Urho3D/bin/Data/LuaScripts/32_Urho2DConstraints.lua

470 lines
22 KiB
Lua

-- Urho2D physics Constraints sample.
-- This sample is designed to help understanding and chosing the right constraint.
-- This sample demonstrates:
-- - Creating physics constraints
-- - Creating Edge and Polygon Shapes from vertices
-- - Displaying physics debug geometry and constraints' joints
-- - Using SetOrderInLayer to alter the way sprites are drawn in relation to each other
-- - Using Text3D to display some text affected by zoom
-- - Setting the background color for the scene
require "LuaScripts/Utilities/Sample"
local camera = nil
local physicsWorld = nil
local pickedNode = nil
local dummyBody = nil
function Start()
SampleStart()
CreateScene()
input.mouseVisible = true -- Show mouse cursor
CreateInstructions()
-- Set the mouse mode to use in the sample
SampleInitMouseMode(MM_FREE)
SubscribeToEvents()
end
function CreateScene()
scene_ = Scene()
scene_:CreateComponent("Octree")
scene_:CreateComponent("DebugRenderer")
physicsWorld = scene_:CreateComponent("PhysicsWorld2D")
physicsWorld.drawJoint = true -- Display the joints (Note that DrawDebugGeometry() must be set to true to acually draw the joints)
drawDebug = true -- Set DrawDebugGeometry() to true
-- Create camera
cameraNode = scene_:CreateChild("Camera")
cameraNode.position = Vector3(0, 0, 0) -- Note that Z setting is discarded; use camera.zoom instead (see MoveCamera() below for example)
camera = cameraNode:CreateComponent("Camera")
camera.orthographic = true
camera.orthoSize = graphics.height * PIXEL_SIZE
camera.zoom = 1.2 * Min(graphics.width / 1280, graphics.height / 800) -- Set zoom according to user's resolution to ensure full visibility (initial zoom (1.2) is set for full visibility at 1280x800 resolution)
renderer:SetViewport(0, Viewport:new(scene_, camera))
renderer.defaultZone.fogColor = Color(0.1, 0.1, 0.1) -- Set background color for the scene
-- Create a 4x3 grid
for i=0, 4 do
local edgeNode = scene_:CreateChild("VerticalEdge")
local edgeBody = edgeNode:CreateComponent("RigidBody2D")
if dummyBody == nil then dummyBody = edgeBody end -- Mark first edge as dummy body (used by mouse pick)
local edgeShape = edgeNode:CreateComponent("CollisionEdge2D")
edgeShape:SetVertices(Vector2(i*2.5 -5, -3), Vector2(i*2.5 -5, 3))
edgeShape.friction = 0.5 -- Set friction
end
for j=0, 3 do
local edgeNode = scene_:CreateChild("HorizontalEdge")
local edgeBody = edgeNode:CreateComponent("RigidBody2D")
local edgeShape = edgeNode:CreateComponent("CollisionEdge2D")
edgeShape:SetVertices(Vector2(-5, j*2 -3), Vector2(5, j*2 -3))
edgeShape.friction = 0.5 -- Set friction
end
-- Create a box (will be cloned later)
local box = scene_:CreateChild("Box")
box.position = Vector3(0.8, -2, 0)
local staticSprite = box:CreateComponent("StaticSprite2D")
staticSprite.sprite = cache:GetResource("Sprite2D", "Urho2D/Box.png")
local body = box:CreateComponent("RigidBody2D")
body.bodyType = BT_DYNAMIC
body.linearDamping = 0
body.angularDamping = 0
local shape = box:CreateComponent("CollisionBox2D") -- Create box shape
shape.size = Vector2(0.32, 0.32) -- Set size
shape.density = 1 -- Set shape density (kilograms per meter squared)
shape.friction = 0.5 -- Set friction
shape.restitution = 0.1 -- Set restitution (slight bounce)
-- Create a ball (will be cloned later)
local ball = scene_:CreateChild("Ball")
ball.position = Vector3(1.8, -2, 0)
local staticSprite = ball:CreateComponent("StaticSprite2D")
staticSprite.sprite = cache:GetResource("Sprite2D", "Urho2D/Ball.png")
