Buoyant Force simulation - android

I am trying to simulate a buoyant force behavior on a 2D object of an Android application, there is no friction involved. Something is not working correctly: the height of the "bounce" changes in an irregular manner, I think the error should be in the update of the speed but I'm not sure.
Can anyone see the error in my code?
public class MainActivity extends Activity {
Semaphore moveSemaphore = new Semaphore(1);
static WindowManager.LayoutParams params;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
params = new WindowManager.LayoutParams( 80, 80,
WindowManager.LayoutParams.TYPE_APPLICATION,
WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
PixelFormat.TRANSPARENT);
final BallView ball = new BallView(this);
addContentView(ball, params);
ball.setX(100);
ball.setY(50);
final Thread move = new Thread(new Runnable(){
double speed = 0;
double G = 9;
double fullBuoyancy = -G * 10;
double prevtime = System.currentTimeMillis();
double elapsed;
double fluidstart = 300;
double objectHeight = 100;
double currPosy = 50;
double p;
#Override
public void run() {
while(true){
try {
moveSemaphore.acquire();
} catch (InterruptedException e) {
e.printStackTrace();
}
runOnUiThread(new Runnable() {
#Override
public void run() {
double currDepth = 0;
long currtime = System.currentTimeMillis();
elapsed = (currtime - prevtime) * 0.01;
prevtime = currtime;
currPosy = ball.getY();
// COMPUTE HOW MUCH OF THE BALL IS INSIDE OF THE FLUID
if (currPosy > (fluidstart + objectHeight/2)){
currDepth = objectHeight;
} else if (currPosy > (fluidstart - objectHeight/2)) {
currDepth = currPosy - fluidstart;
}
p = currDepth / objectHeight; // PERCENTAGE OF THE FULL BUOYANT FORCE TO BE APPLIED
speed = speed + (G + fullBuoyancy * p) * elapsed;
currPosy += speed * elapsed;
ball.setY((float)currPosy);
moveSemaphore.release();
}
});
}
}
});
move.start();
}
}

The problem was in the if-statement, this is the correct solution:
if (currPosy > (fluidstart + objectHeight/2)){//complete submersion
currDepth = objectHeight;
} else if (currPosy > (fluidstart - objectHeight/2)) {//partial submersion
currDepth = (currPosy + objectHeight/2) - fluidstart;
}

The if-statement logic is incorrect.
double emerge = fluidstart - (currPosy - (objectHeight / 2));
if (emerge <= 0) { // complete submersion
currDepth = objectHeight;
} else {
currDepth = objectHeight - emerge;
}

Related

Text filling up from left to right

How can I get started filling up text similar to this screen? Should I use a Handler and delay every character?
The background is that I am coding a mini game for Android similar to the classic Moon Patrol and now I want to create bonus for completing a checkpoint.
You can find my beta in the appstore https://play.google.com/store/apps/details?id=dev.android.buggy It is currently named "Moon Buggy". The code is available on request, right now the repo is closed source.
I put a test checkpoint at checkpoint "C" to show what I try:
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Handler;
import android.support.v4.view.MotionEventCompat;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
public class ParallaxView extends SurfaceView implements Runnable, SurfaceHolder.Callback {
int bombed = 5;
boolean waitForTimer = false;
boolean waitForTimer2 = false;
boolean recent = true;
char checkpoint;
boolean checkp = true;
Rect fromRect1;
Rect toRect1;
Rect fromRect2;
Rect toRect2;
boolean incCheck = true;
boolean increment = false;
int numberOfshots = 1;
int[] missiles = new int[200];
int alienBombYDelta = 0;
int alienBombXDelta = 20;
int p = 7;
boolean started = false;
final int buggyXDisplacement = 50;
boolean buggyDown = false;
int jumpHeight = 0;
int xbuggy2 = 0;
boolean down2 = true;
long lastTurn2 = System.currentTimeMillis();
long lastTurn3 = System.currentTimeMillis();
boolean jump = false;
boolean shoot = false;
int index = 0;
int missileOffSetY = 0;
boolean alienReset = false;
int score = 0;
double buggyXDistance = 0;
double distanceDelta = 1.15;
double retardation = 0.5;
boolean alienFire = false;
List<Background> backgrounds;
int spacerocki, resID, explodeID, explodeID2, alienResID2;
private volatile boolean running;
private Thread gameThread = null;
Bitmap explode, buggy, alien, explode2, spacerock;
boolean alienexplode = false;
TextView tvId;
//Activity a;
// For drawing
private Paint paint;
private Canvas canvas;
private SurfaceHolder ourHolder;
// Holds a reference to the Activity
Context context;
// Control the fps
long fps = 60;
// Screen resolution
int screenWidth;
int screenHeight;
boolean bexplode = false;
boolean brake = false;
boolean scoring = false;
class BuggyExploded extends TimerTask {
public void run() {
//Log.d("## BuggyExploded", "## BuggyExploded timer task running after 2 seconds" + buggyXDistance);
//buggy = BitmapFactory.decodeResource(context.getResources(), context.getResources().getIdentifier("vehicle",
// "drawable", context.getPackageName()));
canvas.drawBitmap(explode, (float) (buggyXDisplacement + buggyXDistance), (float) (screenHeight * 0.5) - jumpHeight, paint);
buggyXDistance = 0;
distanceDelta = 1.15;
retardation = 0.5;
jumpHeight = 0;
waitForTimer = false;
//canvas.drawBitmap(buggy, (float) (buggyXDisplacement + buggyXDistance), (float) (screenHeight * 0.5) - jumpHeight, paint);
}
}
class SetRecent extends TimerTask {
public void run() {
recent = false;
}
}
class ResetCheckpoint extends TimerTask {
public void run() {
Background.checkpoint = 'A';
}
}
class SetAlienBombs extends TimerTask {
public void run() {
missileOffSetY = 0;
}
}
class AlienBombed extends TimerTask {
public void run() {
alienBombXDelta = 20;
alienBombYDelta = 0;
alienReset = false;
alienexplode = false;
waitForTimer2 = false;
}
}
public void surfaceCreated(SurfaceHolder holder) {
//Canvas c = getHolder().lockCanvas();
//draw();
//getHolder().unlockCanvasAndPost(c);
}
public void surfaceDestroyed(SurfaceHolder holder3) {
//Canvas c = getHolder().lockCanvas();
//draw();
//getHolder().unlockCanvasAndPost(c);
}
public void surfaceChanged(SurfaceHolder holder, int i1, int i2, int i3) {
//Canvas c = getHolder().lockCanvas();
//draw();
//getHolder().unlockCanvasAndPost(c);
}
private void update() {
// Update all the background positions
for (Background bg : backgrounds) {
bg.update(fps);
}
}
public ParallaxView(Context c, AttributeSet a) {
super(c, a);
this.context = c;
Background.checkpoint--;
this.screenWidth = getContext().getResources().getDisplayMetrics().widthPixels;
this.screenHeight = getContext().getResources().getDisplayMetrics().heightPixels;
// Initialize our drawing objects
ourHolder = getHolder();
paint = new Paint();
// Initialize our array list
backgrounds = new ArrayList<>();
//load the background data into the Background objects and
// place them in our GameObject arraylist
backgrounds.add(new Background(
this.context,
screenWidth,
screenHeight,
"bg", 0, 120, 50));
backgrounds.add(new Background(
this.context,
screenWidth,
screenHeight,
"grass", 70, 110, 200));
//To execute the task every second after 3 s.
