[Answered] How do you handle collision detection in Love2D?

Answer

Collision detection in Love2D can be handled in several ways, depending on the complexity of your game and the types of shapes involved. Below are two common methods using Love2D's built-in capabilities and a popular library called Bump.lua.

AABB (Axis-Aligned Bounding Box) Collision

For simple rectangular objects, you can use AABB collision detection. Here's an example:

function checkCollision(a, b)
    return a.x < b.x + b.width and
           b.x < a.x + a.width and
           a.y < b.y + b.height and
           b.y < a.y + a.height
end

-- In your update function:
if checkCollision(object1, object2) then
    -- Handle collision
end

This function simply checks if any of the sides of one rectangle is beyond the side of another rectangle.

Circle Collision

For circle collisions, you can use the distance between the centers of the circles:

function checkCircleCollision(circle1, circle2)
    local distance = math.sqrt((circle1.x - circle2.x)^2 + (circle1.y - circle2.y)^2)
    return distance < (circle1.radius + circle2.radius)
end

-- In your update function:
if checkCircleCollision(circle1, circle2) then
    -- Handle collision
end

Using Bump.lua for More Complex Collisions

For more complex scenarios or when you need spatial partitioning for performance reasons, you can use a library like Bump.lua. Here's a small example:

First, include the library at the beginning of your code:

local bump = require 'bump'

Then create a world and add items to it:

local world = bump.newWorld(50) -- 50 is the cell size

world:add(player, player.x, player.y, player.width, player.height)

-- To add blocks or other entities:
world:add(block, block.x, block.y, block.width, block.height)

To move and handle collisions, use the world:move function:

local actualX, actualY, cols, len = world:move(player, player.x + dx, player.y + dy, playerFilter)

for i=1, len do
    local col = cols[i]
    -- Handle your collisions for each col object
end