On 7/9/2021 11:33 PM, Aditya Mahajan wrote:

On Fri, 9 Jul 2021, Hans Hagen wrote:

...

Hi,

This weekend upload has something new for metapost animation lovers:

\starttext

\startuseMPgraphic{demo} stacking := 6; fill fullcircle scaled 10cm withcolor "red" ; % stacking := 3; stacking := 9; fill fullcircle scaled 10cm shifted (3cm,0) withcolor "green" ; interim stacking := 4; fill fullcircle scaled 10cm shifted (3cm,3cm) withcolor "blue" ; for i=1 upto 10 : draw fullcircle scaled (i*cm) withstacking 8 withpen pencircle scaled 1mm withcolor "gray" ; endfor ; for i=1 upto 20 : draw fullcircle scaled (i*cm/2) withstacking (if odd(i) : i else : 5 fi) withpen pencircle scaled 2mm ; endfor ; draw boundingbox currentpicture withpen pencircle scaled 1pt withstacking 0 ; currentpicture := currentpicture xsized 15mm; \stopuseMPgraphic

\setupMPvariables[demo]

\startTEXpage \vskip1ex \hbox{\space\dorecurse{10}{\useMPgraphic{demo}{list={0,#1}}\space}} \vskip1ex \nointerlineskip \hbox{\space\dorecurse{10}{\useMPgraphic{demo}{list={0,1-#1}}\space}} \vskip1ex \stopTEXpage

\stoptext

I have some more ideas but want to approach it stepwise. It bpils down to the fact that one can put stuff on different 'layers' and optionally flush these (by default all are flushed but the stackling order is honored). An advantage is that one doesn't have to set up a graphic in order (read: save pictures, flush them later on) and it is actually a rather cheap extension in terms of runtime and overhead. Although I could emulate it in mkiv, it is currently an LMTX only feature.

The (optional) list accepts the usual {1,2,5,7-9} kind of specification.

Very interesting. What will be the syntax to use this with \processMPbuffer and \startMPcode?

In order to avoid a slash I went for the 'stacking' key: \startMPcode[instance=doublefun,stacking=0] % 4 draw (fullcircle scaled 5cm shifted (0cm,0cm)) withstacking 4; draw (fullcircle scaled 5cm shifted (0cm,0cm)) withpattern image (fill fullcircle scaled 1cm withcolor "darkred" ;) withpatternscale (1/10,1/10) ; \stopMPcode \startMPpage[offset=1cm,instance=doublefun,stacking=0] % 4 draw (fullcircle scaled 5cm shifted (0cm,0cm)) withstacking 4; draw (fullcircle scaled 5cm shifted (0cm,0cm)) withpattern image (fill fullcircle scaled 1cm withcolor "darkblue";) withpatternscale (1/10,1/10) ; \stopMPpage we also have optionals to \use.., \reuse.. and \unique.. \startTEXpage \vskip1ex \hbox{\space\dorecurse{10}{\useMPgraphic {demo}{stacking={0,#1}}\space}} \vskip1ex \nointerlineskip \hbox{\space\dorecurse{10}{\useMPgraphic {demo}{stacking={0,1-#1}}\space}} \vskip1ex \nointerlineskip \hbox{\space\dorecurse{10}{\useMPgraphic [instance=doublefun,stacking={0,1-#1}]{demo}\space}} \vskip1ex \stopTEXpage work in progress (new upload anyway, also with clipping fixed wrt stacking) (i was wondering for a moment if "undergraphic removal" makes sense but it is a somewhat costly operation) (an other feature to explore is not to rerun but use some wrapper that keeps the image for as long as we flush ... it might save some runtime but first i need to run into a case where it pays off) Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

On 7/11/2021 3:04 PM, Bruce Horrocks wrote:

...

On 9 Jul 2021, at 17:29, Hans Hagen wrote:

This weekend upload has something new for metapost animation lovers:

Forgive my ignorance but what exactly am I supposed to be seeing here? I run the example and get two rows of ten boxes. They don't move so it's not like an animated GIF was put into the PDF and they don't appear to be consecutive frames that could be joined into an animated GIF.

It's not an animation ... but there are users who make animations with mp and then they need stepwise build images so this feature provides that (instead of defining 10 different mp graphicss one can dedine just one). Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

On 7/12/2021 5:31 AM, Aditya Mahajan wrote:

On Sun, 11 Jul 2021, Bruce Horrocks wrote:

...

