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References: <mailman.11027.1402548495.18130.python-list@python.org> <bvthovFg8ldU1@mid.individual.net>
Date: Thu, 12 Jun 2014 16:11:34 -0700 (PDT)
From: Pedro Izecksohn <izecksohn@yahoo.com>
Subject: Re: Lines on a tkinter.Canvas
To: "python-list@python.org" <python-list@python.org>
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----- Original Message -----=0A=0A> From: Gregory Ewing=0A> To: python-list=
@python.org=0A> Cc: =0A> Sent: Thursday, June 12, 2014 8:38 AM=0A> Subject:=
 Re: Lines on a tkinter.Canvas=0A> =0A> Pedro Izecksohn wrote:=0A>>  The Ca=
nvas' method create_line turns on at least 2 pixels. But I want =0A> to tur=
n=0A>>  on many single pixels on a Canvas.=0A> =0A> You could try using a 1=
x1 rectangle instead.=0A> =0A> However, be aware that either of these will =
use quite a=0A> lot of memory per pixel. If you are drawing a very large=0A=
> number of pixels, this could cause performance problems.=0A> In that case=
, you might want to use a different approach,=0A> such as creating an image=
 and telling the canvas to display=0A> the image.=0A=0A=A0 Thank you Greg. =
Your second approach works and the script became:=0A=0A#!/usr/bin/python3=
=0A=0Aimport tkinter as tk=0A=0ABITMAP =3D '''=0A#define im_width 1=0A#defi=
ne im_height 1=0Astatic char im_bits[] =3D {=0A0xff=0A};=0A'''=0A=0Aclass P=
oint ():=0A=A0 def __init__ (self, x, y):=0A=A0=A0=A0 self.x =3D x=0A=A0=A0=
=A0 self.y =3D y=0A=0Aclass Board (tk.Frame):=0A=A0 def __init__ (self, bg,=
 dimensions):=0A=A0=A0=A0 tk.Frame.__init__ (self, tk.Tk())=0A=A0=A0=A0 sel=
f.pack()=0A=A0=A0=A0 self.canvas =3D tk.Canvas (self, bd =3D 0, bg =3D bg, =
width =3D dimensions.x, height =3D dimensions.y)=0A=A0=A0=A0 self.canvas.pa=
ck (side =3D "top")=0A=A0=A0=A0 self.objects_drawn =3D []=0A=A0 def drawLin=
e (self, pa, pb, color):=0A=A0=A0=A0 self.canvas.create_line (pa.x, pa.y, p=
b.x, pb.y, fill =3D color)=0A=A0 def drawPoint (self, p, color):=0A=A0=A0=
=A0 bitmap =3D tk.BitmapImage (data=3DBITMAP, foreground =3D color)=0A=A0=
=A0=A0 self.objects_drawn.append (bitmap)=0A=A0=A0=A0 self.canvas.create_im=
age (p.x, p.y, image =3D bitmap)=0A=0Adimensions =3D Point (500, 500)=0Aboa=
rd =3D Board ('black', dimensions)=0Acolor =3D 'red'=0Ap =3D Point (0, 250)=
=0Awhile (p.x < dimensions.x):=0A=A0 board.drawPoint (p, color)=0A=A0 p.x +=
=3D 1=0Apa =3D Point (0, 350)=0Apb =3D Point (499, 350)=0Aboard.drawLine (p=
a, pb, color)=0Aboard.mainloop()