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Questions tagged [algorithm]

Algorithms are used for calculation, data processing, and automated reasoning. More precisely, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function.

67
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7answers
14k views

How does A* pathfinding work?

I would like to understand on a fundamental level the way in which A* pathfinding works. Any code or psuedo-code implementations as well as visualizations would be helpful.
20
votes
4answers
20k views

Calculating minimum velocity of the projectile needed to hit target in parabolic arc

If I have a point which I want to hit at the end or during a parabolic arc, how would I calculate the needed x and y velocity?
9
votes
2answers
6k views

Choose tile based on adjacent tiles

I am working on a tiled map editor, and I need to choose tiles automatically, based on the adjacent tiles. For example, when placing a road tile, next to another road tile, the two need to be oriented ...
17
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7answers
7k views

What's the best way of transforming a 2D vector into the closest 8-way compass direction?

If you have a 2D vector expressed as x and y, what's a good way of transforming that into the closest compass direction? e.g. ...
35
votes
5answers
16k views

In 2D, how do I efficiently find the nearest object to a point?

I have a sizable game engine and I'd like a feature for finding the nearest of a list of points. I could simply use the Pythagorean theorem to find each distance and choose the minimum one, but that ...
11
votes
3answers
8k views

Predicting enemy position in order to have an object lead its target

In my 2D game I have AI turrets that should assist the player by automatically firing towards enemies. I would like to make them fire intelligently and lead their target instead of just targeting an ...
7
votes
1answer
3k views

How do I generate a smooth random horizontal 2D tunnel? [duplicate]

I'd like to create a smoother version of the navigable and quite natural-looking random tunnel found in this classic helicopter game. It should ideally be... infinite, so more can be generated as ...
9
votes
1answer
2k views

Documentation on 2D space partitioning

I am looking for documentation that explains the different kinds of (well the major ones anyway) 2D space partitioning algorithms & data structures. Any pointers besides 'Google it and sift ...
47
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3answers
8k views

How can I generate Worms-style terrain?

I'm working on a Worms-styled game and want to generate some terrain procedurally. I've previously done a lot of terrain generation using perlin noise, and this is what I started out using for this ...
22
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3answers
39k views

How can I create a random “world” in a tile engine?

I am designing a game that is working on a classic tile engine, but whose world is generated randomly. Are there existing games or algorithms that do this? The procedural generation algorithms I have ...
21
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1answer
8k views

How to convert mouse coordinates to isometric indexes?

I draw isometric map with tile 64x32: ...
14
votes
5answers
6k views

Which is the best approach to make a 2D character to be able to use tons of different equipments when in action?

I want to create a 2D game but I'd like to have the character to wear tons of different equipments on different combinations, like a RPG or something. So let's say the user changes his/her shoulders ...
9
votes
3answers
1k views

How do I calculate paths for objects with limited acceleration?

For example, say I have a car and a car has a specific minimum turning radius and I want to drive that car from point a to point b, but the car isn't facing point b. How do I compute a path to point ...
51
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9answers
37k views

Texture packing algorithm

What is a good texture packing algorithm? Technically, bin packing is NP-hard, so a heuristic is what I'm really after.
31
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12answers
6k views

How can I make A* finish faster when the destination is impassable?

I am making a simple tile-based 2D game, which uses the A* ("A star") pathfinding algorithm. I've got all working right, but I have a performance problem with the search. Simply put, when I click an ...
13
votes
3answers
7k views

Algorithm for determining random events [duplicate]

I'm struggling with coming up with an elegant solution to generating random events in the game that I'm working on. Say there are 4 classes of events that can happen, with varying events in those ...
73
votes
4answers
22k views

Procedural… house with rooms generator

I've been looking at some algorithms and articles about procedurally generating a dungeon. The problem is, I'm trying to generate a house with rooms, and they don't seem to fit my requirements. For ...
31
votes
2answers
25k views

Understanding Perlin Noise

I'm toying with Perlin Noise after some work with Diamond Square. I followed the implementation by Hugo Elias that basically, makes a series of functions with x,y as input to throw each coordinate ...
17
votes
5answers
11k views

When should vector/list be used?

I can understand when to use lists, but I don't understand when it is better to use vectors than using lists in video games: when it is better to have fast random access ? (And I understand why it's ...
26
votes
4answers
3k views

How do I avoid “too” lucky / unlucky streaks in random number generation?

I'm currently dealing with a multiplayer combat system where the damage dealt by the players is always multiplied by a random factor between 0.8 and 1.2. In theory, a truly random RNG may eventually ...
9
votes
1answer
2k views

Finding out which tile a mouse click landed in

I am working on an isometric grid based game and im having an issue trying to link a mouse click from the user to a tile. I have been able to split the problem into 2 parts : Finding a rectangle that ...
12
votes
3answers
14k views

Road / river generation on 2d grid map

This is a newbie question, but here it goes: My map is a 2d grid, and I want to generate roads and rivers. The route from the starting to ending point must not be the optimal route in number of tiles....
1
vote
1answer
2k views

finding a path from one point to another with obstacles help

Im building a tile based game and im implementing my path finding algorithm. Currently, it can find a path from point A to point B with no problems. However, if there are obstacles between point A and ...
48
votes
1answer
32k views

How do Raymarch shaders work?

I have been looking at shaders found here shadertoy.com and most of the cool ones have noise and raymarch in common. I do not understand the source code at all but I really want to. How do these ...
18
votes
3answers
13k views

Real Time Dynamic Pathfinding?

