t);
}
return true;
}
private Point getAveragePoint() {
float x = 0;
float y = 0;
float z = 0;
for(int i = 0; i < accData.size(); ++i){
Point p = accData.get(i);
x += p.getX();
y += p.getY();
z += p.getZ();
}
return new Point(x, y, z, 1);
}
public float getLastSpeed(){
return data.getLast().getSpeedAfter();
}
public float getLastSpeedKm(){
float ms = getLastSpeed();
return ms*3.6f;
}
}
And, finally, how to use all this in your activity(I cleaned it up a lot, sorry if it will not complie - fill free to write it in comments:
public class TestActivity extends Activity {
static final int TIMER_DONE = 2;
static final int START = 3;
static final int CAL_TIMER_DONE = 4;
static final int ERROR = 5;
private StartCatcher mStartListener;
private XYZAccelerometer xyzAcc;
private SensorManager mSensorManager;
private static final long UPDATE_INTERVAL = 500;
private static final long MEASURE_TIMES = 20;
private Timer timer;
private TextView tv;
private Button testBtn;
int counter;
private MeasureData mdXYZ;
/** handler for async events*/
Handler hRefresh = new Handler() {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case TIMER_DONE:
onMeasureDone();
String es1 = Float.toString(Math.round(mdXYZ.getLastSpeedKm()*100)/100f);
tv.append(" END SPEED " + es1 + " " + es2 + " \n");
enableButtons();
break;
case START:
tv.append(" START");
timer = new Timer();
timer.scheduleAtFixedRate(
new TimerTask() {
public void run() {
dumpSensor();
}
},
0,
UPDATE_INTERVAL);
break;
case ERROR:
Toast.makeText(getApplicationContext(), "ERROR", Toast.LENGTH_SHORT).show();
break;
}
}
};
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv = (TextView) findViewById(R.id.txt);
testBtn = (Button) findViewById(R.id.btn);
}
#Override
protected void onResume() {
super.onResume();
tv.append("\n ..");
mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
setAccelerometer();
setStartCatcher();
mSensorManager.registerListener(xyzAcc,
mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
SensorManager.SENSOR_DELAY_GAME);
}
#Override
protected void onPause() {
mSensorManager.unregisterListener(xyzAcc);
super.onPause();
}
public void onButtonTest(View v) {
disableButtons();
mdXYZ = new MeasureData(UPDATE_INTERVAL);
counter = 0;
tv.setText("");
tv.append("Calibrating");
Calibrator cal = new Calibrator(hRefresh, xyzAcc, START);
cal.calibrate();
}
void dumpSensor() {
++counter;
mdXYZ.addPoint(xyzAcc.getPoint());
hRefresh.sendEmptyMessage(TICK);
if (counter > MEASURE_TIMES) {
timer.cancel();
hRefresh.sendEmptyMessage(TIMER_DONE);
}
}
private void enableButtons() {
testBtn.setEnabled(true);
}
private void setAccelerometer() {
xyzAcc = new XYZAccelerometer();
mSensorManager.registerListener(xyzAcc,
mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
SensorManager.SENSOR_DELAY_UI);
}
private void disableButtons() {
testBtn.setEnabled(false);
}
private void onMeasureDone() {
try {
mdXYZ.process();
long now = System.currentTimeMillis();
mdXYZ.saveExt(this, Long.toString(now) + ".csv");
} catch (Throwable ex) {
Toast.makeText(this, ex.getMessage().toString(), Toast.LENGTH_SHORT);
}
}
}
<serviceLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<serviceButton
android:id="#+id/btn"
android:text="TEST"
android:layout_width="300px"
android:layout_height="200px"
android:onClick="onButtonTest" />
<serviceTextView
android:id = "#+id/txt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text=":"
/>
<service/LinearLayout>

Although at the developer.android.com site it is stated clearly that
you could use the linear accelerometer to see how fast your car is going"
But I did not find anything (in testing or in examples or code) that showed this is really true.
Now, unfortunately, I am convinced that it is not possible to calculate the speed of a car with the linear accelerometer.

