Tagged Questions

4
votes
1answer
211 views

2D car physics and high speed turning

I've been looking at the following page, which has been very helpful: http://www.asawicki.info/Mirror/Car%20Physics%20for%20Games/Car%20Physics%20for%20Games.html but have come into problems with the ...
5
votes
1answer
371 views

3D isometric depth sorting

How is it possible to depth sort tiles and objects in an isometric environments without any limitations? I've been researching this for a while now and there seems to be no publicly available answers ...
0
votes
1answer
277 views

Please help me with my 2D isometric tile picking [duplicate]

Possible Duplicate: How to convert mouse coordinates to isometric indexes? Okay, I apologise in advance if I make no sense here. Basically, I've got a simple application that takes in a ...
2
votes
1answer
180 views

How to do perspective projection “parallax” but without changing the scale or offset of objects?

Hello everyone I have this problem that I have tried everything I could think of. The problem: I am making a 2D game with parallax effect but I am using 3d space so am not simulating the parallax but ...
0
votes
1answer
73 views

Find the footprint of an isometric entity

I'm working on making a 2D isometric engine in Java. I'm getting into collision detection and I've hit a bit of a problem. Characters in-game are not restricted to movement from tile to tile - they ...
3
votes
1answer
58 views

Retrieve outer most points on a 2d graph

G'day everyone, I have a 2d graph which has some points plotted on it. What I need to do is get only the outer most points so that I can connect them up (isn't really relevant). What I can't seem ...
-1
votes
3answers
306 views

Scale a normalized 2D vector always to the same length

For any normalized 2D vector, except for ( 0, 0 ), how would I scale the vector to always be the same length? For example: int length = 10; vector v = vector( 0.1, 0.5 ); vector v2 = vector( 0.3, ...
1
vote
2answers
571 views

Line Intersection from parametric equation

I'm sure this question has been asked before. However, I'm trying to connect the dots by translating an equation on paper into an actual function. I thought It would be interesting to ask here instead ...
4
votes
1answer
429 views

Re-create 2D side-on wave effect from Worms game

I'm trying to recreate the waves/water effect from Worms ( see here http://youtu.be/S6lrRqst9Z4?t=31s ) From what I understand its not actually a sprite, its procedurally generated by something like a ...
1
vote
1answer
209 views

Point inside Oriented Bounding Box?

I have an OBB2D class based on SAT. This is my point in OBB method: public boolean pointInside(float x, float y) { float newy = (float) (Math.sin(angle) * (y - center.y) + Math.cos(angle) * ...
5
votes
2answers
324 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. ...
5
votes
3answers
758 views

Is it possible to map mouse coordinates to isometric tiles with this coordinate system?

I'm trying to implement mouse interaction in a 2D isometric game, but I'm not sure if it's possible given the coordinate system used for tile maps in the game. I've read some helpful things like ...
1
vote
1answer
138 views

Can't work out how matrix is applied to 2D vertices

I have a texture, some 2D vertices, and a matrix. The matrix is used to calculate the texture coordinates for each vertex, but the problem is that the matrix comes with absolutely no documentation and ...
-5
votes
1answer
117 views

is object facing another object or facing it in opposite direction?

In 2d, in degrees, negative degrees possible. What I want is to rotate the player to face the same direction as the door before opening it, but when I'll do the same again now from the opposite side, ...
2
votes
0answers
82 views

Constrained/penalized distance function

Assume a character is located on a n by n grid and has to reach a certain entry on that grid. Its current position is (x1,y1). Also on the same grid is an enemy with coordinates (x2,y2). Each step ...
2
votes
2answers
849 views

How to move a line of sprites in a sine wave?

So, I'm spawning a horizontal line of enemies that I would like to have move in a nice wave. Currently I tried: Enemy.position.X += Enemy.velocity.X; Enemy.position.Y += ...
3
votes
2answers
2k views

Basics of drawing in 2d with OpenGL 3 shaders

I am new to OpenGL 3 and graphics programming, and want to create some basic 2d graphics. I have the following scenario of how I might go about drawing a basic (but general) 2d rectangle. I'm not ...
3
votes
2answers
432 views

Trying to understand 2D vector -> projection space conversion

I'm trying to understand how I can transform 2D vectors (x, y) to projection space. Something hasn't quite clicked for me yet. As per my previous question, here's the effect I'm trying to achieve: ...
4
votes
2answers
2k views

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 ...
4
votes
2answers
845 views

Matrix for 2D perspective

I'm trying to determine whether what I'm attempting to achieve is even possible mathematically. I'm obviously not a seasoned game developer so I'm having trouble even coming up with the terminology to ...
4
votes
2answers
263 views

How to draw equal length line stripes on a parabola?

Simply put I'm making a basketball game. I'm using these equations to predict the ball position and it works fine: x = vx * t y = vy * t + 0.5 * gravity * t * t But I can't find a way to draw equal ...
1
vote
1answer
448 views

Relating a point after an image is panned and zoomed

For Android, let's say you have a image of a map that you draw inside your view. On this map there are many, many "hot spot" locations where you want your user to be able to select. Given that there ...
4
votes
1answer
470 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, ...
7
votes
1answer
570 views

Helicopter game, but waves?

