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20
votes
2answers
3k views

How to Interpolate between two game states?

What is the best pattern to create a system that all the objects positions to be interpolated between two update states? The update will always run at the same frequency, but I want to be able to ...
18
votes
6answers
1k views

Data structures for interpolation and threading?

I've been dealing with some frame-rate jittering issues with my game lately, and it seems that the best solution would be the one suggested by Glenn Fiedler (Gaffer on Games) in the classic Fix Your ...
8
votes
1answer
933 views

Separating logic/update from render/drawing code in a single thread using sleep

I've read that the speed of game objects should not be hindered by FPS but instead should be based on time. How can I seperate the update/draw code to maximize performance without limiting the drawing ...
6
votes
1answer
670 views

Mitigating the noticability of a frame drop in XNA

I have been having some minor frame drop issues in a 2D XNA game. To start with, I am a vsync'ed, mixed timestep. That is: IsFixedTimestep = false; ...
4
votes
2answers
413 views

What is the point in using real time?

I understand that using real time frame elapses (which should vary between 16-17ms on average) are provided by a lot of frameworks. GetTimeElapsedSinceLastFrame, and it gives you the wall clock time. ...
4
votes
4answers
1k views

Still confused about timesteps in XNA

I have been reading many different posts and articles about timesteps and while I now understand that fixed timesteps are generally considered superior, I'm having a bit of difficulty implementing one ...
4
votes
3answers
759 views

Simple speed deceleration with variable time step?

When you use a fixed time step you can call speed=speed*0.95 to emulate speed deceleration in a simple way. I want to do the same thing with variable time step. I wish to have a simple function ...
4
votes
2answers
1k views

How to achieve smooth movement with a fixed timestep

Previously in the update method of my game I was using a variable time step which provided very smooth movement of a player sprite except when the frame rate would drop, even slightly. At that point I ...
4
votes
4answers
950 views

Physics timestep questions

I've got a projectile working perfectly using the code below: //initialised in loading screen 60 is the FPS - projectilEposition and velocity are Vector3 types gravity = new Vector3(0, ...
3
votes
3answers
338 views

How precise should timers in update loops be?

What is the suggestion of "enough precision" in a timer for a fixed game update loop? Currently I'm testing with this code, but it sometimes misses 1-2 updates @ 50hz. While at 30hz it seems to work ...
3
votes
3answers
461 views

Semi Fixed-timestep ported to javascript

In Gaffer's "Fix Your Timestep!" article, the author explains how to free your physics' loop from the paint one. Here is the final code, written in C: double t = 0.0; const double dt = 0.01; double ...
3
votes
2answers
1k views

Why does my position interpolation code result in “jumpy” motion?

I am developing an android game with box2d and use a fixed timestep system for advancing the physics. However as I use this system it requires the box2d positions to be interpolates. I read this ...
3
votes
1answer
90 views

Game loop in Javascript

I've been into javascript game programming with html5 and canvas lately. So far I've only been able to implement a game loop with setInterval, but I'm aware this means using fixed timestep. I've ...
2
votes
2answers
284 views

For timed levels, how do you determine time steps that are less than 1/(frames per second)?

I have made a simple HTML5 racing game. The laps are timed. I am running the game are 40 frames per second, each frame represents 40 milliseconds. There for my timer will increase in 0.025 ...
2
votes
1answer
169 views

Implementing a time scale in game with fixed physics update

I'm currently putting together my game loop based on the "Fix Your Timestep" article at gafferongames.com. This is going fine, but I'm also trying to implement a 'time scale', i.e. a way to control ...
2
votes
1answer
2k views

in iOS, does CADisplayLink automatically control the app's 'timestep'?

I'm writing an iOS game that uses OpenGL ES 2.0. I have my 'OpenGLView' which contains a - (void)setupDisplayLink { CADisplayLink* displayLink = [CADisplayLink displayLinkWithTarget:self ...
2
votes
1answer
124 views

Does client side prediction sync with the server in the past?

I've spent some time now messing around and just trying to learn dead reckoning and client side prediction for the fun of it. Most of what I do doesn't need it, so i've never had a need to go down ...
2
votes
1answer
171 views

Calculate Distance Using Lifetime, Speed, and Time Between Ticks

I am trying to draw a line from the player to where he is facing, with the line being the distance his rockets will travel. I have ShipMissile.Speed, which is the number of pixels to move per tick, ...
1
vote
2answers
497 views

Variable physics step, bad idea?

Currently, when I update the entities I calculate the time passed since the last update, and then pass that to their update function. They will in turn pass that duration to all their components. ...
1
vote
2answers
288 views

Smooth animation when using fixed time step

I'm trying to implement the game loop where the physics is independent from rendering but my animation isn't as smooth as I would like it to be and it seems to periodically jump. Here is my code: // ...
1
vote
1answer
478 views

default xna 4.0 gametime don´t works well for 2D physics

I am developing a game using Visual Studio 2010 and XNA 4.0, after advancing to some extent with the project (a platform based 2d platformer msdn starter kit) I got to test it on different computers ...
1
vote
3answers
66 views

Getting sprites to move exactly the same on different devices

Background When moving a sprite along the X axis, this is my code: spriteXReal = spriteXReal + (spriteXVel * dt); //.5 would be halfway point of, 1 would be right hand side screen etc... ...
0
votes
2answers
154 views

Serious gameplay issue by spawning enemies according to elapsed time

EDIT: I have changed the title as I think that this is a general gamedevelopment question but, on a technical note, I am using Cocos2d v2.0 Some time ago I had asked a question on which was the most ...
0
votes
2answers
380 views

What is XNA's GameTime used for?

I'm developing a game using fixed time step, and so far I haven't been using XNA's GameTime class in my code. What uses does the class have, and should I definitely use it in my game, or can I ignore ...
-1
votes
1answer
173 views

Server fixed timestep not running at 30Hz but way way too fast [closed]

I'm trying to make my game's server thread run at a fixed 30Hz but can't figure out how. Basically, before I just had a stupid while(1) { //do everything as fast as you can} which means that for my ...
-1
votes
1answer
96 views

why are there draw rate and update rate in fixed time step game loop?

http://www.gameprogblog.com/generic-game-loop/ Java boolean onLoop( Game game, GameState state, GameInput input, Graphics2D gr ) { long nanosElapsed = state.tick(); updateTime += nanosElapsed; ...