Please see the below code to get the velocity using accelerometer
public class SensorTestActivity extends Activity implements SensorEventListener {
double calibration = Double.NaN;
private SensorManager sensorManager;
private boolean color = false;
private TextView view;
private long lastUpdate;
float appliedAcceleration = 0;
float currentAcceleration = 0;
float velocity = 0;
Date lastUpdatedate;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
view = findViewById(R.id.textView);
// view.setBackgroundColor(Color.GREEN);
lastUpdatedate = new Date(System.currentTimeMillis());
sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
lastUpdate = System.currentTimeMillis();
}
#Override
public void onSensorChanged(SensorEvent event) {
// if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
// getAccelerometer(event);
// }
double x = event.values[0];
double y = event.values[1];
double z = event.values[2];
double a = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2) + Math.pow(z, 2));
if (calibration == Double.NaN)
calibration = a;
else {
updateVelocity();
currentAcceleration = (float)a;
}
}
private void getAccelerometer(SensorEvent event) {
float[] values = event.values;
// Movement
float x = values[0];
float y = values[1];
float z = values[2];
float accelationSquareRoot = (x * x + y * y + z * z)
/ (SensorManager.GRAVITY_EARTH * SensorManager.GRAVITY_EARTH);
long actualTime = event.timestamp;
if (accelationSquareRoot >= 2) //
{
if (actualTime - lastUpdate < 200) {
return;
}
lastUpdate = actualTime;
// Toast.makeText(this, "Device was shuffed", Toast.LENGTH_SHORT)
// .show();
if (color) {
view.setBackgroundColor(Color.GREEN);
} else {
view.setBackgroundColor(Color.RED);
}
color = !color;
view.setText("SPEEDDDDD=== "+accelationSquareRoot);
// Log.i("SensorTestActivity","SPEEDDDDD=== "+accelationSquareRoot+" ");
}
}
private void updateVelocity() {
// Calculate how long this acceleration has been applied.
Date timeNow = new Date(System.currentTimeMillis());
long timeDelta = timeNow.getTime()-lastUpdatedate.getTime();
lastUpdatedate.setTime(timeNow.getTime());
// Calculate the change in velocity at the
// current acceleration since the last update.
float deltaVelocity = appliedAcceleration * (timeDelta/1000);
appliedAcceleration = currentAcceleration;
// Add the velocity change to the current velocity.
velocity += deltaVelocity;
final double mph = (Math.round(100*velocity / 1.6 * 3.6))/100;
Log.i("SensorTestActivity","SPEEDDDDD=== "+mph+" "+velocity);
}
#Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
#Override
protected void onResume() {
super.onResume();
// register this class as a listener for the orientation and
// accelerometer sensors
sensorManager.registerListener(this,
sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
SensorManager.SENSOR_DELAY_NORMAL);
}
#Override
protected void onPause() {
// unregister listener
super.onPause();
sensorManager.unregisterListener(this);
}
}

unable to make 2nd circle follow its own path

I am unable to create more circles which follows its own path with drawCircle .
I have used the code below which creates another circle but follows the path along the lines of 1st circle but not independent .How do I move both circles independent of each other?
I have added
c.drawCircle(ballX-100, ballY-100, 50, ballPaintyellow);
How do I make the above circle independent from the 1st circle?. I really appreciate any help.Thanks in Advance.
BouncingBallActivity.java
package com.stuffthathappens.games;
import static android.hardware.SensorManager.DATA_X;
import static android.hardware.SensorManager.DATA_Y;
import static android.hardware.SensorManager.SENSOR_ACCELEROMETER;
import static android.hardware.SensorManager.SENSOR_DELAY_GAME;
import java.util.concurrent.TimeUnit;
import android.app.Activity;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.hardware.SensorListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.os.Vibrator;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.SurfaceHolder.Callback;
/**
* This activity shows a ball that bounces around. The phone's
* accelerometer acts as gravity on the ball. When the ball hits
* the edge, it bounces back and triggers the phone vibrator.
