MetaFun questions

MetaFun questions

[Jens-Uwe Morawski]

Hi,

i would like to know

- if i can draw a gradient/shading with two RGBA colors, for example,
  a gradient starting with red=1 and alpha=0.5 and ending with green=1
  and alpha=0.7

- if it is possible to add some capabilities to texutil, or where else
  it is needed, so that
  externalfigure "somefile" scaled 2 ;

  has the original figure-size scaled 2 and not unitsquare scaled 2

Best,
  Jens

Re: MetaFun questions

[Hans Hagen]

At 02:09 PM 2/27/2003 +0100, you wrote:

>- if i can draw a gradient/shading with two RGBA colors, for example,
>   a gradient starting with red=1 and alpha=0.5 and ending with green=1
>   and alpha=0.7

in supp-mpe.tex seatch for:

  CircularShade  LinearShade  DuotoneShade

>- if it is possible to add some capabilities to texutil, or where else
>   it is needed, so that
>   externalfigure "somefile" scaled 2 ;
>
>   has the original figure-size scaled 2 and not unitsquare scaled 2

can you be a bit more explicit

Hans
-------------------------------------------------------------------------
                                   Hans Hagen | PRAGMA ADE | pragma@wxs.nl
                       Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------
                        information: http://www.pragma-ade.com/roadmap.pdf
                     documentation: http://www.pragma-ade.com/showcase.pdf
-------------------------------------------------------------------------

Re: MetaFun questions

[Nigel King]

>>   has the original figure-size scaled 2 and not unitsquare scaled 2
> 
> can you be a bit more explicit

I might be able to help since I had this problem with scaling external
figures in mpost MetaFun.

In ConTeXt \externalfigure[xxx.pdf] brings in a picture at the size of the
picture. Scaling modifies that size.

In mpost MetaFun externalfigure("xxx.jpg") brings in a figure at the size of
unitsquare scaled 2 which then has to be scaled up by other values to get to
a useable picture which involved me in quite a lot of trial and error. I did
not try this with pdf.

-- 
Nigel

Re: MetaFun questions

[Hans Hagen]

At 07:05 PM 2/27/2003 +0000, you wrote:
> >>   has the original figure-size scaled 2 and not unitsquare scaled 2
> >
> > can you be a bit more explicit
>
>I might be able to help since I had this problem with scaling external
>figures in mpost MetaFun.
>
>In ConTeXt \externalfigure[xxx.pdf] brings in a picture at the size of the
>picture. Scaling modifies that size.

how about

   scaled 2
   xscaled 2 yscaled 5
   xyscaled (2,5)

and

   xsized 2cm
   ysized 4cm
   xysized (2cm,4cm)

Hans

-------------------------------------------------------------------------
                                   Hans Hagen | PRAGMA ADE | pragma@wxs.nl
                       Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------
                        information: http://www.pragma-ade.com/roadmap.pdf
                     documentation: http://www.pragma-ade.com/showcase.pdf
-------------------------------------------------------------------------

Re: MetaFun questions

[Nigel King]

>>>>   has the original figure-size scaled 2 and not unitsquare scaled 2
>>> 
>>> can you be a bit more explicit
>> 
>> I might be able to help since I had this problem with scaling external
>> figures in mpost MetaFun.
>> 
>> In ConTeXt \externalfigure[xxx.pdf] brings in a picture at the size of the
>> picture. Scaling modifies that size.
> 
> how about
> 
>  scaled 2
>  xscaled 2 yscaled 5
>  xyscaled (2,5)
> 
> and
> 
>  xsized 2cm
>  ysized 4cm
>  xysized (2cm,4cm)
> 
I think we understand that. The point is that whereas Context knows the size
of the original picture, MetaFun does not.

