I'm a novice programmer and recently I came across many methods of animation:
Using BufferedImages , ie. draw to image and display using double buffering or triple buffering methods .
Making my sprites components by extending Component or Button . and repainting by repaint(g).
Rastering, using rasters and integer arrays, bitmaps and the like.
I realise that method 1 and 2 are similar as they use paint() methods , however Rastering involves self-made functions , eg. creating functions that set background by traversing the whole array representing each pixel and setting colour to desired colour .
I've seen many folks online use raster methods even though 1 & 2 seem simpler .
Please help me out here guys and tell me what path i should follow and why .
The first and second methods are very similar and would come down to the context of the problem.
The third option would, for the most part come down to providing a flexible API which was independent of the toolkit or framework which was to be used to dipslay it. One could argue that there is a speed increase, but with Swing and JavaFX working more directly with the DirectX and OpenGL pipelines, this is less of an issue.
Unless your planning on dong some seriously low level functionality or interfacing to a non-standard API I wouldn't worry to much about it (some effects painting might be faster done this way, but it's all about context)
Personally, it would focus on developing an understanding of the basics and principles involved and how they might be implemented using the first two options as it allows you to focus on those concepts with a relatively easy API
As time progress or you come across a situation that can't be resolved using these techniques, then it might be time to consider playing with the rastering approach.
Remember though, you still need to get that byte array into a format that the API wants which in of itself, will add overheads
Related
I am developing a shoot'em up type video game using Java Swing and I'm using a Java Swing Timer to control all of the screen updating. The main screen uses a BorderLayout, and I perform my graphics on a Panel contained within the BorderLayout, and use the AWT Graphics calls to draw.
Now as my game progresses, I would like to speed up the movement of my screen objects (ships), yet I still want them to smoothly cross the screen. I thought I could speeed things up by dropping the timeout value for the Java Swing Timer, down to around 5ms. But, I've noticed when I set it to anything less than 15ms, there does not seem to be much difference. Once you cross that threshold, there is almost no noticeable difference in performance. -Why is that?-
Another option would be to increase how many pixels each ship moves per update, but anything beyond 3 or 4 pixels, and things start to look jumpy.
Any ideas? And really want to keep the game in Swing, would prefer at this point not porting to a 3rd party library.
Thanks.
In all likelihood, this isn't a software issue, nor is it fixable with software. Your screen probably only refreshes about 60 times a second, meaning that the frames are only drawn 60 times per second, or once every (approximately) 16 milliseconds. Since this is a hardware barrier, there's no way to get it to update faster with software. You can probably count on your users only having 60Hz monitors, too, so it's more worthwhile to look into other solutions.
One solution that pops to mind is adding in motion blur, to make it seem like the ships are moving faster when they really aren't. It'll allow you to 'jump' a greater distance before it looks jumpy, since the blur tricks the eye into thinking it's going really fast instead of hopping across the screen. Unfortunately, the only things that I see to do motion blur are third-party libraries, though you may have better luck Googling.
I advise you that you change your Swing engine for JavaFX (at least), a technology with better performance and more tools to your disposal. Swing nowadays is considered a dead technology, as well as with the AWT before it. A great place to study and start JavaFX would be this one:
http://docs.oracle.com/javase/8/javase-clienttechnologies.htm
The ideal for the development of games, would be to use a library prepared for it, such as libGDX:
http://libgdx.badlogicgames.com/
But if your desire is to create a game in Swing, who am I to judge? Sometimes it is good to see old things. I myself still like Swing, even being obsolete compared to other things.
I think you may be implementing a wrong gameloop. Swing Timer does not really seem like a good way to update game logic. Even with different settings between different computers, is generally practical and easy to implement a gameloop to work properly, especially for the correct movement of the characters.
You see, a gameloop is the heart of a game, and needs to be implemented straight otherwise the game is developed wrong and with several limitations. Generally, in gameloop we have to take into account the desired FPS. Among game updates, we must take the time elapsed between the last update and the current update, so-called delta by many developers. You will find many materials about it on the internet, which I recommend:
http://dewitters.koonsolo.com/gameloop.html
http://www.java-gaming.org/index.php?topic=21919.0
https://www.youtube.com/watch?v=9dzhgsVaiSo
The past links will help you for sure, but if you want more about it, I recommend that you take a look at this book:
http://www.brackeen.com/javagamebook/
Even the material being old (as Swing is) you'll find details of how to implement a good gameloop with a keyboard and mouse iinput system, sound, the use of the best possible performance swing has to offer, among other cool things. And one more thing... To give you a better result with respect to the movement of the characters, I advice you to use position variables (X and Y) with decimal types such as float or double.