*/
#SuppressWarnings("deprecation")
public class BouncingBallActivity extends Activity implements Callback, SensorListener {
private static final int BALL_RADIUS =20;
private SurfaceView surface;
private SurfaceHolder holder;
private final BouncingBallModel model = new BouncingBallModel(BALL_RADIUS);
private GameLoop gameLoop;
private Paint backgroundPaint;
private Paint ballPaint;
private SensorManager sensorMgr;
private long lastSensorUpdate = -1;
private Paint ballPaintyellow;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.bouncing_ball);
surface = (SurfaceView) findViewById(R.id.bouncing_ball_surface);
holder = surface.getHolder();
surface.getHolder().addCallback(this);
backgroundPaint = new Paint();
backgroundPaint.setColor(Color.WHITE);
ballPaint = new Paint();
ballPaint.setColor(Color.BLUE);
ballPaint.setAntiAlias(true);
ballPaintyellow = new Paint();
ballPaintyellow.setColor(Color.YELLOW);
ballPaintyellow.setAntiAlias(true);
}
#Override
protected void onPause() {
super.onPause();
model.setVibrator(null);
sensorMgr.unregisterListener(this, SENSOR_ACCELEROMETER);
sensorMgr = null;
model.setAccel(0, 0);
}
#Override
protected void onResume() {
super.onResume();
sensorMgr = (SensorManager) getSystemService(SENSOR_SERVICE);
boolean accelSupported = sensorMgr.registerListener(this,
SENSOR_ACCELEROMETER,
SENSOR_DELAY_GAME);
if (!accelSupported) {
// on accelerometer on this device
sensorMgr.unregisterListener(this, SENSOR_ACCELEROMETER);
// TODO show an error
}
// NOTE 1: you cannot get system services before onCreate()
// NOTE 2: AndroidManifest.xml must contain this line:
// <uses-permission android:name="android.permission.VIBRATE"/>
Vibrator vibrator = (Vibrator) getSystemService(Activity.VIBRATOR_SERVICE);
model.setVibrator(vibrator);
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
model.setSize(width, height);
}
public void surfaceCreated(SurfaceHolder holder) {
gameLoop = new GameLoop();
gameLoop.start();
}
private void draw() {
// thread safety - the SurfaceView could go away while we are drawing
Canvas c = null;
try {
// NOTE: in the LunarLander they don't have any synchronization here,
// so I guess this is OK. It will return null if the holder is not ready
c = holder.lockCanvas();
// this needs to synchronize on something
if (c != null) {
doDraw(c);
}
} finally {
if (c != null) {
holder.unlockCanvasAndPost(c);
}
}
}
private void doDraw(Canvas c) {
int width = c.getWidth();
int height = c.getHeight();
c.drawRect(0, 0, width, height, backgroundPaint);
float ballX, ballY;
synchronized (model.LOCK) {
ballX = model.ballPixelX;
ballY = model.ballPixelY;
}
c.drawCircle(ballX, ballY, BALL_RADIUS, ballPaint);
c.drawCircle(ballX-100, ballY-100, 50, ballPaintyellow);
}
public void surfaceDestroyed(SurfaceHolder holder) {
try {
model.setSize(0,0);
gameLoop.safeStop();
} finally {
gameLoop = null;
}
}
private class GameLoop extends Thread {
private volatile boolean running = true;
public void run() {
while (running) {
try {
// don't like this hardcoding
TimeUnit.MILLISECONDS.sleep(5);
draw();
model.updatePhysics();
} catch (InterruptedException ie) {
running = false;
}
}
}
public void safeStop() {
running = false;
interrupt();
}
}
public void onAccuracyChanged(int sensor, int accuracy) {
}
public void onSensorChanged(int sensor, float[] values) {
if (sensor == SENSOR_ACCELEROMETER) {
long curTime = System.currentTimeMillis();
// only allow one update every 50ms, otherwise updates
// come way too fast
if (lastSensorUpdate == -1 || (curTime - lastSensorUpdate) > 50) {
lastSensorUpdate = curTime;
model.setAccel(values[DATA_X], values[DATA_Y]);
}
}
}
}
Bouncingballmodel.java
package com.stuffthathappens.games;
import java.util.concurrent.atomic.AtomicReference;
import android.os.Vibrator;
/**
* This data model tracks the width and height of the playing field along
* with the current position of a ball.
*/
public class BouncingBallModel {
// the ball speed is meters / second. When we draw to the screen,
// 1 pixel represents 1 meter. That ends up too slow, so multiply
// by this number. Bigger numbers speeds things up.
private final float pixelsPerMeter = 10;
private final int ballRadius;
// these are public, so make sure you synchronize on LOCK
// when reading these. I made them public since you need to
// get both X and Y in pairs, and this is more efficient than
// getter methods. With two getters, you'd still need to
// synchronize.
public float ballPixelX, ballPixelY;
private int pixelWidth, pixelHeight;
// values are in meters/second
private float velocityX, velocityY;
// typical values range from -10...10, but could be higher or lower if
// the user moves the phone rapidly
private float accelX, accelY;
/**
* When the ball hits an edge, multiply the velocity by the rebound.
