I am at the early stages of developing a 2d shooter game (Picture Metal Slug) using JAVA. I want to be able to shoot many bullets at the time. In order to do so i use a Set to control the current bullets on the screen, each time you click you spam a bullet, adding it to the screen and to the set of bullets (so in each frame, you move each bullet in the set according to their speed).
My problem is that if I click fast enough I get an
ConcurrentModificationException
Is there a data structure able to add and remove fast enough different objects without getting such exception? I can not find any that suit me.
Thanks in advance
The data structure able to suit your requirements is a ConcurrentHashMap, check:
http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentHashMap.html
Related
So basically every time i shoot, a new dynamic body is created with linear impulse , after constantly shooting my bullets game starts to get slow( it's obvious because i constantly create a new object..). What should i do to avoid this problem, i tried deleting objects, bodies?
Thank you for your answers in advance.
I'm still new to Java, but the way I understand it is that if anything references an object, that object won't be picked up by the recycler. Triple check all of your arrays and lists to make sure one isn't filling up with bullets. Display the sizes of your arrays while playing to see if one is acting weird.
For each bullet you probably want to see if it is off screen. If so, remove it from the list/array.
I know I am late but for future readers, Libgdx has something called object pooling specifically meant for things like this.
first post on here so be gentle!
I am currently designing an ad banner for my college assignment, the main feature i have is a car spinning, like a full 360 degree view.
Now I have took all of the media I needed and photoshopped them to how they need to look I just need some diction of where to go next.
I did want it where you can click and drag anywhere on the screen and it pulls the car around to where you want it, but I don't even know where to start with that! (please help if you can)
So I thought I would instead have it as a sort of image gallery with a next and previous button to select the next frame you want. But I don't like the way it looks so I was wondering if there was a way with action script where I could click on a button(next/previous) and the car would spin until I un-click? Rather than me having to keep clicking to load the next frame.
Also if I could I wanted a left to right scroll bar what could control the images, do you know any way of doing that?
Many Thanks in advance for ANY help!
Jordan.
If you want a commercial solution:
Krpano -> very advanced, excellent support, highly recommended for panoramas, 2D object is a bit lacking tho. Examples of 2D object
Object2VR -> very easy to use, not that great support, lacking API.
I would go personally for krpano because it is simply a superior tool. Great for panos, tons of possibilities. If you want it easy, go for Object2VR.
Now if you want to program it, and you need to program it, there are many options how you can do it. First of all, you need to load all the images into your app. Even if you don't maintain them in memory (that would be prefered, tho), you should load them so they are cached and can be reloaded fast. Your rotation can be achieved by "re-loading" the next image, or if you keep them in memory by simply referencing the next index of the array/vector. You always keep a reference index and upon click you simple increase the index and load the image. You than swap the images. It is too broad to explain, you will simply have to begin and ask for advice with some specific code.
I'm making a game similar to 'Run' (http://www.albinoblacksheep.com/games/run) but I can't quite figure out the floor part. I'm not wanting the sides and a ceiling like in 'Run', just the main floor.
I'm new to Flash game development (AS3) but I know the basics. I realise the character isn't moving and is just turning (the level itself moves). How do a make a continuous floor, do I have to make a very long .fla file, or do I have to do this with code?
All ideas and help appreciated, Thanks. =)
You should use Tiles. Basically, a tile game consists of a lot of squared tiles, which are inserted when appear in screen and removed when goes out.
In your case, maybe you could use a big tile, with screen's size.
You can visualize a good example here, also a very good resource for gamedev on Flash.
You need to generate sprites of the edge of the screen and either recycle them when their x < some value or dispose and create new ones.
I think you can just use Bitmap.draw() to draw different pixels on a Bitmap that you've applied a 3D transformation to. You can see the basic concept illustrated here.
I am working on a project that will have the user seeming to fly in 3D from point to point in an architectural model, based on choices. It is a tree-flow, with everything starting from one point and branching out from there, and it only needs to animate in one direction, which makes things easier.
The thing is that the animations from place to place are C4D animations rendered as PNG sequences, and in total they will be VERY large, so I want to package each segment as an individual SWF and load and unload them dynamically as needed.
I expect the first thing to do will be to see if I can have my upstream guy render them as JPG sequences instead... is that a good idea performance-wise? I imagine it will be in terms of bandwidth.
The main question, however, is how I can dynamically load one of these sequences, have it play and stop on its final frame (over which data and choices will display), and then - based on the user's selection - load and play the next animation seamlessly from the first, without endlessly stacking up loaded clips. When the user goes back a level, I only need to jump to the first frame of the animation, but going forward always involves a smooth flight.
I suspect the solution may have to do with adding, say, to the loader by specific names, then as we transition out, load the next one with a specific name, and then unloadChild() and do whatever other kind of garbage collection I need to do to purge from memory entirely. I want to be as cognizant of memory usage and performance as I can, because at certain spots there will be other images and videos loaded on top of the flight animations.
Does anyone have any ideas about this? I'm sure it's a common need, I've just never done it before, and I want to do this as timeline-free as possible.
Thanks in advance for any advice!
Mattynabib
When i play a video game (any old game like a racing game or pack man or whatever) how does everything get displayed on the screen in terms of what is going on in the program? is there some big RenderEverything method that is executed once a frame? this strikes me as a bit of a slow way to go about such a thing though.
EDIT: as a follow up question:
How does the computer doing the rendering define the frame both for rendering graphis and for doing in game activites like having a character walk across a room slowly. Like is there some clock t that keeps increasing and every render and every movment hapens as a function of t? If so how is t defined relative to the system that it runs on?
I intend this question to be somewhat synonomous to: When my cursor in the screen right now blinks twice every second how does it know what a second is? Also in java how would i make a program that displays a line of text then waits a second and desplays another line? (perahps this is getting too spacific)
They have a loop. Inside this loop it's called a method for rendering graphics and another for processing logic (and getting input). So this method will calculate everything based on the input and the graphics method print on screen based on the data already computed -- like what should be printed and its position.
Is that what you asked?
Questions about game development should be made here: https://gamedev.stackexchange.com/ :)
When i play a video game (any old game like a racing game or pack man or whatever) how does everything get displayed on the screen in terms of what is going on in the program? is there some big RenderEverything method that is executed once a frame?
Depends on the game. 2D games may be able to keep part of scenes rendered in previous frames, especially old games without scrolling screens. 3D game most likely redraws entire screen. Also good game never renders everything - only visible objects. Because rendering everything is slow, while rendering only visible objects is significantly faster.
this strikes me as a bit of a slow way to go about such a thing though.
You are free to try to find different way. Normal game repaints every visible object. Non-hardware-accelerated game may track unmodified screen regions, and repaint only objects that changed, moved, etc. Hardware accelerated game doesn't have to do that - it can redraw everything on screen every frame. As game/frame/scene complexity increases, it is much easier to simply repaint every visible object during every frame instead of tracking things that changed from previous frame.
That's basically it. The 'video game' is effectively a big state machine where all state is updated according to a frame rate. User input combined with game rules and enemy AI affect the state of the game. Once every frame the players view of the game, not the complete view of the game, is rendered.
Download the quake source, it makes for some interesting reading in the comments and also gives excellent insight as to how a game is constructed.