local body = ball:CreateComponent("RigidBody2D")
body.bodyType = BT_DYNAMIC
body.linearDamping = 0
body.angularDamping = 0
local shape = ball:CreateComponent("CollisionCircle2D") -- Create circle shape
shape.radius = 0.16 -- Set radius
shape.density = 1 -- Set shape density (kilograms per meter squared)
shape.friction = 0.5 -- Set friction
shape.restitution = 0.6 -- Set restitution: make it bounce
-- Create a polygon
local node = scene_:CreateChild("Polygon")
node.position = Vector3(1.6, -2, 0)
node:SetScale(0.7)
local staticSprite = node:CreateComponent("StaticSprite2D")
staticSprite.sprite = cache:GetResource("Sprite2D", "Urho2D/Aster.png")
local body = node:CreateComponent("RigidBody2D")
body.bodyType = BT_DYNAMIC
local shape = node:CreateComponent("CollisionPolygon2D")
shape:SetVertices{Vector2(-0.8, -0.3), Vector2(0.5, -0.8), Vector2(0.8, -0.3), Vector2(0.8, 0.5), Vector2(0.5, 0.9), Vector2(-0.5, 0.7)}
shape.density = 1 -- Set shape density (kilograms per meter squared)
shape.friction = 0.3 -- Set friction
shape.restitution = 0 -- Set restitution (no bounce)
-- Create a ConstraintDistance2D
CreateFlag("ConstraintDistance2D", -4.97, 3) -- Display Text3D flag
local boxNode = box:Clone()
local ballNode = ball:Clone()
local ballBody = ballNode:GetComponent("RigidBody2D")
boxNode.position = Vector3(-4.5, 2, 0)
ballNode.position = Vector3(-3, 2, 0)
local constraintDistance = boxNode:CreateComponent("ConstraintDistance2D") -- Apply ConstraintDistance2D to box
constraintDistance.otherBody = ballBody -- Constrain ball to box
constraintDistance.ownerBodyAnchor = boxNode.position2D
constraintDistance.otherBodyAnchor = ballNode.position2D
-- Make the constraint soft (comment to make it rigid, which is its basic behavior)
constraintDistance.frequencyHz = 4
constraintDistance.dampingRatio = 0.5
-- Create a ConstraintFriction2D ********** Not functional. From Box2d samples it seems that 2 anchors are required, Urho2D only provides 1, needs investigation ***********
CreateFlag("ConstraintFriction2D", 0.03, 1) -- Display Text3D flag
local boxNode = box:Clone()
local ballNode = ball:Clone()
boxNode.position = Vector3(0.5, 0, 0)
ballNode.position = Vector3(1.5, 0, 0)
local constraintFriction = boxNode:CreateComponent("ConstraintFriction2D") -- Apply ConstraintDistance2D to box
constraintFriction.otherBody = ballNode:GetComponent("RigidBody2D") -- Constraint ball to box
constraintFriction.ownerBodyAnchor = boxNode.position2D
--constraintFriction.otherBodyAnchor = ballNode.position2D
--constraintFriction.maxForce = 10 -- ballBody.mass * gravity
--constraintDistance.maxTorque = 10 -- ballBody.mass * radius * gravity
-- Create a ConstraintGear2D
CreateFlag("ConstraintGear2D", -4.97, -1) -- Display Text3D flag
local baseNode = box:Clone()
baseNode:GetComponent("RigidBody2D").bodyType = BT_STATIC
baseNode.position = Vector3(-3.7, -2.5, 0)
local ball1Node = ball:Clone()
ball1Node.position = Vector3(-4.5, -2, 0)
local ball1Body = ball1Node:GetComponent("RigidBody2D")
local ball2Node = ball:Clone()
ball2Node.position = Vector3(-3, -2, 0)
local ball2Body = ball2Node:GetComponent("RigidBody2D")
local gear1 = baseNode:CreateComponent("ConstraintRevolute2D") -- Apply constraint to baseBox
gear1.otherBody = ball1Body -- Constrain ball1 to baseBox
gear1.anchor = ball1Node.position2D
local gear2 = baseNode:CreateComponent("ConstraintRevolute2D") -- Apply constraint to baseBox
gear2.otherBody = ball2Body -- Constrain ball2 to baseBox
gear2.anchor = ball2Node.position2D
