Circle->Line Collision Response, stop jittering?

BlitzMax Forums/BlitzMax Programming/Circle->Line Collision Response, stop jittering?

codermax (Posted 2013) [#1]

I'm using circle to line collision with Oddball's source from the archives, and the detection part works. But here's the thing - the circle jitters as it moves along a line. I want the circle to be able to "slide" along a line... The response should be that the circle is pushed back enough distance to keep the circle away from the line point(making sure that the circle isn't stuck, not being able to move), but keep it close enough NOT to intersect a great distance into the line, making it jitter as it's relocated. I've been at this for a couple days and I'm out of ideas, so I'm asking the Blitzmax community for help! I've looked in MANY places here and around the web, but I haven't found the appropriate collision response for this code. Keep in mind that I didn't indent most of the code, however I indented the problem area and higlighted it here. :) This is where the problem lies. 'PROBLEM IS HERE. Type Player Field Pos:Vector2,Speed,Size:Float,HP,MaxHP,MP,MaxMP Field CollisionShape:Polygon, Test:Polygon Field OldPos:Vector2[4], Block[4] Function Create:Player() Local tmp:Player=New Player For Local p=0 Until 4 Step+1 tmp.Block[p]=0 tmp.OldPos[p]=New Vector2 Next Return tmp End Function Method Move(Dir) Local BaseSpeed:Float=0.5 Local s=Self.Speed For Local p=0 Until 4 Step+1 Self.Block[p]=0 Next OldPos[0].X=Pos.X OldPos[0].Y=Pos.Y For Local p=0 Until Self.Speed Step+1 If Dir=0 If Block[0]=0 Then Self.Pos.Y:- BaseSpeed EndIf If Dir=1 If Block[1]=0 Then Self.Pos.Y:+ BaseSpeed EndIf If Dir=2 If Block[2]=0 Then Self.Pos.X:- BaseSpeed EndIf If Dir=3 If Block[3]=0 Then Self.Pos.X:+ BaseSpeed EndIf Next 'collision between the circle(player) and the line(wall). Local V:Vector2=LineToCircle(WallLine.X,WallLine.Y,WallLine.X2,WallLine.Y2, Pos.X,Pos.Y,Size) If V<>Null Pos.X=OldPos[0].X Pos.Y=OldPos[0].Y Print "pos "+Pos.X+","+Pos.Y SetColor 180,0,255 DrawLine Pos.X,Pos.Y,V.X,V.Y SetColor 255,255,255 'get the outward angle of the two points. Local VA:Float=GetAngle2D(V.X,V.Y,Pos.X,Pos.Y) Print "outward "+VA 'get the inward angle of the two points. Local VIA:Float=GetAngle2D(Pos.X,Pos.Y,V.X,V.Y) Print "inward "+VIA 'get the distance between the two points. Local VD:Float=GetDistance2D(V.X,V.Y,Pos.X,Pos.Y) Print "dist "+(VD+(s*BaseSpeed)) 'get the position of the edge point, that intersected the line. Local VP:Vector2=GetCircleEdgePoint:Vector2(Pos,Size,VIA) Print "edge "+VP.X+","+VP.Y Print "Push "+(LengthDirX(BaseSpeed,VIA))+","+(LengthDirY(BaseSpeed,VIA)) 'Move the player in the outward angle direction, at its movement speed. Print "Len "+LengthDirX((VD+(s*BaseSpeed)),VIA)+","+LengthDirY((VD+(s*BaseSpeed)),VIA) Pos.X:+(LengthDirX(s*BaseSpeed,VIA)) Pos.Y:+(LengthDirY(BaseSpeed,VIA)) SetColor 0,200,55 DrawCircle VP.X,VP.Y,2 SetColor 255,255,255 EndIf End Method End Type Here's the entire source, so no one has to figure out how to make an example to test properly. Strict Import BRL.EventQueue Import BRL.Event Extern "win32" ' Crazy WinAPI stuff Function GetActiveWindow%() Function IsZoomed%(hwnd%) End Extern Include "polycollision.bmx" Global GX=DesktopWidth() Global GY=DesktopHeight() Global GSlide:Float=0 Graphics GX-64,GY-48 SetBlend ALPHABLEND Global hWnd% = GetActiveWindow() ' Save current Window handle ' Init Buttons enableMinimize( hwnd% ) enableMaximize( hwnd% ) AppTitle$="Game Name" SetVirtualResolution 600,400 Global GameRun=1 Global Overlap:Vector2=New Vector2 Global GamePaused=1 Global FPS:FramesPerSecond=New FramesPerSecond 'create player. Global MainPlayer:Player=Player.Create() MainPlayer.Pos=New Vector2 MainPlayer.Pos.X=60 MainPlayer.Pos.Y=120 MainPlayer.Size=10 MainPlayer.Speed=5 MainPlayer.CollisionShape=Polygon.Create(6,30,Vector2.Create(0,0)) MainPlayer.Test=Polygon.Create(6,30,Vector2.Create(0,0)) Global MainWall:Wall=Wall.Create(190,300,6,40) MainWall.Shape=Polygon.Create(6,30,Vector2.Create(0,0)) Global WallLine:Vector4=Vector4.Create(70,260,190,310) 'MAIN LOOP. While GameRun=1 Cls SetColor 255,255,255 DrawText MainPlayer.Pos.X+","+MainPlayer.Pos.Y,300,5 If AppTerminate() Or KeyDown(KEY_ESCAPE) Then GameRun=0 DrawCircle(MainPlayer.Pos.X,MainPlayer.Pos.Y,MainPlayer.Size) DrawCircle(MainWall.Pos.X,MainWall.Pos.Y,10) SetColor 60,60,80 DrawLine WallLine.X,WallLine.Y,WallLine.X2,WallLine.Y2 SetColor 255,255,255 MainPlayer.CollisionShape.UpdatePolygon(Vector2.Create(MainPlayer.Pos.X,MainPlayer.Pos.Y)) MainWall.Shape.UpdatePolygon(Vector2.Create(MainWall.Pos.X,MainWall.Pos.Y)) 'DrawPolyEX(MainPlayer.CollisionShape.APoints,0) 'DrawPolyEX(MainWall.Shape.APoints,0) 'MainPlayer.CollisionShape.UpdatePolygon(Vector2.Create(MainPlayer.Pos.X,MainPlayer.Pos.Y)) 'MainWall.Shape.UpdatePolygon(Vector2.Create(MainWall.Pos.X,MainWall.Pos.Y)) 'MainPlayer.CollisionShape.DrawVertexes() 'MainPlayer.CollisionShape.DrawVertexData(Vector2.Create(100,0)) 