collision detection

Question

hi guys..
i want to check collision for entity with other entities in a scene
im wondering if its okay to implement collision detection like this
example, somewhere in update loop (pseudo code)
for i from 0 to entities.len
for j from 0 to entities.len
if entities[i] != entities[j] , checkcollision(entities[i], entities[j])

this is O(n^2) right?is there a better way to check collision for every entity?

Answer 1

for i from 0 to entities.len - 2
for j from i + 1 to entities len - 1

Answer 2

With collision detection you want to avoid doing a collision test at all on entities that are far away.

Take a look at Quadtrees for 2D games or Octrees for 3D games.
https://en.wikipedia.org/wiki/Quadtree
https://en.wikipedia.org/wiki/Octree

Answer 3

Mirielle i see..prob i should take account the area too..thanks :)

Answer 4

Dennis Thanks..i will look into that:)

Answer 5

@gordon
nice.. i should do like this.. thanks :)