Can you submit those Cairo changes as a pull request?
If you do, `destroy` needs to be `CairoPatternDestroy`. Actually, I'm not sure
why it's `CairoPatternDestroy` rather than `destroy`, and it looks like I
wrote that! You could presumably change it to `destroy`. Running the code in
the samples directory would be the closest thing we have to a test of whether
that breaks anything.
--Tim
On Thursday, February 27, 2014 09:59:13 PM Roger Herikstad wrote:
> Hi all,
> I tried to get a better understanding of Cairo drawing by implementing
> this solution myself. This is just a proof-of-concept and I didn't do any
> rigorous testing, but subjectively comparing the resize performance of a
> Winston scatter plot of ~10000 points and this new solution, I noticed a
> significant speed-up. Note that I still find it too slow, but that's
> probably due to my lack of understanding of Cairo.
> Basically, this is what I did:
>
> In Cairo.jl, add the following two functions:
>
> +function push_group(ctx::CairoContext)
> + if ctx.ptr == C_NULL
> + return
> + end
> + ccall((:cairo_push_group, _jl_libcairo), Void, (Ptr{Void},),ctx.ptr)
> + nothing
> +end
> +
> +function pop_group(ctx::CairoContext)
> + if ctx.ptr == C_NULL
> + return
> + end
> + ptr = ccall((:cairo_pop_group, _jl_libcairo), Ptr{Void},
> (Ptr{Void},),ctx.ptr)
> + pattern = CairoPattern(ptr)
> + finalizer(pattern, destroy)
> + pattern
> +end
>
>
> And this is my test code:
>
> using Base.Graphics
> using Cairo
> using Tk
>
>
>
> function example(num::Integer)
> x = 100*rand(num)
> y = 100*rand(num)
> win = Toplevel("Scatter",800,600)
> c = Canvas(win, 800,600)
> pack(c,expand=true,fill="both")
>
> function update(c)
> r = 0.2
> lw = 1.0
> cc = r + (lw+1)/2 + 1
> ctx = getgc(c)
>
> set_coords(ctx,0,0,Tk.width(c),Tk.height(c),-2*cc,100+2*cc,-2*cc,100+2*cc)
> set_source_rgb(ctx,1,1,1)
> paint(ctx)
>
> rectangle(ctx, 0,0,2*cc,2*cc)
> clip(ctx)
> push_group(ctx)
>
> set_line_width(ctx,lw)
> set_source_rgb(ctx,1,0,0)
> arc(ctx,cc,cc,r,0,2*pi)
> stroke_preserve(ctx)
> fill_preserve(ctx)
> p = pop_group(ctx)
> reset_clip(ctx)
>
>
>
> for i=1:num
> save(ctx)
> translate(ctx,x[i]-cc,y[i]-cc)
> set_source(ctx,p)
> paint(ctx)
> restore(ctx)
> end
> reveal(c)
> Tk.update()
> end
> c.resize = c->update(c)
> end
>
>
> I appreciate any comments on this. Thanks!
>
> On Thursday, February 13, 2014 2:24:25 PM UTC+8, Mike Nolta wrote:
> > Thanks Roger! I'll give this a try.
> >
> > -Mike
> >
> > On Wed, Feb 12, 2014 at 11:57 PM, Roger Herikstad
> >
> > <[email protected] <javascript:>> wrote:
> > > Hi,
> > >
> > > I'm enjoying the ease with which Winston allows me to create beautiful
> > >
> > > plots. However, I often have the need to create scatter plots consisting
> >
> > of
> >
> > > ~1e5 points. This is currently too slow, and for those situations I
> >
> > resort
> >
> > > to Matlab using the excellent Matlab.jl
> > > (https://github.com/lindahua/MATLAB.jl). I'm aware of a previous thread
> >
> > on
> >
> > > this list concerning plotting performance of a large number of lines,
> >
> > but I
> >
> > > believe scatter plots might be a different issue, since it would involve
> > > drawing a separate path for each symbol in any case. I came across this
> > > thread: http://comments.gmane.org/gmane.comp.lib.cairo/18734 where a
> >
> > similar
> >
> > > problem was addressed. Could something like that be implemented in
> >
> > Winston
> >
> > > as well?
> > > After a cursory look at the the Cairo source code, it seems that the
> > > suggested solution relies on functions that are currently not wrapped by
> > > Cairo.jl, such as push_group/pop_group. I was considering trying to hack
> > > this out myself, but my knowledge of Cairo graphics is virtually
> > > non-existent. Anyway, I just thought I'd raise the issue in case someone
> > > would want to pursue it.
> > >
> > > ~ Roger