'MainWall.Shape.DrawVertexes() 'MainWall.Shape.DrawVertexData(Vector2.Create(160,60)) 'MainPlayer.CollisionShape.DrawPoints() MainWall.Shape.DrawPoints() Rem Local ft:Float[][]=CheckOvalToLineCollision(MainPlayer.Pos,MainPlayer.Size,Wall) Local Count=0 For Local tmp:Float[] = EachIn ft 'DrawText tmp[0]+","+tmp[1],30,500+(24*Count) Count:+1 Next End Rem SetColor 0,255,0 DrawText "FPS: "+FPS.Calc(),10,30 CheckInput() Flip GCCollect() 'Garbage Collection Wend Function CheckInput() If KeyDown(KEY_UP) MainPlayer.Move(0) EndIf If KeyDown(KEY_DOWN) MainPlayer.Move(1) EndIf If KeyDown(KEY_LEFT) MainPlayer.Move(2) EndIf If KeyDown(KEY_RIGHT) MainPlayer.Move(3) EndIf Rem Local Test:Polygon=MainPlayer.CollisionShape Test.Center.X=MainPlayer.Pos.X+MoveTrace[0] Test.Center.Y=MainPlayer.Pos.Y+MoveTrace[1] Test.UpdatePolygon(Vector2.Create(Test.Center.X,Test.Center.Y)) If Test.Collision(Wall)=True If MainPlayer.OldPos.Y<0 Then MainPlayer.Block[0]=1 MainPlayer.Pos.Y:+(MainPlayer.OldPos.Y*-1) EndIf End Rem End Function Function enableMaximize(hWnd:Long) ' Adds the Maximize Button "[]" Local tmp:Int = GetWindowLongA(hWnd, GWL_STYLE) tmp = tmp | WS_MAXIMIZEBOX SetWindowLongA(hWnd, GWL_STYLE, tmp) DrawMenuBar(hWnd) End Function Function enableMinimize(hWnd:Long) ' Adds the Minimize Button "_" Local tmp:Long = GetWindowLongA(hWnd, GWL_STYLE) tmp = tmp | WS_MINIMIZEBOX SetWindowLongA(hWnd, GWL_STYLE, tmp) DrawMenuBar(hWnd) End Function 'GAME OBJECTS. Type Wall Field Pos:Vector2, Shape:Polygon Function Create:Wall(X,Y,Sides,Size) Local tmp:Wall=New Wall tmp.Pos=Vector2.Create(X,Y) 'tmp.Shape=Polygon.Create(Sides,Size,Vector2.Create(X,Y)) Return tmp End Function End Type 'PROBLEM HERE. Type Player Field Pos:Vector2,Speed,Size:Float,HP,MaxHP,MP,MaxMP Field CollisionShape:Polygon, Test:Polygon Field OldPos:Vector2[4], Block[4] Function Create:Player() Local tmp:Player=New Player For Local p=0 Until 4 Step+1 tmp.Block[p]=0 tmp.OldPos[p]=New Vector2 Next Return tmp End Function Method Move(Dir) Local BaseSpeed:Float=0.5 Local s=Self.Speed For Local p=0 Until 4 Step+1 Self.Block[p]=0 Next OldPos[0].X=Pos.X OldPos[0].Y=Pos.Y For Local p=0 Until Self.Speed Step+1 If Dir=0 If Block[0]=0 Then Self.Pos.Y:- BaseSpeed EndIf If Dir=1 If Block[1]=0 Then Self.Pos.Y:+ BaseSpeed EndIf If Dir=2 If Block[2]=0 Then Self.Pos.X:- BaseSpeed EndIf If Dir=3 If Block[3]=0 Then Self.Pos.X:+ BaseSpeed EndIf Next 'collision between the circle(player) and the line(wall). Local V:Vector2=LineToCircle(WallLine.X,WallLine.Y,WallLine.X2,WallLine.Y2, Pos.X,Pos.Y,Size) If V<>Null Pos.X=OldPos[0].X Pos.Y=OldPos[0].Y Print "pos "+Pos.X+","+Pos.Y SetColor 180,0,255 DrawLine Pos.X,Pos.Y,V.X,V.Y SetColor 255,255,255 'get the outward angle of the two points. Local VA:Float=GetAngle2D(V.X,V.Y,Pos.X,Pos.Y) Print "outward "+VA 'get the inward angle of the two points. Local VIA:Float=GetAngle2D(Pos.X,Pos.Y,V.X,V.Y) Print "inward "+VIA 'get the distance between the two points. Local VD:Float=GetDistance2D(V.X,V.Y,Pos.X,Pos.Y) Print "dist "+(VD+(s*BaseSpeed)) 'get the position of the edge point, that intersected the line. Local VP:Vector2=GetCircleEdgePoint:Vector2(Pos,Size,VIA) Print "edge "+VP.X+","+VP.Y Print "Push "+(LengthDirX(BaseSpeed,VIA))+","+(LengthDirY(BaseSpeed,VIA)) 'Move the player in the outward angle direction, at its movement speed. Print "Len "+LengthDirX((VD+(s*BaseSpeed)),VIA)+","+LengthDirY((VD+(s*BaseSpeed)),VIA) Pos.X:+(LengthDirX(s*BaseSpeed,VIA)) Pos.Y:+(LengthDirY(BaseSpeed,VIA)) SetColor 0,200,55 DrawCircle VP.X,VP.Y,2 SetColor 255,255,255 EndIf End Method End Type Type Enemy Field Pos:Vector2,Speed,Size:Float,HP,MaxHP Field CollisionShape:Polygon, Test:Polygon Field OldPos:Vector2, Block[4] Function Create:Enemy() Local tmp:Enemy=New Enemy tmp.OldPos=New Vector2 For Local p=0 Until 4 Step+1 tmp.Block[p]=0 Next Return tmp End Function Method Move(Dir) End Method End Type Type List Field ListPos:Vector2,MaxPlaces:Vector2,MaxDisplayPlaces:Vector2,Scrolling End Type Type Vector2 Field X:Float,Y:Float, Angle:Float Function Create:Vector2(X2:Float,Y2:Float) Local tmp:Vector2=New Vector2 tmp.X=X2 tmp.Y=Y2 Return tmp End Function Method DivEq(_scale#) X:/ _scale Y:/ _scale End Method Method MulEq(_scale#) X:* _scale Y:* _scale End Method Method AddEq(v:Vector2) X:+ v.X Y:+ v.Y End Method Method MinEq(v:Vector2) X:- v.X Y:- v.Y End Method Method Mul:Vector2(_scale#) Return Vector2.Create(X * _scale, Y * _scale) End Method Method Div:Vector2(_scale#) Return Vector2.Create(X / _scale, Y / _scale) End Method Method Add:Vector2(v:Vector2) Return Vector2.Create(X + v.X, Y + v.Y) End Method Method Sub:Vector2(v:Vector2) Return Vector2.Create(X - v.X, Y - v.Y) End Method Method Length#() Return Sqr(X * X + Y * Y) End Method Method CrossProduct#(v:Vector2) Return X * v.Y- Y * v.X End Method Method Dot#(v:Vector2) Return X * v.X + Y * v.Y End Method Rem Do two vectors intersect along a given axis EndRem Function