local constraintGear = ball1Node:CreateComponent("ConstraintGear2D") -- Apply constraint to ball1
constraintGear.otherBody = ball2Body -- Constrain ball2 to ball1
constraintGear.ownerConstraint = gear1
constraintGear.otherConstraint = gear2
constraintGear.ratio=1
ball1Body:ApplyAngularImpulse(0.015, true) -- Animate
-- Create a vehicle from a compound of 2 ConstraintWheel2Ds
CreateFlag("ConstraintWheel2Ds compound", -2.45, -1) -- Display Text3D flag
local car = box:Clone()
car.scale = Vector3(4, 1, 0)
car.position = Vector3(-1.2, -2.3, 0)
car:GetComponent("StaticSprite2D").orderInLayer = 0 -- Draw car on top of the wheels (set to -1 to draw below)
local ball1Node = ball:Clone()
ball1Node.position = Vector3(-1.6, -2.5, 0)
local ball2Node = ball:Clone()
ball2Node.position = Vector3(-0.8, -2.5, 0)
local wheel1 = car:CreateComponent("ConstraintWheel2D")
wheel1.otherBody = ball1Node:GetComponent("RigidBody2D")
wheel1.anchor = ball1Node.position2D
wheel1.axis = Vector2(0, 1)
wheel1.maxMotorTorque = 20
wheel1.frequencyHz = 4
wheel1.dampingRatio = 0.4
local wheel2 = car:CreateComponent("ConstraintWheel2D")
wheel2.otherBody = ball2Node:GetComponent("RigidBody2D")
wheel2.anchor = ball2Node.position2D
wheel2.axis = Vector2(0, 1)
wheel2.maxMotorTorque = 10
wheel2.frequencyHz = 4
wheel2.dampingRatio = 0.4
-- Create a ConstraintMotor2D
CreateFlag("ConstraintMotor2D", 2.53, -1) -- Display Text3D flag
local boxNode = box:Clone()
boxNode:GetComponent("RigidBody2D").bodyType = BT_STATIC
local ballNode = ball:Clone()
boxNode.position = Vector3(3.8, -2.1, 0)
ballNode.position = Vector3(3.8, -1.5, 0)
constraintMotor = boxNode:CreateComponent("ConstraintMotor2D")
constraintMotor.otherBody = ballNode:GetComponent("RigidBody2D") -- Constrain ball to box
constraintMotor.linearOffset = Vector2(0, 0.8) -- Set ballNode position relative to boxNode position = (0,0)
constraintMotor.angularOffset = 0.1
constraintMotor.maxForce = 5
constraintMotor.maxTorque = 10
constraintMotor.correctionFactor = 1
constraintMotor.collideConnected = true -- doesn't work
-- Create a ConstraintMouse2D is demonstrated in HandleMouseButtonDown() function. It is used to "grasp" the sprites with the mouse.
CreateFlag("ConstraintMouse2D", 0.03, -1) -- Display Text3D flag
-- Create a ConstraintPrismatic2D
CreateFlag("ConstraintPrismatic2D", 2.53, 3) -- Display Text3D flag
local boxNode = box:Clone()
boxNode:GetComponent("RigidBody2D").bodyType = BT_STATIC
local ballNode = ball:Clone()
boxNode.position = Vector3(3.3, 2.5, 0)
ballNode.position = Vector3(4.3, 2, 0)
local constraintPrismatic = boxNode:CreateComponent("ConstraintPrismatic2D")
constraintPrismatic.otherBody = ballNode:GetComponent("RigidBody2D") -- Constrain ball to box
constraintPrismatic.axis = Vector2(1, 1) -- Slide from [0,0] to [1,1]
constraintPrismatic.anchor = Vector2(4, 2)
constraintPrismatic.lowerTranslation = -1
constraintPrismatic.upperTranslation = 0.5
constraintPrismatic.enableLimit = true
constraintPrismatic.maxMotorForce = 1
constraintPrismatic.motorSpeed = 0
-- Create a ConstraintPulley2D
CreateFlag("ConstraintPulley2D", 0.03, 3) -- Display Text3D flag
local boxNode = box:Clone()
local ballNode = ball:Clone()
boxNode.position = Vector3(0.5, 2, 0)
ballNode.position = Vector3(2, 2, 0)
local constraintPulley = boxNode:CreateComponent("ConstraintPulley2D") -- Apply constraint to box
constraintPulley.otherBody = ballNode:GetComponent("RigidBody2D") -- Constrain ball to box
constraintPulley.ownerBodyAnchor = boxNode.position2D
constraintPulley.otherBodyAnchor = ballNode.position2D
