collision

问题 I am attempting to create a racing game in pygame. I want it such that when the car goes off the track, it slows down. I have tried to do this by having another sprite that is an outline of the track and when the car touches that sprite, it slows down. This does not work and I don't know why. Is there a better way to do this? Img is the car image Back is the racetrack BackHit is the outline I receive this error code: Traceback (most recent call last): File "C:\Users\Daniella\Desktop\Python

问题 I've recently learned a little bit about hash values, and therefore also heard of about the problem of hash collisions. I therefore wondered: How does one deal with those? E.g. Swift's Dictonary uses hash values with its keys. I assume that it looks up its values via the hash. So how would Swift's Dictionary then store values for different keys, that happen to have the same hash? 回答1: Fundamentally, there are two major ways of handling hash collisions - separate chaining , when items with

问题 I am re-asking this question since I did not make myself clear in what I wanted in my last question. Does anyone know how to do elastic collision or handle collision in Canvas using rectangles? Or can point me in the right direction? I created a canvas that has multiple square and would like each square to deflect when they touch. Here is a quick fiddle that I put together showing to black buffer canvases http://jsfiddle.net/claireC/Y7MFq/10/ line 39 is where I started the collision detection

问题 First of all please don't be too critical with my English. I'm not a native speaker. I hope I can explain myself never the less! Further more, I read that I should show I made some efforts to solve the given problem myself. To show this my post became relatively long. What I want to do: I am new (three weeks) to javascript and I try to build a pool billiard table via html5 canvas and javascript. In the end a user should be able to present a certain playing situation on the virtual pool tabe

问题 does anyone know whether bodies only collide when (body1.categoryBits & body2.maskBits) && (body1.maskBits & body2.categoryBits) ? or do they already collide when (body1.categoryBits & body2.maskBits) || (body1.maskBits & body2.categoryBits) ? 回答1: If anyone is still looking for more explanations, I made a detailed tutorial here : http://aurelienribon.wordpress.com/2011/07/01/box2d-tutorial-collision-filtering/ 回答2: From the Box2D manual: 6.2.3. Filtering Collision filtering is a system for

问题 The problem I'm looking for feedback on this exploration of a locally unique alternative for GUIDs , with the following requirements: Has very low chance of collisions (to the point that we'd rather collide once a year than perform checks) Does not leak sensitive information, such as how many items exist Has high performance in an SQL database Is copy/pastable for manual querying (as both query string and query result) Is usable as a URI component without encoding To meet the requirements, I

问题 We have a package that ends with exception e.g. package a.b.c.exception; Our code base had no issues up till eclipse 3.3, however when we shifted to eclipse 3.4, it started giving errors related to this package: "The package a.b.c.exception collides with a type" When I refactor the package name to a.b.c.exceptions, there are no issues. Is this due to a bug in eclipse 3.4 or is there some setting to rectify this behavior? 回答1: It's because you have a class named exception (with a lower case "e

问题 I just found out murmur hash, seems to be the fastest known and quite collision resistant. I tried to dig more about the algorithm or implementation in full source code, but I am having difficulty understanding it. Could someone here explain the algorithm used, or implement it in full source code, preferably in C. I read the C source code from the author website but has no idea, like: what is seed, h, k, m ? what does this mean : k *= m; k ^= k >> r; k *= m; h *= m; h ^= k; data += 4; len -=

问题 I'm trying to find a safe way to prevent a cron job collision (ie. prevent it from running if another instance is already running). Some options I've found recommend using a lock on a file. Is that really a safe option? What would happen if the script dies for example? Will the lock remain? Are there other ways of doing this? 回答1: This sample was taken at http://php.net/flock and changed a little and this is a correct way to do what you want: $fp = fopen("/path/to/lock/file", "w+"); if (flock

问题 I am trying to make a replica of Asteroids in Unity. The problem is that my bullets are not triggering the OnTriggerEnter2D method on the asteroids. The asteroids have the following script attached: using UnityEngine; using System.Collections; public class Asteroid : MonoBehaviour { void Start () { print ("class initiated"); } void onTriggerEnter2D (Collider2D collider) { Debug.Log (collider); } } The bullet GameObject has Is Kinematic and Is Trigger enabled, and has Rigidbody 2D and Box