Intersect@(a:Vector2[], b:Vector2[], xa:Vector2, _offset:Vector2, P1C:Vector2,P2C:Vector2) Local min0#, max0# Local min1#, max1# min0 = IntervalMin(a, xa) max0 = IntervalMax(a, xa) min1 = IntervalMin(b, xa) max1 = IntervalMax(b, xa) Local h# = _offset.Dot(xa) 'Print "do"+xa.X+","+xa.Y min0:+ h max0:+ h Local d0# = min0 - max1 Local d1# = min1 - max0 If d0 > 0.0 Or d1 > 0.0 Then Return False Else Rem Local dist:Float=IntervalDistance:Float(min0,max0,min1,max1) 'if the polygons overlap. If d0>d1 dist=d0 Else dist=d1 EndIf Local Taxis:Vector2 Local mindist:Float=-100.0/0 ' Check If the Current interval distance is the minimum one. If so store ' the interval distance And the Current distance. ' This will be used To calculate the minimum translation vector dist = Abs(dist) Print "dist "+dist If dist < mindist mindist = dist Taxis = xa'axis Print "taxis "+Taxis.X+","+Taxis.Y Local d:Vector2=Vector2.Create(P1C.X - P2C.X,P1C.Y - P2C.Y) If d.Dot(Taxis) < 0 Print "dot "+d.Dot(Taxis) Taxis.X:*-1 Taxis.Y:*-1 EndIf EndIf 'The minimum translation vector 'can be used To push the polygons apart. Local P:Vector2=Vector2.Create(Taxis.X*mindist,Taxis.Y*mindist) Print "push!"+P.X+","+P.Y End Rem Return True EndIf End Function Rem Min / Max functions nothing sepcial EndRem Function IntervalMin#(verts:Vector2[], xa:Vector2) Local m# = verts[0].Dot(xa) For Local i% = 0 To verts.Length - 1 Local d# = verts[i].Dot(xa) If d < m Then m = d Next Return m End Function Function IntervalMax#(verts:Vector2[], xa:Vector2) Local m# = verts[0].Dot(xa) For Local i% = 0 To verts.length - 1 Local d# = verts[i].Dot(xa) If d > m Then m = d Next Return m End Function End Type Type Vector4 Field X:Float,Y:Float,X2:Float,Y2:Float Function Create:Vector4(X2:Float,Y2:Float,X3:Float,Y3:Float) Local tmp:Vector4=New Vector4 tmp.X=X2 tmp.Y=Y2 tmp.X2=X3 tmp.Y2=Y3 Return tmp End Function End Type Type Polygon Rem MaxSides=vertex count Points=vx and vy Center=x and y End Rem Field MaxSides,MaxSidesF:Float,Size:Float,Points:Vector2[],APoints:Float[],Angle:Float Field Center:Vector2,DrawOffset:Vector2 Function Create:Polygon(MSides,Scale,Pos:Vector2) Local tmp:Polygon=New Polygon tmp.Size=Scale tmp.Center=Pos tmp.DrawOffset=Vector2.Create(0,0) tmp.MaxSides=MSides tmp.MaxSidesF=MSides tmp.Points=New Vector2[tmp.MaxSides] tmp.APoints=New Float[tmp.MaxSides*2] For Local g=0 Until tmp.MaxSides Step+1 tmp.Points[g]=Vector2.Create(tmp.Center.X,tmp.Center.Y-tmp.Size) tmp.Points[g].Angle=g*(360/tmp.MaxSidesF) '----If current angle = 0 degrees----- Local dx:Float = tmp.Points[g].X-tmp.Center.X Local dy:Float = tmp.Points[g].Y-tmp.Center.Y Local AddAngle:Float = ATan2(dy,dx) Local CenterDistance:Float = Sqr(dx^2+dy^2) '----when you change angle-------- Local NewAngle:Float=tmp.Points[g].Angle+AddAngle '--------New position after rotation------- tmp.Points[g].X =tmp.Center.X+(Cos(NewAngle)* CenterDistance) tmp.Points[g].Y=tmp.Center.Y+(Sin(NewAngle)* CenterDistance) Next Local TotalSides=0, Count=0 Repeat tmp.APoints[Count]=tmp.Points[TotalSides].X tmp.APoints[Count+1]=tmp.Points[TotalSides].Y TotalSides:+1 Count:+2 Until TotalSides=tmp.MaxSides Return tmp End Function Function Length(P1:Polygon) Local VLen=0 VLen=P1.MaxSides Return VLen End Function Method UpdatePolygon(Pos:Vector2) Center.X=Pos.X Center.Y=Pos.Y For Local g=0 Until MaxSides Step+1 Points[g]=Vector2.Create(Center.X,Center.Y-Size) Points[g].Angle=g*(360/MaxSidesF) '----If current angle = 0 degrees----- Local dx:Float = Points[g].X-Center.X Local dy:Float = Points[g].Y-Center.Y Local AddAngle:Float = ATan2(dy,dx) Local CenterDistance:Float = Sqr(dx^2+dy^2) '----when you change angle-------- Local NewAngle:Float=Points[g].Angle+AddAngle '--------New position after rotation------- Points[g].X =Center.X+(Cos(NewAngle)* CenterDistance) Points[g].Y=Center.Y+(Sin(NewAngle)* CenterDistance) Next Local TotalSides=0, Count=0 Repeat APoints[Count]=Points[TotalSides].X APoints[Count+1]=Points[TotalSides].Y TotalSides:+1 Count:+2 Until TotalSides=MaxSides Rem For Local g=0 Until Self.MaxSides Step+1 Self.Points[g]=Vector2.Create(Self.Center.X,Self.Center.Y-Self.Size) Self.Points[g].Angle=g*(360/Self.MaxSidesF) '----If current angle = 0 degrees----- Local dx:Float = Self.Points[g].X-Self.Center.X Local dy:Float = Self.Points[g].Y-Self.Center.Y Local AddAngle:Float = ATan2(dy,dx) Local CenterDistance:Float = Sqr(dx^2+dy^2) '----when you change angle-------- Local NewAngle:Float=Self.Points[g].Angle+AddAngle '--------New position after rotation------- Self.Points[g].X=Self.Center.X+(Cos(NewAngle)* CenterDistance) Self.Points[g].Y=Self.Center.Y+(Sin(NewAngle)* CenterDistance) Next End Rem End Method Method RotatePolygon(XAngle:Float=-1) Self.Angle=XAngle If Self.Angle>360 Then Self.Angle:-360 DrawText Self.Angle,300,400 For Local g=0 Until MaxSides Step+1 '----If current angle of Room = 0 degrees----- Local dx:Float = Self.Points[g].X-Self.Center.X Local dy:Float = Self.Points[g].Y-Self.Center.Y Local AddAngle:Float = ATan2(dy,dx) Local CenterDistance:Float = Sqr(dx^2+dy^2) '----when you change RoomAngle-------- Local NewAngle:Float=Self.Points[g].Angle+Self.Angle '--------New position of circle------- Self.Points[g].X = Self.Center.X+(Cos(NewAngle)* CenterDistance) Self.Points[g].Y =Self.Center.Y+(Sin(NewAngle)* CenterDistance) Next End Method Method DrawPoints() SetColor 90,90,160 For Local g=0 Until Self.MaxSides Step+1 DrawCircle Self.Points[g].X,Self.Points[g].Y,1.5 Next DrawCircle Self.Center.X,Self.Center.Y,1.5 SetColor 255,255,255 End Method Method DrawVertexData(P:Vector2) SetColor 0, 255, 0 Local _vx#[2], _vy#[2] For Local i% = 0 To MaxSides - 2 _vx[0] = Points[i].X + Center.X _vy[0] = Points[i].Y + Center.Y _vx[1] = Points[i+1].X + Center.X _vy[1] = Points[i+1].Y + Center.Y 'draw position of vertex. SetColor 255,255,255 SetScale 0.8,0.8 DrawText Int(_vx[0])+","+Int(_vy[0]),_vx[0]+P.X, _vy[0]+P.Y SetColor 0, 255, 0 SetScale 1,1 Next _vx[0] = Points[MaxSides - 1].X + Center.X _vy[0] = Points[MaxSides - 1].Y + Center.Y _vx[1] = Points[0].X + Center.X _vy[1] = Points[0].Y + Center.Y 'draw position of vertex. SetColor 255,255,255 SetScale 0.8,0.8 DrawText Int(_vx[0])+","+Int(_vy[0]),_vx[0]+P.X, _vy[0]+P.Y SetColor 0, 255, 0 SetScale 1,1 SetColor 0, 0, 0 End Method Method DrawVertexes() SetColor 0, 255, 0 Local _vx#[2], _vy#[2] For Local i% = 0 To (MaxSides*2) - 4 _vx[0] = APoints[i] + Center.X _vy[0] = APoints[i+1] + Center.Y _vx[1] = APoints[i+2] + Center.X _vy[1] = APoints[i+3] + Center.Y DrawLine _vx[0], _vy[0], _vx[1], _vy[1] 'draw position of vertex. SetColor 255,255,255 SetScale 0.8,0.8 SetColor 0, 255, 0 SetScale 1,1 Next _vx[0] = APoints[(MaxSides*2) - 4] + Center.X _vy[0] = APoints[(MaxSides*2) - 3] + Center.Y _vx[1] = APoints[0] + Center.X _vy[1] = APoints[1] + Center.Y DrawLine _vx[0], _vy[0], _vx[1], _vy[1] 'draw position of vertex. SetColor 255,255,255 SetScale 0.8,0.8 SetColor 0, 255, 0 SetScale 1,1 SetColor 0, 0, 0 End Method Rem separating axis theorem(SAT) intersection calculation, which tests a circle against the sides of a polygon. ARGUMENTS: -circle: 2d vector representing the circle's position, which is the center of the circle. -circle radius: the outer size of the circle, or how far away from the circle's center should it be tested for collision. -polygon: an array of 2d vectors. Each index in the 2d vector array holds a X and Y coordinate, which represents one of a polygon's sides to be tested for collision Circle:Vector2, CircleRadius:Float, End Rem Rem Method Collision:Vector3() 'Are the polygons going To intersect forward in time? Local WillIntersect 'Are the polygons currently intersecting? Local Intersect 'The translation To apply To the first polygon To push the polygons apart. Local MinimumTranslationVector:Vector2 End Method 'Calculate the projection of a polygon on an axis 'And returns it as a [Min, Max] interval Method ProjectPolygon(axis:Vector2, Poly:Polygon) 'To project a point on an axis use the dot product Float dotProduct = axis.Dot(Poly.Points[0]) Local Min0:Float = dotProduct Local Max0:Float = dotProduct For Local i = 0 Until Len(Poly.MaxSides) Step+1 dotProduct = Poly.Points[i].Dot(axis) If d < Min0 Min0 = dotProduct Else If dotProduct> Max0 Max0 = dotProduct EndIf EndIf Next End Method End Rem Rem Method Collision(Poly:Polygon,_offset:Vector2 = Null) 'get the offset. if it doesn't exist, set the offset as a created vector. If _offset = Null Then _offset = Vector2.Create(Center.X, Center.Y).Sub(Vector2.Create(Poly.Center.X, Poly.Center.Y)) EndIf Local a:Vector2[], b:Vector2[] Local i% a = New Vector2[MaxSides] For i = 0 To MaxSides - 1 a[i] = New Vector2 a[i].X = Points[i].X a[i].Y = Points[i].Y Next b = New Vector2[Poly.MaxSides] For i = 0 To Poly.MaxSides- 1 b[i] = New Vector2 b[i].X = Poly.Points[i].X b[i].Y = Poly.Points[i].Y Next Local xv:Vector2[64] Local ai% = 0 Local BF:Vector4=Vector4.Create(0,0,0,0) Local j% = MaxSides - 1 For Local i% = 0 To MaxSides - 1 Local e0:Vector2 = a[j] Local e1:Vector2 = a[i] Local e:Vector2 = e1.Sub(e0) xv[ai] = Vector2.Create(-e.y, e.x) Local MoveVector:Vector2=Vector2.Intersect(a, b, xv[ai], _offset,Center,Poly.Center) If Not Vector2.Intersect(a, b, xv[ai], _offset,Center,Poly.Center) Return 0 EndIf If MoveVector<>Null Local MoveIt:Float=ATan2(MoveVector.X,MoveVector.Y) ' Print "angle: "+MoveIt'+","+g.X+","+g.Y ' Print "ONE: "+"side: "+i+"("+a[i].X+","+a[i].Y+")" ' Print "XV.X:"+e0.X+","+"XV.Y:"+e0.Y+" "+"XV2.X:"+e1.X+","+"XV2.Y:"+e1.Y ' Print "AIX1: "+xv[ai].X+" "+"AIX2: "+xv[ai].Y ' Print "PPos: "+MainPlayer.Pos.X+","+MainPlayer.Pos.Y ' Print "WPos: "+MainWall.Shape.Center.X+","+MainWall.Shape.Center.Y EndIf j = i ai:+ 1 Next j% = Poly.MaxSides - 1 For Local i% = 0 To Poly.MaxSides- 1 Local e0:Vector2 = b[j] Local e1:Vector2 = b[i] Local e:Vector2 = e1.Sub(e0) xv[ai] =Vector2.Create(-e.y, e.x) Local MoveVector:Vector2=Vector2.Intersect(a, b, xv[ai], _offset,Center,Poly.Center) If MoveVector=Null