...

On 9 Jul 2021, at 17:29, Hans Hagen wrote:

This weekend upload has something new for metapost animation lovers:

Forgive my ignorance but what exactly am I supposed to be seeing here? I run the example and get two rows of ten boxes. They don't move so it's not like an animated GIF was put into the PDF and they don't appear to be consecutive frames that could be joined into an animated GIF.

For me, this feature provides the same capability as 'layers' in a graphical program. Consider the diagram shown in page 1 of the attached PDF. Suppose I want to "highlight" boxes A and B by drawing a square around them. That is easy; simply determine the bounding box of A, B (I do that manually here), and expand it a bit and draw it. Simple. See page 2.

Now, suppose I want to fill this highlighted box. Suddenly, we have a problem. The highlight box needs to be "behind" the other boxes. How do we do it. We determine the location of boxes A, B, and C, but do not draw them. Determine the highlight box. Now draw the highlight box first and then draw the boxes. Suddenly the code became an order of magnitude more complicated.

With the new stacking mechanism, I can just put the highlight box on "stack -1", and everything works well. See page 4. What's also super cool is that I can control what gets shown by changing the stacking key.

Let's assume that the last MPpage was a \startuseMPgraphic{boxes} .... \stopuseMPgraphic. Suppose I wanted to use these pictures in a presentation. On the first slide, I can use

\useMPgraphic[stacking=0]{boxes}

to show the three boxes, and on the next slide, I can use

\useMPgraphic[stacking={-1,0}]{boxes}

to show the boxes and the highlight. Drawing such "conditional" graphics was cumbersome in the past. Now, it is easier.

If you show a bunch of such "conditional" graphics in a sequence, you get an animation (or you could wrap around the animation module).

Aditya

PS: Hans, stacking doesn't completely work with the boxes macro. drawunboxed is always drawn on stack 0, which the bpath is drawn on the right stack. That is the reason I use stack = -1 to put the highlight in the "background". I need to ckeck if the range checked does negative numbers ... anyway, you can do this

\startMPpage[offset=2mm, stacking={1,2,3,4}] boxit.A("\boxframed{Box A}"); boxit.B("\boxframed{Box B}"); boxit.C("\boxframed{Box C}"); defaultdx := 0pt; defaultdy := 0pt; A.c = origin; B.w - A.e = (1cm, 0); 0.5[ A.s, B.s ] - C.n = (0, 1cm); draw image (drawunboxed(A,B,C)) withstacking 2; drawarrow A.s +- C.w withstacking 3 ; drawarrow B.s +- C.e withstacking 4 ; newpath highlight; highlight := (A.sw -- B.se -- B.ne -- A.nw) enlarged EmWidth; fill highlight withcolor "darkgray" withstacking 1; \stopMPpage but only the first edge in an image picture is adapted ... (i actually know that i need to fix that in mplib because i noticed the same issue with color etc (some old issue) Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

On 7/12/2021 12:12 PM, Floris van Manen wrote:

with the latest version not everything gets drawn as intended.

$ context --version mtx-context     | ConTeXt Process Management 1.04 mtx-context     | current version: 2021.07.10 21:51

On 12/07/2021 10:07, Hans Hagen wrote:

...

I need to ckeck if the range checked does negative numbers ... anyway, you can do this

\startMPpage[offset=2mm, stacking={1,2,3,4}]

   boxit.A("\boxframed{Box A}");    boxit.B("\boxframed{Box B}");    boxit.C("\boxframed{Box C}");

   defaultdx := 0pt;    defaultdy := 0pt;

   A.c = origin;

   B.w - A.e = (1cm, 0);

   0.5[ A.s, B.s ] - C.n = (0, 1cm);

   draw image (drawunboxed(A,B,C)) withstacking 2;

   drawarrow A.s +- C.w withstacking 3 ;    drawarrow B.s +- C.e withstacking 4 ;

   newpath highlight;

   highlight := (A.sw -- B.se -- B.ne -- A.nw) enlarged EmWidth;    fill highlight withcolor "darkgray" withstacking 1;

\stopMPpage indeed, that why i mentioned that the next version will do (but no upload today)

Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------