Lua圆形碰撞：两点距离与半径和判定

local function hit(a, b)
    local d = math.sqrt((a.x-b.x)^2 + (a.y-b.y)^2)
    return d <= a.r + b.r           -- 批量检测每对都开方，浪费
end

local function hit(a, b)
    local dx, dy = a.x - b.x, a.y - b.y
    local rr = a.r + b.r
    return dx * dx + dy * dy <= rr * rr   -- 平方比较免开方
end
local A = {x = 0, y = 0, r = 30}
local B = {x = 40, y = 0, r = 30}
sendmsg(actor, 1, "两范围圈碰撞：" .. tostring(hit(A, B)))