I wanted to animate a line on the view. Ex: A progressive line starting at (0,120) and progresses upto (100,120). I've already tried this with plain canvas.drawLine() but was unable to apply an animation while drawing a line.
What I wanted to see is once the view is loaded a set of straight lines(of varying length) being drawn on the view. I don't want them as static lines. I wanted to see these lines when they are being drawn on the canvas.
I've tried couple of other options like, using the shape drawables and applying animations from the anim/xmls. Most of them didn't solve my problem. Extensive googling show the animations which are applied to the views directly. Here I dont want to create multiple image views as I'll end up having 6 lines on the view and i need to animate each of the line with different colors.
In future I should be able to move the lines up and down change there colors and do other kind of animations on each one of the lines.
Remembering the above constraints can you suggest me how to write a custom implementation for the same.
well are you not just using canvas.drawline(...), or canvas.drawlines(...), Your View could have the variables which represent the lines, maybe an arraylist of Points or something. I am currently trying to draw a line with moving values on a game I am making. I simply just change the values put into the drawline function, and my line animates as those values change. However it seams whenever the line has a slope closer to 1 my loop slow down and my other animations slow along with it. Are you having a similar problem when animating the lines? or are you just not able to get them drawn?
it sounds like your problem is in your game loop... I use a thread to loop through my draw and update methods, as I never was able to get the invalidate() thing working...
so below is a class called mainthread, it is created in your surfaceview in this case the surfaceview is called DrawView...
import android.graphics.Canvas;
import android.view.SurfaceHolder;
public class MainThread extends Thread {
// desired fps
private final static int MAX_FPS = 75;
// maximum number of frames to be skipped
private final static int MAX_FRAME_SKIPS = 0;
// the frame period
private final static int FRAME_PERIOD = 1000 / MAX_FPS;
// Surface holder that can access the physical surface
private SurfaceHolder surfaceHolder;
// The actual view that handles inputs
// and draws to the surface
private DrawView gamePanel;
// flag to hold game state
public boolean running;
public void setRunning(boolean running) {
this.running = running;
}
public MainThread(SurfaceHolder surfaceHolder, DrawView gamePanel) {
super();
this.surfaceHolder = surfaceHolder;
this.gamePanel = gamePanel;
}
#Override
public void run() {
Canvas canvas;
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.gamePanel.doUpdate();
// render state to the screen
// draws the canvas on the panel
this.gamePanel.doDraw(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.gamePanel.doUpdate(); // update without rendering
sleepTime += FRAME_PERIOD; // add frame period to check if in next frame
framesSkipped++;
}
}
} catch(ClassCastException cce) {
}finally {
// in case of an exception the surface is not left in
// an inconsistent state
if (canvas != null) {
surfaceHolder.unlockCanvasAndPost(canvas);
}
} // end finally
}
}
}
using this thread it will call your update and draw methods approprietly, for onTouch just override the surfaceview (DrawView)'s onTouch method to access it normally. in order to stop the thread for what ever reason just set running to false.
Related
I am trying to create an animation for my game. I am trying to make an animation of a coin flip that will stop under certain conditions.
So far I have tried to change an image view multiple times within one method and using thread.sleep to delay the transition between the pictures.
Using 12 different images I am now trying to make it so the alpha of the first image will set to 0 and the second image will set to one, the the second image will set to 0 and the third will set to 1, etc...
The way I am currently trying to do it is by putting images inside of an array of ImageViews and then calling them sequentially.
setContentView(R.layout.coin_flip_screen);
for(int i = 0; i < 4; i++){
headsTails[i].animate().alpha(0).setDuration(100);
headsTails[i+1].animate().alpha(1).setDuration(100);
try {
Thread.sleep(100);
} catch (Exception e) {
}
}
final int size = imageView.length;
final int animTime = 300;
final Handler animationHandler = new Handler();
Runnable animationRunnable = new Runnable() {
int i = 0;
#Override
public void run() {
if(i == size-1){
animationHandler.removeCallbacks(this);
return;
}
imageView[i++].animate().alpha(0f).setDuration(animTime).start();
imageView[i].animate().alpha(1f).setDuration(animTime).start();
animationHandler.postDelayed(this, animTime);
}
};
animationHandler.post(animationRunnable);
This code will iterate through all your imageviews in the array and stop itself once all the images are consumed.
Play along with your animTime variable until you get the perfect animation effect. Ideally it should be around 300 to 500 ms.
I will personally not use array of imageviews to create this effect as
it will eat up the memory. There are many more efficient ways to do
the coin flip animation, which you can google when you get time.