I hope you can do what you want. Good luck!
If I was making a 2D game in Java, would using the default Graphics2D be fast enough? Would I get good FPS if it's just 2D? (even if there is a good amount of sprites and other things going on)
Or when your doing any kind of game programming, 2d or 3d, should you opt for opengl/directx?
Also when you render stuff with Graphics2D, is it all rendered on the CPU? Or is it hardware accelerated?
You should use opengl/directx, or some java binding if you must use java (such as JMonkey). If you are new to game programming, I'd suggest using the XNA framework, as it simplifies a lot of things. I have used XNA, and it is fairly easy to use, and plug in different libraries. If you want a browser based game, javascript + HTML5 Canvas2d, or webgl may be the best route.
You will always get better performance out of using direct binding libraries over a 2D Graphics API type library. The main thing to do is make sure you know how images and textures are being stored / rendered, so you aren't making the framework do extra work. Extra work will result in low FPS.
I was given the task of improving the performance of a stock market charting software that uses SWT's GC to draw the charts. The chart drawing needs to be improved because the charts sometimes are redrawn many times per second, and it consumes lots of processor time.
After googling a little, I found a blog entry that suggests the direct modification of ImageData objects instead of using GC's methods, promising great performance gains.
It's an easy task to draw horizontal and vertical straight lines and square shapes using this technique, but when it comes to drawing circles and other irregular shapes there is no easy way.
Does anyone know if there is a library to draw shapes on ImageData objects, just like GC's methods do on Image objects?
Also, does anyone know another way to improve SWT performance?
Thanks in advance.
Measure the performance of your solution. Where is most time spent? Guessing is not enough. In 90% of the cases, your guesses will be wrong. If you don't know, you can't solve the issue.
SWT itself is not slow. In fact, SWT is just a very thin layer over the respective OS system calls to draw.
One of the problems of SWT is that it's synchronized. To make sure that threading issues cause no problems, there is a global lock. So if you render from several threads at once, this can be a problem.
Or maybe you're not caching resources like colors and fonts properly. These are expensive to create. How many GCs do you create? Do you keep one around or do you create a new one per frame?
But I'm just guessing here. Unless you can prove with a performance monitor "most time is spent in ...", there is no way to help you.
Instead of improving the performance of the drawing routines I would concentrate on the drawing logic. Maybe you can just redraw the difference between the old and the new chart? This of course largely depends on how the charts look like and what data they present.
Try to reduce the drawing operations. Do not try to make them faster.
It may seem like a big step (and it is), but the best approach to improve SWT drawing performance for me was to switch to OpenGL rendering. I do not imply that you should draw your whole UI with it, but the charts part.
There are many approaches to do that. My choice was to use the JOGL library. There are also some examples around the net, showing how to integrate with SWT.
The downside to this approach is that you have to learn and use a new API which is very different from what one knows from java.
On the other hand, as your scenes are getting more complex, the gains of externalizing the rendering to the GPU are getting bigger. I have experienced FPS gains between 2x and 10x. Another good thing is that you don't have to make a deep dive into OpenGL, there are great libraries like jMonkeyEngine, hiding much of the underlying complexity.
Whenever I try to write graphical programs (whether a game or really any GUI app) I always wind up with one or two god classes with way too many methods (and long methods, too), and each class having far too many responsibilities. I have graphics being done at the same time as calculations and logic, and I feel like this is a really bad way to go about organizing my code. I want to get better at organizing my code and abstracting out responsibilities to different classes. Here's an example of where I'd like to start - I want to write a Minesweeper clone, just sort of as practice and to try to improve my software engineering skills. How would I go about making this nice and object-oriented? For the sake of discussion, let's just say I'm using Java (because I probably will, either that or C#). Here's some things I would think about:
should each tile inherit from JButton or JComponent and handle drawing itself?
or should the tiles just be stored as some non-graphical MinesweeperTile object and some other class handles drawing them?
is the 8-segment display countdown timer (pre-Vista, at least) a separate class that handles drawing itself?
when the user clicks, do the tiles have mouse event listeners or does some other collision detection method loop through the tiles and check each one to see if it's been hit?
I realize that there's not just one way to write a GUI application, but what are some pretty basic things I can start doing to make my code more organized, manageable, object-oriented, and just over all write better programs?
edit: I guess I should add that I'm familiar with MVC, and I was originally going to incorporate that into my question, but I guess I didn't want to shoehorn myself into MVC if that's not necessarily what I need. I did searched for topics on MVC with GUI apps but didn't really find anything that answers my specific question.
edit2: Thanks to everyone who answered. I wish I could accept more than one answer..
Here is a simple (but effective) OO design to get you started:
First create a Game object that is pure Java/C# code. With no UI or anything else platform specific. The Game object handles a Board object and a Player object. The Board object manages a number of Tile objects (where the mines are). The Player object keeps track of "Number of turns", "Score" etc. You will also need a Timer object to keep track of the game time.
Then create a separate UI object that doesn't know anything about the Game object. It is completely stand alone and completely platform dependent. It has its own UIBoard, UITile, UITimer etc. and can be told how to change its states. The UI object is responsible for the User Interface (output to the screen/sound and input from the user).
And finally, add the top level Application object that reads input from the UI object, tells the Game what to do based on the input, is notified by the Game about state changes and then turns around and tells the UI how to update itself.
This is (by the way) an adaption of the MVP (Model, View, Presenter) pattern. And (oh by the way) the MVP pattern is really just a specialization of the Mediator pattern. And (another oh by the way) the MVP pattern is basically the MVC (Model, View, Control) pattern where the View does NOT have access to the model. Which is a big improvement IMHO.
Have fun!
use a MVC framework that handles all the hard organization work for you. there's a ton of MVC framework topics on SO.
using high quality stuff written by others will probably teach you faster - you will get further and see more patterns with less headache.
I'm not suggesting this is the only way to do it, but what I would suggest is something like the following. Other people, please feel free to comment on this and make corrections.
Each tile should inherit from something and handle drawing itself. A button seems like the best solution because it already has the button drawing functionality (pressed, unpressed, etc) built in.
Each tile should also be aware of its neighbors. You would have eight pointers to each of its eight neighbors, setting them to null of course if there is no neighbor. When it goes to draw, it would query each neighbor's IsMine() function and display the count.
If none of its neighbors are a mine, it would then recurse into each neighbor's Reveal() method.
For the 7-segment display, each digit is its own class that handles drawing. Then I would make a CountdownSegmentDigit class that inherits from this class, but has additional functionality, namely CountDown(), Set(), and Reset() methods, as well as a HitZero event. Then the display timer itself is a collection of these digits, wired up to propagate zeroes left. Then have a Timer within the timer class which ticks every second and counts down the rightmost digit.
When the user clicks, see above. The tile itself will handle the mouse click (it is a button after all) and call its Reveal() method. If it is a mine, it will fire the MineExploded event, which your main form will be listening to.
For me, when I think of how to encapsulate objects, it helps to imagine it as a manufacturing process for physical parts. Ask yourself, "How can I design this system so it can be most efficiently built and reused?" Think about future reuse possibilities too. Remember the assembly process takes small pieces and builds them up into larger and larger pieces until the entire object is built. Each bit should be as independent as possible and handle its own logic, but be able to talk to the outside world when necessary.
Take the 7-segment display bit, you could have another use for it later that does not count down. Say you want a speedometer in a car or something. You will already have the digits that you can wire up together. (Think hardware: stock 7-segment displays that do nothing but light up. Then you attach a controller to them and they get functionality.)
In fact if you think hard enough, you might find you want CountUp() functionality too. And an event argument in HitZero to tell whether it was by counting up or down. But you can wait until later to add this functionality when you need it. This is where inheritance shines: inherit for your CountDownDigit and make a CountUpOrDownDigit.
Thinking about how I might design it in hardware, you might want to design each digit so it knows about its neighbors and count them up or down when appropriate. Have them remember a max value (remember, 60 seconds to a minute, not 100) so when they roll over 0, they reset appropriately. There's a world of possibilites.
The central concern of a Graphic User Interface is handling events. The user does X and you need to response or not respond to it. The games have the added complexity in that it needs to change state in real time. In a lot of cases it does this by transforming the current state into a new state and telling the UI to display the results. It does this in a very short amount of time.
You start off with a model. A collection of classes that represents the data the user wants to manipulate. This could represent the accounts of a business or vast frontiers of an unknown world.
The UI starts with defining a series of forms or screens. The idea is that is for each form or screen you create a interface that defines how the UI Controller will interact with it. In general there is one UI Controller classes for each form or screen.
The form passes the event to the UI Controller. The UI Controller then decides which command to execute. This is best done through the Command design pattern where each command is it own class.
The Command then is executed and manipulate the model. The Command then tells the UI Controller that a screen or a portion of a screen needs to be redraw. The UI Control then looks at the data in the model and uses the Screen Interface to redraw the screen.
By putting all the forms and screen behind a interface you can rip out what you have and put something different in. This includes even not having any forms at all but rather mock objects. This is good for automated testing. As long as something implements the Screen Interface properly the rest of the software will be happy.
