[NTG-context] Metapost lines with fancy line endings and connections

[NTG-context] Metapost lines with fancy line endings and connections

[Wolfgang Schuster]

Hi,

I have a bunch of similar graphics on a 7x7 where some lines have 
exceptions for the endings and connections.

- When a line ends in one of the four corners the line end has an angle 
of 45 degrees.
- When a line takes a turn the outer corner results also in a 45 degree 
angle.
- Single points always use straight endings.
- Lines which end outside of a corner end with a straight line.

While I can get the desired result which a filled path I'm looking for a 
solution where I have to set fewer control points.

The example below shows the simpler draw alternative where I need only a 
start and end point versus the outline alternative where I need at least 
twice as many points to get the desired output.

\starttext

\startuseMPgraphic{draw}
draw hlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted 
(0.5,0.5) withcolor "darkgray" ;
draw vlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted 
(0.5,0.5) withcolor "darkgray" ;
pickup pensquare scaled 1;
drawoptions(withcolor "red");
draw (1,7) -- (7,7) ;
draw (1,1) -- (3,1) -- (3,5) ;
draw (7,3) -- (5,3) -- (5,5) -- (7,5) ;
draw (7,1) ;
\stopuseMPgraphic

\startuseMPgraphic{fill}
draw hlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 withcolor 
"darkgray" ;
draw vlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 withcolor 
"darkgray" ;
drawoptions(withcolor "green");
fill (0,6) -- (7,6) -- (6,7) -- (1,7) -- cycle ;
fill (1,0) -- (2,0) -- (3,1) -- (3,5) -- (2,5) -- (2,1) -- (0,1) -- cycle ;
fill (7,2) -- (5,2) -- (4,3) -- (4,4) -- (5,5) -- (7,5) -- (7,4) -- 
(5,4) -- (5,3) -- (7,3) -- cycle ;
fill (6,0) -- (7,0) -- (7,1) -- (6,1) -- cycle ;
\stopuseMPgraphic

\startcombination[2*1]
   {\scale[s=10]{\useMPgraphic{draw}}}{draw option}
   {\scale[s=10]{\useMPgraphic{fill}}}{fill option}
\stopcombination

\startoverlay
   {\scale[s=10]{\useMPgraphic{draw}}}
   {\scale[s=10]{\useMPgraphic{fill}}}
\stopoverlay

\stoptext

Wolfgang

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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Bruce Horrocks]

> On 1 Dec 2024, at 09:51, Wolfgang Schuster <wolfgang.schuster.lists@gmail.com> wrote:
> 
> While I can get the desired result which a filled path I'm looking for a solution where I have to set fewer control points.

Draw the paths two grid squares sorter and at each end draw a “dot” which is a triangle of the right direction and shading?

So your first line

  draw (1,7) -- (7,7) ;

becomes

  triangle_dot_bottom_right_fill (1,7) ; draw (2,6) ; triangle_dot_bottom_left_fill (7,7) ;

If there are load of them then it might be easier to write a macro to walk the (1,7) — (7,7) path and insert “dots” at the changes of direction.

Regards,


—
Bruce Horrocks
Hampshire, UK

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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Bruce Horrocks]

> On 1 Dec 2024, at 10:45, Bruce Horrocks <ntg@scorecrow.com> wrote:
> 
> 
> 
>> On 1 Dec 2024, at 09:51, Wolfgang Schuster <wolfgang.schuster.lists@gmail.com> wrote:
>> 
>> While I can get the desired result which a filled path I'm looking for a solution where I have to set fewer control points.
> 
> Draw the paths two grid squares sorter and at each end draw a “dot” which is a triangle of the right direction and shading?

s/sorter/shorter/

> 
> So your first line
> 
>  draw (1,7) -- (7,7) ;
> 
> becomes
> 
>  triangle_dot_bottom_right_fill (1,7) ; draw (2,6) ; triangle_dot_bottom_left_fill (7,7) ;

 triangle_dot_bottom_right_fill (1,7) ; draw (2,7) -- (6,7) ; triangle_dot_bottom_left_fill (7,7) ;

<sigh> Sorry, brain not in gear

> 
> If there are load of them then it might be easier to write a macro to walk the (1,7) — (7,7) path and insert “dots” at the changes of direction.
> 
> Regards,

