# HG changeset patch
# User Laman
# Date 2018-12-30 18:47:24
# Node ID f125391c937df906a327a2839b269cdd18078169
# Parent  3203933cf112aa85ffe7f80f673a6a6082f7628f

corners: order canonization moved to the add method

diff --git a/exp/color_sampler.py b/exp/color_sampler.py
--- a/exp/color_sampler.py
+++ b/exp/color_sampler.py
@@ -124,7 +124,7 @@ class Sampler:
 		for c in self.corners:
 			(x,y)=(c.x,c.y)
 			self.canvas.create_oval(x-2,y-2,x+2,y+2,fill="#00ff00",tags="mark")
-		if self.corners.canonizeOrder():
+		if self.corners.is_canon():
 			(a,b,c,d)=self.corners
 			self.canvas.create_line(a.x,a.y,b.x,b.y,fill="#00ff00",tags="mark")
 			self.canvas.create_line(b.x,b.y,c.x,c.y,fill="#00ff00",tags="mark")
diff --git a/src/analyzer/corners.py b/src/analyzer/corners.py
--- a/src/analyzer/corners.py
+++ b/src/analyzer/corners.py
@@ -8,6 +8,8 @@ log=logging.getLogger(__name__)
 class Corners:
 	def __init__(self,cornerList=[]):
 		self._corners=cornerList[:]
+		self._is_canon=False
+		self._canonizeOrder()
 
 	## Adds a new corner if there are less than four, replaces the closest otherwise.
 	def add(self,x,y):
@@ -29,6 +31,7 @@ class Corners:
 				index,minDist=i,a.dist(c)
 
 		self._corners[index]=a
+		self._canonizeOrder()
 
 	## Order the corners (0,1,2,3) so they make a quadrangle with vertices KLMN in counter-clockwise order, K being in the upper left.
 	#
@@ -51,8 +54,8 @@ class Corners:
 	#  From these pick the one with the lowest slope (dy/dx) and declare its ending point the upper left corner. For the same slope pick the one further left.
 	#
 	#  @return True for a convex quadrangle, False for concave and degenerate cases.
-	def canonizeOrder(self):
-		if len(self._corners)!=4: return False # erroneus call
+	def _canonizeOrder(self):
+		if len(self._corners)!=4: self._is_canon=False
 
 		a,b,c,d=self._corners
 		abc=doubleTriangleArea(a,b,c)
@@ -60,7 +63,7 @@ class Corners:
 		acd=doubleTriangleArea(a,c,d)
 		bcd=doubleTriangleArea(b,c,d)
 
-		if any(x==0 for x in (abc,abd,acd,bcd)): return False # collinear degenerate
+		if any(x==0 for x in (abc,abd,acd,bcd)): self._is_canon=False # collinear degenerate
 
 		swaps=[(1,3),(0,1),(1,2),(0,3),(2,3),(0,0)]
 		index=(8 if abc>0 else 0)|(4 if abd>0 else 0)|(2 if acd>0 else 0)|(1 if bcd>0 else 0)
@@ -82,7 +85,7 @@ class Corners:
 		self._corners= self._corners[kIndex:] + self._corners[:kIndex] # rotate the upper left corner to the first place
 
 		log.debug(self._corners)
-		return True # success
+		self._is_canon=True # success
 
 	def scale(self,scale):
 		self._corners=[c * scale for c in self._corners]
@@ -93,6 +96,9 @@ class Corners:
 	def __len__(self):
 		return len(self._corners)
 
+	def is_canon(self):
+		return self._is_canon
+
 
 ## Computes twice the area of the triangle formed by points a,b,c.
 #
diff --git a/src/analyzer/grid.py b/src/analyzer/grid.py
--- a/src/analyzer/grid.py
+++ b/src/analyzer/grid.py
@@ -21,7 +21,7 @@ class Grid:
 	#
 	#  The result is stored in grid.intersections, a boardSize*boardSize list with [row][column] coordinates.
 	#
-	#  @param corners list of EPoints in ABCD order per corners.Corners.canonizeOrder().
+	#  @param corners iterable of 4 EPoints in ABCD order per corners.Corners._canonizeOrder().
 	# !! Needs a check for proper initialization.
 	def __init__(self,corners):
 		# ad
diff --git a/src/gui/imgview.py b/src/gui/imgview.py
--- a/src/gui/imgview.py
+++ b/src/gui/imgview.py
@@ -63,7 +63,7 @@ class ImgView(ResizableCanvas):
 	def addCorner(self,x,y):
 		self._corners.add(x,y)
 		log.debug("click on %d,%d",x,y)
-		if self._corners.canonizeOrder():
+		if self._corners.is_canon():
 			# transform corners from show coordinates to real coordinates
 			self._boardGrid=Grid(self._corners)
 			corners=[self._transformPoint(c) for c in self._corners]