//Log.d("Timer", "Timer ");
resID = context.getResources().getIdentifier("vehicle",
"drawable", context.getPackageName());
explodeID = context.getResources().getIdentifier("explode",
"drawable", context.getPackageName());
explodeID2 = context.getResources().getIdentifier("explode2",
"drawable", context.getPackageName());
spacerocki = context.getResources().getIdentifier("spacerock",
"drawable", context.getPackageName());
buggy = BitmapFactory.decodeResource(context.getResources(), resID);
explode = BitmapFactory.decodeResource(context.getResources(), explodeID);
explode2 = BitmapFactory.decodeResource(context.getResources(), explodeID2);
spacerock = BitmapFactory.decodeResource(context.getResources(), spacerocki);
alienResID2 = context.getResources().getIdentifier("right_side_hdpi",
"drawable", context.getPackageName());
alien = BitmapFactory.decodeResource(context.getResources(), alienResID2);
//resume();
//pause();
//resume();
}
#Override
public void run() {
while (running) {
long startFrameTime = System.currentTimeMillis();
update();
if (alienBombXDelta > screenWidth - 250 || alienBombXDelta < 10) { // alien ship change direction
p = -p;
}
draw();
// Calculate the fps this frame
long timeThisFrame = System.currentTimeMillis() - startFrameTime;
if (timeThisFrame >= 1) {
fps = 1000 / timeThisFrame;
}
}
}
private void checkJump() {
if (System.currentTimeMillis() - lastTurn3 >= 650) { // 650 means how long the vehicle is in the air at a jump
// Change direction here
jump = false;
lastTurn3 = System.currentTimeMillis();
}
}
private void checkBuggyBombed(Bitmap b1, Bitmap b2, Bitmap explode) {
if (!recent && java.lang.Math.abs(((buggyXDisplacement + buggyXDistance) + b1.getWidth() / 2) - (alienBombXDelta + 10 + b2.getWidth() / 2)) < b1.getWidth() / 2 && java.lang.Math.abs((alienBombYDelta + screenHeight / 100 * 25 + 75 + missileOffSetY) - ((screenHeight * 0.3) - jumpHeight + b1.getHeight())) < 65) {
bombed--;
missileOffSetY = 0;
checkpoint = 'A';
canvas.drawBitmap(explode, (float) (buggyXDisplacement + buggyXDistance), (float) (screenHeight * 0.5) - jumpHeight, paint);
recent = true;
waitForTimer = true;
new Timer().schedule(new BuggyExploded(), 2000);
new Timer().schedule(new SetRecent(), 10000);
new Timer().schedule(new ResetCheckpoint(), 1000);
} else {
canvas.drawText("●", alienBombXDelta + 10 + b2.getWidth() / 2, alienBombYDelta + screenHeight / 100 * 25 + 75 + missileOffSetY, paint);
missileOffSetY = missileOffSetY + 10;
}
}
private void makeShots(Bitmap b) {
for (int i1 = 0; i1 < numberOfshots; i1++) {
// if vertical missile hits alien
if (java.lang.Math.abs(alienBombXDelta + 10 - 185 - buggyXDistance) * 2 < (b.getWidth() + 60) && java.lang.Math.abs(alienBombYDelta + screenHeight / 100 * 25 - (screenHeight / 100 * 95 - missiles[i1] - xbuggy2)) * 2 < (b.getHeight() + 60)) {
missileOffSetY = 9999;
canvas.drawBitmap(explode2, alienBombXDelta + 10, alienBombYDelta + screenHeight / 100 * 25, paint);
new Timer().schedule(new AlienBombed(), 2000);
waitForTimer2 = true;
if (!alienexplode) {
changeText();
}
alienexplode = true;
}
if (shoot) {
canvas.drawText("o", (float) (missiles[i1] + buggyXDistance), (float) (screenHeight * 0.7) - jumpHeight, paint); // add to y the jump height
canvas.drawText("o", (float) (buggyXDistance + 185), screenHeight / 110 * 95 - missiles[i1] - xbuggy2, paint);
}
if (i1 == numberOfshots - 1 && missiles[i1] > screenWidth) {
if (numberOfshots > 0) numberOfshots--;
if (index > 0) index--;
}
}
}
private void updateDeltas() {
alienBombXDelta = alienBombXDelta + p;
if (!down2)
alienBombYDelta++;
else
alienBombYDelta--;
}
private void changeDirections() {
if (System.currentTimeMillis() - lastTurn2 >= 7000) {
// Change direction here
down2 = !down2;
lastTurn2 = System.currentTimeMillis();
}
}
private void controlVelocity() {
if (!brake && buggyXDistance > 0) buggyXDistance = buggyXDistance + distanceDelta;
else if (brake && buggyXDistance > 0) buggyXDistance = buggyXDistance - retardation;
}
TextView tvId1;
private void drawDetails() {
//draw a background color
}
private void makeShots() {
for (int n = 0; n < numberOfshots; n++)
missiles[n] = missiles[n] + 20;
}
public void changeText() {
if (scoring) {
((Activity) this.getContext()).runOnUiThread(new Runnable() {
#Override
public void run() {
score++;
String str = "Player 1 " + String.format("%06d", score);
// Stuff that updates the UI
tvId.setText(str);
scoring = false;
}
});
}
}
double lastTurn4 = System.currentTimeMillis();
private void checkFire() {
if (System.currentTimeMillis() - lastTurn4 >= 18500) { // 18500 means how often the alien fires
lastTurn4 = System.currentTimeMillis();
missileOffSetY = 0;
}
}
boolean checkpointComplete = false;
private void draw() {
if (ourHolder.getSurface().isValid()) {
//First we lock the area of memory we will be drawing to
canvas = ourHolder.lockCanvas();
if (checkpointComplete) {
canvas.drawColor(Color.BLACK);
paint.setTextSize(60);
paint.setColor(Color.argb(255, 255, 255, 255));
paint.setTextSize(60);
canvas.drawText("CHECKPOINT COMPLETE", (float) (screenWidth * 0.5), (float) (screenHeight * 0.45), paint);
((Activity) this.getContext()).runOnUiThread(new Runnable() {
#Override
public void run() {
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
checkpointComplete = false;
}
}, 3000);
