quadtree

问题 I didn't find any fast algorithm for getting quad-trees differences in following format. Let's say that we have two arbitrary 4 level trees: var tree1 = [ { id: "1.1", children: [ { id: "1.1.1", children: null }, { id: "1.1.2", children: null }, { id: "1.1.3", children: [ { id: "1.1.3.1", children: null }, { id: "1.1.3.2", children: null }, { id: "1.1.3.3", children: null }, { id: "1.1.3.4", children: null } ] }, { id: "1.1.4", children: null } ] }, { id: "1.2", children: null }, { id: "1.3",

问题 I was reading this answer Efficient (and well explained) implementation of a Quadtree for 2D collision detection and encountered this paragraph All right, so actually quadtrees are not my favorite data structure for this purpose. I tend to prefer a grid hierarchy, like a coarse grid for the world, a finer grid for a region, and an even finer grid for a sub-region (3 fixed levels of dense grids, and no trees involved), with row-based optimizations so that a row that has no entities in it will

问题 Imagine a quadtree defined as follow: data (Eq a, Show a) => QT a = C a | Q (QT a) (QT a) (QT a) (QT a) deriving (Eq, Show) bad1 = Q u u u u where u = C 255 bad2 = Q (C 0) (C 255) (Q u u u u) (C 64) where u = C 255 The constructor allows you to create not well-formed quadtrees. bad1 should be simply C 255 and bad2 is not valid too because its bottom-right quadtree (for the same reason, it should be Q (C 0) (C 255) (C 244) (C 64) . So far so good. Checking its well-formness is simply a matter

问题 Imagine a quadtree defined as follow: data (Eq a, Show a) => QT a = C a | Q (QT a) (QT a) (QT a) (QT a) deriving (Eq, Show) bad1 = Q u u u u where u = C 255 bad2 = Q (C 0) (C 255) (Q u u u u) (C 64) where u = C 255 The constructor allows you to create not well-formed quadtrees. bad1 should be simply C 255 and bad2 is not valid too because its bottom-right quadtree (for the same reason, it should be Q (C 0) (C 255) (C 244) (C 64) . So far so good. Checking its well-formness is simply a matter

问题 I'm having trouble with spatial partitioning for my class. The problem I'm having is implementing the Quadtree in C++ using DirectX. I get the concept behind it but the coding to implement it is what I'm having trouble with. Right now I have the environment to test the tree. And the structure for the tree. struct Node { vector3 element; Node* left, right; }; Node root; 来源： https://stackoverflow.com/questions/5994778/how-to-implement-a-quadtree-for-spatial-partitioning

问题 I did a project a while back on path finding with quadtrees and I would like to improve on its performance. It seems that using tesseral arithmetic to determine node adjacency (as per this page, courtesy of the Geography department of the University of British Columbia) would be much faster than the brute force method I'm using at the moment (I'm checking for shared edges, which works fine for a static quadtree but would be too much overhead if the map were changing). I more or less

问题 I have implemented a quadtree in Mathematica. I am new to coding in a functional programming language like Mathematica, and I was wondering if I could improve this or make it more compact by better use of patterns. (I understand that I could perhaps optimize the tree by pruning unused nodes, and there might be better data structures like k-d trees for spatial decomposition.) Also, I am still not comfortable with the idea of copying the entire tree/expression every time a new point is added.

问题 Leading up from this question Detecting mouse coordinates with precision, I have learnt quite a bit in the past few days. Here are what I picked as best learning resources on this topic: http://gamedev.tutsplus.com/tutorials/implementation/quick-tip-use-quadtrees-to-detect-likely-collisions-in-2d-space/ http://www.gamedev.net/page/resources/_/technical/graphics-programming-and-theory/quadtrees-r1303 http://jsfiddle.net/2dchA/2/ The code in (3) works in JSFiddle but breaks at this section in

问题 I have been studying about quadtrees and their usage in collision detection in videogame code. However, all the implementations so far rely on object-oriented features of C++,C#, javascript and Lua to do every node, and I have absolutely no idea of how to translate that to raw C. The objective is to test multiple objects (shots) against actors (constantly moving) and terrain (static). Then actors with terrain. Since I cannot find an example I can read in "pure" C terms (that is, not using

问题 I've an ArrayList which contains my nodes. A node has a source, target and costs. Now I have to iterate over the whole ArrayList. That lasts for for over 1000 nodes a while. Therefore I tried to sort my List by source. But to find the corresponding pair in the List I tried the binary search. Unfortunately that works only if I want to compare either source or target. But I have to compare both to get the right pair. Is there another possibility to search an ArrayList efficient? 回答1: