Nice effect!
Here's the superstrict version with locals declared and the like
Here's the superstrict version with locals declared and the like
SuperStrict Type circle Field x:Float, y:Float, r:Float Field nonarcs:TList Field vx:Float, vy:Float Method New() nonarcs = New TList End Method Function Create:circle(x:Float, y:Float, r:Float) Local c:circle = New circle c.x = x c.y = y c.r = r Local an:Float = Rnd(360) Local v:Float = Rnd(.5, 2) c.vx = v * Cos(an) c.vy = v * Sin(an) Return c End Function Method update() x:+vx If x < 0 Or x > 800 vx = -vx x:+vx EndIf y:+vy If y < 0 Or y > 800 vy = -vy y:+vy EndIf End Method Method intersect(c2:circle) debugo "<<<<<" Local dx:Float = c2.x - x Local dy:Float = c2.y - y Local d:Int = Sqr(dx * dx + dy * dy) If d >= r + c2.r Then Return Local fullcircle:nonarc = nonarc.Create(0, 360) If r > c2.r If d + c2.r <= r c2.nonarcs = New TList c2.nonarcs.addlast fullcircle debugo "removed second circle!" Return EndIf Else If d + r <= c2.r nonarcs = New TList nonarcs.addlast fullcircle debugo "removed first circle" Return EndIf EndIf dx:/d dy:/d Local b:Float = (r * r - c2.r * c2.r + d * d) / (2 * d) Local theta:Float = ACos(b / r) Local phi:Float = ATan2(dy, dx) addnonarc(phi - theta, phi + theta) Local theta2:Float = ACos((d - b) / c2.r) Local phi2:Float = phi + 180 c2.addnonarc(phi2 - theta2, phi2 + theta2) End Method Method addnonarc(b1:Float, b2:Float) Local newna:nonarc = nonarc.Create(b1, b2) For Local na:nonarc = EachIn nonarcs debugo "compare " + newna.repr() + " with " + na.repr() If na.contains(b1) If na.contains(b2) If newna.contains(na.an1) And newna.contains(na.an2) debugo("both arcs contained in each other - full circle") nonarcs = New TList nonarcs.addlast nonarc.Create(0, 360) Return EndIf debugo("new arc wholly contained in old arc") Return Else debugo("a1->b2") nonarcs.remove na addnonarc(na.an1, b2) Return EndIf Else If na.contains(b2) debugo("b1->a2") nonarcs.remove na addnonarc(b1, na.an2) Return Else If newna.contains(na.an1) debugo("old arc wholly contained in new arc") nonarcs.remove na Else debugo("arcs don't intersect") EndIf EndIf EndIf Next nonarcs.addlast newna End Method Method draw() DrawText nonarcs.count(), x + 8, y Select nonarcs.count() Case 0 'this circle doesn't intersect any other, so just draw all of it drawarc(0, 360) Case 1 'this circle intersects one other, so only need to look at one nonarc Local na:nonarc = nonarc(nonarcs.first()) 'If na.an1=0 And na.an2=360 Then Return drawarc(na.an2, na.an1) Default 'this circle intersects several others, so work through list of nonarcs, drawing 'from end of previous one to start of next one SortList nonarcs, True, nonarc.comparestarts Local ona:nonarc = nonarc(nonarcs.last()) For Local na:nonarc = EachIn nonarcs drawarc(ona.an2, na.an1) ona = na Next End Select If drawnonarcs SetColor 255, 0, 0 For Local na:nonarc = EachIn nonarcs drawarc(na.an1, na.an2) Next SetColor 255, 255, 255 EndIf End Method Method drawarc(a:Float, b:Float) If b < a Then b:+360 Local steps:Int = 2 * Pi * r / 10 Local s:Float = 360.0 / steps Local theta:Float = a Local ox:Float = x + r * Cos(theta) Local oy:Float = y + r * Sin(theta) While theta < b Local dx:Float, dy:Float dx:Float = x + r * Cos(theta) dy:Float = y + r * Sin(theta) DrawLine ox, oy, dx, dy ox = dx oy = dy theta:+s Wend DrawLine ox, oy, x + r * Cos(b), y + r * Sin(b) End Method End Type Type nonarc Field an1:Float, an2:Float Function Create:nonarc(an1:Float, an2:Float) Local na:nonarc = New nonarc an1 = an1 Mod 360 If an1 < 0 Then an1:+360 If an2 <> 360 Then an2 = an2 Mod 360 If an2 < 0 Then an2:+360 na.an1 = an1 na.an2 = an2 Return na End Function Method contains:Int(an:Float) Local d1:Float = andiff(an2, an1) If d1 < 0 Then d1:+360 Local d2:Float = andiff(an, an1) If d2 = 0 Then Return 1 If d2 < 0 Then d2:+360 debugo " " + d1 debugo " " + d2 If d2 < d1 Then Return 1 Else Return 0 End Method Function comparestarts:Int(o1:Object, o2:Object) Local na1:nonarc = nonarc(o1) Local na2:nonarc = nonarc(o2) If nicean(na1.an1) < nicean(na2.an1) Then Return - 1 Else Return 1 End Function Method repr:String() Return "(" + String(Int(an1)) + "," + String(Int(an2)) + ")" End Method End Type Function nicean:Float(an:Float) an = an Mod 360 If an <= - 180 Then an:+360 Return an End Function Function andiff:Float(an1:Float, an2:Float) 'debugo String(an1)+" , "+String(an2) If an2 = 0 And an1 = 360 Then Return 360 Local dan:Float = (an1 - an2) Mod 360 If dan > 180 dan:-360 If dan < - 180 dan:+360 Return dan End Function Function anbetween(an:Float, an1:Float, an2:Float) End Function Function intersectcircles(circles:TList) For Local c:circle = EachIn circles c.nonarcs = New TList Next Local l:TList = circles.copy() While l.count() > 1 debugo "?????" Local c1:circle = circle(l.removefirst()) For Local c2:circle = EachIn l c1.intersect(c2) Next Wend End Function ''''TEST EXAMPLE Global debugging:Int = 0 Function debugo(txt:String) If debugging Print txt EndIf End Function Global drawnonarcs:Int = 0 Local circles:TList = New TList SeedRnd MilliSecs() For Local n:Int = 0 To 20 circles.addlast circle.Create(Rand(300, 500), Rand(300, 500), Rand(30, 100)) Next Local c2:circle = circle.Create(400, 400, 80) circles.addlast c2 Graphics 800, 800, 0 While Not KeyHit(KEY_ESCAPE) Or AppTerminate() c2.x = MouseX() c2.y = MouseY() If MouseHit(2) debugging = 1 debugo "------------------" Else debugging = 0 EndIf If MouseHit(1) drawnonarcs = 1 - drawnonarcs EndIf For Local c:circle = EachIn circles c.update() Next intersectcircles(circles) For Local c:circle = EachIn circles c.draw() Next DrawText "click mouse to see non-arcs", 0, 0 Flip Cls Wend