GC Error: Bad Refs

BlitzMax Forums/BlitzMax Programming/GC Error: Bad Refs

N (Posted 2006) [#1]

Strict Import Brl.Blitz Import Brl.Math Import Brl.System Import Brl.StandardIO Import Brl.Pixmap Import Brl.TGALoader Import Brl.Max2D Import Brl.GLMax2D ?Win32 Import Brl.D3D7Max2D Import Pub.DirectX ? Import Pub.OpenGL Import Pub.Glew Import Pub.StdC Global State:State2D = New State2D Function Push2D( ) State = State.Push( ) End Function Function Pop2D( ) State = State.Pop( ) End Function Type State2D Const CF_TRANSFORM = 0 Const CF_BLEND = 1 Const CF_VIEWPORT = 2 Const CF_HANDLE = 3 Const CF_ORIGIN = 4 Const CF_ALPHA = 5 Const CF_COLOR = 6 Const CF_CLSCOLOR = 7 Field _pred:State2D Field sx#=1, sy#=1 Field rot# Field r%,g%,b%,a# Field ox#, oy# Field hx#, hy# Field vx%, vy%, vw%, vh% Field blend_% = SOLIDBLEND Field cr%, cg%, cb% Field cf[]=[1,1,1,1,1,1,1,1] ' Does not copy its predecessor Method Clone:State2D( ) Local s:State2D = New State2D MemCopy( Varptr s.sx, Varptr sx, 80 ) Return s End Method ' Creates a copy of the top state (Self prior to Push()ing) and sets self as its predecessor Method Push:State2D( ) Local s:State2D = Clone( ) s._pred = Self Return s End Method Method Pop:State2D( ) Assert _pred,"State2D error: stack underflow" Local p:State2D = _pred _pred = Null p.Bind( ) Return p End Method Method Scale( x#, y# ) sx :* x sy :* y cf[CF_TRANSFORM]=True End Method Method Rotate( r# ) rot :+ r cf[CF_TRANSFORM]=True End Method Method ScaleAbsolute( x#, y# ) sx = x sy = y cf[CF_TRANSFORM]=True End Method Method Rotation( r# ) rot = r cf[CF_TRANSFORM]=True End Method Method Color( r%, g%, b% ) Self.r = r Self.g = g Self.b = b cf[CF_COLOR]=True End Method Method Alpha( a# ) Self.a = a cf[CF_ALPHA]=True End Method Method ClearColor( r%, g%, b% ) cr = r cg = g cb = b cf[CF_CLSCOLOR]=True End Method Method Handle( hx#, hy# ) Self.hx = hx Self.hy = hy cf[CF_HANDLE]=True End Method Method Viewport( x%, y%, w%, h% ) vx = x vy = y vw = w vh = h cf[CF_VIEWPORT]=True End Method Method Blend( b% ) blend_ = b cf[CF_BLEND]=True End Method Method Origin( ox#, oy# ) Self.ox = ox Self.oy = oy cf[CF_ORIGIN]=True End Method Method MoveOrigin( ox_#, oy_# ) Self.ox :+ ox_ Self.oy :+ oy_ cf[CF_ORIGIN]=True End Method Method Identity( ) sx = 1 sy = 1 rot = 0 r = 255 g = 255 b = 255 a = 1 ox = 0 oy = 0 hx = 0 hy = 0 vx = 0 vy = 0 vw = GraphicsWidth( ) vh = GraphicsHeight( ) blend_ = SOLIDBLEND cr = 0 cg = 0 cb = 0 cf = [1,1,1,1,1,1,1,1] End Method Method Bind( ) Update( True ) End Method Method Update( Force=0 ) If cf[CF_ORIGIN] Or Force Then SetOrigin( ox, oy ) If cf[CF_HANDLE] Or Force Then SetHandle( hx, hy ) If cf[CF_TRANSFORM] Or Force Then SetTransform( rot, sx, sy ) If cf[CF_VIEWPORT] Or Force Then SetViewport( vx, vy, vw, vh ) If cf[CF_COLOR] Or Force Then SetColor( r, g, b ) If cf[CF_ALPHA] Or Force Then SetAlpha( a ) If cf[CF_BLEND] Or Force Then SetBlend( blend_ ) If cf[CF_CLSCOLOR] Or Force Then SetClsColor( cr, cg, cb ) cf = [0,0,0,0,0,0,0,0] End Method End Type Type Sprite Field img:TImage Field x#, y# Field w#=1, h#=1 Field r%=255, g%=255, b%=255, a#=1 Field blend%=SOLIDBLEND Field sx#=1, sy#=1 Field rot# Field hidden%=0 Field children:TList = New TList Field link:TLink Field parent:Sprite Field frame% Method New( ) End Method Method Hide( ) hidden = True End Method Method Show( ) hidden = False End Method Method IsHidden( ) Return hidden End Method Method Draw( ) If hidden Then Return Push2D( ) State.Scale( sx, sy ) State.Rotate( rot ) Local tx#=x, ty#=y If parent Then TForm(tx, ty, State.sx, State.sy, State.rot) State.MoveOrigin( tx, ty ) If img Then State.Color( r, g, b ) State.Alpha( a ) State.Blend( blend ) State.Update( False ) DrawImageRect( img, 0, 0, w*img.width, h*img.height, frame ) EndIf For Local i:Sprite = EachIn children i.Draw( ) Next Pop2D( ) End Method Method Dispose( ) link.Remove( ) For Local i:Sprite = EachIn children i.Dispose( ) Next End Method Method Delete( ) Dispose( ) End Method Method SetParent( p:Sprite ) If p = parent Then Return If link Then link.Remove( ) link = Null EndIf parent = p If parent Then link = parent.children.AddLast( Self ) End Method End Type Function TForm( x# Var, y# Var, sx#, sy#, a# ) Local c#=Cos( a ) Local s#=Sin( a ) Local cx# = x Local cy# = y x = (c*sx)*cx+((-s)*sy)*cy y = (s*sx)*cx+(c*sy)*cy End Function 'SetGraphicsDriver( GLMax2DDriver( ) ) Graphics( 800, 600, 0 ) 'Local i:TImage = LoadImage( "./media/test.tga" ) Local s:Sprite = New Sprite 's.img = i s.x = 256 s.y = 256 s.sx = .5 s.sy = .5 Local s2:Sprite = New Sprite 's2.img = i s2.x = 0 s2.y = 0 s2.sx = .5 s2.sy = .5 s2.SetParent( s ) Repeat Cls( ) s.Draw( ) s.rot :+ 1 ' DrawImage i, 384, 384 Flip( ) Until KeyHit( KEY_ESCAPE ) Or AppTerminate( ) Having trouble figuring out what's causing this even after going over the GC code. So, I present to you the code that produces the 'error.' No, it doesn't draw anything right now (and doesn't even if you add an image -- I borked it somehow, but that's irrelevant). So, anyone have any ideas? Would be a good idea for BRL to step in and comment on this.

Perturbatio (Posted 2006) [#2]

Near as I can tell, it's the memcopy doing it.

Dreamora (Posted 2006) [#3]

Yepp definitely the memcopy. It does not update the refcounter which is used by the GC to decide "whats unneeded" as it is no BM internal functionality but a C functionality to operate on external / C data. You need to fully writeout your clone functionality to solve the ref count problem.

N (Posted 2006) [#4]

Oh yeah, copying four too many bytes. Thanks, guys.