I am building a three-dimensional tic-tac-toe game. I have already built the game itself that runs in command prompt, and now I am building a system that runs the game on a cube of bi-color LED lamps and an input button.
As the input through the button and the output through the cube will happen simultaneously, this is going to be my first concurrent/reactive programming in functional languages. I am clueless at all. I have read and understood the basics of those programming concepts, but can't quite apply them to my problem.
What kind of strategy and library is suit to this problem? (I don't know if this is a legitimate question..) I'm so lost that I need advice even about where to start from/with.
(In the stragety/library above,) How can an even listener (or anything that reacts to certain events in the system) "update" data, how can such mutable data (which I expect are called rather like mutable reference because data themselves should be immutable) be used like, and how do you explain that it keeps the referential transparency (please ignore this question if nonsense)?
(In the stragety/library above,) How does it deal with such a kind of input that the user can unintentionally input many times? For example, it's hard for us to "tap" a button at just one point of time. I want my program to recognize such sequential inputs as a single input.
Thank you so much for reading my weird English, and I would appreciate a lot if you could give me any pieces of guide or information. Thank you again!
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I've been trying to find a way to capture keyboard input during runtime simulation of my Verilog code. Is this even possible?
I have taken a look at resources like asic-world and the Quick Reference for Verilog found on Google, but found nothing regarding a way to take keyboard inputs.
There seems to be a fundamental misunderstanding here in the difference between a hardware description language used to simulate a design versus using that same description to implement a design in actual hardware. It's like drawing a picture of a pinwheel, blowing on that picture, and expecting the pinwheel to start turning.
You can certainly build a 3-D model of that pinwheel, simulate the force of the wind on that model and watch it turn, and then send that model to a 3-d printer to get your pinwheel. I suppose you could put wind sensors in front of your monitor, and write a program that converts a value from the sensor to a value used in the simulation. The point is, the simulator has no knowledge that the value came from someone blowing on the monitor, it just sees a parameter value change.
Unless you are designing the keyboard hardware yourself and simulating that, there really is not much point in taking keyboard input from a computer and using that to stimulate your design in simulation. The operating system has already abstracted away the keyboard hardware and provides you with a string of character codes. The reason you are simulating in the first place is to verify the functionality of your design. If you find a problem, you are going to want to replay the exact same stimulus until you fix your problem.
Just like the pinwheel example, I do know it's possible for someone to set up a program that reads keyboard input and provides that as stimulus to a simulation. But that involves inter-process communication(IPC) and specific tool knowledge to set that up.
I'm looking to create this project in processing, however, I'm finding the terminology a bit hard. I'm not sure how to call the effect where the line is staying permanently throughout the song to 'draw' the music data.
I would appreciate any guidance on what tutorials I could look at or an answer from someone.
My aim is to create something as close to this as possible:
https://www.youtube.com/watch?v=Bb5PTitqtlc&t=58s
Stack Overflow isn't really designed for general "how do I do this" type questions. It's for specific "I tried X, expected Y, but got Z instead" type questions. But I'll try to help in a general sense:
You need to break your problem down into smaller pieces and then take those pieces on one at a time. Write down exactly what you want to happen, in English, and that will be an algorithm that you can think about implementing with code.
Get something simple working. Can you write a simple sketch that plays a song? Then work your way forward in small steps. Can you write a simple sketch that prints out some numeric values based on the song that's playing? Separately from that, can you create a very simple visualization using hard-coded numbers? Get all of that working separately before you think about combining them into a sketch that shows a visualization based on a song that's playing.
Then if you get stuck, you can post a more specific question along with a MCVE. Good luck.
First I want to apologize for my approximate English, as I'm French. I'm currently making a real-time game in java, using LWJGL.
I have some questions regarding game loops:
I'm running the rendering routine in a thread. Is it a good idea? Usually, the rendering routine is fairly slow and should not slow down the world update (tick) routine, which is way more important. So I guess using a thread here seems like a good idea (minus the complications from using a thread).
