CanRotate Property, UniversalMass and changes to Friction (#32)

README.md

@@ -1,6 +1,6 @@
 <div align="center">
     <img src="https://doy2mn9upadnk.cloudfront.net/uploads/default/original/4X/e/7/0/e709b34f89add2336a7d74faee3b2a839a9391b0.png" width="480" /><br/><br/>
-    <a href="https://github.com/jaipack17/Nature2D/releases"><img alt="version" src="https://img.shields.io/badge/v0.6.3--beta-version-%231FD67F"></img></a>
+    <a href="https://github.com/jaipack17/Nature2D/releases"><img alt="version" src="https://img.shields.io/badge/v0.6.4--beta-version-%231FD67F"></img></a>
     <br/>
     <a href="https://devforum.roblox.com/t/physics-library-nature2d-bring-ui-elements-to-life/1510935/"><img alt="devforum" src="https://img.shields.io/badge/topic-devforum-white"></img></a>
     <a href="https://www.roblox.com/library/7625799164/Nature2D"><img alt="model" src="https://img.shields.io/badge/asset-roblox-white"></img></a>
@@ -37,7 +37,7 @@ https://www.roblox.com/library/7625799164/Nature2D
 **Using wally** - Use [wally](https://github.com/UpliftGames/wally), a package manager for roblox to install Nature2D in your external code editor. This requires wally to be installed on your device. Then, add Nature2D to the dependencies listed in your `wally.toml` file.<br/>
 ```toml
 [dependencies]
-Nature2D = "jaipack17/[email protected].3"
+Nature2D = "jaipack17/[email protected].4"
 ```
 After that, Run `wally install` in the cli. Nature2D should be installed in your root directory. If you encounter any errors or problems installing Nature2D using wally, [open an issue!](https://github.com/jaipack17/Nature2D/issues)
 

src/Constants/Globals.lua

@@ -3,8 +3,8 @@
 return {
 	engineInit = {
 		gravity = Vector2.new(0, .3),
-		friction = 0.99,
-		airfriction = 0.99,
+		friction = 0.9,
+		airfriction = 0.98,
 		bounce = 0.8,
 		timeSteps = 1,
 		canvas = {
@@ -19,6 +19,7 @@ return {
 		"friction",
 		"collisionmultiplier",
 		"airfriction",
+		"universalmass"
 	},
 	rigidbody = {
 		props = {
@@ -31,7 +32,8 @@ return {
 			"Friction",
 			"AirFriction",
 			"Structure",
-			"Mass"
+			"Mass",
+			"CanRotate"
 		},
 		must_have = {
 			"Object"
@@ -100,7 +102,8 @@ return {
 		"Friction",
 		"AirFriction",
 		"Structure",
-		"Mass"
+		"Mass",
+		"CanRotate"
 	},
 
 	OBJECT_PROPS_TYPES = {
@@ -122,6 +125,7 @@ return {
 		Friction = "number",
 		AirFriction = "number",
 		Structure = "table",
-		Mass = "number"
+		Mass = "number",
+		CanRotate = "boolean"
 	},
 }

src/Engine.lua

@@ -93,6 +93,7 @@ function Engine.init(screengui: Instance)
 		airfriction = Globals.engineInit.airfriction,
 		bounce = Globals.engineInit.bounce,
 		timeSteps = Globals.engineInit.timeSteps,
+		mass = Globals.universalMass,
 		path = screengui,
 		speed = Globals.speed,
 		quadtrees = false,
@@ -432,7 +433,7 @@ function Engine:Create(object: string, properties: Types.Properties)
 
 		local newBody = RigidBody.new(
 			obj,
-			properties.Mass or Globals.universalMass,
+			properties.Mass or self.mass,
 			properties.Collidable,
 			properties.Anchored,
 			self,
@@ -446,6 +447,7 @@ function Engine:Create(object: string, properties: Types.Properties)
 		if properties.Gravity then newBody:SetGravity(properties.Gravity) end
 		if properties.Friction then newBody:SetFriction(properties.Friction) end
 		if properties.AirFriction then newBody:SetAirFriction(properties.AirFriction) end
+		if typeof(properties.CanRotate) == "boolean" and not properties.Structure then newBody:CanRotate(properties.CanRotate) end
 
 		table.insert(self.bodies, newBody)
 		newObject = newBody
@@ -513,6 +515,9 @@ function Engine:SetPhysicalProperty(property: string, value: Vector2 | number)
 		elseif string.lower(property) == "airfriction" then
 			throwTypeError("value", value, 2, "number")
 			object.airfriction = math.clamp(1 - value, 0, 1)
+		elseif string.lower(property) == "universalmass" then
+			throwTypeError("value", value, 2, "number")
+			object.mass = math.max(0, value)
 		end
 	end
 
