On 6/5/07, David Arnold wrote:
> All,
>
> In working through the beginning chapters of the metafun manual, I am
> getting a very unusual effect when I open the resulting pdf file in
> Preview on Mac OS X. Here's a snapshot of what I see.
>
> http://online.redwoods.edu/instruct/darnold/context/meta.gif
>
> In acrobat, it looks fine.
>
> http://online.redwoods.edu/instruct/darnold/context/meta.pdf
>
> Any thoughts?
Hello,
It all boils down to
\starttext
\startMPcode
z0 = (0.5cm,1.5cm) ; z1 = (2.5cm,2.5cm) ;
z2 = (6.5cm,0.5cm) ; z3 = (2.5cm,1.5cm) ;
draw z0---z1---z2---z3---cycle withpen pencircle scaled 5pt;
\stopMPcode
\stoptext
resulting in
newpath
14.17323 42.51968 moveto
14.17139 42.52553 70.85913 70.86505 70.86613 70.86613 curveto
70.88313 70.86877 184.25645 14.18352 184.25194 14.17323 curveto
184.2461 14.15994 70.87599 42.51889 70.86613 42.51968 cureveto
70.86118 42.52008 14.17513 42.5137 14.17323 42.51968 curveto
closepath
If you ask me, this looks pretty much like a rendering bug in Mac's
Preview (if anyone bothers about that, please do that), but on the
other hand metapost could have generated a shorter & cleaner output as
well:
newpath
14.17323 42.51968 moveto
70.86613 70.86613 lineto
184.25194 14.17323 lineto
70.86613 42.51968 lineto
14.17323 42.51968 lineto
closepath
I suspect that the problem lies in control points of bezier curve
which are way too close to original points and thus lead to problems
with numerical precision, but I didn't experiment much deeper, so my
assumption might be wrong.
Taco?
Mojca
PS: I'm using mp 0.993 from TeXLive, but Supelec was down, so I wasn't
able to try it with the latest metapost version.
> \setuppapersize[S6][S6]
>
> \usetypescriptonce [map] [times,helvetica,palatino] [texnansi]
> \usetypescriptonce [serif] [times] [name,texnansi]
> \usetypescriptonce [sans] [helvetica] [name,texnansi]
> \usetypescriptonce [palatino] [texnansi]
>
> \setupbodyfont [palatino,10pt]
>
> \startbuffer[mpenv]
> \startMPenvironment
> \usetypescriptonce[map][times,helvetica,palatino][texnansi]
> \usetypescriptonce[serif][times][name,texnansi]
> \usetypescriptonce[sans][helvetica][name,texnansi]
> \usetypescriptonce[palatino][texnansi]
> \setupbodyfont[palatino,10pt]
> \definefont[RotFont][RegularBold]
> \stopMPenvironment
> \stopbuffer
>
> \definefont[RotFont][RegularBold]
>
> \getbuffer[mpenv]
>
> \setupcolors[state=start]
>
> \starttext
>
> \startuseMPgraphic{axis}
> tickstep := 1cm ; ticklength := 2mm ;
> drawticks unitsquare xscaled 8cm yscaled 3cm ;
> tickstep := tickstep/2 ; ticklength := ticklength/2 ;
> drawticks unitsquare xscaled 8cm yscaled 3cm ;
> \stopuseMPgraphic
>
> \startuseMPgraphic{points}
> z0 = (0.5cm,1.5cm) ; z1 = (2.5cm,2.5cm) ;
> z2 = (6.5cm,0.5cm) ; z3 = (2.5cm,1.5cm) ;
> \stopuseMPgraphic
>
> \startuseMPgraphic{path}
> str := "z0---z1---z2---z3---cycle" ;
> \stopuseMPgraphic
>
> \startbuffer
> \startlinecorrection[blank]
> \startMPcode
> string str ; defaultfont := "\truefontname{Mono}" ;
> \includeMPgraphic{axis}
> \includeMPgraphic{points}
> \includeMPgraphic{path}
> label.lft(str,(14.5cm,2.5cm)) ;
> drawwholepath scantokens(str) ;
> \stopMPcode
> \stoplinecorrection
> \stopbuffer
>
> \getbuffer
>
>
> \stoptext
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