Return 0 EndIf j = i ai:+ 1 Next Return 1 End Method End Rem End Type Type LevelEditorSettings End Type 'class to store FPS. ' -------------------------------------------- Type FramesPerSecond Global Counter:Float=0 Global Time:Float=0 Global TFPS:Float=0 Function Calc:Float() Counter:+1 If Time < MilliSecs() TFPS = Counter ' <-Frames/Sec Time = MilliSecs() + 1000 'Update Counter = 0 EndIf Return TFPS End Function End Type ' ------------------------------------------- Function LengthDirX:Float(length:Float,direction:Float) Local x_com:Float= 0 x_com = Float(Sin(direction) * length) Return x_com End Function Function LengthDirY:Float(length:Float,direction:Float) Local y_com:Float= 0 y_com = Float(Cos(direction) * length) Return y_com End Function Function RectsOverlap:Int(x0:Double,y0:Double,w0:Double,h0:Double,x2:Double,y2:Double,w2:Double,h2:Double) If (x0 > (x2 + w2) Or (x0 + w0) < x2) Return 0 EndIf If (y0 > (y2 + h2) Or (y0 + h0) < y2) Return 0 EndIf Return 1 End Function Function DrawCircle(xCentre:Float, yCentre:Float, Radius:Float) DrawOval(xCentre - (Radius), yCentre - (Radius), Radius*2, Radius*2) EndFunction Function DrawPolygon(P:Polygon) Local Tri:Float[P.MaxSides*2] Local Count=0 For Local g=0 Until Len(Tri) Step+2 Tri[g]=P.Points[Count].X Tri[g+1]=P.Points[Count].Y Count:+1 Next DrawPoly Tri EndFunction Function ClosestPointFromCircle:Vector2(CirclePos:Vector2,Radius, Line:Vector4) Local closest:Vector2=Vector2.Create(0,0) Local segmentVector:Vector2=SubtractVectors(Vector2.Create(Line.X2,Line.Y2),Vector2.Create(Line.X,Line.Y)) Local circleRelative:Vector2=SubtractVectors(CirclePos,Vector2.Create(Line.X,Line.Y)) Local segmentUnit:Vector2=NormalizeVector(segmentVector) Local projection:Float=DotProduct(circleRelative,segmentUnit) Print "proj"+projection If projection <= 0 closest.X=Line.X closest.Y=Line.Y Return closest EndIf If (projection * projection) >=(segmentVector.Length()*segmentVector.Length()) closest.X=Line.X2 closest.Y=Line.Y2 Return closest EndIf Local projectionVector:Vector2 = Vector2.Create(segmentUnit.X * projection,segmentUnit.Y * projection) closest = AddVectors(projectionVector,Vector2.Create(Line.X,Line.Y)) Print "closest"+closest.X Return closest End Function Function CircleToLineCollision:Vector2(CirclePos:Vector2,Radius:Float, Line:Vector4) Local depth:Vector2=New Vector2 Local closest:Vector2=ClosestPointFromCircle(CirclePos,Radius,Line) Local distanceVector:Vector2 =SubtractVectors(CirclePos,closest) Print "closest"+closest.X+","+closest.Y+"dist vec"+(distanceVector.Length()*distanceVector.Length())+"/"+ (Radius * Radius) If (distanceVector.Length()*distanceVector.Length()) > (Radius * Radius) Return depth EndIf If (distanceVector.Length()*distanceVector.Length()) <= 0 Return Null 'Throw New ApplicationException("Circle center is exactly on line segment"); EndIf Local unitDist:Vector2=NormalizeVector(distanceVector) Print "unit"+unitDist.X+","+unitDist.Y Local Cdist:Float=(Radius - distanceVector.Length()) Print "CD"+CDIst depth = Vector2.Create(unitDist.X *CDist,unitDist.Y * CDist) Return depth EndFunction Function NormalizeVector:Vector2(a:Vector2) Local len_v:Float = Sqr(a.X*a.X + a.Y*a.Y) a.X:/ len_v a.Y:/ len_v End Function Function AddVectors:Vector2(a:Vector2,b:Vector2) Return Vector2.Create(a.X + b.X, a.Y + b.Y) End Function Function SubtractVectors:Vector2(a:Vector2,b:Vector2) Return Vector2.Create(a.X - b.X, a.Y - b.Y) End Function Function VectorLength:Float(a:Vector2) Return Sqr(a.X * a.X + a.Y * a.Y) End Function Function DotProduct:Float(a:Vector2,b:Vector2) Return (a.X * b.X) + (a.Y * b.Y) End Function Rem bbdoc: returns the distance between two points in 2D space about: return value is an absolute float EndRem Function GetDistance2D:Float(X1:Float, Y1:Float, X2:Float, Y2:Float) Local l1:Float = Abs(x1-x2) Local l2:Float = Abs(y1-y2) Return Sqr((l1*l1)+(l2*l2)) End Function Rem bbdoc: returns an angle between 0 and 360 degrees about: return value is an Float EndRem Function GetAngle2D:Float(X1:Float,Y1:Float,X2:Float,Y2:Float) Local dx# = x2 - x1 Local dy# = y2 - y1 Return ATan2(dy#,dx#)+360 Mod 360 End Function Function GetCircleCircumference:Float(Radius:Float) Return (Radius*2)*Pi End Function Function GetCircleEdgePoint:Vector2(CirclePos:Vector2,Radius:Float,Angle:Float) Local r:Float=Radius Local x0:Float=CirclePos.X Local y0:Float=CirclePos.Y Local NewX:Double= x0 + r * Cos(Angle) Local NewY:Double= y0 + r * Sin(Angle) Local V:Vector2=Vector2.Create(NewX,NewY) Return V Rem 'X POS 'Find the cosine of the angle Local S1:Float=Cos(Angle) 'Multiply the cosine of the angle by the radius Local S2:Float=S1*Radius 'Add the origin's X coordinate of the circle to the product Local S3:Float=CirclePos.X+S2 'Y POS 'Find the sine of the angle Local S4:Float=Sin(Angle) 'Multiply the sine of the angle by the radius Local S5:Float=S4*Radius 'Add the y-coordinate of the origin of the circle to the product Local S6:Float=CirclePos.Y+S5 Local V:Vector2=Vector2.Create(S3,S6) Return V End Rem End Function And oddball's source, used as "polycollision.bmx" in the main source. 