—
Bruce Horrocks
Hampshire, UK

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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Hans Hagen via ntg-context]

On 12/1/2024 11:54 AM, Bruce Horrocks wrote:

> <sigh> Sorry, brain not in gear

so once you're rebooted, you can figure out the logic behind this:

linecap := butt ;
linejoin := beveled ;

or even

pickup pensquare rotated -60 scaled (1/sqrt(2)) ;
linecap := 1 ;

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
-----------------------------------------------------------------
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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Wolfgang Schuster]

Bruce Horrocks schrieb am 01.12.2024 um 11:45:
>
>> On 1 Dec 2024, at 09:51, Wolfgang Schuster <wolfgang.schuster.lists@gmail.com> wrote:
>>
>> While I can get the desired result which a filled path I'm looking for a solution where I have to set fewer control points.
> Draw the paths two grid squares sorter and at each end draw a “dot” which is a triangle of the right direction and shading?
>
> So your first line
>
>    draw (1,7) -- (7,7) ;
>
> becomes
>
>    triangle_dot_bottom_right_fill (1,7) ; draw (2,6) ; triangle_dot_bottom_left_fill (7,7) ;
>
> If there are load of them then it might be easier to write a macro to walk the (1,7) — (7,7) path and insert “dots” at the changes of direction.

I had this in my mind but wasn't sure if this is the best solution.

Using a macro to create the line is a must here but I have to think how 
to set which delimiters for the line should be used (using different 
macros for each variation or passing the shape as argument).

BTW: Use && to connect the parts of the line to avoid graphical errors 
in your pdf viewer.

\startMPpage[offset=1pt]

pickup pensquare scaled 1 ;

draw (0,0) ;
draw (1,0) ;

draw (0,2) && (1,2) ;

\stopMPpage

Wolfgang

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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Wolfgang Schuster]

Hans Hagen via ntg-context schrieb am 01.12.2024 um 12:34:
> On 12/1/2024 11:54 AM, Bruce Horrocks wrote:
>
>> <sigh> Sorry, brain not in gear
>
> so once you're rebooted, you can figure out the logic behind this:
>
> linecap := butt ;
> linejoin := beveled ;

This doesn't result in the desired output I want.
> or even
>
> pickup pensquare rotated -60 scaled (1/sqrt(2)) ;
> linecap := 1 ;

I played with custom pens but failed to create a working triangle pen. 
I'll take another look into it because a few custom pens can draw all lines.

Wolfgang

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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Mikael Sundqvist]

Hi

On Sun, Dec 1, 2024 at 1:28 PM Wolfgang Schuster
<wolfgang.schuster.lists@gmail.com> wrote:
>
> Hans Hagen via ntg-context schrieb am 01.12.2024 um 12:34:
> > On 12/1/2024 11:54 AM, Bruce Horrocks wrote:
> >
> >> <sigh> Sorry, brain not in gear
> >
> > so once you're rebooted, you can figure out the logic behind this:
> >
> > linecap := butt ;
> > linejoin := beveled ;
>
> This doesn't result in the desired output I want.
> > or even
> >
> > pickup pensquare rotated -60 scaled (1/sqrt(2)) ;
> > linecap := 1 ;
>
> I played with custom pens but failed to create a working triangle pen.
> I'll take another look into it because a few custom pens can draw all lines.

\startuseMPgraphic{draw}
draw hlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted
(0.5,0.5) withcolor "darkgray" ;
draw vlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted
(0.5,0.5) withcolor "darkgray" ;
pen pentriangle ;
pentriangle := (makepen ((0,0) -- (1,0) -- (1,1) -- cycle) shifted
(-1/2,-1/2)) scaled 1 ;
drawoptions(withcolor "red");
pickup pensquare scaled 1;
draw (1,7) -- (7,7) ;
draw (7,1) ;
draw (5,4) ;
pickup pentriangle ;
draw (1,1) -- (2,1) withpen pentriangle rotated 90 ;
draw (3,1) -- (3,5) withpen pentriangle rotated 180 ;
draw (7,3) -- (5,3) withpen pentriangle rotated 90 ;
draw (7,5) -- (5,5) withpen pentriangle rotated 0 ;
\stopuseMPgraphic

seems to work here. But I happily admit it is a bit cumbersome...