Finally a game that has to operate in real time will have a loop (or loops) running that will be continually transforming the state of the game. It will use the UI Controller to redraw what it updated. Commands will insert or change information in the model. The next time the loop comes around the new information will be used. For example altering a vector of a object traveling through the air.
I don't like the MVC architecture as I feel it doesn't handle the issues of GUIs well. I prefer the use of a Supervising Controller which you can read about here. The reason for this is that I believe automated tests are one of the most important tools you have. The more you can automate the better off you are. The supervising presenter pattern makes the forms a thin shell so there is very little that can't be tested automatically.
Sorry to say it, but it seems you have mess in your head trying to improve your coding too much in one step.
There is no way to answer your question as such, but here we go.
First start with OOP, think about what objects are required for your game/GUI and start implementing them a little at a time, see if there are chances to break up these objects further, or perhaps reunite some objects that make no sense on their own, then try to figure out if you have repeated functionality among your objects, if you do, figure out if this repeated functionality is a (or many) base class or not.
Now this will take you a few days, or weeks to really grok it well, then worry about dividing your logic and rendering.
I have some tutorials that are written in C#. It discusses this very same topic. It is a starting point for a RogueLike game.
Object Oriented Design in C# Converting Legacy Game
Object Oriented Design: Domain Type Objects
Object Oriented Design: Rethinking Design Issues
BROKEN LINK - Object Oriented Design: Baby Steps in Acceptance Testing
For my university assignment I have to make a networkable version of pacman. I thought I would best approach this problem with making a local copy of pacman first and then extend this functionality for network play.
I would have to say that I am relatively new to java GUI development and utilizing such features within java.
http://www.planetalia.com/cursos/Java-Invaders/
http://javaboutique.internet.com/PacMan/source.html
I have started following the above links with regards to game development within java and an example of the pacman game.
I decided to represent the maze as an int array with different values meaning different things. However when the paint method inside the main game loop is run i am redrawing the whole maze with this method.
for (int i : theGame.getMaze())
{
if (i == 4)
{
g.setColor(mazeWallColour);
g.fillRect(curX, curY, cellSize, cellSize);
curX += 25;
}
else
{
curX += cellSize;
}
index++;
// Move to new row
if (index == 25)
{
index = 0;
curX = 10;
curY += cellSize;
}
}
However this is providing me with less then 1fps. Although i've noticed the example linked above uses a similar way of redrawing each time the paint method is called and i believe does this on a image that is not viewable (kinda like double buffering [I've used a BufferStrategy like the first link explains]) What would be a better way to redraw the maze?
Any pointers/advice with this would be useful.
Thank you for your time.
http://pastebin.com/m25052d5a - for the main game class.
Edit: I have just noticed something very weird happening after trying to see what code was taking so long to execute.
In the paintClear(Graphics g) method i have added
ocean = sprites.getSprite("oceano.gif");
g.setPaint(new TexturePaint(ocean, new Rectangle(0,t,ocean.getWidth(),ocean.getHeight())));
g.fillRect(10, 10,getWidth() - 20,getHeight() - 110);
which made the whole thing run smoothly - however when i removed these lines the whole thing slowed down? What could have caused this?
Updated code
First off, I'd recommend that you use named constants rather than having random magic numbers in your code and consider using enums for your cell types. While it won't make your code run any faster, it certainly will make it easier to understand. Also, 'i' is normally used as a counter, not for a return value. You should probably call it cellType or something similar. I'd also recommend that you use a 2D array for your stage map since it makes a number of things easier, both logistically and conceptually.
That said, here are a few things to try:
Pull the setColor() out of the loop and do it once. The compiler might be able to do loop-invariant hoisting and thus do this for you (and probably will), but conceptually, you should probably do this anyway since it appears you want all of your walls to be one color anyway.
Try calling drawRect() instead of fillRect() and see if that draws faster. I don't think it will, but it is worth a shot, even if it looks uglier. Similarly, you can try creating an Image and then drawing that. This has the advantage that it is really easy to tell your Graphics object to implement a transform on your image. Also, consider taking this out completely and make sure that it is being a significant performance hit.
Also, normally you don't need to ask for the parent for its Graphics object and implement painting directly on it. Rather, you should override its paintComponent() method and just utilize the Graphics given to you (possibly calling helper methods as you do). Swing components are double-buffered by default, so you don't need to implement that yourself; just let the swing object do its job and let you know when to paint.
Also, you end up repainting the entire screen, which is something of overkill. If you call repaint(Rectangle), Swing can choose to redraw only the sections of your board that are explicitly marked dirty. When you update one of your sprites, call repaint(r) only on the area of the sprite's old and new locations. When you complete a level and need a new board, then you can call repaint() (without parameters) to redraw the entire map.