'Code by Dave 'Oddball' Williamson Rem TFormPolyToTFormPoly() Checks for collisions between two transformed polygons. PolyToTFormPoly() Checks for collisions between a standard polygon and a transformed polygon. PolyToPoly() Checks for collision between two standard polygon arrays. CircleToTFormPoly() Checks for collision between a circle and a transformed polygon. CircleToPoly() Checks for collision between a circle and a standard polygon array. LineToTFormPoly() Checks for collision between a line and a transformed polygon. LineToPoly() Checks for collision between a line and a standard polygon array. PointInTFormPoly() Checks if the given point is in a transformed polygon. PointInPoly() Checks if the given point is in a standard polygon array. TFormPoly() Returns a transformed polygon from a standard polygon array. TFormGlobalToLocal() Transforms a point from global/screen coordinates too local/polygon/image coordinates. TFormLocalToGlobal() Transforms a point from local/polygon/image coordinates to global/screen coordinates. LinesCross() Checks if two lines intersect. Adapted from code by Fredborg. LineToCircle() Checks for collision between a line and a circle. Adapted from code by TomToad. End Rem Function TFormPolyToTFormPoly( p1_xy:Float[], p1_x:Float=0, p1_y:Float=0,.. p1_rot:Float=0, p1_scale_x:Float=1, p1_scale_y:Float=1,.. p1_handle_x:Float=0, p1_handle_y:Float=0,.. p1_origin_x:Float=0, p1_origin_y:Float=0,.. p2_xy:Float[], p2_x:Float=0, p2_y:Float=0,.. p2_rot:Float=0, p2_scale_x:Float=1, p2_scale_y:Float=1,.. p2_handle_x:Float=0, p2_handle_y:Float=0,.. p2_origin_x:Float=0, p2_origin_y:Float=0) If p1_xy.length<6 Or (p1_xy.length&1) Return False If p2_xy.length<6 Or (p2_xy.length&1) Return False Local tform1_xy:Float[]=TFormPoly(p1_xy,p1_x,p1_y,p1_rot,p1_scale_x,p1_scale_y,.. p1_handle_x,p1_handle_y,p1_origin_x,p1_origin_y) Local tform2_xy:Float[]=TFormPoly(p2_xy,p2_x,p2_y,p2_rot,p2_scale_x,p2_scale_y,.. p2_handle_x,p2_handle_y,p2_origin_x,p2_origin_y) If PolyToPoly(tform1_xy,tform2_xy) Return True Else Return False EndIf End Function Function PolyToTFormPoly( p1_xy:Float[], p2_xy:Float[],.. p2_x:Float=0, p2_y:Float=0, rot:Float=0,.. scale_x:Float=1, scale_y:Float=1,.. handle_x:Float=0, handle_y:Float=0,.. origin_x:Float=0, origin_y:Float=0 ) If p1_xy.length<6 Or (p1_xy.length&1) Return False If p2_xy.length<6 Or (p2_xy.length&1) Return False Local tform_xy:Float[]=TFormPoly(p2_xy,p2_x,p2_y,rot,scale_x,scale_y,.. handle_x,handle_y,origin_x,origin_y) If PolyToPoly(p1_xy,tform_xy) Return True Else Return False EndIf End Function Function PolyToPoly( p1_xy:Float[], p2_xy:Float[] ) If p1_xy.length<6 Or (p1_xy.length&1) Return False If p2_xy.length<6 Or (p2_xy.length&1) Return False For Local i:Int=0 Until p1_xy.Length Step 2 If PointInPoly(p1_xy[i],p1_xy[i+1],p2_xy) Then Return True Next For Local i:Int=0 Until p2_xy.Length Step 2 If PointInPoly(p2_xy[i],p2_xy[i+1],p1_xy) Then Return True Next Local l1_x1:Float=p1_xy[p1_xy.Length-2] Local l1_y1:Float=p1_xy[p1_xy.Length-1] For Local i1:Int=0 Until p1_xy.Length Step 2 Local l1_x2=p1_xy[i1] Local l1_y2=p1_xy[i1+1] Local l2_x1:Float=p2_xy[p2_xy.Length-2] Local l2_y1:Float=p2_xy[p2_xy.Length-1] For Local i2:Int=0 Until p2_xy.Length Step 2 Local l2_x2=p2_xy[i2] Local l2_y2=p2_xy[i2+1] If LinesCross(l1_x1,l1_y1,l1_x2,l1_y2,l2_x1,l2_y1,l2_x2,l2_y2) Return True EndIf l2_x1=l2_x2 l2_y1=l2_y2 Next l1_x1=l1_x2 l1_y1=l1_y2 Next Return False End Function Function CircleToTFormPoly( circle_x:Float, circle_y:Float, radius:Float,.. xy:Float[], poly_x:Float=0, poly_y:Float=0, rot:Float=0,.. scale_x:Float=1, scale_y:Float=1,.. handle_x:Float=0, handle_y:Float=0,.. origin_x:Float=0, origin_y:Float=0 ) If xy.length<6 Or (xy.length&1) Return False Local tform_xy:Float[]=TFormPoly(xy,poly_x,poly_y,rot,scale_x,scale_y,.. handle_x,handle_y,origin_x,origin_y) Return CircleToPoly(circle_x,circle_y,radius,tform_xy) End Function Function CircleToPoly( circle_x:Float, circle_y:Float, radius:Float, xy:Float[] ) If xy.length<6 Or (xy.length&1) Return False If PointInPoly(circle_x,circle_y,xy) Then Return True Local x1:Float=xy[xy.Length-2] Local y1:Float=xy[xy.Length-1] For Local i:Int=0 Until Len xy Step 2 Local x2:Float=xy[i] Local y2:Float=xy[i+1] If LineToCircle(x1,y1,x2,y2,circle_x,circle_y,radius) Then Return True x1=x2 y1=y2 Next Return False End Function Function LineToTFormPoly( line_x1:Float, line_y1:Float, line_x2:Float, line_y2:Float,.. xy:Float[], poly_x:Float=0, poly_y:Float=0,.. rot:Float=0, scale_x:Float=1, scale_y:Float=1,.. handle_x:Float=0, handle_y:Float=0,.. origin_x:Float=0, origin_y:Float=0 ) If xy.length<6 Or (xy.length&1) Return False TFormGlobalToLocal(line_x1,line_y1,poly_x,poly_y,rot,scale_x,.. scale_y,handle_x,handle_y,origin_x,origin_y) TFormGlobalToLocal(line_x2,line_y2,poly_x,poly_y,rot,scale_x,.. scale_y,handle_x,handle_y,origin_x,origin_y) Return