constraintPulley.ownerBodyGroundAnchor = boxNode.position2D + Vector2(0, 1)
constraintPulley.otherBodyGroundAnchor = ballNode.position2D + Vector2(0, 1)
constraintPulley.ratio = 1 -- Weight ratio between ownerBody and otherBody
-- Create a ConstraintRevolute2D
CreateFlag("ConstraintRevolute2D", -2.45, 3) -- Display Text3D flag
local boxNode = box:Clone()
boxNode:GetComponent("RigidBody2D").bodyType = BT_STATIC
local ballNode = ball:Clone()
boxNode.position = Vector3(-2, 1.5, 0)
ballNode.position = Vector3(-1, 2, 0)
local constraintRevolute = boxNode:CreateComponent("ConstraintRevolute2D") -- Apply constraint to box
constraintRevolute.otherBody = ballNode:GetComponent("RigidBody2D") -- Constrain ball to box
constraintRevolute.anchor = Vector2(-1, 1.5)
constraintRevolute.lowerAngle = -1 -- In radians
constraintRevolute.upperAngle = 0.5 -- In radians
constraintRevolute.enableLimit = true
constraintRevolute.maxMotorTorque = 10
constraintRevolute.motorSpeed = 0
constraintRevolute.enableMotor = true
-- Create a ConstraintRope2D
CreateFlag("ConstraintRope2D", -4.97, 1) -- Display Text3D flag
local boxNode = box:Clone()
boxNode:GetComponent("RigidBody2D").bodyType = BT_STATIC
local ballNode = ball:Clone()
boxNode.position = Vector3(-3.7, 0.7, 0)
ballNode.position = Vector3(-4.5, 0, 0)
local constraintRope = boxNode:CreateComponent("ConstraintRope2D")
constraintRope.otherBody = ballNode:GetComponent("RigidBody2D") -- Constrain ball to box
constraintRope.ownerBodyAnchor = Vector2(0, -0.5) -- Offset from box (OwnerBody) : the rope is rigid from OwnerBody center to this ownerBodyAnchor
constraintRope.maxLength = 0.9 -- Rope length
constraintRope.collideConnected = true
-- Create a ConstraintWeld2D
CreateFlag("ConstraintWeld2D", -2.45, 1) -- Display Text3D flag
local boxNode = box:Clone()
local ballNode = ball:Clone()
boxNode.position = Vector3(-0.5, 0, 0)
ballNode.position = Vector3(-2, 0, 0)
local constraintWeld = boxNode:CreateComponent("ConstraintWeld2D")
constraintWeld.otherBody = ballNode:GetComponent("RigidBody2D") -- Constrain ball to box
constraintWeld.anchor = boxNode.position2D
constraintWeld.frequencyHz = 4
constraintWeld.dampingRatio = 0.5
-- ConstraintWheel2D
CreateFlag("ConstraintWheel2D", 2.53, 1) -- Display Text3D flag
local boxNode = box:Clone()
local ballNode = ball:Clone()
boxNode.position = Vector3(3.8, 0, 0)
ballNode.position = Vector3(3.8, 0.9, 0)
local constraintWheel = boxNode:CreateComponent("ConstraintWheel2D")
constraintWheel.otherBody = ballNode:GetComponent("RigidBody2D") -- Constrain ball to box
constraintWheel.anchor = ballNode.position2D
constraintWheel.axis = Vector2(0, 1)
constraintWheel.enableMotor = true
constraintWheel.maxMotorTorque = 1
constraintWheel.motorSpeed = 0
constraintWheel.frequencyHz = 4
constraintWheel.dampingRatio = 0.5
constraintWheel.collideConnected = true -- doesn't work
end
function CreateFlag(text, x, y) -- Used to create Tex3D flags
local flagNode = scene_:CreateChild("Flag")
flagNode.position = Vector3(x, y, 0)
local flag3D = flagNode:CreateComponent("Text3D") -- We use Text3D in order to make the text affected by zoom (so that it sticks to 2D)
flag3D.text = text
flag3D:SetFont(cache:GetResource("Font", "Fonts/Anonymous Pro.ttf"), 15)
end
function CreateInstructions()
-- Construct new Text object, set string to display and font to use
local instructionText = ui.root:CreateChild("Text")
instructionText:SetText("Use WASD keys and mouse to move, Use PageUp PageDown to zoom.\n Space to toggle debug geometry and joints - F5 to save the scene.")