This should fix it
headsTails[i].animate().alpha(0).setDuration(100).start();
I try to improve the movement of my figures but i dont find the real reason why they stutter a bit. I am moving them with an SequenceAction containing an MoveToAction and an RunnableAction that does reset the moveDone flag so there can be started a new move.
The game itself is gridbased so if a move is done the squence starts a move to the next grid depending on the direction. So here is how it looks like:
note that this is inside of the Act of the figure
....//some more here
if (checkNextMove(Status.LEFT)) //check if the position is valid
{
status = Status.LEFT; //change enum status
move(Status.LEFT); // calls the move
screen.map.mapArray[(int) mapPos.x][(int) mapPos.y] = Config.EMPTYPOSITION;
screen.map.mapArray[(int) (mapPos.x - 1)][(int) mapPos.y] = Config.CHARSTATE;
mapPos.x--;
moveDone = false;
}
//... same for the up down right and so on.
//at the end of this checking the updating of the actor:
// methode from the absctract to change sprites
updateSprite(delta);
super.act(delta); // so the actions work
//end of act
And here is the move Method that does add the Actions
protected void move(Status direction)
{
// delete all old actions if there are some left.
clearActions();
moveAction.setDuration(speed);
//restart all actions to they can used again
sequence.restart();
switch (direction)
{
case LEFT:
moveAction.setPosition(getX() - Config.TILE_SIZE, getY());
addAction(sequence);
break;
case RIGHT:
moveAction.setPosition(getX() + Config.TILE_SIZE, getY());
addAction(sequence);
break;
case UP:
moveAction.setPosition(getX(), getY() + Config.TILE_SIZE);
addAction(sequence);
break;
case DOWN:
moveAction.setPosition(getX(), getY() - Config.TILE_SIZE);
addAction(sequence);
break;
default:
break;
}
}
The figures dont really move smothy.
Anyone does see a misstake or isnt it possible to let them move smothy like this?
It always stutter a bit if a new move is started. So i think this might not work good. Is there a differnt approach to move them exactly from one Grid to an nother? (Tried it myself with movementspeed * delta time but this does not work exactly and i struggeled around and used the Actionmodel)
it seems to make troubles with the one Frame where it does not move for example.
Here is an mp4 Video of the stuttering:
stuttering.mp4
just to mention, the camera movement is just fine. it's smothy but the figure stutters as you can see i hope
If you use your moveAction each move, you should call moveAction.restart() to reset the counter inside it:
// delete all old actions if there are some left.
clearActions();
sequence.reset(); // clear sequence
// add movementspeed. Note it can change!
moveAction.restart();
moveAction.setDuration(speed);
UPDATE:
Now issue occurs, because you call restart of SequenceAction after clearActions(). If your clearActions() removes all actions from SequenceAction then restart will be called for empty SequenceAction. So, do this instead:
//restart all actions to they can used again
sequence.restart();
// delete all old actions if there are some left.
clearActions();
moveAction.setDuration(speed);
Okay so i solved it myself. It has nothing todo with changing sequences around. It has something todo with the updatefrequency of the act() of the figures. The MoveToAction interpolates between the 2 points given by time. So if the last update, updates the MoveToAction by "to much time" it would need to go over the 100% of the action. So it would move to far but the action does not do this it set the final position and thats what it should do. Thats why it does not look fluent.
So how to solve this issue?
By decreasing the updatetime the "to far movement" decreases too because the steplength is getting smaller. So i need to increase the updatespeed above the 60fps. Luckily i got an thread for my updating of the figures and positions and so on. GameLogicThread. This ran on 60fps too. So i solved the stuttering by increasing it's frequence. up to around 210fps at the moment so the "overstep" is minimal. You can't even notice it.
