Box2D - RaycastOne missing parameter

BlitzMax Forums/Brucey's Modules/Box2D - RaycastOne missing parameter

Armitage 1982

(Posted 2010) [#1]

I have a small request in regard to box2D RaycastOne current version of the mod.

As explained in the wiki http://www.box2d.org/wiki/index.php?title=Raycasting

you can pass any shape pointer in the userdata parameters to have the ray filtered in the same way that that shape would be.

Unfortunately, the parameter is missing.
Can you possibly add this feature please ?

Also, any news on Box2D 2.1.2 module ?

Thanks

Armitage 1982

(Posted 2010) [#2]

Hi again :)

No news about all this ?
I hope you're not too busy at the moment ;)

Thanks

Volker

(Posted 2010) [#3]

Has anyone got Raycast() working (not RaycastOne).
The returned array is always empty here.
The code I use:

Function Raycast2:b2Shape[] (startvec:b2Vec2, endvec:b2Vec2)

		Local seg:b2Segment = New b2Segment.Create()		'(pos, New b2Vec2.Create(pos.X(), pos.Y() - 10))
		seg.SetStartPoint(startvec)
		seg.SetEndPoint(endvec)
		Local lambda:Float = 1
		Local shapes:b2Shape[]
		Local ok:Int = WORLD.Raycast(seg, shapes, False)
		If ok = True
			Throw("raycast successfull")
		End If
		If shapes.Length <> 0
			Throw("shapes found")
			
		End If
		DebugLog("shapes len:" + shapes.Length)
		Return shapes
End Function

I modified Bruceys Raycast example to be sure that it is
not my fault (the new code is marked with ********):

SuperStrict

Framework BaH.Box2d
Import BRL.GLMax2D

Import "test.bmx"


Graphics 800,600, 0
SetBlend alphablend

Run(New Raycast.Create(), New TSettings)


Type Raycast Extends Test

	Field laserBody:b2Body

	Method Create:Raycast()
	
		Init(15, 15)
	
		Local ground:b2Body
		
		Local sd:b2PolygonDef = New b2PolygonDef
		sd.SetAsBox(50.0, 10.0)

		Local bd:b2BodyDef = New b2BodyDef
		bd.SetPosition(New b2Vec2.Create(0.0, -10.0))
		ground = m_world.CreateBody(bd)
		ground.CreateShape(sd)
		
		
		bd = New b2BodyDef
		bd.SetPositionXY(0.0, 1.0)
		laserBody = m_world.CreateBody(bd)
		
		b2PolygonDef sd
		sd.SetAsBox(5.0, 1.0)
		sd.SetDensity(4.0)
		laserBody.CreateShape(sd)
		laserBody.SetMassFromShapes()
		
		Local body:b2Body
		' Create a few shapes
		bd.SetPositionXY(-5.0, 10.0)
		body = m_world.CreateBody(bd)
		
		Local cd:b2CircleDef = New b2CircleDef
		cd.SetRadius(3)
		body.CreateShape(cd)
		
		bd.SetPositionXY(5.0, 10.0)
		body = m_world.CreateBody(bd)
		
		body.CreateShape(cd)


		Return Self
		
	End Method

	Method DoStep(settings:TSettings)

		Super.DoStep(settings)

		Local segmentLength:Float = 40
		
		Local segment:b2Segment = New b2Segment.Create()
		Local laserStart:b2Vec2 = Vec2(5.0 - 0.1, 0.0)
		Local laserDir:b2Vec2 = Vec2(segmentLength, 0.0)
		segment.SetStartPoint(laserBody.GetWorldPoint(laserStart))
		segment.SetEndPoint(laserBody.GetWorldVector(laserDir))
		segment.SetEndPoint(segment.GetEndPoint().Plus(segment.GetStartPoint()))
		
		For Local rebounds:Int = 0 Until 10
		
			Local lambda:Float = 1
			Local normal:b2Vec2 = New b2Vec2.Create()
			Local shape:b2Shape = m_world.RaycastOne(segment, lambda, normal, False)
			
			' new code ********************************************************************
			Local shapes:b2Shape[]
			m_world.Raycast(segment, shapes, false)
			If shapes.Length <> 0 Then Throw("raycast - shapes found")
			' end new code *************************************************************
			
			
			Local laserColor:b2Color = New b2Color.Set(255,0,0)
		
			If shape Then
				m_debugDraw.DrawSegment(segment.GetStartPoint(), ..
					segment.GetStartPoint().Multiply(1-lambda).Plus(segment.GetEndPoint().Multiply(lambda)),laserColor)
			Else
				m_debugDraw.DrawSegment(segment.GetStartPoint(), segment.GetEndPoint(), laserColor)
				Exit
			End If
			
			' Bounce
			segmentLength :* (1 - lambda)
			If segmentLength <= 0.00007 Then
				Exit
			End If
			laserStart = segment.GetStartPoint().Multiply(1 - lambda).Plus(segment.GetEndPoint().Multiply(lambda))
			laserDir = segment.GetEndPoint().Subtract(segment.GetStartPoint())
			laserDir.Normalize()
			laserDir = laserDir.Subtract(normal.Multiply(2 * b2Dot(laserDir, normal)))
			segment.SetStartPoint(laserStart.Subtract(laserDir.Multiply(0.1)))
			segment.SetEndPoint(laserStart.Plus(laserDir.Multiply(segmentLength)))
		Next

		
	End Method

End Type