LineToPoly(line_x1,line_y1,line_x2,line_y2,xy) End Function Function LineToPoly( line_x1:Float, line_y1:Float, line_x2:Float, line_y2:Float, xy:Float[] ) If xy.length<6 Or (xy.length&1) Return False If PointInPoly(line_x1,line_y1,xy) Then Return True Local poly_x1:Float=xy[xy.Length-2] Local poly_y1:Float=xy[xy.Length-1] For Local i:Int=0 Until Len xy Step 2 Local poly_x2:Float=xy[i] Local poly_y2:Float=xy[i+1] If LinesCross(line_x1,line_y1,line_x2,line_y2,.. poly_x1,poly_y1,poly_x2,poly_y2) Then Return True poly_x1=poly_x2 poly_y1=poly_y2 Next Return False End Function Function PointInTFormPoly( point_x:Float, point_y:Float, xy:Float[],.. poly_x:Float=0, poly_y:Float=0, rot:Float=0,.. scale_x:Float=1, scale_y:Float=1,.. handle_x:Float=0, handle_y:Float=0,.. origin_x:Float=0, origin_y:Float=0 ) If xy.length<6 Or (xy.length&1) Return False TFormGlobalToLocal(point_x,point_y,poly_x,poly_y,rot,scale_x,.. scale_y,handle_x,handle_y,origin_x,origin_y) Return PointInPoly(point_x,point_y,xy) End Function Function PointInPoly( point_x:Float, point_y:Float, xy:Float[] ) If xy.length<6 Or (xy.length&1) Return False Local x1:Float=xy[xy.Length-2] Local y1:Float=xy[xy.Length-1] Local cur_quad:Int=GetQuad(point_x,point_y,x1,y1) Local next_quad:Int Local total:Int For Local i=0 Until Len xy Step 2 Local x2:Float=xy[i] Local y2:Float=xy[i+1] next_quad=GetQuad(point_x,point_y,x2,y2) Local diff:Int=next_quad-cur_quad Select diff Case 2,-2 If ( x2 - ( ((y2 - point_y) * (x1 - x2)) / (y1 - y2) ) )<point_x diff=-diff EndIf Case 3 diff=-1 Case -3 diff=1 End Select total:+diff cur_quad=next_quad x1=x2 y1=y2 Print x1+","+y1 Next If Abs(total)=4 Return True Else Return False EndIf End Function Function TFormPoly:Float[]( xy:Float[], tform_x:Float=0, tform_y:Float=0, rot:Float=0,.. scale_x:Float=1, scale_y:Float=1,.. handle_x:Float=0, handle_y:Float=0,.. origin_x:Float=0, origin_y:Float=0 ) If xy.length<6 Or (xy.length&1) Return Null Local tform_xy:Float[]=xy[..] For Local i=0 Until tform_xy.Length Step 2 TFormLocalToGlobal(tform_xy[i],tform_xy[i+1],tform_x,tform_y,rot,.. scale_x,scale_y,handle_x,handle_y,origin_x,origin_y) Next Return tform_xy End Function Function TFormGlobalToLocal( point_x:Float Var, point_y:Float Var,.. tform_x:Float=0, tform_y:Float=0, rot:Float=0,.. scale_x:Float=1, scale_y:Float=1,.. handle_x:Float=0, handle_y:Float=0,.. origin_x:Float=0, origin_y:Float=0 ) point_x:-origin_x point_y:-origin_y point_x:-tform_x point_y:-tform_y Local mag:Float=Sqr(point_x*point_x+point_y*point_y) Local ang:Float=ATan2(point_y,point_x) point_x=Cos(ang-rot)*mag point_y=Sin(ang-rot)*mag point_x:/scale_x point_y:/scale_y point_x:+handle_x point_y:+handle_y End Function Function TFormLocalToGlobal( point_x:Float Var, point_y:Float Var,.. tform_x:Float=0, tform_y:Float=0, rot:Float=0,.. scale_x:Float=1, scale_y:Float=1,.. handle_x:Float=0, handle_y:Float=0,.. origin_x:Float=0, origin_y:Float=0 ) point_x:-handle_x point_y:-handle_y point_x:*scale_x point_y:*scale_y Local mag:Float=Sqr(point_x*point_x+point_y*point_y) Local ang:Float=ATan2(point_y,point_x) point_x=Cos(ang+rot)*mag point_y=Sin(ang+rot)*mag point_x:+tform_x point_y:+tform_y point_x:+origin_x point_y:+origin_y End Function 'Adapted from Fredborg's code Function LinesCross( x0:Float, y0:Float , x1:Float, y1:Float,.. x2:Float ,y2:Float, x3:Float, y3:Float ) Local n:Float=(y0-y2)*(x3-x2)-(x0-x2)*(y3-y2) Local d:Float=(x1-x0)*(y3-y2)-(y1-y0)*(x3-x2) If Abs(d) < 0.0001 ' Lines are parallel! Return False Else ' Lines might cross! Local Sn:Float=(y0-y2)*(x1-x0)-(x0-x2)*(y1-y0) Local AB:Float=n/d If AB>0.0 And AB<1.0 Local CD:Float=Sn/d If CD>0.0 And CD<1.0 ' Intersection Point Local X=x0+AB*(x1-x0) Local Y=y0+AB*(y1-y0) Return True End If End If ' Lines didn't cross, because the intersection was beyond the end points of the lines EndIf ' Lines do Not cross! Return False End Function 'Adapted from TomToad's code Function LineToCircle:Vector2( x1:Float, y1:Float, x2:Float, y2:Float, px:Float, py:Float, r:Float ) Local sx:Float = x2-x1 Local sy:Float = y2-y1 Local V:Vector2=New Vector2 Local q:Float = ((px-x1) * (x2-x1) + (py - y1) * (y2-y1)) / (sx*sx + sy*sy) If q < 0.0 Then q = 0.0 If q > 1.0 Then q = 1.0 Local cx:Float=(1-q)*x1+q*x2 Local cy:Float=(1-q)*y1 + q*y2 If PointToPointDist(px,py,cx,cy)<r V.X=cx V.Y=cy Return V Else Return Null EndIf End Function Function PointToPointDist:Float( x1:Float, y1:Float, x2:Float, y2:Float ) Local dx:Float = x1-x2 Local dy:Float = y1-y2 Return Sqr(dx*dx + dy*dy) End Function Function GetQuad(axis_x:Float,axis_y:Float,vert_x:Float,vert_y:Float) If vert_x<axis_x If vert_y<axis_y Return 1 Else Return 4 EndIf Else If vert_y<axis_y Return 2 Else Return 3 EndIf EndIf End Function Rem ?win SetGraphicsDriver GLMax2DDriver() ? Graphics 800,600,32,60 HideMouse Local verts:Float[]=[-25.0,0.0,-75.0,75.0,0.0,50.0,100.0,100.0,.. 