I'm looking for articles on tile based games, like the old ultima 6&7, or even puzzle pirates. Specifically:
How they keep track of objects on the map. Objects such as other characters, or trees, or things the character can move.
AI behind the characters. How the game handles character behavior for
characters on the map that are off screen. Especially with very large maps and numerous characters.
I remember checking out Amit's Game Development page back when I wrote some games. He has a great sub-section on tiles that has most of what you want.
You could look through back issues of Game Developer magazine to see if something addresses what you're asking in detail.
For (1) the easiest way of dealing with a tile-based map where each tile can contain multiple objects is to just have a big multidimensional array of structs representing each tile. The struct contains a pointer to the head of a linked list representing all the objects in that tile. This is very memory efficient and lets you quickly find everything in a certain tile while also enumerating them along some other axis (eg, owner, allocation arena, etc).
RogueBasin is devoted to Rogue-like games (e.g. Rogue, NetHack, ). All of those games were based on a simple square grid. The site has an extensive section on developing games like that: http://roguebasin.roguelikedevelopment.org/index.php?title=Articles
You will find both suggestions and code there which could be used to build a game like you describe. After all, the only real difference between Rogue/Larn/NetHack/etc. and Diablo or the Ultima series is using simple text characters to depict the map and gameplay vs. isometric sprites.
In particular you will find information about calculating the area illuminated by a torch or lantern the user is carrying, data structures for storing maps, algorithms for automatic generation of maps, and lots of notes for how different games which have already been written chose to address these problems.
Check out Gamasutra. They have loads of articles for all kinds of game development.
The map would be an array of values. It could be divided into discrete parts. Only parts in range of the player would be loaded and the objects & npc in these parts active.
Since the old hardware had very limited memory and cpu, those games would only be able to load and process parts of the maps.
Related
I am trying to create multiple SKSpriteNodes that each have their own independent variables that I can change/modify. I would like to be able to run a function when the app starts, for example "createSprites(5)" which would create 5 sprites with the image/texture "shape.png" at random x and y coordinates and add all 5 Sprites to an array that I can access and edit different Sprite's positioning based on the index value. I would then like to be able to have another function "addSprite()" which, each time it is called, create a new Sprite with the same "shape.png" texture, place it at another random X and Y coordinate and also add it to the array of all Sprites to, again, be able to access later and change coordinates etc.
I have been looking through so many other Stack Overflow pages and can not seem to find a solution. My ideal solution would simply be the two functions I stated earlier. One to create an "n" number of Sprites and another function to create and add one more sprite to the array each time it is called.
Hope that makes sense, I'm fairly new to Swift and all this Sprite stuff, so simple informative answers would be very much appreciated.
You're not going to find an ideal solution from the past because nobody has likely had exactly the same desire with both Swift and SpriteKit. Having said that, there's likely partial answers you can blend together, and get the result you want or, at least, an understanding of how to do it.
Sprite Positioning in SK is probably the first thing to read up on:
https://developer.apple.com/library/content/documentation/GraphicsAnimation/Conceptual/SpriteKit_PG/Sprites/Sprites.html
having gotten that figured out, you can move to random positions.
Random positioning of Sprites:
Duplicate Sprite in Random Positions with SpriteKit
Sprite Kit random positions
Both use earlier versions of randomisation that aren't as powerful as what's available now, in GameplayKit. So... Generating random numbers in Swift with GameplayKit:
https://www.hackingwithswift.com/read/35/overview
It's hard to overstate the importance of understanding the various possibilities of game design implications of varying types of randomisation, so probably wise to read this, from Apple:
https://developer.apple.com/library/content/documentation/General/Conceptual/GameplayKit_Guide/RandomSources.html
After that, it's a case of needing to determine what constitutes a time or event at which to create more sprites at more random positions, and how fussy you want to be about proximity to other sprites, and overlaps.
This is a Theoretical question about the use of classes, something which I haven't yet had too much experience. I just want some opinions about whether this would be the best way to go about programming for my task.
The goal of my project is to track objects that move across the frame of the camera, I have been able to detect the objects and store their centre point for each frame (note that this point is only stored until the next frame is read and new points are stored).
I am thinking of using a class store the previous positions of the objects as well as an ID of some kind so that I can differentiate the objects from each other.
Would this be over complicating things? or would it be better to simply store the history points into a basic array of points?
For some more insight, I will be tracking people from an overhead counter, so realistically there shouldn't be more than 15 objects present in the frame at one time. The images below show the detected heads and their centre points (these are the objects being tracked).
I'm interested in different algorithms people use to visualise millions of particles in a box. I know you can use Cloud-In-Cell, adaptive mesh, Kernel smoothing, nearest grid point methods etc to reduce the load in memory but there is very little documentation on how to do these things online.
i.e. I have array with:
x,y,z
1,2,3
4,5,6
6,7,8
xi,yi,zi
for i = 100 million for example. I don't want a package like Mayavi/Paraview to do it, I want to code this myself then load the decomposed matrix into Mayavi (rather than on-the-fly rendering) My poor 8Gb Macbook explodes if I try and use the particle positions. Any tutorials would be appreciated.
