optional arguments in lattice spec

src/jam

@@ -1,16 +1,69 @@
 #!/usr/bin/env python3
 
+import sys
+import os.path,os
+import filecheck
+from lattice import Lattice
+
+## read cli before loading kivy, in case there are errors
+
+# read cli
+openfile=""
+lattice=""
+def read_cli():
+    global openfile
+    global lattice
+
+    # init flag
+    flag=""
+
+    # loop over arguments
+    for arg in sys.argv[1:]:
+        # option flag
+        if arg[0]=='-':
+            # loop over options
+            for c in arg[1:]:
+                # lattice
+                if c=='L':
+                    flag="lattice"
+
+        else:
+            # read lattice argument
+            if flag=="lattice":
+                # test the specification
+                (obj,message)=Lattice.new(arg)
+                if obj==None:
+                    print(message,file=sys.stderr)
+                    exit(-1)
+                lattice=arg
+                # reset flag
+                flag=""
+
+            # no flags
+            else:
+                openfile=arg
+                (ret,message)=filecheck.check_edit(openfile)
+                if ret<0:
+                    print(message,file=sys.stderr)
+                    exit(-1)
+
+# read cli
+read_cli()
+
+
+## import kivy
+
+# disable kivy argument parser
+os.environ["KIVY_NO_ARGS"] = "1"
+
 from kivy.app import App
 from kivy.uix.widget import Widget
 from kivy.uix.boxlayout import BoxLayout
 from kivy.config import Config
-import sys
-import os.path
 
 from painter import Painter
 from status_bar import Status_bar
 from command_prompt import Command_prompt
-import filecheck
 
 # App class
 class Jam_app(App):
@@ -21,6 +74,9 @@ class Jam_app(App):
         # the file open for editing
         self.openfile=kwargs.get("openfile","")
 
+        # the lattice open for editing
+        self.lattice=kwargs.get("lattice","")
+
         # readonly mode
         self.readonly=False
 
@@ -48,24 +104,20 @@ class Jam_app(App):
             # set readonly mode
             self.readonly=not os.access(self.openfile,os.W_OK)
 
+        # load lattice
+        if self.lattice!="":
+            (obj,message)=Lattice.new(self.lattice)
+            self.painter.set_lattice(obj)
+
         return layout
 
 
+
 # disable red circles on right click
 Config.set('input', 'mouse', 'mouse,disable_multitouch')
 # do not exit on escape
 Config.set('kivy', 'exit_on_escape', 0)
 
-# read cli
-openfile=""
-if len(sys.argv)==2:
-    openfile=sys.argv[1]
-    # check file
-    (ret,message)=filecheck.check_edit(openfile)
-    if ret<0:
-        print(message,file=sys.stderr)
-        exit(-1)
-
 # run
 if __name__ == '__main__':
-    Jam_app(openfile=openfile).run()
+    Jam_app(openfile=openfile,lattice=lattice).run()

src/lattice.py

@@ -0,0 +1,60 @@
+from point import Point
+
+# parent class of all lattices
+class Lattice():
+    def __init__(self,**kwargs):
+        self.type=kwargs.get("type","")
+
+    # lattice point nearest to point
+    # overwrite in subclasses
+    def nearest(self,point):
+        return point
+
+    # delta to nearest point
+    def nearest_delta(self,point):
+        return self.nearest(point)-point
+
+    # draw lattice
+    # overwrite in subclasses
+    def draw(self,painter):
+        return
+
+    # return the lattice according to a specification
+    def new(spec):
+        specs=spec.split(":")
+        # check type of lattice
+        if specs[0]=="square":
+            return Square_lattice.new_square(specs[1:],spec)
+        else:
+            return(None,"error: unrecognized lattice type: '"+specs[0]+"'")
+
+
+# square lattice
+class Square_lattice(Lattice):
+    def __init__(self,**kwargs):
+
+        self.spacing=kwargs.get("spacing",1.)
+
+        super(Square_lattice,self).__init__(**kwargs,type="square")
+
+    # lattice point nearest to point
+    def nearest(self,point):
+        return Point(round(point.x/self.spacing)*self.spacing,round(point.y/self.spacing)*self.spacing)
+
+    # draw
+    def draw(self,painter):
+        painter.draw_grid(Point(self.spacing/2,self.spacing/2),self.spacing)
+
+    # return the lattice according to a specification
+    def new_square(specs,spec):
+        # no optional args
+        if len(specs)==0:
+            return (Square_lattice(),"")
+        if len(specs)>1:
+            return (None,"error: '"+spec+"' is not a valid specification for the square lattice: should be 'square[:spacing]'")
+        try:
+            spacing=float(specs[0])
+            return (Square_lattice(spacing=spacing),"")
+        except:
+            return (None,"error: '"+spec+"' is not a valid specification for the square lattice: should be 'square[:spacing]'")
+        

src/painter.py

@@ -7,6 +7,7 @@ from kivy.graphics import Color,Line
 from point import Point
 from polyomino import Cross
 from polyomino import Square_element
+from lattice import Square_lattice
 
 from tools import remove_fromlist
 
@@ -20,6 +21,9 @@ class Painter(Widget):
         # list of particles
         self.particles=[]
 
+        # underlying lattice
+        self.lattice=None
+
         # particle under mouse
         self.undermouse=None
 