}
});
} else {
if (bombed == 0) //GAME OVER
{
final int duration = Toast.LENGTH_SHORT;
((Activity) this.getContext()).runOnUiThread(new Runnable() {
#Override
public void run() {
final Toast toast = Toast.makeText(context, "GAME OVER!\nScore: " + score, duration);
toast.show();
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
toast.cancel();
bombed = 5;
score = 0;
}
}, 3000);
}
});
}
if (jump && jumpHeight < 250) {
jumpHeight = jumpHeight + 7;
} else if (jumpHeight > 0) {
jumpHeight = jumpHeight - 4;
}
if (shoot) {
xbuggy2 = xbuggy2 + 4;
}
checkFire();
checkJump();
// drawDetails();
if (canvas != null) canvas.drawColor(Color.argb(255, 0, 0, 0));
// Draw the background parallax
drawBackground(0);
// Draw the rest of the game
paint.setTextSize(60);
paint.setColor(Color.argb(255, 255, 255, 255));
checkBuggyBombed(buggy, alien, explode);
makeShots(alien);
changeDirections();
if (!waitForTimer2)
canvas.drawBitmap(alien, alienBombXDelta + 10, alienBombYDelta + screenHeight / 100 * 25, paint);
drawBackground(1);
// canvas.drawText("X", (float) (50 + buggyXDistance)+buggy.getWidth()/2, (float) (screenHeight * 0.3) - jumpHeight+buggy.getHeight(), paint);
paint.setTextSize(60);
canvas.drawText("A E J O T Z", (float) (screenWidth * 0.7), (float) (screenHeight * 0.15), paint);
// Prevent buggy from moving outside horizontal screen
if (!brake && buggyXDisplacement + buggyXDistance > screenWidth - buggy.getWidth() - 200)
buggyXDistance = screenWidth - buggy.getWidth() - 200;
//Log.d("buggyXDistance", "buggyXDistance " + buggyXDistance);
if (!waitForTimer)
canvas.drawBitmap(buggy, (float) (buggyXDisplacement + buggyXDistance), (float) (screenHeight * 0.5) - jumpHeight, paint);
else if (bexplode)
canvas.drawBitmap(explode, (float) (buggyXDisplacement + buggyXDistance), (float) (screenHeight * 0.5) - jumpHeight, paint);
int inc = 0;
for (int i = 0; i < bombed; i++) {
canvas.drawBitmap(Bitmap.createScaledBitmap(buggy, (int) (0.75 * (buggy.getWidth() / 3)), buggy.getHeight() / 3, false), inc, 100, paint);
inc = inc + buggy.getWidth() / 3;
}
makeShots();
updateDeltas();
controlVelocity();
}
ourHolder.unlockCanvasAndPost(canvas);
}
}
// Clean up our thread if the game is stopped
public void pause() {
running = false;
try {
gameThread.join();
} catch (InterruptedException e) {
// Error
//e.printStackTrace();
}
}
// Make a new thread and start it
// Execution moves to our run method
public void resume() {
running = true;
gameThread = new Thread(this);
gameThread.start();
}
private void drawBackground(int position) {
// Make a copy of the relevant background
Background bg = backgrounds.get(position);
// define what portion of images to capture and
// what coordinates of screen to draw them at
// For the regular bitmap
fromRect1 = new Rect(0, 0, bg.width - bg.xClip, bg.height);
toRect1 = new Rect(bg.xClip, bg.startY, bg.width, bg.endY);
// For the reversed background
fromRect2 = new Rect(bg.width - bg.xClip, 0, bg.width, bg.height);
toRect2 = new Rect(0, bg.startY, bg.xClip, bg.endY);
// Log.d("### bg.xClip", "bg.xClip " + bg.xClip);
//draw the two background bitmaps
if (!bg.reversedFirst) {
if (canvas != null) canvas.drawBitmap(bg.bitmap, fromRect1, toRect1, paint);
if (canvas != null) canvas.drawBitmap(bg.bitmapReversed, fromRect2, toRect2, paint);
if (position == 1) { // && Background.count % 2 == 0) {
if (increment) Background.checkpoint++;
if (Background.checkpoint == 'C' && (buggyXDisplacement + buggyXDistance) < (bg.xClip) && java.lang.Math.abs((buggyXDisplacement + buggyXDistance) - (bg.xClip)) < buggy.getWidth()) { // && java.lang.Math.abs((alienBombYDelta + screenHeight / 100 * 25 + 75 + missileOffSetY) - ((screenHeight * 0.3) - jumpHeight )) < 65) {) checkpointComplete = true;
checkpointComplete=true;
}
increment = false;
if (bg.xClip == bg.width) increment = true;
if (canvas != null) canvas.drawBitmap(spacerock, fromRect1, toRect1, paint);
paint.setTextSize(160);
if (canvas != null)
canvas.drawText(Character.toString(Background.checkpoint), bg.xClip, (float) (bg.startY * 1.4), paint);
//increment checkpoint once per what? "Background.checkpoint++;"
((Activity) this.getContext()).runOnUiThread(new Runnable() {
#Override
public void run() {
tvId1.setText(Character.toString(Background.checkpoint));
}
});
if (!recent && (buggyXDisplacement + buggyXDistance) < (bg.xClip) && java.lang.Math.abs((screenHeight * 0.5) - jumpHeight - bg.startY) < 180 && java.lang.Math.abs((buggyXDisplacement + buggyXDistance) - (bg.xClip)) < buggy.getWidth()) { // && java.lang.Math.abs((alienBombYDelta + screenHeight / 100 * 25 + 75 + missileOffSetY) - ((screenHeight * 0.3) - jumpHeight )) < 65) {
canvas.drawBitmap(explode, (float) (buggyXDisplacement + buggyXDistance), (float) (screenHeight * 0.5) - jumpHeight, paint);
// Background.checkpoint = 'A';
bombed--;
recent = true;
waitForTimer = true;
bexplode = true;
canvas.drawBitmap(explode, (float) (buggyXDisplacement + buggyXDistance), (float) (screenHeight * 0.5) - jumpHeight, paint);
distanceDelta = 1.15;
retardation = 0.5;
jumpHeight = 0;
((Activity) this.getContext()).runOnUiThread(new Runnable() {
#Override
public void run() {
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
waitForTimer = false;
buggyXDistance = 0;
}
}, 2000);
}
});
// new Timer().schedule(new BuggyExploded(), 2000);