Analysing and creating visualisations for complex multi-dimensional data is complex. The best visualisation almost always depends on what the data is, and what relationships exists within the data. Of course, you are probably wanting to create visualisation of the data to show and explore relationships. Ultimately, this comes down to trying different posibilities.
My advice is to think about the data, and try to find sensible ways to slice up the dimensions. 3D plots, like surface plots or voxel renderings may be what you want. Personally, I prefer trying to find 2D representations, because they are easier to understand and to communicate to other people. Contour plots are great because they show 3D information in a 2D form. You can show a sequence of contour plots side by side, or in a timelapse to add a fourth dimension. There are also creative ways to use colour to add dimensions, while keeping the visualisation comprehensible -- which is the most important thing.
I see you want to write the code yourself. I understand that. Doing so will take a non-trivial effort, and afterwards, you might not have an effective visualisation. My advice is this: use a tool to help you prototype visualisations first! I've used gnuplot with some success, although I'm sure there are other options.
Once you have a good handle on the data, and how to communicate what it means, then you will be well positioned to code a good visualisation.
UPDATE
I'll offer a suggestion for the data you have described. It sounds as though you want/need a point density map. These are popular in geographical information systems, but have other uses. I haven't used one before, but the basic idea is to use a function to enstimate the density in a 3D space. The density becomes the fourth dimension. Something relatively simple, like the equation below, may be good enough.
The point density map might be easier to slice, summarise and render than the raw particle data.
The data I have analysed has been of a different nature, so I have not used this particular method before. Hopefully it proves helpful.
PS. I've just seen your comment below, and I'm not sure that this information will help you with that. However, I am posting my update anyway, just in case it is useful information.
QUERY
I am creating a program that has a lot of tiles in the environment that are all movie clips. The player can move around in this environment. How can I hide the tiles that are off the screen to decrease lag?
The tiles are all in a 2D array that is 20 horizontal units by 10 vertical units.
Let me know if you have any suggestions!
MORE INFO
I have a Tile class for the tile, so I can add functions for removal within this. I'm just unsure how to go about it.
-Olin
Sounds like you're looking for how to do some more fine grained memory management by recollecting memory from tiles no longer on screen, in Flash or any other language that results in bytecode that is then run in a virtual machine that handles the low level memory management and garbage collection, your control is limited with regard to reclaiming memory. Your best bet in these instances is to use object pools to dynamically allocate the number of objects you need then retain them and simply mark them as unused when they're ready to be recycled.
Read up on object pooling in AS3 here:
http://help.adobe.com/en_US/as3/mobile/WS948100b6829bd5a6-19cd3c2412513c24bce-8000.html
or on working with the garbage collector here:
http://help.adobe.com/en_US/as3/mobile/WS4bebcd66a74275c3-576ba64d124318d7189-7ffc.html
All part of the top level (conserving memory):
http://help.adobe.com/en_US/as3/mobile/WS4bebcd66a74275c333637c44124318c9bf9-8000.html
even though this is all in the mobile dirctory I'm willing to bet the information is just as pertinent on the desktop.
I have to make an application that recognizes inside an black and white image a piece of tetris given by the user. I read the image to analyze into an array.
How can I do something like this using C?
Assuming that you already loaded the images into arrays, what about using regular expressions?
You don't need exact shape matching but approximately, so why not give it a try!
Edit: I downloaded your doc file. You must identify a random pattern among random figures on a 2D array so regex isn't suitable for this problem, lets say that's the bad news. The good news is that your homework is not exactly image processing, and it's much easier.
It's your homework so I won't create the code for you but I can give you directions.
You need a routine that can create a new piece from the original pattern/piece rotated. (note: with piece I mean the 4x4 square - all the cells of it)
You need a routine that checks if a piece matches an area from the 2D image at position x,y - the matching area would have corners (x-2, y-2, x+1, y+1).
You search by checking every image position (x,y) for a match.
Since you must use parallelism you can create 4 threads and assign to each thread a different rotation to search.
You might not want to implement that from scratch (unless required, of course) ... I'd recommend looking for a suitable library. I've heard that OpenCV is good, but never done any work with machine vision myself so I haven't tested it.
Search for connected components (i.e. using depth-first search; you might want to avoid recursion if efficiency is an issue; use your own stack instead). The largest connected component should be your tetris piece. You can then further analyze it (using the shape, the size or some kind of border description)
Looking at the shapes given for tetris pieces in Wikipedia, called "I,J,L,O,S,T,Z", it seems that the ratios of the sides of the bounding box (easy to find given a binary image and C) reveal whether you have I (4:1) or O (1:1); the other shapes are 2:3.
To detect which of the remaining shapes you have (J,L,S,T, or Z), it looks like you could collect the length and position of the shape's edges that fall on the bounding box's edges. Thus, T would show 3 and 1 along the 3-sides, and 1 and 1 along the 2 sides. Keeping track of the positions helps distinguish J from L, S from Z.