From bf365bc725a63b6b6b81ff6bbbfb091a3e300387 Mon Sep 17 00:00:00 2001
From: Ian Jauslin <ian@jauslin.org>
Date: Wed, 24 Nov 2021 20:30:51 -0500
Subject: [PATCH] Fixes to motion of squares

---
 painter.py   |  7 ++++--
 polyomino.py | 61 ++++++++++++++++++++++++++++++++++++----------------
 2 files changed, 47 insertions(+), 21 deletions(-)

diff --git a/painter.py b/painter.py
index 484cf62..9974cf9 100644
--- a/painter.py
+++ b/painter.py
@@ -4,6 +4,7 @@ from kivy.core.window import Window
 
 from point import Point
 from polyomino import Square
+from polyomino import Square_element
 
 # painter class
 class Painter(Widget):
@@ -128,6 +129,7 @@ class Painter(Widget):
             if touch.button=="left" and self.modifiers==[] and self.undermouse!=None:
                 # change in position
                 delta=self.check_move(Point(touch.x/Square_element.size,touch.y/Square_element.size)-(self.offset+self.undermouse.squares[0].pos),self.undermouse)
+                self.undermouse.move(delta)
                 # multiple particles
                 # TODO: group moves
                 #else:
@@ -173,7 +175,8 @@ class Painter(Widget):
     # check whether a position intersects with any of the particles
     def check_interaction_any(self,candidate,offset):
         for particle in self.particles:
-            if particle.check_interaction(candidate,offset):
+            # do not check interaction if candidate=particle
+            if candidate!=particle and particle.check_interaction(candidate,offset):
                 return True
         return False
 
@@ -193,7 +196,7 @@ class Painter(Widget):
                         # TODO: this assumes other is a square
                         newdelta=other.squares[0].move_along(delta,particle.squares[0].pos)
                     else:
-                        newdelta=other.move_on_line_to_stick(particle.squares[0].pos,delta)
+                        newdelta=other.squares[0].move_on_line_to_stick(particle.squares[0].pos,delta)
                     if not self.check_interaction_any(particle,newdelta):
                         return newdelta
         if accept_newpos:
diff --git a/polyomino.py b/polyomino.py
index 25af5a3..d401759 100644
--- a/polyomino.py
+++ b/polyomino.py
@@ -39,9 +39,15 @@ class Polyomino():
             *((square.pos.x-0.5)*square.size,(square.pos.y-0.5)*square.size),
             *((square.pos.x-0.5)*square.size,(square.pos.y+0.5)*square.size),
             *((square.pos.x+0.5)*square.size,(square.pos.y+0.5)*square.size),
-            *((square.pos.x+0.5)*square.size,(square.pos.y-0.5)*square.size)
+            *((square.pos.x+0.5)*square.size,(square.pos.y-0.5)*square.size),
+            *((square.pos.x-0.5)*square.size,(square.pos.y-0.5)*square.size)
             ))
 
+    # move by delta
+    def move(self,delta):
+        for square in self.squares:
+            square.pos+=delta
+
     # whether x is in the support of the polyomino
     def in_support(self,x):
         for square in self.squares:
@@ -69,7 +75,7 @@ class Polyomino():
 # square
 class Square(Polyomino):
     def __init__(self,x,y,**kwargs):
-        super(Square,self).__init__(kwargs,squares=[Square_element(x,y)])
+        super(Square,self).__init__(**kwargs,squares=[Square_element(x,y)])
 
 
 
@@ -94,35 +100,52 @@ class Square_element():
     # check whether a square at position pos is touching self
     def check_touch(self,pos):
         # allow for error
-        if in_interval(l_infinity(pos-solf.pos),1-1e-11,1+1e-11):
+        if in_interval(l_infinity(pos-self.pos),1-1e-11,1+1e-11):
                 return True
         return False
 