instructionText:SetFont(cache:GetResource("Font", "Fonts/Anonymous Pro.ttf"), 15)
instructionText.textAlignment = HA_CENTER -- Center rows in relation to each other
-- Position the text relative to the screen center
instructionText.horizontalAlignment = HA_CENTER
instructionText.verticalAlignment = VA_CENTER
instructionText:SetPosition(0, ui.root.height / 4)
end
function MoveCamera(timeStep)
if ui.focusElement ~= nil then return end -- Do not move if the UI has a focused element (the console)
local MOVE_SPEED = 4 -- Movement speed as world units per second
-- Read WASD keys and move the camera scene node to the corresponding direction if they are pressed
if input:GetKeyDown(KEY_W) then cameraNode:Translate(Vector3(0, 1, 0) * MOVE_SPEED * timeStep) end
if input:GetKeyDown(KEY_S) then cameraNode:Translate(Vector3(0, -1, 0) * MOVE_SPEED * timeStep) end
if input:GetKeyDown(KEY_A) then cameraNode:Translate(Vector3(-1, 0, 0) * MOVE_SPEED * timeStep) end
if input:GetKeyDown(KEY_D) then cameraNode:Translate(Vector3(1, 0, 0) * MOVE_SPEED * timeStep) end
if input:GetKeyDown(KEY_PAGEUP) then camera.zoom = camera.zoom * 1.01 end -- Zoom In
if input:GetKeyDown(KEY_PAGEDOWN) then camera.zoom = camera.zoom * 0.99 end -- Zoom Out
end
function SubscribeToEvents()
SubscribeToEvent("Update", "HandleUpdate")
SubscribeToEvent("PostRenderUpdate", "HandlePostRenderUpdate")
SubscribeToEvent("MouseButtonDown", "HandleMouseButtonDown")
if touchEnabled then SubscribeToEvent("TouchBegin", "HandleTouchBegin3") end
-- Unsubscribe the SceneUpdate event from base class to prevent camera pitch and yaw in 2D sample
UnsubscribeFromEvent("SceneUpdate")
end
function HandleUpdate(eventType, eventData)
local timestep = eventData["TimeStep"]:GetFloat()
MoveCamera(timestep) -- Move the camera according to frame's time step
if input:GetKeyPress(KEY_SPACE) then drawDebug = not drawDebug end -- Toggle debug geometry with space
if input:GetKeyPress(KEY_F5) then scene_:SaveXML(fileSystem:GetProgramDir().."Data/Scenes/Constraints.xml") end -- Save scene
end
function HandlePostRenderUpdate(eventType, eventData)
if drawDebug then physicsWorld:DrawDebugGeometry() end
end
function HandleMouseButtonDown(eventType, eventData)
local rigidBody = physicsWorld:GetRigidBody(input.mousePosition.x, input.mousePosition.y) -- Raycast for RigidBody2Ds to pick
if rigidBody ~= nil then
pickedNode = rigidBody.node
local staticSprite = pickedNode:GetComponent("StaticSprite2D")
staticSprite.color = Color(1, 0, 0, 1) -- Temporary modify color of the picked sprite
-- ConstraintMouse2D - Temporary apply this constraint to the pickedNode to allow grasping and moving with the mouse
local constraintMouse = pickedNode:CreateComponent("ConstraintMouse2D")
constraintMouse.target = GetMousePositionXY()
constraintMouse.maxForce = 1000 * rigidBody.mass
constraintMouse.collideConnected = true
constraintMouse.otherBody = dummyBody -- Use dummy body instead of rigidBody. It's better to create a dummy body automatically in ConstraintMouse2D
end
SubscribeToEvent("MouseMove", "HandleMouseMove")
SubscribeToEvent("MouseButtonUp", "HandleMouseButtonUp")
end
function HandleMouseButtonUp(eventType, eventData)
if pickedNode ~= nil then
local staticSprite = pickedNode:GetComponent("StaticSprite2D")
staticSprite.color = Color(1, 1, 1, 1) -- Restore picked sprite color
pickedNode:RemoveComponent("ConstraintMouse2D") -- Remove temporary constraint