@@ -47,12 +51,29 @@ class Painter(Widget):
         self.keyboard = Window.request_keyboard(None,self,"text")
         self.keyboard.bind(on_key_down=self.on_key_down,on_key_up=self.on_key_up,on_textinput=self.on_textinput)
 
+        # redraw on resize
+        self.bind(size=lambda obj,value: self.draw())
+
     
     def reset(self):
         self.particles=[]
         self.undermouse=None
         self.draw()
 
+    # set lattice
+    def set_lattice(self,lattice):
+        self.lattice=lattice
+
+        # draw
+        self.draw()
+
+        # snap all existing particles to grid
+        for particle in self.particles:
+            delta=self.lattice.nearest_delta(particle.squares[0].pos)
+            if not self.check_interaction_any(particle,delta):
+                particle.move(delta)
+
+
     # convert logical coordinates (normalized and centered) to the ones that are plotted
     def pos_tocoord_x(self,x):
         return self.width/2+x*Square_element.size
@@ -74,6 +95,10 @@ class Painter(Widget):
             for particle in self.particles:
                 particle.draw(self)
 
+            # draw lattice
+            if self.lattice!=None:
+                self.lattice.draw(self)
+
             # draw grids
             for particle in self.particles:
                 if particle.grid>0:
@@ -87,17 +112,30 @@ class Painter(Widget):
         # height offset due to status bar and command prompt
         height_offset=self.app.status_bar.height+self.app.command_prompt.height
         # vertical lines
-        # offest wrt 0
-        offset=(pos.x-0.5)%mesh
-        for i in range(math.floor((self.width/Square_element.size-offset)/mesh)+1):
+        # lines right of pos
+        xx=pos.x+mesh/2
+        while self.pos_tocoord_x(xx)<self.width:
             Color(1,1,1)
-            Line(points=((i*mesh+offset)*Square_element.size,height_offset,(i*mesh+offset)*Square_element.size,self.height+height_offset))
-        # horizontal lines
-        # offset wrt 0
-        offset=(pos.y-0.5)%1-height_offset/Square_element.size
-        for i in range(math.floor((self.height/Square_element.size-offset)/mesh)+1):
+            Line(points=(self.pos_tocoord_x(xx),height_offset,self.pos_tocoord_x(xx),self.height+height_offset))
+            xx+=mesh
+        # lines left of pos
+        xx=pos.x-mesh/2
+        while self.pos_tocoord_x(xx)>0:
             Color(1,1,1)
-            Line(points=(0,(i*mesh+offset)*Square_element.size+height_offset,self.width,(i*mesh+offset)*Square_element.size+height_offset))
+            Line(points=(self.pos_tocoord_x(xx),height_offset,self.pos_tocoord_x(xx),self.height+height_offset))
+            xx-=mesh
+        # lines above pos
+        yy=pos.y+mesh/2
+        while self.pos_tocoord_y(yy)<self.height:
+            Color(1,1,1)
+            Line(points=(0,self.pos_tocoord_y(yy),self.width,self.pos_tocoord_y(yy)))
+            yy+=mesh
+        # lines below pos
+        yy=pos.y-mesh/2
+        while self.pos_tocoord_y(yy)>0:
+            Color(1,1,1)
+            Line(points=(0,self.pos_tocoord_y(yy),self.width,self.pos_tocoord_y(yy)))
+            yy-=mesh
 
 
     # respond to keyboard
@@ -175,6 +213,10 @@ class Painter(Widget):
             # create new cross
             if touch.button=="right":
                 new=Cross(touchx,touchy)
+                # snap to lattice
+                if self.lattice!=None:
+                    new.move(self.lattice.nearest_delta(new.squares[0].pos))
+
                 if not self.check_interaction_any(new,Point(0,0)):
                     # add to list
                     self.particles.append(new)
@@ -237,18 +279,30 @@ class Painter(Widget):
 
     # respond to drag
     def on_touch_move(self,touch):
-        # convert to logical
-        touchx=self.coord_topos_x(touch.x)
-        touchy=self.coord_topos_y(touch.y)
 
         # only respond to touch in drawing area
         if self.collide_point(*touch.pos):
+            # convert to logical
+            touchx=self.coord_topos_x(touch.x)
+            touchy=self.coord_topos_y(touch.y)
+
             # only move on left click
             if touch.button=="left" and self.modifiers==[] and self.undermouse!=None:
                 # attempted move determined by the relative position to the relative position of click within self.undermouse
                 delta=self.adjust_move(Point(touchx,touchy)-(self.offset+self.undermouse.squares[0].pos),0)
-                for particle in self.selected:
-                    particle.move(delta)
+
+                # snap to lattice
+                if self.lattice!=None:
+                    delta=self.lattice.nearest(delta)
+                    # check that the move is possible (which is not guaranteed after snapping to lattice)
+                    if not self.check_interaction_unselected_list(self.selected,delta):
+                        for particle in self.selected:
+                            particle.move(delta)
+
+                # no lattice, move is guaranteed to be acceptable
+                else:
+                    for particle in self.selected:
+                        particle.move(delta)
 
                 # redraw
                 self.draw()

src/polyomino.py

@@ -8,7 +8,7 @@ from tools import isint_nonzero,sgn,in_interval
 # parent class of all polyominos
 class Polyomino():
     def __init__(self,**kwargs):
-        # square elements that maje up the polyomino 
+        # square elements that make up the polyomino 
         self.squares=kwargs.get("squares",[])
 
         self.color=kwargs.get("color",(0,0,1))