To Show how my thread works:
public class GameLogicThread extends Thread
{
private GameScreen m_screen;
private boolean m_runing;
private long m_timeBegin;
private long m_timeDiff;
private long m_sleepTime;
private final static float FRAMERATE = 210f;
public GameLogicThread(GameScreen screen)
{
m_screen = screen;
setName("GameLogic");
}
#Override
public void run()
{
m_runing = true;
Logger.log("Started");
while (m_runing)
{
m_timeBegin = TimeUtils.millis();
// hanlde events
m_screen.m_main.handler.processEvents();
synchronized (m_screen.figureStage)
{
// now figures
if (m_screen.m_status == GameStatus.GAME)
{
m_screen.character.myAct(1f / GameLogicThread.FRAMERATE);// and here it is ;)
m_screen.figureStage.act(1f / GameLogicThread.FRAMERATE);
}
}
m_timeDiff = TimeUtils.millis() - m_timeBegin;
m_sleepTime = (long) (1f / GameLogicThread.FRAMERATE * 1000f - m_timeDiff);
if (m_sleepTime > 0)
{
try
{
Thread.sleep(m_sleepTime);
}
catch (InterruptedException e)
{
Logger.error("Couldn't sleep " + e.getStackTrace());
}
}
else
{
Logger.error("we are to slow! " + m_sleepTime);
}
}
}
public void stopThread()
{
m_runing = false;
boolean retry = true;
while (retry)
{
try
{
this.join();
retry = false;
}
catch (Exception e)
{
Logger.error(e.getMessage());
}
}
}
}
I am attempting to create a simple animation in which a series of bubble rotate around a centre point. I have one version of animation where the bubbles spread from the centrepoint before they begin to rotate, which works fine, but as soon as I click one of the images (which sparks the animation) the screen freezes for a moment and then the bubbles appear in their end position, rather than showing each step they made.
What I have so far is:
while(bubble[1].getDegree() != 270)
{
long time = System.currentTimeMillis();
//the below if statement contains the function calls for
//the rotating bubble animations.
next();
draw();
// delay for each frame - time it took for one frame
time = (1000 / fps) - (System.currentTimeMillis() - time);
if (time > 0)
{
try
{
Thread.sleep(time);
}
catch(Exception e){}
}
}
public void draw()
{
for(int i = 1; i < bubble.length; i++)
{
iconLabel[i].setLocation(bubble[i].getX(), bubble[i].getY());
textLabel[i].setLocation((bubble[i].getX()+10),(bubble[i].getY()+10));
}
}
For clarity, the method "next()" merely changes the position of the bubble to the appropriate place, I know this to be functioning as I have had the animation work before but once I implemented the animation to JLabels it stopped working.
Any help would be appreciated.
The drawing is frozen because you block the event dispatch thread. Drawing is done in the same thread as the while loop, and since the loop prevents anything else happening while it's running, swing can get to drawing only after the loop is finished, so only the last position is drawn.
Use a swing Timer instead:
timer = new Timer(delay, new ActionListener() {
public void actionPerformed(ActionEvent e) {
// whatever you need for the animation
updatePositions();
repaint();
}
});
timer.start();
And then call timer.stop() when all the frames you need have been processed.
Iv'e looked all over for answers to this book. And I know anyone else who has tried to read this book feels the same way. It's called "Programming Video Games for The Evil Genius" Is there anyone who has read this book? I'm on project 10:Radical Racing-The Cars. Everything compiles correctly but for some reason my cars are not showing up in the correct spot on the JFrame. They should be showing up under the two white lines. I'm positive the code is exactly the same as in the book, but the book is wrong. I have already tried changing the HEIGHT part of the point of origin but no matter what I do it does not budge. I can't attach an image because I don't have a rep of at least 10 .This is the code that the deals with the placement of the cars.
public class TheCars extends JFrame
{
final int WIDTH = 900; int HEIGHT = 650;
double p1Speed = .5, p2Speed = .5;
Rectangle p1 = new Rectangle(WIDTH/9,HEIGHT/2, WIDTH/30,WIDTH/30);
Rectangle p2 = new Rectangle(((WIDTH/9)+((int)((WIDTH/9)*1.5)/2)),(HEIGHT/2)+
(HEIGHT/10),WIDTH/30,WIDTH/30);
//the constructor
public TheCars()
{
//the following code creates the JFrame
super("Radical Racing");
setSize(WIDTH,HEIGHT);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
//start the inner class (which works on it's own because it is a thread)
Move1 m1 = new Move1();
Move2 m2 = new Move2();
m1.start();
m2.start();
}
//this will draw the cars and the racetrack
public void paint(Graphics g)
{
super.paint(g);
//set the color to blue for p1
g.setColor(Color.BLUE);
//now draw the actual player
g.fill3DRect(p1.x,p1.width,p1.width,p1.height,true);
//set the color to red for p2
g.setColor(Color.red);
//now draw the actual player
g.fill3DRect(p2.x,p2.width,p2.width,p2.height,true);
}
private class Move1 extends Thread
{
public void run()
//This should all be in an infinite loop so that the process repeats.