-- 
Nigel

Re: MetaFun questions

[Jens-Uwe Morawski]

On Thu, 27 Feb 2003 15:55:41 +0100
Hans Hagen <pragma@wxs.nl> wrote:

> At 02:09 PM 2/27/2003 +0100, you wrote:
> 
> >- if i can draw a gradient/shading with two RGBA colors, for example,
> >   a gradient starting with red=1 and alpha=0.5 and ending with green=1
> >   and alpha=0.7
> 
> in supp-mpe.tex seatch for:
> 
>   CircularShade  LinearShade  DuotoneShade


i know linear_shade, circular_shade...; the question is how can
i use them with transparency:

\definecolor[sa][r=1,t=0.7,a=1]
\definecolor[ea][g=1,t=0.5,a=1]

\definecolor[s][r=1]
\definecolor[e][g=1]

\startMPgraphic
  path p ; p := unitsquare xscaled 5cm yscaled 5cm ;
  fill p shifted (4cm,4cm) withcolor .7white ;
  fill p shifted (-3cm,-3cm) withcolor .8white ;

  linear_shade(p,0,\MPcolor{s},\MPcolor{e});
\stopMPgraphic

\loadcurrentMPgraphic\placeMPgraphic

the code above draws a gradient for colors s and e but not for colors
 sa and ea. Is this because gradients _and_ transparency together
are not supported or is it because i do it the wrong way.
 
> >- if it is possible to add some capabilities to texutil, or where else
> >   it is needed, so that
> >   externalfigure "somefile" scaled 2 ;
> >
> >   has the original figure-size scaled 2 and not unitsquare scaled 2
> 
> can you be a bit more explicit

for example, if i have a PNG graphic with width 216 pixels and height of
144 pixels, then the ratio of width/height is 3/2. If i scale this
figure with factor 2 using \externalfigure in ConTeXt then the
aspectratio is kept.
Using the

externalfigure("figurefile") scaled 2

in MetaPost results in figure with a size of
unitsquare scaled 2

Neither the ratio of width and height nor the size of the original
graphic are maintained or have any influence on the output.

Thus, i would like to suggest something that:

- assuming following MP code:
  externalfigure("mygraphic.png") scaled 2 ;
  externalfigure("anothergraphic.pdf"") scaled 5 ;
 
- in a first metapost-run each "externalfigure" writes the name
  of the graphic file in a temporary file, for example
  <jobname>-extfigures.tmp

- texutil, or something else, reads this file, determines the
  original size of the graphics and writes an input file
  (<jobname>-extfigures.mp) for the following MP
  run that contains for example:

numeric numof_externalfigures, widthof_externalfigure[],
        heightof_externalfigure[] ;
string nameof_externalfigure[] ;

numof_externalfigures:=2 ;
nameof_externalfigure[1]  := "mygraphic.png" ;
widthof_externalfigure[1] := 2cm ;
heightof_externalfigure[1]:= 4cm ;

nameof_externalfigure[2]  := "anothergraphic.pdf" ;
widthof_externalfigure[2] := 3cm ;
heightof_externalfigure[2]:= 5cm ;

- then the macro "doexternalfigure" could be :

def doexternalfigure (expr filename) text transformation =
  begingroup ; save p, t ; picture p ; transform t ;

%% here comes the part that writes the filename to
%% <jobname>-extfigures.tmp

%%>> added
   save w_, h_ ; numeric w_, h_ ;
   w_ := 1 ; h_ := 1 ;
   if (known numof_externalfigures):
     if (numof_externalfigures>0):
       for i=1 upto numof_externalfigures:
         if (nameof_externalfigure[i]=filename):
            w_ := widthof_externalfigure[i] ;
            h_ := heightof_externalfigure[i] ;
         fi;
       endfor;
     fi;
   fi;
%%<<

%%>> changed
%
% original:
%
% p := nullpicture ; t := identity transformation ;
%
  p := nullpicture ; t := ( (identity xscaled w_) yscaled h_ ) transformation ;
%%<<

  flush_special(10, 9,
    dddecimal (xxpart t, yxpart t, xypart t) & " " &
    dddecimal (yypart t,  xpart t,  ypart t) & " " & filename) ;

   addto p contour unitsquare scaled 0 ;
   setbounds p to unitsquare transformed t ;
  _color_counter_ := _color_counter_ + 1 ;
  draw p withcolor (_special_signal_/1000,_color_counter_/1000,_special_counter_/1000) ;
  endgroup ;
enddef ;

This should allow to maintain size and aspectratio of external figures, even
in MP. The problem is, how can texutil determine the original size of the
figures?! Is it possible to implement this?

