# Tagged Questions

2D refers to two dimensional space where coordinates are represented with X and Y values.

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### How do you approach resolution independence in raster based graphics content?

Those games that are not fortunate enough to run on a locked platform spec, like handhelds, need to run across various resolution formats and aspect ratios. In a 3D game you might have a HUD or menu ...
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### Optimizing an XNA 2D game

Does it make sense to implement the logic to skip rendering objects outside the viewport or should I not care about it and let the Framework do it?
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### How do I make a 2D game resolution independent?

I'm working on a simple 2D game. I've finished the mobile phone version. However, my boss wants the game to works on his RT. I'm doing the "conversion" but my buttons are in the wrong places, because ...
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### How can I calculate the angle and proper turn direction between two 2D vectors?

I am working on some movement AI where there are no obstacles and movement is restricted to the XY plane. I am calculating two vectors, v, the facing direction of ship 1, and w, the vector pointing ...
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### 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 ...
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### 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 ...
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### 2D graphics - why use spritesheets?

I have seen many examples of how to render sprites from a spritesheet but I havent grasped why it is the most common way of dealing with sprites in 2d games. I have started out with 2d sprite ...
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### In Pong, how do you calculate the ball's direction when it bounces off the paddle?

I'm trying to wrap my head around this very Hello World-y problem in game development. I've created a TicTacToe game in XNA so I guess the next step would be a Breakout clone. Keep in mind that I ...
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### How did LoZ: A Link to the Past handle sub-tile collisions?

The Legend of Zelda: A Link To The Past is rendered with 16×16 tiles. How did they implement collision with tiles where only a quarter or half is occupied? You can see such tiles in the cliff corners ...
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### New to creating AI - where to start? [closed]

I am new to game programming and am trying to make a basic 2d top-down space game with 2 space ships that fight each other. I am doing well with the user controlled space ship, but have no idea how ...
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### How does one prevent homing missiles from orbiting their targets?

I am developing a 2D space game with no friction, and I am finding it very easy to make a homing missile orbit its target. I am curious about anti-orbiting strategies. A simple example is a homing ...
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### Implementing a 2D destructible landscape (like Worms)

What steps would be involved in constructing a destructible 2D landscape, like in Worms? Ideally, What are some ways that this process could be made efficient as possible?
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### Top Down RPG Movement w/ Correction?

I would hope that we have all played Zelda: A Link to the Past, please correct me if I'm wrong, but I want to emulate that kind of 2D, top-down character movement with a touch of correction. It has ...
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### Best way to mask 2D sprites in XNA?

I currently am trying to mask some sprites. Rather than explaining it in words, I've made up some example pictures: The area to mask (in white) Now, the red sprite that needs to be cropped. The ...
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### “Unclutter” units in RTS game

For intentional reasons, certain units in the game I'm currently programming don't have any collision detection and response among each other. This enables them to clutter right on top of each other....
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### How to learn 2d animation? [closed]

Where can I learn how to do simple 2d animation well? Or is it really just literally drawing every single frame of something in photoshop? Is there tips or tricks? Tutorials to help get started? Also,...
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### 2D Platformer AABB collision problems

I have a problem with AABB collision resolution. I resolve AABB intersection by resolving the X axis first, then the Y axis. This is done to prevent this bug: http://i.stack.imgur.com/NLg4j.png ...
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### How do I implement parallax scrolling in 2D?

Suppose I have three layers: a foreground, an intermediate-ground and a background. What is involved in using these three layers to create parallax scrolling?
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### Implementing a camera / viewport to a 2D game

What is the most practical way to implement camera/viewport to a 2D-game? I've read, that I should store the object world position instead of position relative to the screen? Current situation: I ...
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### Fast, accurate 2d collision

I'm working on a 2d topdown shooter, and now need to go beyond my basic rectangle bounding box collision system. I have large levels with many different sprites, all of which are different shapes and ...
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### How do I detect the direction of 2D rectangular object collisions?

After this question, I need some more help. How can I find out which side of a rectangle a collision came from and react accordingly? The blue arrows are the paths that some circular objects ...
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### How do I calculate rotation caused by bounce friction?

Following on from my previous question: I have the ball quite realistically bouncing from surfaces it hits. Now I'd like to make it spin from the friction of the hit. Showing this is simple enough: I ...
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### How to implement uniform grids

Up until now, I implemented all-against-all collision detection in my games. It worked fine. But I reached a point where implementing this kind of collision detection, makes the game run poorly, ...
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### How is 2D lighting implemented?

I am wondering what the best way to approach a "lighting" effect in 2D games is. For instance, if my main character is glowing, what techniques can I use to complete the visual effect of the character ...
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### Best Way to Create A Map for a 2D Game?

I apologize for the subjective "best" keyword. My friend and I have started creation of a 2D adventure game. It will be top-down in the style of pokemon or zelda (just the perspective). We have been ...
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### 2D Planet Gravity

I'm trying to make a simple game where a spaceship is launched and then its path is effected by the gravity of planets. Similar to this game: http://sciencenetlinks.com/interactives/gravity.html I ...
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### Can I achieve a torchlight effect (lighter area around a light source) in a 2D game?