{
while(true)
{
//now put in the try block. This will let
//the program exit if there is an error
try
{
//first refresh the screen
repaint();
//increase speed a bit
if(p1Speed<=5)
p1Speed+=.2;
p1.y-=p1Speed;
//this delays the refresh rate
Thread.sleep(75);
}
catch(Exception e)
{
//if there is an exception (an error), exit the loop
break;
}
}
}
}
private class Move2 extends Thread
{
public void run()
{
//this should all be in an infinite loop so the process repeats
while(true)
{
//now put the code in a "try" block.
//this will let the program exit if there is an error
try
{
//first refresh the screen
repaint();
//increase the speed a bit
if(p2Speed<=5)
p2Speed+=.2;
p2.y-=p2Speed;
//this delays the refresh rate
Thread.sleep(75);
}
catch(Exception e)
{
//if there is an exception (an error), exitthe loop
break;
}
}
}
}
public static void main(String[]args)
{
new TheCars();
}
}
Assuming you're painting those Rectangle objects directly onto the screen, we have to assume that the expressions "HEIGHT/2" and "HEIGHT/2 + HEIGHT/10" are coming out equal, and nonzero but small. That would be the case if HEIGHT is an int, and the value is more than 2 and less than 10. Presumably the value would need to be a couple hundred, at least, for those boxes to show up in the middle of the screen. Check the value of HEIGHT (just using a System.out.println() would be fine) and make sure it's the actual height of the window.
EDIT
Now that we see the rest of the code: the second argument to each call to fill3DRect() is wrong. It should be the y member of the Rectangle objects, which is a large, varying number, but you're passing the width member, which is a small fixed number. Change both the calls to look like this and you'll be back on track:
g.fill3DRect(p1.x, p1.y, p1.width, p1.height, true);
I'm looking for a method of counting Frames Per Second in game applications, the problem is that i dont have the source code for any of those apps, they dont have such functionality implemented inside. To be honest i dont really expect this to be possible but it was worth to ask.
And to be perfectly clear i understand that i need a basic knowledge and code of the main painting loop to count FPS.
Best Regards
What is the problem of making FPS counting when you have a main paint loop (don't you?).
I'm not familiar with Android features, but I'm sure it is done there the same in any game on any OS. The easiest way to make a game - is to make 2 threads. First one will be for logic actions (calculating trajectories, object position change over time, etc.). Second thread will take current game state (calculated by first thread) and draw it on the screen.
Here is the commented code on both threads with FPS counter:
//Class that contain current game state
class GameState {
private Point objectPosition;
public Point getObjectPosition() {
return objectPosition;
}
public void setObjectPosition(Point pos) {
this.objectPosition = pos;
}
}
//Runnable for thread that will calculate changes in game state
class GameLogics implements Runnable {
private GameState gameState; //State of the game
public GameLogics(GameState gameState) {
this.gameState = gameState;
}
public void run() {
//Main thread loop
while (true) { //Some exit check code should be here
synchronize (gameState) {
gameState.setObjectPosition(gameState.getObjectPosition()+1); //Move object by 1 unit
}
Thread.sleep(1000); //Wait 1 second until next movement
}
}
}
//Runnable for thread that will draw the game state on the screen
class GamePainter implements Runnable {
private Canvas canvas; //Some kind of canvas to draw object on
private GameState gameState; //State of the game
public GamePainter(Canvas canvas, GameState gameState) {
this.canvas = canvas;
this.gameState = gameState;
}
public void drawStateOnCanvas() {
//Some code that is rendering the gameState on canvas
canvas.drawLine(...);
canvas.drawOtherLine(...);
....
}
public void run() {
//Last time we updated our FPS
long lastFpsTime = 0;
//How many frames were in last FPS update
int frameCounter = 0;
//Main thread loop
//Main thread loop
while (true) { //Some exit check code should be here
synchronize (gameState) {
//Draw the state on the canvas
drawStateOnCanvas();
}
//Increment frame counter
frameCounter++;
int delay = (int)(System.getCurrentTimeMillis() - lastFpsTime);
//If last FPS was calculated more than 1 second ago
if (delay > 1000) {
//Calculate FPS
double FPS = (((double)frameCounter)/delay)*1000; //delay is in milliseconds, that's why *1000
frameCounter = 0; //Reset frame counter
lastFpsTime = System.getCurrentTimeMillis(); //Reset fps timer
log.debug("FPS: "+FPS);
}
}
}
}
I'm not too knowledgeable with Android Game development, but in Java2D (it's a bit hacky but it works...) I would xboot a jar with the edited JRE class which controls the rendering (eg Canvas) into the process.
This is a good read on game loop. It explains the various implementations and pros/cons of game loops.
And this is a good tutorial on implementing the gameloop + FPS counter in Android.