In the world update routine, I'm updating a list of entities with the current time. Each entity can then compute their own deltaTime, corresponding to the last time they were updated. This differs from the usual update loop, which updates every entity in the list with the same deltaTime. This seemed appropriate because of the threaded rendering. Is it a good idea? Should I use the second method instead? If so, is the threaded rendering still needed? If so, do I have to add a maximum deltaTime?
In general, is it a good idea to have a maximum deltaTime?
Thanks for your time!
Is it a good idea? Separate threads are fairly advanced stuff, I see no reason to do multithreading to begin with. All the mobile games I have worked on so far have not needed multiple threads, even though they are 'real-time'. Hardcore PC and console games are where multithreading really starts to come into play. Here is a link to a recent talk on the subject if interested : http://archive.assembly.org/2011/seminars/adventures-in-multithreaded-gameplay-coding.
Sounds like this could cause some strange things if the physics are not handled in one go. Not sure about this. Colliding an object that has already been updated to another position with an object that comes another time, for example, correcting this sort of situation may become problematic? Fast moving collisions may need to be subdivided, which may be why you have the separate update thread, but why not have them all calculated as happening at the same time?
'Variable timestep' and 'Fixed timestep' are the options available for rendering. Most games at the moment seem to choose a 30 fps fixed timestep. The rendering has to be kept under the limits so no catching up should be needed.
One problem with variable timestep is you are forced to pass deltaTime to all time-dependent areas. Fixed timestep is handy as you can assume you are running at say 30 fps, and use that value everywhere. It is a preferred method at the moment as far as I know.
Though this question is a few years old…
AFAIK,
Rendering is usually done in separated processor — GPU, so they're already a separated thread. But, drawing command must be processed by graphics driver (which is running in CPU) before dispatched to GPU, and this processing may be saved by being multi-threaded. Anyway in this case, you're responsible to manage synchronization between logics and rendering thread.
Generally speaking, games are all about interactions between objects, and it's very hard to divide state-graph into fully separated divisions. As a result, whole game state usually becomes single graph, and this graph cannot be updated while being rendered. In this case, you have no benefit by being multi-threaded.
If you can keep a separated immutable data for rendering, than you may gain some benefit from rendering in separated thread. But otherwise, I don't recommend it.
In addition, you should consider GC if you truly want a realtime game. GC related performance issues usually the biggest obstacles to make realtime stuffs.
I want to code a trading bot for Magic: The Gathering Online. This bot should wait until someone offers to trade, accept, look through the cards available from the other trader (the information is shown on screen), and perform other similar functions. I have several questions:
How can it know that someone is offering a trade?
How can it know that the other trader has some card (the informaion is stored in pictures)?
I just cannot imagine right now how to do it, I have no experience with it, until now I've been coding only console programs for my physics neсessities.
First, you should note that some online games forbid bots, as they can give certain players unfair advantages. The MTGO Terms of Service do not seem to say anything about this, though they do put restrictions on anything that might negatively impact the service. They have also said that there is a possibility they will add an API in the future, so they don't seem to be against the idea of automation, but are not supporting it at the moment. Tread carefully here, but it looks like it should be OK to write a bot as long as it is not harmful or abusive. This is not legal advice, and it would be a good idea to ask the folks who run MTGO for permission. edit since I wrote this, it has been pointed out that there are lots of bots already, so there should be no problems writing bots.
Assuming that it is not forbidden by the terms of service, but they do not have an API, you will have to find a way to detect what's going on, and control the game automatically. There's a pretty good series of articles on writing poker bots (archived copy), which has some good information on how to inject a DLL into an application, scrape the screen, and control the application. That might provide you with a starting point for doing this sort of thing.
You might also want to look for tools that other people have already written for doing this. It looks like there are several existing MTGO bots, but they all seem a bit sketchy (there have been some reports of them stealing passwords), so be careful there.
