I've been working with several different programming languages recently, and I've come to the conclusion that I don't really like the display list in Actionscript. I would much rather have an update/draw loop and draw and manage everything manually like in XNA (C#).
What I do like in actionscript is the ease of use of events, movieclips animations and vector graphics.
What are the possibillites for this?
I would really like to be able to use animated movieclips, but I think that would be impossible without the display list, so I could settle with writing my own animation system with spritesheets.
Rewriting the entire event system isn't something I look forward to though.
Are there any (molehill) frameworks that work without the display list?
You can do something similar by creating a Bitmap with the same size as the stage, attaching it to the stage as a child and using it like a "screen", by blitting your graphics on it every frame (on ENTER_FRAME event). I think it's even mentioned somewhere in the official Adobe documentation, as a method of efficiently animating a large number of objects.
I would advise you to muster up the courage and let go of C# when programming in ActionScript. As Bjarne Stroustrup wisely said in his book The C++ Programming Language:
...applying techniques effective in one language to another typically
leads to awkward, poorly performing, and hard-to-maintain code. Such
code is also most frustrating to write because every line of code and
every compiler error message reminds the programmer that the language
used differs from 'the old language.' You can write in the style of
[another language], but doing so is neither pleasant nor economical in a language
with a different philosophy.
I think that applies very well to the question you're asking here.
Related
I started learning libgdx lately and, obviously, I've been looking into several sample games and tutorials.
I couldn't help but notice inconsistencies into how authors/developers choose to design their game classes - especially when it comes to the "renderer" classes.
In some examples, I see some authors relying solely on the "renderer" classes to draw using the SpriteBatch. While others tend to send a SpriteBatch reference to game objects to do the rendering themselves.
For example, considering a Bird class, some would associate it with a Texture type, load it and render the bird inside a Bird.render method. Others load the Texture in separate "Renderer" classes (Like WorldRenderer) and draw the bird texture from there by relying on position parameters such as bird.getX() and bird.getY().
I wrote some sample games using XNA in the past and I used to embed the rendering logic into my game classes. My renderer class used to simply loop over all "enabled" game objects and call "GameObject.render()". Is this a bad practice in libgdx?
It is not about bad practice in libgdx, it's a general opinion oriented problem.
Usually, it's always better if you can separate game logic and rendering logic (preferably in different classes). This way, if you want to change look and feel of the game (re-skin it) later, you won't have to touch the code containing game logic (less testing required, no new bugs).
But not everyone follows this (some might think it as overkill for small things). Having renderer class for each and every small thing might seem too much. So you'd see a lot of code having mixed both rendering and game logic.
If you want to build scalable games, I'd suggest you to follow MVC (game codes so large that developers might get lost). But at the same time, you should be pragmatic enough to know when not to use it (small games taking 2 weeks to make).
So it's for you to decide really, since it's about personal preferences.
Hope this helps.
A lot probably depends if the developer has used MVC (Model-View-Controller) before. In an MVC design the "game" objects like bird are part of the model and don't directly have anything to do with the display(view). Sometimes it depends on the technologies being used, for instance the LibGDX Scene2d API warns you that "Scene graphs have the drawback that they couple model and view".
In a worldRenderer you should render all your objects. All your objects belongs to a world so it makes sense. A benefit to add attention to is that you can always keep all gameObjects in separate arrays aswell as in a big array (containing all).
Array: GameObjects
Array: Birds (also in GameObjects)
Array: Cows (also in GameObjects)
Array: Cats (also in GameObjects)
This makes it possible for you to decide on what "z" axis all gameobjects should rely on (render) aswell as just loop through them all right away (update)
Novice programmer here.
I'm currently coding a simple game with the title screen and the main game loop in separate "keyframes" (this is in CS6). Once I transition from the title screen to the game keyframe I'm concerned that the buttons/movieclips/variables are going to stick around and waste memory + clutter the screen.
If I have the variables/functions set to "private" will that help the garbage collector take care of them? How should I go about "clearing the screen" and making sure I'm not being wasteful/leaking memory?
None of the tutorials or books I've been reading to learn AS3 have really covered this topic, if there are any good guides or obvious tips I've missed as far as memory management best practice goes in AS3 I'm interested in seeing them. The only thing I've learned so far is that I should manually set all my event listeners to weak reference.
Bonus question: I'm using a full-screen bitmap and blitting things onto it for my display. If I am blitting dozens of objects onto the screen per frame I don't need to worry about the blitted "sprites" that are being "covered up," do I? I'm hoping that the bitmap is one pixel thick and not just stacking things on top of each other.
Firstly, the only way you will have total control over your resources is if you leave the timeline for what it was intended for, creating and exporting assets in to swc or swf format, which you can embed the former and either embed or load the latter.
What you should be doing is learning how to develop in an Object Oriented manner, starting with a Document class (as you're using CS6) and then building your game using a series of classes which have defined tasks. Using classes promotes re-usability throughout your game. Depending on the complexity, I would consider a framework like PureMVC or Robot legs.
Garbage collection in flash is mark and sweep, which means you have to de-reference all your objects, which usually starts with removing associated listeners, timers and any further references to them, eg. clearing from arrays or objects hashes. Finally you would set the object in question to null which makes it 'elligible' for garbage collection but does not actually guarantee it. Flash will come and clean up as it sees fit.
