tkInter Canvas Antialiasing hack!

[Harvie]

I've figured little hack to do antialiasing in tkinter canvas (which is otherwise known to not be able to do antialiasing by itself):

#No antialiasing
self.create_line(0,10,70,200, fill="#000", width=5)

#Antialiasing (do 0.5px thicker line with approx 33% of color intensity before rendering line)
self.create_line(10,10,80,200, fill="#AAA", width=5.5)
self.create_line(10,10,80,200, fill="#000", width=5)

5px:

1px:

It's not extremely smooth subpixel antialiasing, but i think it's much easier on eyes!
All we have to do is override tkinter Canvas methods like create_line() or create_oval() to do this.
Only problem is that we have to calculate right color somehow. That can be done like this:

                rgb = self.winfo_rgb("red")
                print rgb[0], rgb[1], rgb[2]

[sfinexer]

@Harvie And how can this be applied?
It is possible for the depth of milling, but the coordinates are already quite small.
For my purposes, I have the original b-CNC and I want to get anti-aliasing but without rgb, I need a line ... Without kinks ...

[sfinexer]

If it's just for display, then I think it's superfluous, because you need to see what will be done.

[Harvie]

@sfinexer

And how can this be applied?

i've already applied it in my commit

It is possible for the depth of milling, but the coordinates are already quite small

it does not affect milling or precision

If it's just for display, then I think it's superfluous, because you need to see what will be done.

It will not affect your ability to see details (which is quite bad in bCNC anyway). Currently the view of bCNC is far from accurate. It approximates arcs using lines, etc... But missing antialiasing is one of the reasons why you can't see lines accurately. Read something on the topic if you need. However my eyes hurt from non-antialiased lines, so i've added this, because it was simple to do.

However this was just cheap simple fix until we move to OpenGL #591

[Harvie]

Just for reference if someone is looking for Tkinter Canvas antialiasing:

ANTIALIAS_CHEAP = True

class CNCCanvas(Canvas, object):
	#Calculate arguments for antialiasing
	def antialias_args(self, args, winc=0.5, cw=2):
		nargs = {}

		#set defaults
		nargs['width'] = 1
		nargs['fill'] = "#000"

		#get original args
		for arg in args:
			nargs[arg] = args[arg]
		if nargs['width'] == 0:
			nargs['width'] = 1

		#calculate width
		nargs['width'] += winc

		#calculate color
		#cbg = self.winfo_rgb(CANVAS_COLOR)
		cbg = self.winfo_rgb(self.cget("bg"))
		cfg = list(self.winfo_rgb(nargs['fill']))
		#print cbg, cfg
		cfg[0] = (cfg[0] + cbg[0]*cw)/(cw+1)
		cfg[1] = (cfg[1] + cbg[1]*cw)/(cw+1)
		cfg[2] = (cfg[2] + cbg[2]*cw)/(cw+1)
		nargs['fill'] = '#%02x%02x%02x' % (cfg[0]/256, cfg[1]/256, cfg[2]/256)
		#nargs['fill'] = '#AAA'
		#print cfg, nargs['fill']

		return nargs

	#Override alias method if antialiasing enabled:
	if ANTIALIAS_CHEAP:
		def create_line(self, *args, **kwargs):
			nkwargs = self.antialias_args(kwargs)
			super(CNCCanvas, self).create_line(*args, **nkwargs)
			return super(CNCCanvas, self).create_line(*args, **kwargs)

[Talhoid-Coder]

Also, tkinter canvas antialiasing is enabled on OSX.
Is there a way we can change the code to enable antialiasing in the canvas?

[Harvie]

Also, tkinter canvas antialiasing is enabled on OSX.

What are you refering to? I am not aware the tkinter canvas has antialiasing... And this hack was not huge success, especialy in terms of performance. bCNC canvas needs complete rewrite to C.