new Timer().schedule(new SetRecent(), 10000);
new Timer().schedule(new ResetCheckpoint(), 1000);
}
}
} else {
canvas.drawBitmap(bg.bitmap, fromRect2, toRect2, paint);
canvas.drawBitmap(bg.bitmapReversed, fromRect1, toRect1, paint);
}
}
// Because we call this from onTouchEvent, this code will be executed for both
// normal touch events and for when the system calls this using Accessibility
#Override
public boolean performClick() {
super.performClick();
launchMissile();
return true;
}
protected void launchMissile() {
missiles[index] = 350; // what does it do?
index++;
xbuggy2 = 0;
shoot = true;
}
// event listener for when the user touches the screen
#Override
public boolean onTouchEvent(MotionEvent event) {
boolean gameOver = false;
//if (paused) {
// paused = false;
//}
int action = MotionEventCompat.getActionMasked(event);
int coordX = (int) event.getX();
int coordY = (int) event.getY();
//Log.d("coordY", "coordY " + coordY);
if (coordX < 220 && jumpHeight == 0 && action == MotionEvent.ACTION_MOVE) {
jump = true;
shoot = false;
lastTurn3 = System.currentTimeMillis();
return true; // do nothing
}
if (coordX > 219 && action == MotionEvent.ACTION_DOWN) {
numberOfshots++;
performClick();
return true;
}
return true;
}
}
[
2]: https://i.stack.imgur.com/3NAmp.gif
You can follow the below code
public void setText(final String s)
{
TextView tv= (TextView) tf.getView().findViewById(R.id.textview1);
final int[] i = new int[1];
i[0] = 0;
final int length = s.length();
final Handler handler = new Handler()
{
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
char c= s.charAt(i[0]);
Log.d("Strange",""+c);
tv.append(String.valueOf(c));
i[0]++;
}
};
final Timer timer = new Timer();
TimerTask timerTask = new TimerTask() {
#Override
public void run() {
handler.sendEmptyMessage(0);
if (i[0] == length - 1) {
timer.cancel();
}
}
};
timer.schedule(timerTask, 1, 500);
}
Think this will help you for sure

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);
}
}

Marker move on map but sometimes it is revolving at 360 degree in android

I am facing an issue right now I am developing an Android app similar to Uber or lyft but the problem that I am facing is the car is moving on the map smoothly but sometimes it is revolving at 360 degree at one position, I need to stop that please help, here is my animation code.
private void animateMarkr(double laat, double lnng,Location prevLocation)
{
final LatLng toPosition=new LatLng(laat,lnng);
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
Projection proj = mGoogleMap.getProjection();
Point startPoint = proj.toScreenLocation(carMarker.getPosition());
final LatLng startLatLng = proj.fromScreenLocation(startPoint);
final long duration = 3000;
final boolean hideMarker=false;
final Interpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
#Override
public void run() {
long elapsed = SystemClock.uptimeMillis() - start;
LatLng pre=carMarker.getPosition();
float t = interpolator.getInterpolation((float) elapsed / duration);
double lng = t toPosition.longitude + (1 - t) startLatLng.longitude;
double lat = t toPosition.latitude + (1 - t) startLatLng.latitude;
// carMarker.setRotation(getBearing(pre,new LatLng(lat,lng)));
carMarker.setPosition(new LatLng(lat, lng));
if (t < 1.0) {
// Post again 16ms later.
handler.postDelayed(this, 20);
} else {
if (hideMarker) {
carMarker.setVisible(false);
} else {
carMarker.setVisible(true);
}
}
}
});
}
Here is my Rotation Code
private void rotateMarker(Location location,Location preLocation){
Location prevLocation = new Location(LocationManager.GPS_PROVIDER);
prevLocation.setLatitude(carMarker.getPosition().latitude);
prevLocation.setLongitude(carMarker.getPosition().longitude);
final float toRotation = prevLocation.bearingTo(location);
performRotaion(toRotation);
}
private void performRotaion(final float toRotation){
if(!isMarkerRotating) {
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
final float startRotation = carMarker.getRotation();
final float totalDegree=0;
final long duration = 1000;
final Interpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
#Override
public void run() {
isMarkerRotating = true;
long elapsed = SystemClock.uptimeMillis() - start;
float t = interpolator.getInterpolation((float) elapsed / duration);
float rot = t toRotation + (1 - t) startRotation;
if(carMarker != null){
carMarker.setAnchor(0.5f, 0.5f);
// if(rot<0.0f && rot>-355.0f) {
carMarker.setRotation(-rot > 180 ? rot / 2 : rot);
carMarker.setFlat(true);
}
if (t < 1.0) {
handler.postDelayed(this, 16);
} else {
isMarkerRotating = false;
}
}
});
}
}
// method call
rotateMarker(location,previcsLocation);
animateMarkr(location.getLatitude(), location.getLongitude(),previcsLocation);
I have implemented the check to stop rotation if the degree is 360 also I have checked if the degree is more than 180 degree than divide the same and move the car on that angle. But nothing works
Before calling these functions
rotateMarker(location,previcsLocation);
animateMarkr(location.getLatitude(), location.getLongitude(),previcsLocation);
in your code. You'll have to add a check for the new (Latitude,Logitude) which comes through the server and marker's (Latitude,Logitude) if both values are same then you should avoid to call the above functions.