Personally if you could get hold of Flash Builder, this has a fantastic memory management profiling tool, when you are developing using OOP mentioned above, you can use this tool to see all the instances that exist in your game. Now the good part here is you can do a memory snapshots in time, and compare them to see which objects linger around and are causing memory leaks. There is a garbage collection button which you should invoke between capturing snapshots, this is only available as you are developing, though using Adobe AIR you can force gc calls manually.
Regarding your bonus question, im not sure how you are doing this blitting, if you are adding objects to the stage this is increasing memory, you cannot avoid this. What you describe as 1px thick is what flash renders, you can see what is being redrawn by right clicking on the stage and selecting the redraw regions option, to see a red box showing what flash has to redraw, it will only redraw what it needs to, this is useful to check if your frame rate suffers.
So to summarize:
Consider using Flash CS6 for creating assets.
Learn about Object Oriented programming in Actionscript 3.
Consider developing in Flash Builder (or free Flash Develop).
OOP will help with organisation and de-referencing objects for garbage collection.
I hope this helps and good luck with your game.
I'm finally taking the time to go from Actionscript 2.0 to Actionscript 3.0, and I'm trying to figure out how to pull off a simple depthing system I had at my disposal in 2 that doesn't seem to be possible in 3.
The code goes something like this:
onClipEvent(enterFrame){
this.swapDepths(1000+Math.ceil(this._y));
}
This way, I could easily get mock 3D effects as something moves up and down on the screen.
Also understand, this is a really basic application of the idea. Usually I'd put in logic to allow multiple movieclips to exist at one Y value.
Whatever the case, with the changes to AS's depthing, this method is no longer possible in this state. Maybe I just have an incomplete knowledge of how the new system works, I am just a hobbyist AS programmer, but is there a better/simpler/more elegant way to pull this off in AS3.0, short of keeping track of every clip/sprite on the stage?
I'm using Adobe Flash CS4 professional, if that makes any difference. Additionally, this isn't of much importance, yet. I'm still getting my bearings, but I came across the depthing changes during a quick project a few weeks ago when learning about adding Child MovieClips, and it seemed like I could only easily add things to the front or back of the stage, not inbetween.
The main difference between AS 2.0 and AS 3.0 is the depth management. In AS 2.0 you could use any depth you wanted. However, with AS 3.0 you can not (leave any depth unused/empty).
There are still several methods that allow you to change depth, swap depths etc. so you are free to use those.
I'm making a flash game, and I can't decide to use a bigger stage or a smaller one, with scrolling background to make it run smoother. I's going to be some kind of strategy game if it matters.
Thanks
One option is to have a bitmap object the size of your stage for example 800x600, then draw your objects into the bitmapdata of that bitmap using copyPixels this is known as blitting and is pretty fast.
Another option is to just use the flash display list and add every object as sprites onto the stage.
Second method is easier to handle in terms of mouse events and stuff.
My advice is to start with the second option and see if performance is enough, if not go with option 1.
There are many, many variables that determine the performance of your application.
To answer your question, a smaller stage area will make your program run faster. The amount of difference will depend on the way your application deals with display objects. Flash will not render things that are completely outside the stage bounds. So keeping only those objects that are needed at any given time on the stage is a good practice.
using flash player 11's new stage3D features (even for 2D stuff) will likely make your game very smooth. Lots of good frameworks out there that can take care of the low-level stuff if you don't want to get into it. For 2D, starling is very easy to get started with, and seems to be Adobe's favored framework.
At a bare minimum, make sure you use GPU acceleration in your output/compiler options.
There are LOTS of other tips for optimization people could get into, but that is better suited for google searches as Stackoverflow is about specific questions.
I am looking to get into learning how to use the html5 canvas to do animations as well as other things. I have an excellent knowledge of javascript and programming in general (mostly php but can adapt to anything). However, I have not had the opportunity to do much with graphics in the past. I have created nice smooth animations using javascript/jquery but the canvas object seems to be alot more than just that. The hardest part I am finding as I have been playing with it is that you have no reference to an object on the stage unless you store the reference. For example if I create a div on the page I have that reference to the object. However, with the canvas object if you create something within it, it draws that element on the stage giving you no reference to it. So you have to manually store the details of that object as I understand it and I could be wrong (if I am please correct me).
Anyways the whole point of this post is to see if anyone can point me to some really good articles/help about working with the canvas object. Not just drawing graphics to it cause I have been able to accomplish that very easily. But I would like to articles/help on managing the objects on the canvas. I want to make sure that I am doing this correctly/efficiently for the future of the technology. Also I am willing to purchase a book on working with html5 canvas/graphics/animations but most of them that I have seen go over the whole scope of html5 and leave out alot of the details of actually working with the canvas. So if you know any good books with my requirements please recommend them here.
Any help is appreciated.
There are nice libraries to do very basic to complex graphics using HTML5/WebGL
This may not actually teach you how the animations work. But if you are interested, check Three.js
https://github.com/mrdoob/three.js/
Read article "Creating a Framework For Canvas: Objects and Mouse". Not animation, but you can find there something interestring.
Read source code of any big framework, e.h. three.js, or LibCanvas
Read "HTML5 Canvas - Native Interactivity and Animation for the Web"