@@ -559,11 +564,6 @@ function Engine:GetConstraintById(id: string)
 	return
 end
 
----- Returns current canvas the engine adheres to.
---function Engine:GetCurrentCanvas() : Types.Canvas
---	return self.canvas
---end
-
 function Engine:GetDebugInfo() : Types.DebugInfo
 	return {
 		Objects = {

src/Physics/RigidBody.lua

@@ -172,6 +172,8 @@ function RigidBody.new(frame: GuiObject?, m: number, collidable: boolean?, ancho
 		anchored = anchored,
 		mass = m,
 		collidable = collidable,
+		canRotate = true,
+		rotationCache = {},
 		center = isCustom and CalculateCenter(vertices) or frame.AbsolutePosition + frame.AbsoluteSize/2,
 		engine = engine,
 		spawnedAt = os.clock(),
@@ -324,14 +326,24 @@ end
 -- This method updates the positions of the RigidBody's points and constraints.
 function RigidBody:Update(dt: number)
 	self.center = CalculateCenter(self.vertices)
-
-	for _, vertex in ipairs(self.vertices) do 
+
+	if not self.canRotate then
+		for i, info in ipairs(self.rotationCache) do
+			local r = info[1]
+			local t = info[2]
+			local v = self.vertices[i]
+
+			v:ApplyForce((self.center + Vector2.new(math.cos(t), math.sin(t)) * r) - v.pos)
+		end
+	end
+
+	for _, vertex in ipairs(self.vertices) do
 		vertex:Update(dt)
 		vertex:Render()
 	end
-	
+
 	for _, edge in ipairs(self.edges) do
-		for i = 1, self.engine.iterations.constraint do 
+		for i = 1, self.engine.iterations.constraint do
 			edge:Constrain()
 		end
 		edge:Render()
@@ -353,13 +365,17 @@ function RigidBody:Render()
 	if self.anchored then
 		local anchorPos = self.anchorPos - CalculateOffset(self.anchorPos, self.frame.AnchorPoint, self.frame.AbsoluteSize)
 		self.frame.Position = UDim2.fromOffset(anchorPos.X, anchorPos.Y)
-		self:Rotate(self.anchorRotation)
+		if self.canRotate then
+			self:Rotate(self.anchorRotation)
+		end
 	else
 		local center = self.center - CalculateOffset(self.center, self.frame.AnchorPoint, self.frame.AbsoluteSize)
 		local dif: Vector2 = self.vertices[2].pos - self.vertices[1].pos
 
 		self.frame.Position = UDim2.new(0, center.X, 0, center.Y)
-		self.frame.Rotation = math.deg(math.atan2(dif.Y, dif.X))
+		if self.canRotate then
+			self.frame.Rotation = math.deg(math.atan2(dif.Y, dif.X))
+		end
 	end
 end
 
@@ -516,6 +532,20 @@ function RigidBody:CanCollide(collidable: boolean)
 	self.collidable = collidable
 end
 
+function RigidBody:CanRotate(canRotate: boolean)
+	restrict(self.custom)
+	throwTypeError("canRotate", canRotate, 1, "boolean")
+	self.canRotate = canRotate
+
+	if not self.canRotate then
+		for _, p in ipairs(self.vertices) do
+			local r = (p.pos - self.center).Magnitude
+			local theta = math.atan2(p.pos.Y - self.center.Y, p.pos.X - self.center.X)
+			table.insert(self.rotationCache, { r, theta })
+		end
+	end
+end
+
 -- The RigidBody's UI Element can be fetched using this method.
 function RigidBody:GetFrame() : GuiObject
 	return self.frame

src/Types.lua

@@ -113,6 +113,7 @@ export type Properties = {
 	AirFriction: number?,
 	Structure: {}?,
 	Mass: number?,
+	CanRotate: boolean
 }
 
 export type Custom = {
@@ -151,4 +152,4 @@ export type DebugInfo = {
 	}
 }
 
-return nil
+return nil

wally.toml

@@ -2,7 +2,7 @@
 name = "jaipack17/nature2d"
 description = "Create versatile physics simulations and mechanics with Guis on Roblox!"
 authors = ["jaipack17"]
-version = "0.6.3"
+version = "0.6.4"
 license = "MIT"
 registry = "https://github.com/UpliftGames/wally-index"
 realm = "shared"