I'm currently doing some pathfinding research and my simulation is the following: I have a 3d scene with a start and end point represented, I'm capable of creating navigational meshes, waypoints and ...
27
votes
4answers
20k views

Simple noise generation

I'm looking to generate noise that looks like this: (images courtesy of Understanding Perlin Noise) I'm basically looking for noise with lots of small "ripples". The following is undesirable: Are ...
27
votes
6answers
25k views

Algorithm for generating a 2d maze

What algorithm have you used in the past to generate a simple 2d maze?
24
votes
2answers
8k views

How can I generate a lightning bolt effect?

Is there an algorithm to generate a lightning bolt? I would like an algorithm that generates a list of segment or point objects specifying where the bolt will land. The method would need a start ...
24
votes
1answer
2k views

Determine position of a rotated element in Tetris

Tetris-Tiles are stored as a 4x4 boolean matrix. Each rotation step has it's own matrix, the representation of the T-Block would look like this: ...
16
votes
9answers
6k views

Dynamic pathing algorithm for tower defense game

I'm making a Tower Defense and I need a good pathing algorithm for it. I have thought about Dijkstra but I need one that can be dynamic; it must be able to update itself when one edge is removed or ...
10
votes
3answers
4k views

Reduce the number of edges of a graph, keeping it connected

I'm designing a game with random generated dungeons. I'd like to view this as a connected, undirected graph in which nodes are rooms and edges are doors or corridors. Then I choose a "side" node as ...
11
votes
1answer
2k views

Algorithm for “healing” multiple rectangles into a smaller number of rectangles?

Say I have a grid of rectangles of different shapes and colors and I want to reduce (reasonably close to optimal is fine, optimal is not necessary) the number of rectangles to represent the same ...
4
votes
2answers
1k views

Factors to consider when building an algorithm for gun recoil

What would be a good algorithm for calculating the recoil of a shooting guns cross-hairs? What I've got now, is something like this: Define min/max recoil based on weapon size Generate random ...
13
votes
6answers
20k views

How do I shuffle cards for a card game?

I am trying to develop an card game for Android Can anyone suggest me how to write code for effectively shuffling the playing cards?
11
votes
3answers
2k views

Algorithm to see if two voxels are interconnected

I'm looking for a good algorithms for the following problem: Given a 3D grid of voxels (which may be either empty or filled), if I pick two non-adjacent voxels, I want to know if they are connected to ...
7
votes
2answers
1k views

Making a symbol appear on any colour

I'm developing an RPG/roguelike-style game. Instead of having maps like: ......... ......... ....@.... ...h..... Oh look, a dwarf. I was having solid background ...
7
votes
4answers
804 views

Creating non-rectangular hotspots and detecting clicks

Say for a game with irregular hotspots (say Risk, or a strategy game like Paradox's Hearts of Iron or Crusader Kings), how do you Define a non-rectangular hotspot of irregular shape (much like a ...
9
votes
3answers
14k views

How to decompose sprite sheet

I have a lot of spritesheets that are poorly formatted that I want to decompose, or split out into many small images, one for each sprite. If I can do that, I can use my custom texture packer tool to ...
8
votes
2answers
558 views

Determining if removal of a voxel will break up a group

I have the following situation: I have a 3d grid of voxels (on/off, the max size is probably 128x128x128). I know in advance that inside the grid, all the voxels that are turned on are interconnected, ...
5
votes
1answer
767 views

Help me please to choose proper path-finding algorithm

I am new to game development and just want to ask for advice. I need to know which path-finding algoritm will be suitable for my scenario: Units - any shape. But in most cases rectangles of different ...
46
votes
3answers
39k views

How to generate random level from a seed? [closed]

How would I go about using a random seed to generate a game level? The same seed should always generate the exact same level. For this example it would be a Worms style level. So each level would ...
33
votes
7answers
3k views

Elegant way to simulate large amounts of entities within a game world

Assume you have a game in which there are many (many many) entities serving some functions, not all of which are constantly needed or need to be considered in every frame. The concrete problem I am ...
18
votes
2answers
10k views

How can I generate a navigation mesh for a tile grid?

I haven't actually started programming for this one yet, but I wanted to see how I would go about doing this anyway. Say I have a grid of tiles, all of the same size, some traversable and some not. ...
24
votes
2answers
15k views

Quad tree vs Grid based collision detection

I'm making a 4 player co-op r-type game, and I'm about to implement the collision detection code. I've read a lot of articles and stuff about how to handle collision detection, but I'm having a hard ...
16
votes
6answers
4k views

How could you parallelise a 2D boids simulation

How could you program a 2D boids simulation in such a way that it could use processing power from different sources (clusters, gpu). In the above example, the non-coloured particles move around ...
24
votes
5answers
9k views

How to quickly calculate the sight area in a 2D tiled game?

I have a matrix of tiles, on some of that tiles there are objects. I want to calculate which tiles are visible to player, and which are not, and I need to do it quite efficiently (so it would compute ...
28
votes
4answers
4k views

Is there an algorithm to detect the “mainland” on a 2D map?

On this map, the "mainland" is all the land that can be connected to the center of the map in the four cardinal directions (north, south, east, west -- not diagonally). I would like to detect the ...
19
votes
5answers
10k views

Calculate random points (pixel) within a circle (image)

I have an image that contains a circles at a specific location, and of a specific diameter. What I need to do is to be able to calculate random points within the circle, and then manipulate the pixels ...
15
votes
3answers
26k views

Sorting array of points in clockwise order

Is there such an algorithm to sort an array of 2D points in clockwise order? I'm specifically dealing with right triangle in my case so only 3 points. However I'm interested in knowing if such an ...
9
votes
2answers
4k views

Building triangle adjacency data

Given a list of triangle indices, how exactly does one go about converting that to a list of indices with adjacency for a geometry shader? Note that we're strictly talking about indices here - ...