* A value of 1.0 means the ball bounces with 100% efficiency. Lower
* numbers simulate balls that don't bounce very much.
*/
private static final float rebound = 0.8f;
// if the ball bounces and the velocity is less than this constant,
// stop bouncing.
private static final float STOP_BOUNCING_VELOCITY = 2f;
private volatile long lastTimeMs = -1;
public final Object LOCK = new Object();
private AtomicReference<Vibrator> vibratorRef =
new AtomicReference<Vibrator>();
public BouncingBallModel(int ballRadius) {
this.ballRadius = ballRadius;
}
public void setAccel(float ax, float ay) {
synchronized (LOCK) {
this.accelX = ax;
this.accelY = ay;
}
}
public void setSize(int width, int height) {
synchronized (LOCK) {
this.pixelWidth = width;
this.pixelHeight = height;
}
}
public int getBallRadius() {
return ballRadius;
}
/**
* Call this to move the ball to a particular location on the screen. This
* resets the velocity to zero, but the acceleration doesn't change so
* the ball should start falling shortly.
*/
public void moveBall(int ballX, int ballY) {
synchronized (LOCK) {
this.ballPixelX = ballX;
this.ballPixelY = ballY;
velocityX = 0;
velocityY = 0;
}
}
public void updatePhysics() {
// copy everything to local vars (hence the 'l' prefix)
float lWidth, lHeight, lBallX, lBallY, lAx, lAy, lVx, lVy;
synchronized (LOCK) {
lWidth = pixelWidth;
lHeight = pixelHeight;
lBallX = ballPixelX;
lBallY = ballPixelY;
lVx = velocityX;
lVy = velocityY;
lAx = accelX;
lAy = -accelY;
}
if (lWidth <= 0 || lHeight <= 0) {
// invalid width and height, nothing to do until the GUI comes up
return;
}
long curTime = System.currentTimeMillis();
if (lastTimeMs < 0) {
lastTimeMs = curTime;
return;
}
long elapsedMs = curTime - lastTimeMs;
lastTimeMs = curTime;
// update the velocity
// (divide by 1000 to convert ms to seconds)
// end result is meters / second
lVx += ((elapsedMs * lAx) / 1000) * pixelsPerMeter;
lVy += ((elapsedMs * lAy) / 1000) * pixelsPerMeter;
// update the position
// (velocity is meters/sec, so divide by 1000 again)
lBallX += ((lVx * elapsedMs) / 1000) * pixelsPerMeter;
lBallY += ((lVy * elapsedMs) / 1000) * pixelsPerMeter;
boolean bouncedX = false;
boolean bouncedY = false;
if (lBallY - ballRadius < 0) {
lBallY = ballRadius;
lVy = -lVy * rebound;
bouncedY = true;
} else if (lBallY + ballRadius > lHeight) {
lBallY = lHeight - ballRadius;
lVy = -lVy * rebound;
bouncedY = true;
}
if (bouncedY && Math.abs(lVy) < STOP_BOUNCING_VELOCITY) {
lVy = 0;
bouncedY = false;
}
if (lBallX - ballRadius < 0) {
lBallX = ballRadius;
lVx = -lVx * rebound;
bouncedX = true;
} else if (lBallX + ballRadius > lWidth) {
lBallX = lWidth - ballRadius;
lVx = -lVx * rebound;
bouncedX = true;
}
if (bouncedX && Math.abs(lVx) < STOP_BOUNCING_VELOCITY) {
lVx = 0;
bouncedX = false;
}
// safely copy local vars back to object fields
synchronized (LOCK) {
ballPixelX = lBallX;
ballPixelY = lBallY;
velocityX = lVx;
velocityY = lVy;
}
if (bouncedX || bouncedY) {
Vibrator v = vibratorRef.get();
if (v != null) {
v.vibrate(20L);
}
}
}
public void setVibrator(Vibrator v) {
vibratorRef.set(v);
}
}

Which view you are using has nothing to do with it ....
At the moment you have only one BouncingBallModel
private final BouncingBallModel model = new BouncingBallModel(BALL_RADIUS);
This is the one you see when you draw something. Now if you want to draw multiple balls, you will need many BouncingBallModel. So either create a BouncingBallModel model2 or make it dynamic using an array.
Then iterate over the array and draw each ball.

Ontouch() isn't work with custom view?

I have a class it extends "View" and Implement "OnTouchListener" so it's will override ontouch method automatically but this method not work. I try to debug by put breakpoint in this method but it isn't called.
