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o3de/Gems/StartingPointMovement/Assets/Scripts/Components/EntityLookAt.lua

89 lines
3.2 KiB
Lua

--
--
-- All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
-- its licensors.
--
-- For complete copyright and license terms please see the LICENSE at the root of this
-- distribution (the "License"). All use of this software is governed by the License,
-- or, if provided, by the license below or the license accompanying this file. Do not
-- remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
--
local EntityLookAt =
{
Properties =
{
EntityTargetToFace = {default=EntityId()},
Advanced = {default="Edit this script to face a different axis towards the target"},
},
Handlers =
{
MyTransform = {},
TargetTransform = {},
}
}
function EntityLookAt:OnActivate()
if self.Properties.EntityTargetToFace:IsValid() then
-- cache properties
local myTM = TransformBus.Event.GetWorldTM(self.entityId)
self.myPos = myTM:GetPosition()
self.targetPos = TransformBus.Event.GetWorldTranslation(self.Properties.EntityTargetToFace)
self.myScale = myTM:RetrieveScale()
self.readyForRotation = true
--attach handlers
self.myTransform = TransformNotificationBus.Connect(self.Handlers.MyTransform, self.entityId)
self.targetTransform = TransformNotificationBus.Connect(self.Handlers.TargetTransform, self.Properties.EntityTargetToFace)
self.Handlers.MyTransform.parent = self
self.Handlers.TargetTransform.parent = self
self:UpdateFacing()
end
end
function EntityLookAt.Handlers.TargetTransform:OnTransformChanged(localTM, worldTM)
local distance = self.parent.targetPos - worldTM:GetPosition()
-- if our target has moved, Update our facing
if not distance:IsZero(0.0001) then
self.parent.targetPos = worldTM:GetPosition()
self.parent:UpdateFacing()
end
end
function EntityLookAt.Handlers.MyTransform:OnTransformChanged(localTM, worldTM)
-- cache the scale
self.parent.myScale = worldTM:RetrieveScale()
local distance = self.parent.myPos - worldTM:GetPosition()
-- if we've moved then update our facing
if self.parent.readyForRotation then
self.parent.myPos = worldTM:GetPosition()
self.parent:UpdateFacing()
end
end
function EntityLookAt:UpdateFacing()
self.readyForRotation = false
-- you can use Model Space relative AxisType's of
-- YPositive : face directly at targetPos,
-- YNegative : face directly away from targetPos,
-- XPositive : "right shoulder" faces targetPos,
-- XNegative : "left shoulder" faces targetPos,
-- ZPositive : top faces targetPos
-- ZNegative : bottom faces targetPos
self.axisToFaceAtTarget = AxisType.YPositive
local tm = MathUtils.CreateLookAt(self.myPos, self.targetPos, self.axisToFaceAtTarget)
tm:MultiplyByScale(self.myScale)
TransformBus.Event.SetWorldTM(self.entityId, tm)
self.readyForRotation = true
end
function EntityLookAt:OnDeactivate()
self.Handlers.MyTransform = {}
self.Handlers.TargetTransform = {}
self.myTransform = nil
self.targetTransform = nil
end
return EntityLookAt