Only you have to add this condition in it.
LatLng new_location = new LatLng(data.getLatitude(), data.getLongitude());
//new_location is coming through the server
LatLng current_location = marker.getPosition();
//this is the marker's location
if (current_location != new_location) {
if (current_location.equals(new_location)) {
Log.d(TAG, "LatLng " + "---------current_location-" + current_location);
Log.d(TAG, "LatLng " + "---------new_location-" + new_location);
return;
}
rotateMarker(location,previcsLocation);
animateMarkr(location.getLatitude(), location.getLongitude(),previcsLocation);
}
It worked in my project.

How to fill the color gradually on drawn view canvas Android

I am having a WaveFormView on which I want to change the color of it while playing Audio file and as the Audio is paused it should be stopped coloring at that certain point and when resumed it should continue forward with coloring. I am not getting how to do it in my code..
This is the screen shot of my generated waveform. Now when I will click on Play button it should change the color of waveform gradually with red color (from start to end slowly).
Here is my code to draw waveform view.
WaveFormView.class
public class WaveformView extends View {
public interface WaveformListener {
public void waveformFling(float x);
public void waveformDraw();
}
;
// Colors
private Paint mGridPaint;
private Paint mSelectedLinePaint;
private Paint mUnselectedLinePaint;
private Paint mUnselectedBkgndLinePaint;
private Paint mBorderLinePaint;
private Paint mPlaybackLinePaint;
private Paint mTimecodePaint;
private SoundFile mSoundFile;
private int[] mLenByZoomLevel;
private double[][] mValuesByZoomLevel;
private double[] mZoomFactorByZoomLevel;
private int[] mHeightsAtThisZoomLevel;
private int mZoomLevel;
private int mNumZoomLevels;
private int mSampleRate;
private int mSamplesPerFrame;
private int mOffset;
private int mSelectionStart;
private int mSelectionEnd;
private int mPlaybackPos;
private float mDensity;
private float mInitialScaleSpan;
private WaveformListener mListener;
private GestureDetector mGestureDetector;
private ScaleGestureDetector mScaleGestureDetector;
private boolean mInitialized;
Color color;
public WaveformView(Context context, AttributeSet attrs) {
super(context, attrs);
// We don't want keys, the markers get these
setFocusable(false);
mGridPaint = new Paint();
mGridPaint.setAntiAlias(false);
mGridPaint.setColor(
getResources().getColor(R.color.grid_line));
mSelectedLinePaint = new Paint();
mSelectedLinePaint.setAntiAlias(false);
mSelectedLinePaint.setColor(
getResources().getColor(R.color.waveform_selected));
mUnselectedLinePaint = new Paint();
mUnselectedLinePaint.setAntiAlias(false);
mUnselectedLinePaint.setColor(
getResources().getColor(R.color.waveform_unselected));
mUnselectedBkgndLinePaint = new Paint();
mUnselectedBkgndLinePaint.setAntiAlias(false);
mUnselectedBkgndLinePaint.setColor(
getResources().getColor(
R.color.selection_border));
mBorderLinePaint = new Paint();
mBorderLinePaint.setAntiAlias(true);
mBorderLinePaint.setStrokeWidth(1.5f);
mBorderLinePaint.setPathEffect(
new DashPathEffect(new float[]{3.0f, 2.0f}, 0.0f));
mBorderLinePaint.setColor(
getResources().getColor(R.color.selection_border));
mPlaybackLinePaint = new Paint();
mPlaybackLinePaint.setAntiAlias(false);
mPlaybackLinePaint.setColor(
getResources().getColor(R.color.playback_indicator));
mTimecodePaint = new Paint();
mTimecodePaint.setTextSize(12);
mTimecodePaint.setAntiAlias(true);
mTimecodePaint.setColor(
getResources().getColor(R.color.timecode));
mTimecodePaint.setShadowLayer(
2, 1, 1,
getResources().getColor(R.color.timecode_shadow));
mGestureDetector = new GestureDetector(
context,
new GestureDetector.SimpleOnGestureListener() {
public boolean onFling(
MotionEvent e1, MotionEvent e2, float vx, float vy) {
mListener.waveformFling(vx);
return true;
}
});
mSoundFile = null;
mLenByZoomLevel = null;
mValuesByZoomLevel = null;
mHeightsAtThisZoomLevel = null;
mOffset = 0;
mPlaybackPos = -1;
mSelectionStart = 0;
mSelectionEnd = 0;
mDensity = 1.0f;
mInitialized = false;
}
public boolean hasSoundFile() {
return mSoundFile != null;
}
public void setSoundFile(SoundFile soundFile) {
mSoundFile = soundFile;
mSampleRate = mSoundFile.getSampleRate();
mSamplesPerFrame = mSoundFile.getSamplesPerFrame();
computeDoublesForAllZoomLevels();
mHeightsAtThisZoomLevel = null;
}
/**
* Called once when a new sound file is added
*/
private void computeDoublesForAllZoomLevels() {
int numFrames = mSoundFile.getNumFrames();
int[] frameGains = mSoundFile.getFrameGains();
double[] smoothedGains = new double[numFrames];
if (numFrames == 1) {
smoothedGains[0] = frameGains[0];
} else if (numFrames == 2) {
smoothedGains[0] = frameGains[0];
smoothedGains[1] = frameGains[1];
} else if (numFrames > 2) {
smoothedGains[0] = (double)(
(frameGains[0] / 2.0) +
(frameGains[1] / 2.0));
for (int i = 1; i < numFrames - 1; i++) {
smoothedGains[i] = (double)(
(frameGains[i - 1] / 3.0) +
(frameGains[i ] / 3.0) +
(frameGains[i + 1] / 3.0));
}
smoothedGains[numFrames - 1] = (double)(
(frameGains[numFrames - 2] / 2.0) +
(frameGains[numFrames - 1] / 2.0));
}
// Make sure the range is no more than 0 - 255
double maxGain = 1.0;
for (int i = 0; i < numFrames; i++) {
if (smoothedGains[i] > maxGain) {
maxGain = smoothedGains[i];
}
}
double scaleFactor = 1.0;