I try to this problem from another forums. they tell that onTouch() must return true; But it's not better.
my class problem :
public class Viewer extends View implements OnTouchListener{
/** Constant tile width. */
public static final int TILEW = 32;
/** Constant tile height. */
public static final int TILEH = 70;
/** Constant tile shift due to increased level. */
public static final int TILESKEW = 7;
/** Tile images. */
private Bitmap[][] tileImages;
/** Highlighted tile images. */
private Bitmap[][] tileImagesHL;
/** Board itself. */
private Board b;
private Tile[][][] tTile;
private float screenWidth = Defines.getScreenWidth();
private float screenHeight = Defines.getScreenHeight();
private float offsetImg = Defines.getOffsetImage();
private float reScalePosX = Defines.getReScalePosX();
private float reScalePosY = Defines.getReScalePosY();
private boolean firstIter;
/** Stores selected tiles */
private ArrayList<Tile> selectedTiles;// = new ArrayList<Tile>();
/** Stores highlighted tiles by Hint */
private ArrayList<Tile> highlightedTiles;// = new ArrayList<Tile>();
//////////////////////////////////////////////////
private static RectF screen;
private Images imgObj;
public Viewer(Context context) {
super(context);
// TODO Auto-generated constructor stub
imgObj = new Images(context);
b = new MainActivity().board;
Defines.setScreenRender(1280, 800);
makeTileImages(Board.MAXGROUPS);
}
#Override
protected void onDraw(Canvas canvas){
drawBackGround(imgObj.bg01, canvas);
try{
tTile = b.getContent();
if(tTile==null || tileImages==null){
return;
}
drawTile(tTile, canvas);
}catch (Exception e) {
// TODO: handle exception
}
}
#Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
Log.d("Mydebug", "YEHHHHHH");
Tile[][][] content = b.getContent();
for (int i = 0; i < content.length; i++) {
for (int y = 0; y < content[i].length; y++) {
for (int x = 0; x < content[i][y].length; x++) {
processMouseClick(content, i, y , x, event);
}
}
}
return true;
}
public void drawBackGround(Bitmap bitmapBG,Canvas canvas){
screen = new RectF(0.0f, 0.0f, Defines.getScreenWidth(),Defines.getScreenHeight());
canvas.drawBitmap(bitmapBG, null, screen, null);
}
private void makeTileImages(int groups){
tileImages = loadTileset(groups, "unlit_");
tileImagesHL = loadTileset(groups, "lit_");
}
private Bitmap[][] loadTileset(int groups,String prefix){
Bitmap[][] tr = new Bitmap[groups][Board.GROUPSIZE];
try{
InputStream is = this.getResources().getAssets().open("Tiles/tiles.set");
BufferedReader f = new BufferedReader(new InputStreamReader(is));
String s = f.readLine();
while (s!=null) {
if (!s.startsWith("#")) {
String[] tokens = s.split(" ");
try{
int groupNum =Integer.parseInt(tokens[0]);
for(int i =1; i<=(Board.GROUPSIZE);i++){
String pathPNG = "Tiles/"+prefix+tokens[i]+".png";
Bitmap img = imgObj.loadImage(pathPNG);
img = imgObj.resizeBitmap(img,Tile.tileHeight, Tile.tileWidth);
//Bitmap img = loadImage(pathPNG);
//Log.d("Mydebug", "PATH:"+pathPNG);
tr[groupNum][i-1] = img;
}
}catch (Exception e) {
// TODO: handle exception
Log.d("Mydebug", "File error TIles/tile.set");
}
}
s = f.readLine();
}
}catch (Exception e) {
// TODO: handle exception
}
return tr;
}
public void drawTile(Tile[][][] content,Canvas canvas){
for (int i = 0; i < content.length; i++) {
for (int y = 0; y < content[i].length; y++) {
for (int x = 0; x < content[i][y].length; x++) {
final Tile t = content[i][y][x];
if (t != null) {
if (y>0 && content[i][y-1][x]!=null && t.equals(content[i][y-1][x])) {
continue;
}
if (x>0 && content[i][y][x-1]!=null && t.equals(content[i][y][x-1])) {
continue;
}
Bitmap image = tileImages[t.getValue()][t.getSubindex()];
if (b.free(t)) {
image = tileImagesHL[t.getValue()][t.getSubindex()];
}
/* Draw tile images to panel */
//canvas.drawBitmap(image, x*TILEW+TILEW/2+i*TILESKEW, (y+1)*TILEH/2-i*TILESKEW, null);
canvas.drawBitmap(image, (x*TILEW+TILEW/2+i*TILESKEW)+200, ((y+1)*TILEH/2-i*TILESKEW)+100, null);