I'm looking into adapting the classic "helicopter" game (i.e. http://www.addictinggames.com/helicopter.html), but I haven't yet figured out how to create the wall-generation engine. Any pointers into ...
8
votes
2answers
562 views

Function for sun movement?

So, given a sun sprite set at the horizon (x = 0, y = worldheight/2) I'm trying to devise a function to make the sun rise, then fall. The best way to do this would be the sin function, but I have no ...
10
votes
5answers
1k views

Quick 2D sight area calculation algorithm?

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 ...
2
votes
3answers
373 views

Find new position of rotated by 10 degrees line

I have a line that goes to x (x1) of 300, and then I rotate the line by -10 degrees. How can I get the new x (x0) of the rotated line? Here's a picture to show what I mean: Are there any books ...
6
votes
3answers
743 views

Find a unit vector exactly halfway between two connected line segments

Seems like a quick and easy question but I haven't been able to find exactly what I'm looking for so: How to calculate a unit length vector that is pointing along the line which is exactly 50% of the ...
4
votes
2answers
1k views

How to calculate the vector of an interception?

Given are a twodimensional space, and 1 friendly spaceship standing still, one foe is moving NOT directly to the friendly ship with known actual position, speed and direction. The friendly ship wants ...
9
votes
1answer
1k views

Angle of Reflection

I have this "Breakeout style" game. I have a cannon at the center, blocks around the cannon and pads around the blocks. This is how the game looks like: I've managed to get the collision per ...
7
votes
3answers
4k 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 ...
5
votes
1answer
944 views

Rotate object to face player

This is probably a simple vector question, but I'm not sure how to do it. I have an object at vector position (ox,oy). Potentially every update, the user walks around the screen, and will be at ...
2
votes
1answer
362 views

Calculating camera zoom value (top-down)

I need some help in 'camera maths'. I have a birds eye view of two characters. One character is static and the other can move. I would like the camera to always show both characters in full and, in ...
1
vote
2answers
2k views

Voronoi regions of a (convex) polygon

I'm looking to add circle-polygon collisions to my Separating Axis Theorem collision detection. The metanet software tutorial (http://www.metanetsoftware.com/technique/tutorialA.html#section3) on ...
3
votes
1answer
371 views

XNA - Weird bug with 2D Sprite Rotation

I have a problem with my XNA Game, I have a function where I need my sprite to face towards an enemy, using this code: Vector2 currentPosition = Position; Vector2 nearestEnemy = ...
4
votes
2answers
724 views

snapping an angle to the closest cardinal direction

I'm developing a 2D sprite-based game, and I'm finding that I'm having trouble with making the sprites rotate correctly. In a nutshell, I've got spritesheets for each of 5 directions (the other 3 come ...
3
votes
5answers
510 views

How to randomly place rectangle inside a larger bounding rectangle without intersecting other rectangles inside

Let us consider the case: there is an overall bounding rectangle (call this Rb) which contains a number of rectangles within it (call this set SRo). Now I would like to randomly position a new ...
6
votes
4answers
981 views

Implementing 2D CSG (for collision shapes)?

Are there any simple (or well documented) algorithms for basic CSG operations on 2D polygons? I'm looking for a way to 'add' a number of overlapping 2D collision shapes. These may be convex or ...
25
votes
5answers
3k views

Moving ships between two planets along a bezier, missing some equations for acceleration

OK, I already posted this over at math.stackechange.com but didn't get any answers :( First of here's a picture of my problem, the description follows afterwards: So I got all the points and ...
3
votes
3answers
954 views

Generating background tiles for a side-scroller with variable player speed

I'm currently working on a side-scroller which lets the player alter their speed and I wondered how should I properly generate and control background tiles for such a kind o game. I'm using Flixel but ...
7
votes
4answers
646 views

Not sure how to handle “deceleration”

I say "deceleration" because I'm not using acceleration at the moment (it is being calculated, it's just set to 0 0); what I mean is moving the velocity back towards zero, eventually stopping. I'm ...
5
votes
1answer
1k views

Local to World coordinates in 2D and back

I'm getting back into hobby game programming after a long 4-year hiatus from college and I find that my understanding of coordinate systems is somewhat lacking. I'm trying my skills at creating a ...
5
votes
1answer
737 views

Zooming and panning a camera simultaneously causes a swooping effect

In a 2d game, I have a basic camera class. The guts of the class creates a transformation matrix that is later passed to the Begin() method of a SpriteBatch. The transformation is done like this: ...
6
votes
2answers
2k views

How to think about 2D scaling/rotation transformations

This is a kind of embarassing question to me since I'm getting more in-depth with XNA but some times my way of thinking about things in my head contradicts an example and I need to re-think it to make ...
9
votes
3answers
1k views

How to calculate the rotation resulting from ball bounce

Hey all, still working to incorporate more physics simulation into my game (mentioned HERE). Now having the ball successfully and quite realistically bouncing a surface it hits, I wanted to make the ...
6
votes
2answers
1k views

How to calculate the exit speed of ball bouncing off a solid surface

Hey all, I am working on a simple game to include some rigid body dynamics, involving placing (moving & rotating) some springs to bounce a falling ball into a target area. My problem is correctly ...