if (maxGain > 255.0) {
scaleFactor = 255 / maxGain;
}
// Build histogram of 256 bins and figure out the new scaled max
maxGain = 0;
int gainHist[] = new int[256];
for (int i = 0; i < numFrames; i++) {
int smoothedGain = (int)(smoothedGains[i] * scaleFactor);
if (smoothedGain < 0)
smoothedGain = 0;
if (smoothedGain > 255)
smoothedGain = 255;
if (smoothedGain > maxGain)
maxGain = smoothedGain;
gainHist[smoothedGain]++;
}
// Re-calibrate the min to be 5%
double minGain = 0;
int sum = 0;
while (minGain < 255 && sum < numFrames / 20) {
sum += gainHist[(int)minGain];
minGain++;
}
// Re-calibrate the max to be 99%
sum = 0;
while (maxGain > 2 && sum < numFrames / 100) {
sum += gainHist[(int)maxGain];
maxGain--;
}
// Compute the heights
double[] heights = new double[numFrames];
double range = maxGain - minGain;
for (int i = 0; i < numFrames; i++) {
double value = (smoothedGains[i] * scaleFactor - minGain) / range;
if (value < 0.0)
value = 0.0;
if (value > 1.0)
value = 1.0;
heights[i] = value * value;
}
mNumZoomLevels = 5;
mLenByZoomLevel = new int[5];
mZoomFactorByZoomLevel = new double[5];
mValuesByZoomLevel = new double[5][];
// Level 0 is doubled, with interpolated values
mLenByZoomLevel[0] = numFrames * 2;
mZoomFactorByZoomLevel[0] = 2.0;
mValuesByZoomLevel[0] = new double[mLenByZoomLevel[0]];
if (numFrames > 0) {
mValuesByZoomLevel[0][0] = 0.5 * heights[0];
mValuesByZoomLevel[0][1] = heights[0];
}
for (int i = 1; i < numFrames; i++) {
mValuesByZoomLevel[0][2 * i] = 0.5 * (heights[i - 1] + heights[i]);
mValuesByZoomLevel[0][2 * i + 1] = heights[i];
}
// Level 1 is normal
mLenByZoomLevel[1] = numFrames;
mValuesByZoomLevel[1] = new double[mLenByZoomLevel[1]];
mZoomFactorByZoomLevel[1] = 1.0;
for (int i = 0; i < mLenByZoomLevel[1]; i++) {
mValuesByZoomLevel[1][i] = heights[i];
}
// 3 more levels are each halved
for (int j = 2; j < 5; j++) {
mLenByZoomLevel[j] = mLenByZoomLevel[j - 1] / 2;
mValuesByZoomLevel[j] = new double[mLenByZoomLevel[j]];
mZoomFactorByZoomLevel[j] = mZoomFactorByZoomLevel[j - 1] / 2.0;
for (int i = 0; i < mLenByZoomLevel[j]; i++) {
mValuesByZoomLevel[j][i] =
0.5 * (mValuesByZoomLevel[j - 1][2 * i] +
mValuesByZoomLevel[j - 1][2 * i + 1]);
}
}
if (numFrames > 5000) {
mZoomLevel = 3;
} else if (numFrames > 1000) {
mZoomLevel = 2;
} else if (numFrames > 300) {
mZoomLevel = 1;
} else {
mZoomLevel = 0;
}
mInitialized = true;
}
public boolean canZoomIn() {
return (mZoomLevel > 0);
}
public void zoomIn() {
if (canZoomIn()) {
mZoomLevel--;
mSelectionStart *= 2;
mSelectionEnd *= 2;
mHeightsAtThisZoomLevel = null;
int offsetCenter = mOffset + getMeasuredWidth() / 2;
offsetCenter *= 2;
mOffset = offsetCenter - getMeasuredWidth() / 2;
if (mOffset < 0)
mOffset = 0;
invalidate();
}
}
public boolean canZoomOut() {
return (mZoomLevel < mNumZoomLevels - 1);
}
public void zoomOut() {
if (canZoomOut()) {
mZoomLevel++;
mSelectionStart /= 2;
mSelectionEnd /= 2;
int offsetCenter = mOffset + getMeasuredWidth() / 2;
offsetCenter /= 2;
mOffset = offsetCenter - getMeasuredWidth() / 2;
if (mOffset < 0)
mOffset = 0;
mHeightsAtThisZoomLevel = null;
invalidate();
}
}
public double pixelsToSeconds(int pixels) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (pixels * (double)mSamplesPerFrame / (mSampleRate * z));
}
public void setListener(WaveformListener listener) {
mListener = listener;
}
public void recomputeHeights(float density) {
mHeightsAtThisZoomLevel = null;
mDensity = density;
mTimecodePaint.setTextSize((int)(12 * density));
invalidate();
}
protected void drawWaveformLine(Canvas canvas,
int x, int y0, int y1,
Paint paint) {
canvas.drawLine(x, y0, x, y1, paint);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mSoundFile == null)
return;
if (mHeightsAtThisZoomLevel == null)
computeIntsForThisZoomLevel();
DisplayMetrics displaymetrics = getContext().getResources().getDisplayMetrics();
int height = displaymetrics.heightPixels;
int widths = displaymetrics.widthPixels;
// Draw waveform
int measuredWidth = getMeasuredWidth();
int measuredHeight = getMeasuredHeight();
int start = mOffset;
int width = mHeightsAtThisZoomLevel.length - start;
int ctr = measuredHeight / 2;
Log.e("wid",String.valueOf(width));
Log.e("widCal",String.valueOf(mHeightsAtThisZoomLevel.length));
Log.e("widstart",String.valueOf(start));
if (width > measuredWidth)
width = measuredWidth;
Log.e("measured",String.valueOf(measuredWidth));
// Draw grid
double onePixelInSecs = pixelsToSeconds(1);
boolean onlyEveryFiveSecs = (onePixelInSecs > 1.0 / 50.0);
double fractionalSecs = mOffset * onePixelInSecs;
int integerSecs = (int) fractionalSecs;
int i = 0;
while (i < width) {
i++;
fractionalSecs += onePixelInSecs;
int integerSecsNew = (int) fractionalSecs;
if (integerSecsNew != integerSecs) {
integerSecs = integerSecsNew;
if (!onlyEveryFiveSecs || 0 == (integerSecs % 5)) {
canvas.drawLine(i, 0, i, measuredHeight, mGridPaint);
}
}
}
// Draw waveform
for ( i = 0; i < width; i++) {
Paint paint;
if (i + start >= mSelectionStart &&
i + start < mSelectionEnd) {
paint = mSelectedLinePaint;
// paint.setColor(color);
} else {
drawWaveformLine(canvas, ((widths/width)*i), 0, measuredHeight,
mUnselectedBkgndLinePaint);
paint = mUnselectedLinePaint;
}
drawWaveformLine(
canvas, ((widths/width)*i),
ctr - mHeightsAtThisZoomLevel[start + i],
ctr + 1 + mHeightsAtThisZoomLevel[start + i],
paint);
if (i + start == mPlaybackPos) {