}
}
}
}
}
/** A helper function for the Viewer constructor which accompanies the mouseListener object on each tiles
* #param content The current board's 3D array of positions
* #param i The current tile's x position
* #param y The current tile's y position
* #param x The current tile's z position
* #param me The mouseEvent for each tile
*/
private void processMouseClick(Tile[][][] content, int i, int y, int x, MotionEvent touchPos){
final Tile t = content[i][y][x];
if (t != null) {
if (y>0 && content[i][y-1][x]!=null && t.equals(content[i][y-1][x])) {
return;
}
if (x>0 && content[i][y][x-1]!=null && t.equals(content[i][y][x-1])) {
return;
}
Bitmap image = tileImages[t.getValue()][t.getSubindex()];
if (b.free(t)) {
image = tileImagesHL[t.getValue()][t.getSubindex()];
}
// Rectangle representing space of tile
final Rect rect = new Rect(x*TILEW+TILEW/2+i*TILESKEW, (y+1)*TILEH/2-i*TILESKEW, image.getWidth(), image.getHeight());
//if ((rect.contains(me.getPoint())) && b.free(t) && t.isVisible()) {
if ((rect.contains((int)touchPos.getX(), (int)touchPos.getY()) && b.free(t))){
t.wasClicked = true;
firstIter = false;
Log.d("MyDebug", "Clicked ME");
//if (content[i][y][x].isVisible()){
//Add corresponding JLabel to panel
// t.tLabel.setBounds(x*TILEW+TILEW/2+i*TILESKEW, (y+1)*TILEH/2-i*TILESKEW, image.getWidth(null), image.getHeight(null));
// t.tLabel.setVisible(false);
// t.tLabel.setBorder(BorderFactory.createLineBorder(Color.blue, 2));
//}
//validClick(t);
}
}
}
}

remove implements OnTouchListener and override the method:
public boolean onTouch(MotionEvent event)
update
of course it's onTouchEvent, not onTouch

How to make sprites in Android

I'm developing a game which includes sprites.
currently I'm loading a bitmap and using Rectangle to get the right frame from the bitmap.
the problem is loading bitmaps takes too much memory and I wont be able to load several sprites at the same time.
what are my alternatives for doing sprite in Android?

Try this one:
import org.cocos2d.layers.CCLayer;
public class GameLayer extends CCLayer{
CCSprite mSprite;
protected GameLayer() {
super();
CGSize winSize = CCDirector.sharedDirector().winSize();
mSprite = new CCSprite("image.png");
mSprite.setPosition(CGPoint.ccp(mSprite.getContentSize().width/2.0f, mSprite.getContentSize().height/2.0f));
addChild(mSprite);
}

/* It is Sprite class */
import android.graphics.*;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
public class Sprite {
int x;
private int y;
private boolean visibility = true;
private Bitmap sprite;
private int verticalFrame,horizontalFrame;
private int frameWidth,frameHeight;
private int sequence[] = new int[1];
private int maxFrame = 0;
private int currentFrame;
private int color;
private Rect src;
private Rect dest;
private int frameCount;
private Paint p = new Paint();
private int spInitX,spInitY;
private int rotate = 0;
private float currentRotateAngle = 0;
//private Graphics g;
public float velocityY;
public float velocityX;
public int height;
public Sprite(Bitmap sprite){
this.sprite = sprite;
this.frameWidth = sprite.getWidth();
this.frameHeight = sprite.getHeight();
setFrameCount();
}
public Sprite(Bitmap sprite,int frameWidth,int frameHeight){
this.sprite = sprite;
this.frameWidth = frameWidth;
this.frameHeight = frameHeight;
setFrameCount();
}
public void rotate(float angle){
currentRotateAngle = angle;
}
public void setImage(Bitmap bm,int frameWidth,int frameHeight){
this.sprite = bm;
this.frameWidth = frameWidth;
this.frameHeight = frameHeight;
}
public Bitmap getBitmap(){
return sprite;
}
public void paint(Canvas canvas){
dest.offsetTo(getX(), getY());
// g.drawImage(sprite, x, y,src.left,src.top,frameWidth,frameHeight);
canvas.drawBitmap(sprite, src, dest, null);
}
public int getMaxFrame(){
return maxFrame;
}
public int getFrameSequenceLength(){
return sequence.length;
}
