work on breaking intersecting lines. Doesn't work.

lightningbeam.py

@@ -219,6 +219,26 @@ def onMouseUpGroup(self, x, y,button=1,clicks=1):
 				lastline = l
 				self.lines.append(l)
 			self.delete(self.activelayer.frames[self.currentframe].objs[-1])
+			for line in self.lines:
+				for otherline in self.lines:
+					if not otherline is line:
+						if line.connection1 and otherline in line.connection1.lines: continue
+						if line.connection2 and otherline in line.connection2.lines: continue
+						inter = line.intersects(otherline)
+						if inter:
+							print "INTERSECTION"
+							inter = svlgui.Point(*inter)
+							l1 = svlgui.Line(line.endpoint1,inter,line.connection1,inter)
+							l2 = svlgui.Line(line.endpoint2,inter,line.connection2,inter)
+							l3 = svlgui.Line(otherline.endpoint1,inter,otherline.connection1,inter)
+							l4 = svlgui.Line(otherline.endpoint2,inter,otherline.connection2,inter)
+							inter.lines.add(l1)
+							inter.lines.add(l2)
+							inter.lines.add(l3)
+							inter.lines.add(l4)
+							self.lines[self.lines.index(line):self.lines.index(line)+1]=[l1,l2]
+							self.lines[self.lines.index(otherline):self.lines.index(otherline)+1]=[l3,l4]
+							break
 		'''for i in self.lines:
 			if abs(self.cshape.endpoint2.x-i.endpoint1.x)<10 and abs(self.cshape.endpoint2.y-i.endpoint1.y)<10:
 				self.cshape.connection2 = i.endpoint1

svlgui.py

@@ -3128,6 +3128,52 @@ class Line(object):
 		cz = x1*y2-y1*x2
 		if cz>0: angle=360-angle
 		return angle
+	def intersects(self,other):
+		'''def IsOnLeft(a,b,c):
+			return Area2(a,b,c) > 0
+		def IsOnRight(a,b,c):
+			return Area2(a,b,c) < 0
+		def IsCollinear(a,b,c):
+			return Area2(a,b,c) == 0
+		def Area2 (a,b,c):
+			return (b.x - a.x) * (c.y - a.y) - (c.x - a.x) * (b.y - a.y)
+		if (IsOnLeft(self.endpoint1,self.endpoint2,other.endpoint1) and IsOnRight(self.endpoint1,self.endpoint2,other.endpoint2))
+			or (IsOnLeft(self.endpoint1,self.endpoint2,other.endpoint2) and IsOnRight(self.endpoint1,self.endpoint2,other.endpoint1):
+			if (IsOnLeft(other.endpoint1,other.endpoint2,self.endpoint1) and IsOnRight(other.endpoint1,other.endpoint2,self.endpoint2))
+				or (IsOnLeft(other.endpoint1,other.endpoint2,self.endpoint2) and IsOnRight(other.endpoint1,other.endpoint2,self.endpoint1):
+					return True'''
+		# Formula for line is y = mx + b
+		try:
+			sm = (self.endpoint1.y-self.endpoint2.y)/(self.endpoint1.x-self.endpoint1.y)
+			om = (other.endpoint1.y-other.endpoint2.y)/(other.endpoint1.x-other.endpoint1.y)
+			sb = self.endpoint1.y-sm*self.endpoint1.x
+			ob = other.endpoint1.y-sm*other.endpoint1.x
+			if sm == om: return False
+			x = (ob-sb)/(sm-om)
+			y = sm*x + sb
+			if min(self.endpoint1.x,self.endpoint2.x)<x<max(self.endpoint1.x,self.endpoint2.x):
+				return [x,y]
+			else:
+				return False
+		except ZeroDivisionError:
+			# One of the lines is vertical.
+			# Formula for line in terms of y is x = my + b
+			try:
+				sm = (self.endpoint1.x-self.endpoint2.x)/(self.endpoint1.y-self.endpoint1.x)
+				om = (other.endpoint1.x-other.endpoint2.x)/(other.endpoint1.y-other.endpoint1.x)
+				sb = self.endpoint1.x-sm*self.endpoint1.y
+				ob = other.endpoint1.x-sm*other.endpoint1.y
+				if sm == om: return False
+				y = (ob-sb)/(sm-om)
+				x = sm*y + sb
+				if min(self.endpoint1.y,self.endpoint2.y)<y<max(self.endpoint1.y,self.endpoint2.y):
+					return [x,y]
+			except ZeroDivisionError:
+				# One of the lines is horizontal, too. Or one has zero length.
+				# Logic this.
+				return False
+
+		return False
 	def draw(self, cr=None, transform=None, rect=None):
 		if self.connection1:
 			self.endpoint1 = self.connection1