Edit
Since this answer still seems to be getting upvotes, I should probably update it with some more useful information. Since writing this, I have found a great UI automation system called Sikuli. It allows you to write programs in Python that automate a GUI. It includes image recognition features which make it very easy to recognize buttons, cards, and other UI elements; you just take a screenshot, crop it down to include just the thing you're interested in, and do fuzzy image matching (so that changing backgrounds and the like doesn't cause the match to fail). It even includes a custom IDE that allows you to embed those screenshots directly in your source code, so you can see exactly what the code is looking for. Here's an example from the documentation (apologies for the code formatting, doing images inline in code is not easy given StackOverflow's restricted subset of HTML):
def resizeApp(app, dx, dy):
switchApp(app)
corner = find(Pattern().targetOffset(3,14))
drop_point = corner.getTarget().offset(dx, dy)
dragDrop(corner, drop_point)
resizeApp("Safari", 50, 50)
This is much easier to get started with than the techniques mentioned in the article linked above, of injecting a DLL into the process you are debugging. Sikuli runs entirely at the UI level, so you never have to modify the program you are automating or worry about changes to the internals breaking your script.
One thing it is a bit poor at is handling text; it has OCR features, but they aren't all that good. If the text is selectable, however, you can select the text, copy it, and then look directly at the clipboard.
If I were to write a bot to automate something without a good API or text-based interface, Sikuli is probably the first tool I would reach for.
This answer is constructed from my comments.
What you are trying to do is hard, any way you try and do it.
Arguably the easiest way to do it is to totally mimic the user. So the application presses buttons, moves the mouse etc. The downside with this is that it is dependant on being able to recognise the screen.
This is easier if you can alter the games files as you can then just skin ( changing the image (texture)) the required cards to a single unique colour.
The major down side is you have to have the game as the top level window or have the game running in a virtual machine. Neither of which is ideal.
Another method is to read the processes memory. You may be able to find a list of memory locations, which would make things simpler, otherwise it involves a lot of hardwork, a debugger to deduce the memory addresses. It also helps (a lot) to be able to understand assembly.
The third method is to intercept the packets, and alter them. This is easier that the method above as it (at least for me) is easier to reverse engine the protocol as you have less information to deal with. It is just a matter of setting up a packet sniffer and preforming a action with one variable different (for example, the card) and comparing the differences.
The thing you need to check are that you are not breaking the EULA. I don't know how the game works, but most of the games I have come across have a EULA that prohibits (i.e. You get banned) doing any of the things I have mentioned.
I am in the process of developping a game, and after two months of work (not full time mind you), I have come to realise that our specs for the game are lacking a lot of details. I am not a professional game developper, this is only a hobby.
What I would like to receive help or advices for is this: What are the major components that you find in games, that have to be developped or already exists as librairies? The objective of this question is for me to be able to specify more game aspects.
Currently, we had specified pretty much only how we would work on the visual, completely forgetting everything about game logic (AI, Entities interactions, Quest logic (how do we decide whether or not a quest is completed)).
So far, I have found those points:
Physics (collision detection, actual forces, etc.)
AI (pathfinding, objectives, etc.)
Model management
Animation management
Scene management
Combat management
Inventory management
Camera (make sure not to render everything that is in the scene)
Heightmaps
Entities communication (Player with NPC, enemy, other players, etc)
Game state
Game state save system
In order to reduce the scope of this queston, I'd like it if you could specifically discuss aspects related to developping an RPG type of game. I will also point out that I am using XNA to develop this game, but I have almost no grasp of all the classes available yet (pretty much only using the Game component with some classes that are related to it such as GameTime, SpriteBatch, GraphicDeviceManager) but not much more.
You have a decent list, but you are missing storage (save load), text (text is important in RPGs : Unicode, font rendering), probably a macro system for text (something that replaces tokens like {player} with the player characters name), and most important of all content generation tools (map editor, chara editor, dialog editor) because RPGs need content (or auto generation tools if you need ). By the way have links to your work?
I do this exact stuff for a living so if you need more pointers perhaps I can help.
I don't know if this is any help, but I have been reading articles from http://www.gamasutra.com/ for many years.
I don't have a perfect set of tools from the beginning, but your list covers most of the usual trouble for RUNNING the game. But have you found out what each one of the items stands for? How much have you made already? "Inventory Management" sounds very heavy, but some games just need a simple "array" of objects. Takes an hour to program + some graphical integration (if you have your GUI Management done already).