public void setFrameSequence(int seq[]){
sequence = seq;
}
public void previousFrame(){
if(sequence.length > 1){
if(frameCount > 0){
setFrame(sequence[frameCount]);
frameCount--;
}else{
frameCount = sequence.length - 1;
setFrame(sequence[frameCount]);
}
}else{
setFrame(frameCount);
if(frameCount > 0){
frameCount++;
}else{
frameCount = maxFrame - 1;
}
}
}
public void setPixel(int x,int y){
spInitX = x;
spInitY = y;
}
public void nextFrame(){
if(sequence.length > 1){
if(frameCount < sequence.length){
setFrame(sequence[frameCount]);
frameCount++;
}else{
frameCount = 0;
setFrame(sequence[frameCount]);
}
}else{
setFrame(frameCount);
if(frameCount < maxFrame){
frameCount++;
}else{
frameCount = 0;
}
}
}
public int getFrame(){
return currentFrame;
}
public void setPosition(int x,int y){
this.x = x;
this.y = y;
}
public void setFrameCount(){
verticalFrame = sprite.getHeight() / frameHeight;
horizontalFrame = sprite.getWidth() / frameWidth;
src = new Rect(0,0,frameWidth,frameHeight);
dest = new Rect(0,0,frameWidth,frameHeight);
maxFrame = verticalFrame * horizontalFrame;
}
public void setFrame(int frame){
if(frame < maxFrame){
currentFrame = frame;
}
int hf = currentFrame % horizontalFrame;
int vf = currentFrame / horizontalFrame;
src.left = hf * frameWidth;
src.right = src.left + frameWidth;
src.top = vf * frameHeight;
src.bottom = src.top + frameHeight;
}
public boolean collidesWith(Sprite sp,boolean cl){
int maxHGap = (getWidth() + sp.getWidth())/2;
int maxVGap = (getHeight() + sp.getHeight())/2;
int x = getX() + getWidth()/2;
int y = getY() + getHeight()/2;
int x1 = sp.getX() + sp.getWidth()/2;
int y1 = sp.getY() + sp.getHeight()/2;
if(Math.abs(x - x1) < maxHGap && Math.abs(y - y1) < maxVGap){
return true;
}
return false;
}
public void setVisible(boolean v){
visibility = v;
}
public final boolean isVisible(){
return visibility;
}
public int getX(){
return x;
}
public int getY(){
return y;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
public void move(int moveX,int moveY){
setX(getX()+moveX);
setY(getY()+moveY);
//this.y+=y;
//this.x+=x;
}
public final int getWidth(){
return frameWidth;
}
public final int getHeight(){
return frameHeight;
}
public void setEventY(int i) {
// TODO Auto-generated method stub
}
public int getEventY() {
// TODO Auto-generated method stub
return 0;
}
}
/*Create Main Thread Class Also */
import java.text.DecimalFormat;
import android.graphics.Canvas;
import android.util.Log;
import android.view.SurfaceHolder;
public class MainThread extends Thread {
boolean isPaused;
private static final String TAG = MainThread.class.getSimpleName();
// desired fps
private final static int MAX_FPS = 50;
// maximum number of frames to be skipped
private final static int MAX_FRAME_SKIPS = 5;
// the frame period
private final static int FRAME_PERIOD = 1000 / MAX_FPS;
/* Stuff for stats */
private DecimalFormat df = new DecimalFormat("0.##"); // 2 dp
// we'll be reading the stats every second
private final static int STAT_INTERVAL = 1000; // ms
// the average will be calculated by storing
// the last n FPSs
private final static int FPS_HISTORY_NR = 10;
// last time the status was stored
private long lastStatusStore = 0;
// the status time counter
private long statusIntervalTimer = 0l;
// number of frames skipped since the game started
private long totalFramesSkipped = 0l;
// number of frames skipped in a store cycle (1 sec)
private long framesSkippedPerStatCycle = 0l;
// number of rendered frames in an interval
private int frameCountPerStatCycle = 0;
private long totalFrameCount = 0l;
// the last FPS values
private double fpsStore[];
// the number of times the stat has been read
private long statsCount = 0;
// the average FPS since the game started
private double averageFps = 0.0;
// Surface holder that can access the physical surface
private SurfaceHolder surfaceHolder;
// The actual view that handles inputs
// and draws to the surface