canvas.drawLine(i, 0, i, measuredHeight, mPlaybackLinePaint);
}
}
if (mListener != null) {
mListener.waveformDraw();
}
}
private void computeIntsForThisZoomLevel() {
int halfHeight = (getMeasuredHeight() / 2) - 1;
mHeightsAtThisZoomLevel = new int[mLenByZoomLevel[mZoomLevel]];
for (int i = 0; i < mLenByZoomLevel[mZoomLevel]; i++) {
mHeightsAtThisZoomLevel[i] =
(int)(mValuesByZoomLevel[mZoomLevel][i] * halfHeight);
}
}
}
MainActivity.class
public class MainActivity extends AppCompatActivity implements WaveformView.WaveformListener {
WaveformView mWaveformView;
SoundFile mSoundFile;
private float mDensity;
private File mFile;
private String mFilename;
private long mLoadingLastUpdateTime;
boolean mLoadingKeepGoing;
boolean mFinishActivity;
private ProgressDialog mProgressDialog;
String mTitle,mArtist;
private Thread mLoadSoundFileThread;
private Thread mRecordAudioThread;
private Thread mSaveSoundFileThread;
private boolean mIsPlaying;
private SamplePlayer mPlayer;
private String mInfoContent;
private int mWidth;
private int mMaxPos;
private int mStartPos;
private int mEndPos;
private boolean mStartVisible;
private boolean mEndVisible;
private int mLastDisplayedStartPos;
private int mLastDisplayedEndPos;
private int mOffset;
private int mOffsetGoal;
private int mFlingVelocity;
private int mPlayStartMsec;
private int mPlayEndMsec;
private Handler mHandler;
Button pla;
MediaPlayer mediaPlayer;
boolean ismIsPlaying;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pla = (Button)findViewById(R.id.play);
mWaveformView = (WaveformView)findViewById(R.id.waveform);
mWaveformView.setListener(this);
mHandler = new Handler();
Uri uri = Uri.parse("/sdcard/audio_file.mp3");
mediaPlayer = new MediaPlayer();
mediaPlayer = MediaPlayer.create(getApplicationContext(),uri);
loadGui();
loadFromFile();
}
/**
* Called from both onCreate and onConfigurationChanged
* (if the user switched layouts)
*/
private void loadGui() {
// Inflate our UI from its XML layout description.
setContentView(R.layout.activity_main);
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
mDensity = metrics.density;
mWaveformView = (WaveformView)findViewById(R.id.waveform);
mWaveformView.setListener(this);
if (mSoundFile != null && !mWaveformView.hasSoundFile()) {
mWaveformView.setSoundFile(mSoundFile);
mWaveformView.recomputeHeights(mDensity);
}
}
private void loadFromFile() {
mFilename = "/sdcard/audio_file.mp3";
mFile = new File(mFilename);
SongMetadataReader metadataReader = new SongMetadataReader(
this, mFilename);
mTitle = metadataReader.mTitle;
mArtist = metadataReader.mArtist;
String titleLabel = mTitle;
if (mArtist != null && mArtist.length() > 0) {
titleLabel += " - " + mArtist;
}
setTitle(titleLabel);
mLoadingLastUpdateTime = getCurrentTime();
mLoadingKeepGoing = true;
mFinishActivity = false;
mProgressDialog = new ProgressDialog(MainActivity.this);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
mProgressDialog.setTitle("Loading...");
mProgressDialog.setCancelable(true);
mProgressDialog.setOnCancelListener(
new DialogInterface.OnCancelListener() {
public void onCancel(DialogInterface dialog) {
mLoadingKeepGoing = false;
mFinishActivity = true;
}
});
mProgressDialog.show();
final SoundFile.ProgressListener listener =
new SoundFile.ProgressListener() {
public boolean reportProgress(double fractionComplete) {
long now = getCurrentTime();
if (now - mLoadingLastUpdateTime > 100) {
mProgressDialog.setProgress(
(int) (mProgressDialog.getMax() * fractionComplete));
mLoadingLastUpdateTime = now;
}
return mLoadingKeepGoing;
}
};
// Load the sound file in a background thread
mLoadSoundFileThread = new Thread() {
public void run() {
try {
mSoundFile = SoundFile.create(mFile.getAbsolutePath(), listener);
if (mSoundFile == null) {
mProgressDialog.dismiss();
String name = mFile.getName().toLowerCase();
String[] components = name.split("\\.");
String err;
if (components.length < 2) {
err = getResources().getString(
R.string.no_extension_error);
} else {
err = getResources().getString(
R.string.bad_extension_error) + " " +
components[components.length - 1];
}
final String finalErr = err;
Runnable runnable = new Runnable() {
public void run() {
showFinalAlert(new Exception(), finalErr);
}
};
mHandler.post(runnable);
return;
}
mPlayer = new SamplePlayer(mSoundFile);
} catch (final Exception e) {
mProgressDialog.dismiss();
e.printStackTrace();
mInfoContent = e.toString();
runOnUiThread(new Runnable() {
public void run() {
}
});
Runnable runnable = new Runnable() {
public void run() {
showFinalAlert(e, getResources().getText(R.string.read_error));
}
};
mHandler.post(runnable);
return;
}
mProgressDialog.dismiss();
if (mLoadingKeepGoing) {
Runnable runnable = new Runnable() {
public void run() {
finishOpeningSoundFile();
}
};
mHandler.post(runnable);
} else if (mFinishActivity){
MainActivity.this.finish();
}
}
};
mLoadSoundFileThread.start();
}
private void finishOpeningSoundFile() {
mWaveformView.setSoundFile(mSoundFile);
mWaveformView.recomputeHeights(mDensity);
Log.e("sound file",mFilename);
Log.e("sound", String.valueOf(mSoundFile));
}
/**
* Show a "final" alert dialog that will exit the activity
* after the user clicks on the OK button. If an exception
* is passed, it's assumed to be an error condition, and the
* dialog is presented as an error, and the stack trace is
* logged. If there's no exception, it's a success message.
