Super-Nostalgia-Zone/Tools/Slingshot/Slingshot.server.lua

139 lines
2.8 KiB
Lua

Tool = script.Parent
VELOCITY = 85 -- constant
local Pellet = Instance.new("Part")
Pellet.Locked = true
Pellet.BottomSurface = 0
Pellet.TopSurface = 0
Pellet.Shape = 0
Pellet.Size = Vector3.new(1,1,1)
Pellet.BrickColor = BrickColor.new(2)
Tool.PelletScript:clone().Parent = Pellet
function spawnSound(sound)
local s = sound:clone()
s.Parent = sound.Parent
s:Play()
s.Ended:connect(function ()
s:Destroy()
end)
end
function fire(mouse_pos)
spawnSound(Tool.Handle.SlingshotSound)
-- find player's head pos
local vCharacter = Tool.Parent
local vPlayer = game.Players:playerFromCharacter(vCharacter)
local head = vCharacter:findFirstChild("Head")
if head == nil then return end
local dir = mouse_pos - head.Position
dir = computeDirection(dir)
local launch = head.Position + 5 * dir
local delta = mouse_pos - launch
local dy = delta.y
local new_delta = Vector3.new(delta.x, 0, delta.z)
delta = new_delta
local dx = delta.magnitude
local unit_delta = delta.unit
-- acceleration due to gravity in RBX units
local g = (-9.81 * 20)
local theta = computeLaunchAngle( dx, dy, g)
local vy = math.sin(theta)
local xz = math.cos(theta)
local vx = unit_delta.x * xz
local vz = unit_delta.z * xz
local missile = Pellet:clone()
missile.Position = launch
missile.Velocity = Vector3.new(vx,vy,vz) * VELOCITY
missile.PelletScript.Disabled = false
local creator_tag = Instance.new("ObjectValue")
creator_tag.Value = vPlayer
creator_tag.Name = "creator"
creator_tag.Parent = missile
missile.Parent = game.Workspace
missile:SetNetworkOwner(vPlayer)
end
function computeLaunchAngle(dx,dy,grav)
-- arcane
-- http://en.wikipedia.org/wiki/Trajectory_of_a_projectile
local g = math.abs(grav)
local inRoot = (VELOCITY*VELOCITY*VELOCITY*VELOCITY) - (g * ((g*dx*dx) + (2*dy*VELOCITY*VELOCITY)))
if inRoot <= 0 then
return .25 * math.pi
end
local root = math.sqrt(inRoot)
local inATan1 = ((VELOCITY*VELOCITY) + root) / (g*dx)
local inATan2 = ((VELOCITY*VELOCITY) - root) / (g*dx)
local answer1 = math.atan(inATan1)
local answer2 = math.atan(inATan2)
if answer1 < answer2 then return answer1 end
return answer2
end
function computeDirection(vec)
local lenSquared = vec.magnitude * vec.magnitude
local invSqrt = 1 / math.sqrt(lenSquared)
return Vector3.new(vec.x * invSqrt, vec.y * invSqrt, vec.z * invSqrt)
end
Tool.Enabled = true
function onActivated()
if not Tool.Enabled then
return
end
Tool.Enabled = false
local character = Tool.Parent;
local humanoid = character.Humanoid
if humanoid == nil then
print("Humanoid not found")
return
end
if humanoid.Health <= 0 then
return
end
local targetPos = humanoid.TargetPoint
fire(targetPos)
wait(.2)
Tool.Enabled = true
end
script.Parent.Activated:connect(onActivated)