/Mikael
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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Hans Hagen]

On 12/1/2024 2:02 PM, Mikael Sundqvist wrote:
> Hi
> 
> On Sun, Dec 1, 2024 at 1:28 PM Wolfgang Schuster
> <wolfgang.schuster.lists@gmail.com> wrote:
>>
>> Hans Hagen via ntg-context schrieb am 01.12.2024 um 12:34:
>>> On 12/1/2024 11:54 AM, Bruce Horrocks wrote:
>>>
>>>> <sigh> Sorry, brain not in gear
>>>
>>> so once you're rebooted, you can figure out the logic behind this:
>>>
>>> linecap := butt ;
>>> linejoin := beveled ;
>>
>> This doesn't result in the desired output I want.
>>> or even
>>>
>>> pickup pensquare rotated -60 scaled (1/sqrt(2)) ;
>>> linecap := 1 ;
>>
>> I played with custom pens but failed to create a working triangle pen.
>> I'll take another look into it because a few custom pens can draw all lines.
> 
> \startuseMPgraphic{draw}
> draw hlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted
> (0.5,0.5) withcolor "darkgray" ;
> draw vlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted
> (0.5,0.5) withcolor "darkgray" ;
> pen pentriangle ;
> pentriangle := (makepen ((0,0) -- (1,0) -- (1,1) -- cycle) shifted
> (-1/2,-1/2)) scaled 1 ;
> drawoptions(withcolor "red");
> pickup pensquare scaled 1;
> draw (1,7) -- (7,7) ;
> draw (7,1) ;
> draw (5,4) ;
> pickup pentriangle ;
> draw (1,1) -- (2,1) withpen pentriangle rotated 90 ;
> draw (3,1) -- (3,5) withpen pentriangle rotated 180 ;
> draw (7,3) -- (5,3) withpen pentriangle rotated 90 ;
> draw (7,5) -- (5,5) withpen pentriangle rotated 0 ;
> \stopuseMPgraphic
> 
> seems to work here. But I happily admit it is a bit cumbersome...

i wonder of we can use our new secret penstroked feature but i'm not in 
that mode now,

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
-----------------------------------------------------------------
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[NTG-context] Re: Metapost lines with fancy line endings and connections

[Wolfgang Schuster]

Mikael Sundqvist schrieb am 01.12.2024 um 14:02:
> Hi
>
> On Sun, Dec 1, 2024 at 1:28 PM Wolfgang Schuster
> <wolfgang.schuster.lists@gmail.com> wrote:
>> Hans Hagen via ntg-context schrieb am 01.12.2024 um 12:34:
>>> On 12/1/2024 11:54 AM, Bruce Horrocks wrote:
>>>
>>>> <sigh> Sorry, brain not in gear
>>> so once you're rebooted, you can figure out the logic behind this:
>>>
>>> linecap := butt ;
>>> linejoin := beveled ;
>> This doesn't result in the desired output I want.
>>> or even
>>>
>>> pickup pensquare rotated -60 scaled (1/sqrt(2)) ;
>>> linecap := 1 ;
>> I played with custom pens but failed to create a working triangle pen.
>> I'll take another look into it because a few custom pens can draw all lines.
> \startuseMPgraphic{draw}
> draw hlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted
> (0.5,0.5) withcolor "darkgray" ;
> draw vlingrid(0, 7, 1, 7, 7) withpen pencircle scaled 1/20 shifted
> (0.5,0.5) withcolor "darkgray" ;
> pen pentriangle ;
> pentriangle := (makepen ((0,0) -- (1,0) -- (1,1) -- cycle) shifted
> (-1/2,-1/2)) scaled 1 ;
> drawoptions(withcolor "red");
> pickup pensquare scaled 1;
> draw (1,7) -- (7,7) ;
> draw (7,1) ;
> draw (5,4) ;
> pickup pentriangle ;
> draw (1,1) -- (2,1) withpen pentriangle rotated 90 ;
> draw (3,1) -- (3,5) withpen pentriangle rotated 180 ;
> draw (7,3) -- (5,3) withpen pentriangle rotated 90 ;
> draw (7,5) -- (5,5) withpen pentriangle rotated 0 ;
> \stopuseMPgraphic
>
> seems to work here. But I happily admit it is a bit cumbersome...

It's a good starting point and I can work with it.

When I look at your pen setting it's possible I forgot the parentheses 
before the shift operation.

Wolfgang

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