I am thinking of writing myself a simple 2D game. It will not shine with perfect graphics or gameplay at first, but I'd consider it my first step in PC game development. So, imagine such simple sprite-...
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### Is there a simple way to group two or more sprites, so all of them will be dependent on each other?

I think that this question is very similar to this one, but I'm not sure if the answers are universal. So, my goal is: Place two sprites in fixed position, for example player and his eyes Make ...
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### How do I implement occluded lighting in a block-based 2D game?

I want to have 2D lighting that can be blocked by in-game objects. My game has a top-down view and all game objects are described by rectangles. Let's say I have a 10x10 world and I place a light at ...
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### How to calculate shot angle and velocity to hit a moving target?

I am developing a 2D Android game and I am making an aiming algorithm for AI projectiles to hit enemies either following a path, or free moving. At the moment it just calculates where the target will ...
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### How do I keep my character centred on screen?

I am making a game similar to Legend of Zelda: Link to the Past (top-down 2D action-adventure). I want the character to stay centred on the screen when he moves. Currently, whenever the player wants ...
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### How do I make an object face the mouse position, but only on one plane?

I want a game object to turn and look towards where the mouse was clicked (in world space). It works well when considering all 3 dimensions, but I really only care for the plane formed by the x and z ...
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### What tools do you use for 2D art/sprite creation? [closed]

What cheap/free tools do you use for 2D art and/or animation? I don't really like Gimp's interface, Paint.NET is limited and GraphicsGale is sort of archaic. Cosmigo ProMotion looks like it could be ...
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### How can I get textures on edge of walls like in Super Metroid and Aquaria?

Games like Super Metroid and Aquaria present the terrain with the other facing parts having rocks and stuff while deeper behind them (i.e. underground) there's different detail or just black. I ...
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### Learning To Create Better Art (2D Games)

Until one of my games "makes it" big, or I get flooded with gold ingots, I will have to handle most or all of my game art myself. The crux of my question is: how can I learn enough art to get beyond "...
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### A way to store potentially infinite 2D map data?

I have a 2D platformer that currently can handle chunks with 100 by 100 tiles, with the chunk coordinates are stored as longs, so this is the only limit of maps (maxlong*maxlong). All entity positions ...
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### How would you handle different aspect ratios in a 2d platformer?

A long time ago, 4:3 was pretty much the only apect ratio you would find on a PC. Today the most common one is 16:10, but most new monitors (especially laptops) are 16:9 I'm writing a 2D platformer, ...
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### How can I implement fast, accurate 2D collision detection?

I'm well aware of how to detect if two or more 2D objects collide but I'm interested in how to decide whether to check for a collision. In previous projects, I just had every object check against ...
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### 3D Illusion of a 2D Planet Texture

Several years ago I overheard a technique that gives the user the illusion of a rotating planet by using a 2D texture. Given that the user isn't able to change its position or viewport. What's the ...
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### 2D Platform Game Jumping

I'm currently writing a game in XNA for fun which uses C#. I have got my sprites loaded and when the character moves right he looks like he is running right and when he moves left he looks like he is ...
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### How can I find a projectile's launch angle?

I am making a 2d game in which units fire arrows at each other. I know the shooter's and the target's position and the initial velocity of the projectile. I want to know the angle the projectile ...
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### Tools for 2D skeletal animation [closed]

What good free and widely used tools are there for editing 2D skeletal animations? Preferably, one that allows me to write custom animation exporters. One pretty good indie tool that I know of Demina,...
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### How do I calculate the angle of the slope at a point on a 2D bitmap terrain?

I have an arbitrary destructible bitmap terrain like the one in "Worms". It's easy to work out if a character or missile intersects the terrain, but how do I work out the angle of the slope at the ...
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### How to get mouse position relative to the map?

I'm creating a game in XNA similar to Minecraft - Minecraft 2D It looks like this Here's how it works: All blocks are generated once with fixed x,y coordinates and just re-drawn. //generate ...
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### 2D non-tile based map editor [closed]

I am currently developing a relatively simple 2D, topdown oriented adventure game for the iPhone and was wondering what would be the easiest way to create the maps for my game. I figured I would need ...
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### Can I use copyrighted sprites for a demo?

I just had a quick question and wanted everyone's opinions. I'm making a 2D demo game for a resume which I want to post online. I'm applying as a programmer position so I don't really have my own art....
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### Set sprite to face direction of mouse

I'm building a html5 canvas game and I need a way to get my sprite to face the mouse cursor. I have the X and Y co-ordinates for the sprite, and also the X and Y co-ordinates of the pointer. All I'm ...
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### 2D Gaming Libraries/ Frameworks/ Engines for Android [closed]

Are any such things available to help me build my Android game?
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### How do I create 2D water with dynamic waves?

New Super Mario Bros has really cool 2D water that I'd like to learn how to create. Here's a video showing it. An illustrative part: Things hitting the water create waves. There are also constant "...
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### How to render 2D particles as fluid?

Suppose you have a nice way to move your 2D particles in order to simulate a fluid (like water). Any ideas on how to render it? This is for a 2D game, where the perspective is from the side, like ...