     # find position along a line that comes in contact with the line going through pos in direction v
     def move_on_line_to_stick(self,pos,v):
         # compute intersections with four lines making up square
-        intersections=[\
-        Point(self.pos.x+1/2,pos.y+v.y/v.x*(self.pos.x+1/2-pos.x)),\
-        Point(self.pos.x-1/2,pos.y+v.y/v.x*(self.pos.x-1/2-pos.x)),\
-        Point(pos.x+v.x/v.y*(self.pos.y+1/2-pos.y),self.pos.y+1/2),\
-        Point(pos.x+v.x/v.y*(self.pos.y-1/2-pos.y),self.pos.y-1/2)\
-        ]
+        if v.x!=0:
+            if v.y!=0:
+                intersections=[\
+                Point(self.pos.x+1,pos.y+v.y/v.x*(self.pos.x+1-pos.x)),\
+                Point(self.pos.x-1,pos.y+v.y/v.x*(self.pos.x-1-pos.x)),\
+                Point(pos.x+v.x/v.y*(self.pos.y+1-pos.y),self.pos.y+1),\
+                Point(pos.x+v.x/v.y*(self.pos.y-1-pos.y),self.pos.y-1)\
+                ]
+            else:
+                intersections=[\
+                Point(self.pos.x+1,pos.y+v.y/v.x*(self.pos.x+1-pos.x)),\
+                Point(self.pos.x-1,pos.y+v.y/v.x*(self.pos.x-1-pos.x))
+                ]
+        else:
+            if v.y!=0:
+                intersections=[\
+                Point(pos.x+v.x/v.y*(self.pos.y+1-pos.y),self.pos.y+1),\
+                Point(pos.x+v.x/v.y*(self.pos.y-1-pos.y),self.pos.y-1)\
+                ]
+            else:
+                print("error: move_on_line_to_stick called with v=0, please file a bug report with the developer",file=sys.stderr)
+                exit(-1)
 
         # compute closest one, on square
         closest=None
         dist=math.inf
-        for i in range(0,4):
+        for i in range(0,len(intersections)):
             # check that it is on square
-            if abs(intersections[i].x-self.pos.x)<=1/2+1e-11 and abs(intersections[i].y-self.pos.y)<=1/2+1e-11:
+            if abs(intersections[i].x-self.pos.x)<=1+1e-11 and abs(intersections[i].y-self.pos.y)<=1+1e-11:
                 if (intersections[i]-pos)**2<dist:
                     closest=intersections[i]
                     dist=(intersections[i]-pos)**2
 
         if closest==None:
-            print("error: cannot move particle at (",pos.x,",",pos.y,") to the boundary of (",self.pos.x,",",self.pos.y,")",file=sys.stderr)
+            print("error: cannot move particle at (",pos.x,",",pos.y,") to the boundary of (",self.pos.x,",",self.pos.y,") in direction (",v.x,",",v.y,")",file=sys.stderr)
             exit(-1)
 
-        return closest
+        # return difference to pos
+        return closest-pos
 
     # move along edge of square
     def move_along(self,delta,pos):
@@ -153,31 +176,31 @@ class Square_element():
     # move when stuck in the x direction
     def move_stuck_x(self,delta,pos):
         # only move in y direction
-        candidate=Point(pos.x,pos.x+delta.y)
+        candidate=Point(0,delta.y)
         # do not move past corners
         rel=pos.y-self.pos.y
         if delta.y>0:
             if rel<math.ceil(rel)-1e-11 and delta.y+rel>math.ceil(rel)+1e-11 and math.ceil(rel)!=0:
                 # stick to corner
-                candidate.y=math.ceil(rel)+self.pos.y
+                candidate.y=math.ceil(rel)+self.pos.y-pos.y
         else:
             if rel>math.floor(rel)+1e-11 and delta.y+rel<math.floor(rel)-1e-11 and math.floor(rel)!=0:
                 # stick to corner
-                candidate.y=math.floor(rel)+self.pos.y
+                candidate.y=math.floor(rel)+self.pos.y-pos.y
         return candidate
     # move when stuck in the y direction
     def move_stuck_y(self,delta,pos):
         # onlx move in x direction
-        candidate=Point(pos.x,newpos.x)
+        candidate=Point(delta.x,0)
         # do not move past corners
         rel=pos.x-self.pos.x
         if delta.x>0:
             if rel<math.ceil(rel)-1e-11 and delta.x+rel>math.ceil(rel)+1e-11 and math.ceil(rel)!=0:
                 # stick to corner
-                candidate.x=math.ceil(rel)+self.pos.x
+                candidate.x=math.ceil(rel)+self.pos.x-pos.x
         else:
             if rel>math.floor(rel)+1e-11 and delta.x+rel<math.floor(rel)-1e-11 and math.floor(rel)!=0:
                 # stick to corner
-                candidate.x=math.floor(rel)+self.pos.x
+                candidate.x=math.floor(rel)+self.pos.x-pos.x
         return candidate