50.0,25.0,100.0,0.0,50.0,-25.0,100.0,-100.0,0.0,-50.0,-75.0,-75.0] Local cursor:Float[]=[0.0,-50.0,100.0,-100.0,50.0,0.0,100.0,100.0,.. 0.0,50.0,-100.0,100.0,-50.0,0.0,-100.0,-100.0] Local ang:Float=0 Local coltype:Int=0 Local rad:Float=20 Repeat If KeyHit(KEY_1) Then coltype=0 If KeyHit(KEY_2) Then coltype=1 If KeyHit(KEY_3) Then coltype=3 If KeyHit(KEY_4) Then coltype=2 Local x:Float=400 Local y:Float=300 Local rot:Float=ang/2 Local sx:Float=Cos(ang)/2+1.5 Local sy:Float=Sin(ang)/2+1.5 Local hx:Float=Cos(ang)*50 Local hy:Float=Sin(ang)*50 Local ox:Float=Cos(ang/2)*50 Local oy:Float=Sin(ang/2)*50 Local lx:Float=400+Cos(-ang)*300 Local ly:Float=300+Sin(-ang)*300 SetRotation rot SetScale sx,sy SetHandle hx,hy SetOrigin ox,oy Local mx:Int=MouseX() Local my:Int=MouseY() Cls Select coltype Case 0 If PointInTFormPoly(mx,my,verts,x,y,rot,sx,sy,hx,hy,ox,oy) SetColor 0,255,255 Else SetColor 0,128,128 EndIf Case 1 If CircleToTFormPoly(mx,my,rad,verts,x,y,rot,sx,sy,hx,hy,ox,oy) SetColor 0,255,255 Else SetColor 0,128,128 EndIf Case 2 If TFormPolyToTFormPoly(verts,x,y,rot,sx,sy,hx,hy,ox,oy,cursor,mx,my,-rot,0.5,0.5) SetColor 0,255,255 Else SetColor 0,128,128 EndIf Case 3 If LineToTFormPoly(mx,my,lx,ly,verts,x,y,rot,sx,sy,hx,hy,ox,oy) SetColor 0,255,255 Else SetColor 0,128,128 EndIf End Select DrawPoly verts,True,x,y SetRotation 0 SetScale 1,1 SetHandle 0,0 SetOrigin 0,0 SetColor 255,255,255 DrawText "Select 1, 2, 3 or 4",5,0 DrawText "1: PointToTFormPoly",5,20 DrawText "2: CircleToTFormPoly",5,35 DrawText "3: LineToTFormPoly",5,50 DrawText "4: TFormPolyToTFormPoly",5,65 SetColor 255,0,0 Select coltype Case 0 DrawLine mx,my-10,mx,my+10,True DrawLine mx-10,my,mx+10,my,True Case 1 DrawOval mx-rad,my-rad,rad*2,rad*2 Case 2 SetRotation -rot SetScale 0.5,0.5 DrawPoly cursor,True,mx,my Case 3 DrawLine mx,my,lx,ly,True End Select Flip ang:+1 Until KeyHit(KEY_ESCAPE) End Rem Function DrawPolyEX( xy:Float[], fill:Int=True, x:Float=0, y:Float=0 ) Local origin_x:Float Local origin_y:Float GetOrigin origin_x,origin_y Local handle_x:Float Local handle_y:Float GetHandle handle_x,handle_y If fill _max2dDriver.DrawPoly xy,.. -handle_x,-handle_y,.. x+origin_x,y+origin_y Else Local x1:Float=xy[xy.Length-2] Local y1:Float=xy[xy.Length-1] For Local i:Int=0 Until Len xy Step 2 Local x2:Float=xy[i] Local y2:Float=xy[i+1] _max2dDriver.DrawLine.. -handle_x+x1,-handle_y+y1,.. -handle_x+x2,-handle_y+y2,.. x+origin_x-0.5,y+origin_y-0.5 x1=x2 y1=y2 Next EndIf End Function

Pete Rigz (Posted 2013) [#2]

I wrote a collision module a while go that can do this. you can get it through SVN here: http://subversion.assembla.com/svn/timelinefx-module/ There's a few examples in the doc folder, and here's one that uses circle to line specifically: SuperStrict Import rigz.collision Graphics 800, 600 'create a line to collide with Local line:tlLine = CreateLine(100, 120, 500, 200) 'create a box to move about Local circle:tlCircle = CreateCircle(100, 100, 20) 'a local collision result to store the result of the collision test Local result:tlCollisionResult = New tlCollisionResult 'some velocity vectors to move the box about Local VelVector:tlVector2 = CreateVector2(0, 0) Local VelMatrix:tlMatrix2 = CreateMatrix2() Local Direction:Float Local speed:Float = 4 While Not KeyDown(KEY_ESCAPE) Cls 'some basic movement controls for the box If KeyDown(KEY_UP) direction = 0 If KeyDown(KEY_RIGHT) direction = 90 If KeyDown(KEY_DOWN) direction = 180 If KeyDown(KEY_LEFT) direction = 270 If KeyDown(KEY_RIGHT) And KeyDown(KEY_DOWN) direction = 135 If KeyDown(KEY_DOWN) And KeyDown(KEY_LEFT) direction = 225 If KeyDown(KEY_UP) And KeyDown(KEY_RIGHT) direction = 45 If KeyDown(KEY_LEFT) And KeyDown(KEY_UP) direction = 315 If KeyDown(KEY_UP) Or KeyDown(KEY_DOWN) Or KeyDown(KEY_LEFT) Or KeyDown(KEY_RIGHT) velvector.SetPosition(0, -speed) Else velvector.SetPosition(0, 0) End If velmatrix.set(Cos(direction) , Sin(direction) , -Sin(direction) , Cos(direction)) velvector = velmatrix.transformvector(velvector).Unit() 'set the box velocity so that the collision check can see whether the 2 objects will collide 'the next frame. You don't *have* to do this, but it makes for more accurate collisions circle.velocity = VelVector.Scale(speed) 'check for a collision with the line result = CheckCollision(circle, line) 'prevent the circle from overlapping the poly PreventOverlap(result) 'move the circle. Important to do this after the collision check, but only if you're setting 'the box velicity. circle.Move(circle.velocity.x, circle.velocity.y) circle.draw() line.draw() Flip Wend In the case of your code it could be the order in which you're checking for a collision and moving the circle, but that's a guess without looking too closely.

codermax (Posted 2013) [#3]

Hey Pete, thanks a lot for your help. I suck at compiling modules, however yours is just plain bmx code, so it actually worked! Great source by the way. I've changed my source to use your modules instead, and it works like a charm. Thanks again! :)