private GameView gv;
// flag to hold game state
private boolean running;
public void setRunning(boolean running) {
this.running = running;
}
public MainThread(SurfaceHolder surfaceHolder, GameView gv) {
super();
this.surfaceHolder = surfaceHolder;
this.gv = gv;
}
public MainThread(Setting setting) {
// TODO Auto-generated constructor stub
}
public void setPause(int i) {
synchronized (gv.getHolder()) {
if (i == 0) {
isPaused = false;
}
if (i == 1) {
isPaused = true;
}
}
}
#Override
public void run() {
Canvas canvas;
Log.d(TAG, "Starting game loop");
initTimingElements();
long beginTime; // the time when the cycle begun
long timeDiff; // the time it took for the cycle to execute
int sleepTime; // ms to sleep (<0 if we're behind)
int framesSkipped; // number of frames being skipped
sleepTime = 0;
while (running) {
canvas = null;
// try locking the canvas for exclusive pixel editing
// in the surface
try {
canvas = this.surfaceHolder.lockCanvas();
synchronized (surfaceHolder) {
beginTime = System.currentTimeMillis();
framesSkipped = 0; // resetting the frames skipped
// update game state
this.gv.update();
// render state to the screen
// draws the canvas on the panel
this.gv.render(canvas);
// calculate how long did the cycle take
timeDiff = System.currentTimeMillis() - beginTime;
// calculate sleep time
sleepTime = (int) (FRAME_PERIOD - timeDiff);
if (sleepTime > 0) {
// if sleepTime > 0 we're OK
try {
// send the thread to sleep for a short period
// very useful for battery saving
Thread.sleep(sleepTime);
} catch (InterruptedException e) {
}
}
while (sleepTime < 0 && framesSkipped < MAX_FRAME_SKIPS) {
// we need to catch up
this.gv.update(); // update without rendering
sleepTime += FRAME_PERIOD; // add frame period to check
// if in next frame
framesSkipped++;
}
if (framesSkipped > 0) {
Log.d(TAG, "Skipped:" + framesSkipped);
}
// for statistics
framesSkippedPerStatCycle += framesSkipped;
// calling the routine to store the gathered statistics
storeStats();
}
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} finally {
// in case of an exception the surface is not left in
// an inconsistent state
if (canvas != null) {
surfaceHolder.unlockCanvasAndPost(canvas);
}
} // end finally
}
}
private void storeStats() {
frameCountPerStatCycle++;
totalFrameCount++;
// assuming that the sleep works each call to storeStats
// happens at 1000/FPS so we just add it up
// statusIntervalTimer += FRAME_PERIOD;
// check the actual time
statusIntervalTimer += (System.currentTimeMillis() - statusIntervalTimer);
if (statusIntervalTimer >= lastStatusStore + STAT_INTERVAL) {
// calculate the actual frames pers status check interval
double actualFps = (double) (frameCountPerStatCycle / (STAT_INTERVAL / 1000));
// stores the latest fps in the array
fpsStore[(int) statsCount % FPS_HISTORY_NR] = actualFps;
// increase the number of times statistics was calculated
statsCount++;
double totalFps = 0.0;
// sum up the stored fps values
for (int i = 0; i < FPS_HISTORY_NR; i++) {
totalFps += fpsStore[i];
}
// obtain the average
if (statsCount < FPS_HISTORY_NR) {
// in case of the first 10 triggers
averageFps = totalFps / statsCount;
} else {
averageFps = totalFps / FPS_HISTORY_NR;
}
// saving the number of total frames skipped
totalFramesSkipped += framesSkippedPerStatCycle;
// resetting the counters after a status record (1 sec)
framesSkippedPerStatCycle = 0;
statusIntervalTimer = 0;
frameCountPerStatCycle = 0;
statusIntervalTimer = System.currentTimeMillis();
lastStatusStore = statusIntervalTimer;
// Log.d(TAG, "Average FPS:" + df.format(averageFps));
gv.setAvgFps("FPS: " + df.format(averageFps));
}
}
private void initTimingElements() {
// initialise timing elements
fpsStore = new double[FPS_HISTORY_NR];
for (int i = 0; i < FPS_HISTORY_NR; i++) {
fpsStore[i] = 0.0;
}
Log.d(TAG + ".initTimingElements()",
"Timing elements for stats initialised");
}
}