You should also look at Sun's tutorial to get some tips for efficiency in Swing.
I still consider myself a beginner with Java, but I recently developed a Frogger-esque game with dynamic map and editor using some of the techniques you've mentioned, and I'm only too happy to provide some help.
As mentioned, enum's are the way to go. I set my map up as a 2-dimensional array and set an enum for each different type, writing a method inside my map class to take in one image and divide each square in the map to each value in my enum.
A tutorial that helped me with mapping can be found on Coke and Code. All the source code is there if you need a hand with any of it, although you do seem to have a decent grasp of what you're doing. If you still need help I could always drag out some source code.
It looks like your call to Thread.sleep doesn't do what you intended, but I don't think it's the source of your trouble. You have:
Thread.sleep(Math.max(0, startTime - System.currentTimeMillis()));
startTime will always be less than System.currentTimeMillis(), so startTime - System.currentTimeMillis() will always be negative and thus your sleep will always be for 0 milliseconds. It's different from the example you showed because the example increments startTime by 40 milliseconds before doing the calculation. It is calculating how long to sleep for to pad out the drawing time to 40 milliseconds.
Anyway, back to your problem. I'd recommend measurement to figure out where your time is being spent. There's no point optimising until you know what's slow. You already know how to use System.currentTimeMillis(). Try using that to measure where all the time goes. Is it all spent drawing the walls?
EDIT - I see this got marked as accepted, so should I infer that the problem went away when you fixed the sleep time? I don't have a lot of Java GUI experience, but I can speculate that perhaps your code was starving out other important threads. By setting your thread to have maximum priority and only ever calling sleep(0), you pretty much guarantee that no other thread in your process can do anything. Here's a post from Raymond Chen's blog that explains why.
The code you listed above can't be the source of the 1fps problem... I have code doing far more than this that runs far faster.
Can you benchmark that code and make sure it's the root of the problem?
I'm no game developer, but that framerate seems very slow.
I'm not quite sure how your code is working, but one possibility for improving rendering performance would be to find those parts of the display that don't change much (such as the walls of the maze) and avoid re-creating them for each frame.
Create a BufferedImage containing the constant elements (maze?, background) and then re-draw it first for each frame. On top of this Buffered image, draw the variable elements (PacMan, ghosts, dots, etc).
This technique, along with many other Java2D performance tips, is discussed in Romain Guy's excellent book Filthy Rich Clients.
Just so you don't worry that it's Java, I worked on a Spectrum Analyzer (Like an o-scope) where the entire GUI portion(the trace, menus, button & wheel handling) was done in Java. When I got there it was getting 1fps, when I left it was 12-20. That had a lot of processing going on and was running on a very slow processor.
Look at only updating parts of the GUI that you need to update. Often you can redraw the entire screen but just set a clipping region to the part that is truly updated.
Be careful about inner loops--they are The Speed Killer.
Try to avoid allocating and freeing huge numbers of objects. I'm not saying don't use objects, I'm saying don't create one for each pixel :)
Good luck
Wow, that's a pretty tough problem to give someone just learning Java.
My advice? Think in terms of objects. Can you write something WITHOUT a user interface that mimics the behavior of the game itself? Once you get that working, you can concentrate on the special problems of the user interface. Yes, start with a local version before the networked piece.
I'm not a gamer. I wonder what Java2D API would offer to make your life better?
How much time do you have to finish it?
This might sound obvious but your performance problem is because you are redrawing the entire maze, which doesn't need to be done, instead you need to redraw only changed parts of your maze.
The way I've approached this issue before is by seperating the updating of the maze from the actual redrawing into different threads (kind of like a threaded MVC). Every time you change a cell in your maze you would mark it as "dirty", your redraw thread will check every now and then to redraw only the dirty cells.
Sorry for the extremly generic advice
Java/Swing double-buffers by default. If you're using Swing, you don't need to double-buffer separately, like other answers suggest.
I agree with Allain, that the code you listed can't be the cause of 1fps. I've written highly inefficient Java/Swing animation code that runs much faster than you describe. Do some more testing to narrow down the cause of the slowness.
If possible, you should keep an image of the maze, and draw it in one library call. It probably doesn't need to be full resolution, either -- if you want a blocky, 8-bit feel, I expect the graphics library will be more than happy to oblige 8^)
Also, as others have mentioned, you can save time by redrawing only those parts of the screen that need updating. This can be annoying to implement, but it may allow you to significantly improve your frame rate. Be sure to do some experiments to make sure this is the case before exerting the required effort!