*/
private void showFinalAlert(Exception e, CharSequence message) {
CharSequence title;
if (e != null) {
Log.e("Ringdroid", "Error: " + message);
Log.e("Ringdroid", getStackTrace(e));
title = getResources().getText(R.string.alert_title_failure);
setResult(RESULT_CANCELED, new Intent());
} else {
Log.v("Ringdroid", "Success: " + message);
title = getResources().getText(R.string.alert_title_success);
}
new AlertDialog.Builder(MainActivity.this)
.setTitle(title)
.setMessage(message)
.setPositiveButton(
R.string.alert_ok_button,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int whichButton) {
finish();
}
})
.setCancelable(false)
.show();
}
private void showFinalAlert(Exception e, int messageResourceId) {
showFinalAlert(e, getResources().getText(messageResourceId));
}
#Override
public void waveformTouchStart(float x) {
}
#Override
public void waveformTouchMove(float x) {
}
#Override
public void waveformTouchEnd() {
}
#Override
public void waveformFling(float x) {
}
#Override
public void waveformDraw() {
mWidth = mWaveformView.getMeasuredWidth();
if (mOffsetGoal != mOffset) {
// updateDisplay();
}
else if (mIsPlaying) {
// updateDisplay();
} else if (mFlingVelocity != 0) {
// updateDisplay();
}
}
private long getCurrentTime() {
return System.nanoTime() / 1000000;
}
private String getStackTrace(Exception e) {
StringWriter writer = new StringWriter();
e.printStackTrace(new PrintWriter(writer));
return writer.toString();
}
public void buttonClick(View view) {
Toast.makeText(MainActivity.this, "test", Toast.LENGTH_SHORT).show();
mediaPlayer.start();
ismIsPlaying = true;
}
}
In your onDraw(Canvas canvas) add the following lines
if (i + start <= mPlaybackPos) {
Paint mPaint = new Paint(paint);
mPaint.setColor(Color.RED);
drawWaveformLine(
canvas, ((widths/width)*i),
ctr - mHeightsAtThisZoomLevel[start + i],
ctr + 1 + mHeightsAtThisZoomLevel[start + i],
mPaint);
}
add them above the line:
if (i + start == mPlaybackPos) {
And if this works, consider to allocate the Paint-object outside the onDraw() method.

How to animate seekbar thumb to move to a specific position

I defined different lock positions:
private static final int[] gears = new int[] { 0, 33, 66, 100 };
In the onStopTrackingTouch i calculate which of my lock positions is the closest to the progress state of my SeekBar:
#Override
public void onStopTrackingTouch(final SeekBar seekBar) {
int progress = seekBar.getProgress();
int distance = Math.abs(gears[0] - progress);
int index = 0;
for(int i = 1; i < gears.length; i++) {
int tempDistance = Math.abs(gears[i] - progress);
if(tempDistance < distance) {
index = i;
distance = tempDistance;
}
}
int lock = gears[index];
}
I now need to somehow set the progress state of the SeekBar to my lock position using a smooth animation.
How can i impelement that animation?
EDIT
Thanks to the answer of #bwoogie here the complete working example using a VerticalSeekBar
#Override
public void onStopTrackingTouch(final SeekBar seekBar) {
int progress = seekBar.getProgress();
int distance = Math.abs(gears[0] - progress);
int index = 0;
for(int i = 1; i < gears.length; i++) {
int tempDistance = Math.abs(gears[i] - progress);
if(tempDistance < distance) {
index = i;
distance = tempDistance;
}
}
final int lock = gears[index];
final int tick = 50;
final VerticalSeekBar verticalSeekBar = (VerticalSeekBar)seekBar;
new Thread(new Runnable() {
long now = System.currentTimeMillis();
public void run() {
while(seekBar.getProgress() != lock) {
if(now + tick < System.currentTimeMillis()) {
if(seekBar.getProgress() > lock) {
getActivity().runOnUiThread(new Runnable() {
public void run() {
verticalSeekBar.setMax(100);
verticalSeekBar.setProgressAndThumb(seekBar.getProgress() - 1);
}
});
} else if(seekBar.getProgress() < lock) {
getActivity().runOnUiThread(new Runnable() {
public void run() {
verticalSeekBar.setMax(100);
verticalSeekBar.setProgressAndThumb(seekBar.getProgress() + 1);
}
});
} else {
break;
}
now = System.currentTimeMillis();
}
}
}
}).start();
}
What I would do is create a loop (in a new thread) that checks every few milliseconds if enough time has passed and if so then we can update the seekBar. Here is the basic idea, just throw it into a thread and implement the updateSeekBar() method since its in a thread you wont be able to access the UI thread directly.
int newPos; // the new position we are seeking to
int ticks = 50; //how many milliseconds
long now = System.getCurrentTimeMillis();
while(seekBar.getPosition() != newPos) {
if(now + ticks < System.getCurrentTimeMillis()) {
if(seekBar.getPosition() > newPos) {
updateSeekbar(seekBar.getPosition()--);}
elseif(seekBar.getPosition() < newPos{
updateSeekbar(seekBar.getPosition()++;}
else {
break; // we've reached out goal
}
now = System.getCurrentTimeMillis(); //Edit - forgot to update the time!!
}
}

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