Best,
  Jens

Re: MetaFun questions

[Hans Hagen]

At 03:22 PM 2/28/2003 +0100, you wrote:

>\definecolor[sa][r=1,t=0.7,a=1]
>\definecolor[ea][g=1,t=0.5,a=1]
>
>\definecolor[s][r=1]
>\definecolor[e][g=1]
>
>\startMPgraphic
>   path p ; p := unitsquare xscaled 5cm yscaled 5cm ;
>   fill p shifted (4cm,4cm) withcolor .7white ;
>   fill p shifted (-3cm,-3cm) withcolor .8white ;
>
>   linear_shade(p,0,\MPcolor{s},\MPcolor{e});
>\stopMPgraphic
>
>\loadcurrentMPgraphic\placeMPgraphic

i'll have a look at it; i'm not even sure if transparent shades are 
possible, since the shading vectors need color vectors (implementing 
shading and transparency took me quite some time to figure out from the 
fuzzy specs]

(btw:

\startMPcode

\stopMPcode

or

\startMPpage

\stopMPpage

saves you some typing)

Hans
-------------------------------------------------------------------------
                                   Hans Hagen | PRAGMA ADE | pragma@wxs.nl
                       Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------
                        information: http://www.pragma-ade.com/roadmap.pdf
                     documentation: http://www.pragma-ade.com/showcase.pdf
-------------------------------------------------------------------------

Re: MetaFun questions

[Hans Hagen]

At 09:17 AM 2/28/2003 +0000, Nigel King wrote:
> >>>>   has the original figure-size scaled 2 and not unitsquare scaled 2
> >>>
> >>> can you be a bit more explicit
> >>
> >> I might be able to help since I had this problem with scaling external
> >> figures in mpost MetaFun.
> >>
> >> In ConTeXt \externalfigure[xxx.pdf] brings in a picture at the size of the
> >> picture. Scaling modifies that size.
> >
> > how about
> >
> >  scaled 2
> >  xscaled 2 yscaled 5
> >  xyscaled (2,5)
> >
> > and
> >
> >  xsized 2cm
> >  ysized 4cm
> >  xysized (2cm,4cm)

\getfiguredimensions[...]
\let\MyFigWid\figurewidth
\let\MyFigHei\figureheight

....

xysized(\MyFigWid,\MyFigHei)


>I think we understand that. The point is that whereas Context knows the size
>of the original picture, MetaFun does not.

see above or meta-fig.tex

Hans
-------------------------------------------------------------------------
                                   Hans Hagen | PRAGMA ADE | pragma@wxs.nl
                       Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------
                        information: http://www.pragma-ade.com/roadmap.pdf
                     documentation: http://www.pragma-ade.com/showcase.pdf
-------------------------------------------------------------------------

Re: MetaFun questions

[Jens-Uwe Morawski]

On Thu, 06 Mar 2003 14:13:47 +0100
Hans Hagen <pragma@wxs.nl> wrote:

> At 09:17 AM 2/28/2003 +0000, Nigel King wrote:
> > >>>>   has the original figure-size scaled 2 and not unitsquare scaled 2
> > >>>
> > >>> can you be a bit more explicit
> > >>
> > >> I might be able to help since I had this problem with scaling external
> > >> figures in mpost MetaFun.
> > >>
> > >> In ConTeXt \externalfigure[xxx.pdf] brings in a picture at the size of the
> > >> picture. Scaling modifies that size.
> > >
> > > how about
> > >
> > >  scaled 2
> > >  xscaled 2 yscaled 5
> > >  xyscaled (2,5)
> > >
> > > and
> > >
> > >  xsized 2cm
> > >  ysized 4cm
> > >  xysized (2cm,4cm)
> 
> \getfiguredimensions[...]
> \let\MyFigWid\figurewidth
> \let\MyFigHei\figureheight
> 
> ....
> 
> xysized(\MyFigWid,\MyFigHei)

ahh, interesting. A plain metapost way as described in my other mail
would be possible if i could run pdftex after the mpost run and run 
afterwards mpost again.
How this could be done?