pickedNode = nil
end
UnsubscribeFromEvent("MouseMove")
UnsubscribeFromEvent("MouseButtonUp")
end
function GetMousePositionXY()
local screenPoint = Vector3(input.mousePosition.x / graphics.width, input.mousePosition.y / graphics.height, 0)
local worldPoint = camera:ScreenToWorldPoint(screenPoint)
return Vector2(worldPoint.x, worldPoint.y)
end
function HandleMouseMove(eventType, eventData)
if pickedNode ~= nil then
local constraintMouse = pickedNode:GetComponent("ConstraintMouse2D")
constraintMouse.target = GetMousePositionXY()
end
end
function HandleTouchBegin3(eventType, eventData)
local rigidBody = physicsWorld:GetRigidBody(eventData["X"]:GetInt(), eventData["Y"]:GetInt()) -- Raycast for RigidBody2Ds to pick
if rigidBody ~= nil then
pickedNode = rigidBody.node
local staticSprite = pickedNode:GetComponent("StaticSprite2D")
staticSprite.color = Color(1, 0, 0, 1) -- Temporary modify color of the picked sprite
local rigidBody = pickedNode:GetComponent("RigidBody2D")
-- ConstraintMouse2D - Temporary apply this constraint to the pickedNode to allow grasping and moving with touch
local constraintMouse = pickedNode:CreateComponent("ConstraintMouse2D")
constraintMouse.target = camera:ScreenToWorldPoint(Vector3(eventData["X"]:GetInt() / graphics.width, eventData["Y"]:GetInt() / graphics.height, 0))
constraintMouse.maxForce = 1000 * rigidBody.mass
constraintMouse.collideConnected = true
constraintMouse.otherBody = dummyBody -- Use dummy body instead of rigidBody. It's better to create a dummy body automatically in ConstraintMouse2D
constraintMouse.dampingRatio = 0
end
SubscribeToEvent("TouchMove", "HandleTouchMove3")
SubscribeToEvent("TouchEnd", "HandleTouchEnd3")
end
function HandleTouchMove3(eventType, eventData)
if pickedNode ~= nil then
local constraintMouse = pickedNode:GetComponent("ConstraintMouse2D")
constraintMouse.target = camera:ScreenToWorldPoint(Vector3(eventData["X"]:GetInt() / graphics.width, eventData["Y"]:GetInt() / graphics.height, 0))
end
end
function HandleTouchEnd3(eventType, eventData)
if pickedNode ~= nil then
local staticSprite = pickedNode:GetComponent("StaticSprite2D")
staticSprite.color = Color(1, 1, 1, 1) -- Restore picked sprite color
pickedNode:RemoveComponent("ConstraintMouse2D") -- Remove temporary constraint
pickedNode = nil
end
UnsubscribeFromEvent("TouchMove")
UnsubscribeFromEvent("TouchEnd")
end
-- Create XML patch instructions for screen joystick layout specific to this sample app
function GetScreenJoystickPatchString()
return
"<patch>" ..
" <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/attribute[@name='Is Visible']\" />" ..
" <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Zoom In</replace>" ..
" <add sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]\">" ..
" <element type=\"Text\">" ..
" <attribute name=\"Name\" value=\"KeyBinding\" />" ..
" <attribute name=\"Text\" value=\"PAGEUP\" />" ..
" </element>" ..
" </add>" ..
" <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/attribute[@name='Is Visible']\" />" ..
" <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Zoom Out</replace>" ..
" <add sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]\">" ..
" <element type=\"Text\">" ..
" <attribute name=\"Name\" value=\"KeyBinding\" />" ..
" <attribute name=\"Text\" value=\"PAGEDOWN\" />" ..
" </element>" ..
" </add>" ..
"</patch>"
end