2
votes
2answers
234 views

Calculate laser bounce inside polygon

I am trying to calculate the reflection of a laser within a polygon. My current calculations are probably quite long-winded because I'm building on line intersection and other functions. The problem ...
2
votes
2answers
75 views

How can I test if a point is behind a polygon in 2D?

In order to improve the performance of my visibility graph generator I am trying to figure out the following. Given the image below; is there a way to find out if a point is 'behind' the polygon? For ...
-2
votes
2answers
103 views

How to calculate a bounding rectangle of a polygon?

Polygon poly = new Polygon(); poly.getPoints().setAll(5d, 15d, 15d, 25d, 5d, 30d); How do I calculate the Polygon's height and width? There is no poly.getWidth() or poly.getHeight() method in ...
-2
votes
1answer
65 views

What do the 6 points stand for in Polygon().getPoints().setAll?

I have the following code to create a polygon: Polygon poly = new Polygon(); poly.getPoints().setAll(14d, 17d, 26d, 17d, 20d, 27d); // What do these mean? What do these 6 points stand for?
1
vote
2answers
122 views

Moai: Clipping an image to a polygon

I'm using Moai SDK. I have an image and some random convex 2D polygons. I want to show only the parts of the image inside these polygons. Here's an example image: The same, shown only where the ...
2
votes
2answers
346 views

Would it be more efficient to handle 2D collision detection with polygons, rather than both squares/polygons?

I'm working on a 2D game engine and I'm trying to get collision detection as efficient as possible. One thing I've noted is that I have a Rectangle Collision collider, a Shape (polygon) collider and a ...
3
votes
2answers
220 views

Subdividing a polygon into boxes of varying size

I would like to be pointed to information / resources for creating algorithms like the one illustrated on this blog, which is a subdivision of a polygon (in my case a voronoi cell) into several boxes ...
7
votes
1answer
268 views

How do I get the areas enclosed by an arbitrary 2D shape?

In my game I want users to be able to draw arbitrary 2D shapes of any length around game objects. The shapes must be closed and drawn with a single stroke that does not overlap. For example: I ...
0
votes
1answer
102 views

How to render polygons of arbitrary shape? [duplicate]

I am trying to render a plane with nodes. FYI : Nodes know what other nodes it is being attached to. I can think of a way to render them as long as they are aligned in a circular pattern; have a ...
1
vote
1answer
376 views

How to make a stack stable? Need help for an explicit resting contact scheme (2-dimensional)

Previously, I struggle with the sequential impulse-based method I developed. Thanks to jedediah referring me to this paper, I managed to rebuild the codes and implement the simultaneous impulse based ...
4
votes
1answer
254 views

Is there any heuristic to polygonize a closed 2D raster shape with n triangles?

Let's say we have a 2D image black on white that shows a closed geometric shape. Is there any (not naive brute force) algorithm that approximates that shape as closely as possible with n triangles? ...
1
vote
1answer
404 views

2D SAT Collision Detection not working when using certain polygons (With example)

My SAT algorithm falsely reports that collision is occurring when using certain polygons. I believe this happens when using a polygon that does not contain a right angle. Here is a simple diagram of ...
4
votes
2answers
1k views

What is a good way to determine if a vector is between two other vectors?

I could operate with the angles, but I do not have the angles calculated yet (and would like to avoid having to do that). It would be possible to calculate and cache the local-coordinate-frame angles, ...
4
votes
2answers
752 views

I need help with 2D collision response (of stacking rotating polygons, with friction and gravity, for a game)

Hi I am looking for suggestions on how to write a collision response for game programming purpose (so not a scientific simulation). I am dealing with 2D polygons that are rotating, and I want them to ...
49
votes
2answers
3k views

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 ...
8
votes
2answers
2k views

How to create 2D game terrain?

Last month, I experimented a lot in game development using cocos2d for the iPhone, especially on moving and modifying sprites. However, vertices and polygons are still new stuff for me. I developed ...