Jens

Re: MetaFun questions

[Jens-Uwe Morawski]

On Mon, 03 Mar 2003 22:10:27 +0100
Hans Hagen <pragma@wxs.nl> wrote:

> At 03:22 PM 2/28/2003 +0100, you wrote:
> 
> >\definecolor[sa][r=1,t=0.7,a=1]
> >\definecolor[ea][g=1,t=0.5,a=1]
> >
> >\definecolor[s][r=1]
> >\definecolor[e][g=1]
> >
> >\startMPgraphic
> >   path p ; p := unitsquare xscaled 5cm yscaled 5cm ;
> >   fill p shifted (4cm,4cm) withcolor .7white ;
> >   fill p shifted (-3cm,-3cm) withcolor .8white ;
> >
> >   linear_shade(p,0,\MPcolor{s},\MPcolor{e});
> >\stopMPgraphic
> >
> >\loadcurrentMPgraphic\placeMPgraphic
> 
> i'll have a look at it; i'm not even sure if transparent shades are 
> possible, since the shading vectors need color vectors (implementing 
> shading and transparency took me quite some time to figure out from the 
> fuzzy specs]

i had a look in the spec today and it seems that it is impossible since
transparency can only be applied to objects or groups but not to a color
vector. So, we need to wait until PDF1.X supports this. If somebody has
good connections to Adobe please ask for this very feature.

Jens

P.S. If somebody has access to Adobe Illustrator then i could help
     to know if it is possible there ;-)

Re: MetaFun questions

[Hans Hagen]

At 06:16 PM 3/6/2003 +0100, you wrote:

> > xysized(\MyFigWid,\MyFigHei)
>
>ahh, interesting. A plain metapost way as described in my other mail
>would be possible if i could run pdftex after the mpost run and run
>afterwards mpost again.
>How this could be done?

Currently we're making a bunch of tools that deal with graphics (a part of 
the example framework). It's not that hard to provide a mechanism that will 
write a file with data which is acceptable for metapost.

anyhow, here's a solution:

In cont-new.tex, add:

\def\showexternalfigured
   {\bgroup
    \immediate\openout\scratchwrite=mpfigs.mp
    \def\presetfigure[##1][##2]%
      {\getfiguredimensionsonly[##1]% \pagefigure[##1]%
       \immediate\write\scratchwrite
          {registerfigure("##1",\figurewidth,\figureheight)}}
    \pushendofline
    \readjobfile\@@exfile\donothing\donothing
    \popendofline
    \immediate\closeout\scratchwrite
    \egroup}

in texexec.pl, patch:

   [abc] into [abcd]

now you can run (in advance!):

   texexec *.png --pdf --fig=d

and get a file mpfigs.mp

copy the following code to mp-figs.mp:

pair figuredimensions[]; string figurenames[] ; numeric noffigures ;

noffigures := 0 ;

def registerfigure(expr name,width,height) =
   noffigures := noffigures + 1 ;
   figurenames[noffigures] := name ;
   figuredimensions[noffigures] := (width,height) ;
enddef ;

vardef figuredimensions(expr name) =
   save ok, i ; boolean ok ; numeric i ; i := 0 ; ok := false ;
   forever :
     i := i + 1 ; ok := (name = figurenames[i]) ; exitif ok ;
   endfor ;
   if ok : figuredimensions[i] else : origin fi
enddef ;

vardef figurewidth(expr name) =
   xpart figuredimensions(name)
enddef ;

vardef figureheight(expr name) =
   ypart figuredimensions(name)
enddef ;

end

and now you can say:

   input mp-figs.mp ;
   input mpfigs.mp ;

and voila:

   figurewidth("yourfig")

returns the width of the graphic

so: just one run in advance is needed

[just for testing; i'll think this over before i freeze/add it to context]

Hans

Hans

-------------------------------------------------------------------------
                                   Hans Hagen | PRAGMA ADE | pragma@wxs.nl
                       Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------
                        information: http://www.pragma-ade.com/roadmap.pdf
                     documentation: http://www.pragma-ade.com/showcase.pdf
-------------------------------------------------------------------------