How to start planning
When I develop games in my spare time, I usually get an idea because another game lacks this function/option. Then I start up what ever development tool I am currently using and try to see if I can make a prototype showing this idea. It's not always about fancy graphics, but most often it's more about finding out how to solve a certain problem. Green and red boxes will help you most of the way, but otherwise, use Google Images and do a quick search for prototype graphics. But remember that these images are probably copyrighted, so only use them for internal test purposes and to explain to your graphic artists what type of game/graphic you want to make.
Secondly, you'll find that you need to find/build tools to create the "maps/missions/quests" too. Today many develop their own "object script" where they can easily add new content/path to a game.
Many of the ideas we (my friends and I) have been testing started with a certain prototype of the interface, to see if its possible to generate that sort of screen output first. Then we build a quick'n'dirty map/level-editor that can supply us with test maps.
No game logic at this point, still figuring out if the game-engine in general is running.
My first game-algorithm problem
Back when I was in my teens I had a Commodore 64 and I was wondering, how do they sort 10 numbers in order for a Highscore? It took me quite a while to find a "scalable" way of doing this, but I learned a lot about programming too.
The second problem I found
How do I make a tank/cannon fire a bullet in the correct direction when I fly my helicopter around the screen?
I sat down and drew quick sketches of the actual problem, looked at the bullet lines, tried some theories of my own and found something that seemed to be working (by dividing and multiplying positions etc.) later on in school I discovered this to be more or less Pythagoras. LOL!
Years and many game attempts later
I played "Dune" and the later C&C + the new game Warcraft (v1/v2) - I remember it started to annoyed me how the lame AI worked. The path finding algorithms were frustrating for the player, I thought. They moved in direction of target position and then found a wall, but if the way was to complex, the object just stopped. Argh!
So I first sat with large amounts of paper, then I tried to draw certain scenarios where an "object" (tank/ork/soldier) would go from A to B and then suddenly there was a "structure" (building/other object) in the pathway - what then?
I learned about A-star pathfinding (after solving it first on my own in a similar way, then later reading about the reason for this working). A very "cpu heavy" way of finding a path, but I learned a lot from the process of "cracking this nut". These thoughts have helped me a lot developing other game algortimes over time.
So what I am saying is: I think you'll have to think more of:
How is the game to be played?
What does the user experience look like?
Why would the user want to come back to the game?
What requirements are needed? Broadband? 19" monitor with 1280x1024?
An RPG, yes - but will it be multi-user or single?
Do we need a fast network/server setup or do we need to develop a strong AI for the NPCs?
And much more...
I am not sure this is what you asked for, but I hope you can use it somehow?
There are hundreds of components needed to make a game, from time management to audio. You'll probably need to roll your own GUI, as native OS controls are very non-gamey. You will probably also need all kinds of tools to generate your worlds, exporters to convert models and textures into something suitable for your game etc.
I would strongly recommend that you start with one of the many free or cheap game engines that are out there. Loads of them come with the source code, so you can learn how they have been put together as you go.
When you think you are ready, you can start to replace parts of the engine you are using to better suit your needs.
I agree with Robert Gould's post , especially about tools and I'd also add
Scripting
Memory Management
Network - especially replication of game object states and match-making
oh and don't forget Localisation - particularly for text strings
Effects and effect timers (could be magical effects, could just be stuff like being stunned.)
Character professions, skills, spells (if that kind of game).
World creation tools, to make it easy for non-programmer builders.
Think about whether or not you want PvP. If so, you need to really think about how you're going to do your combat system and any limits you want on who can attack whom.
Equipment, "treasure", values of things and how you want to do the economy.
This is an older question, but IMHO now there is a better answer: use Unity (or something akin to it). It gives you 90% of what you need to make a game up front, so you can jump in and focus directly on the part you care about, which is the gameplay. When you run aground because there's something it doesn't do out of the box, you can usually find a resource in the Asset Store for free or cheap that will save you a lot of work.
I would also add that if you're not working on your game full-time, be mindful of the complexity and the time-frame of the task. If you'll try to integrate so many different frameworks into your RPG game, you can easily end up with several years worth of work; maybe it would be more advisable to start small and only develop the "core" of your game first and not bother about physics, for example. You could still add it in the second version.