Re: Postsctipt arrows

[Andrew Bernard]

Why do I get the feeling nobody is going to answer this? In all seriousness, I don’t know enough about lilypond to know if this is even possible or not, which is a dark state of ignorance. If the Scheme gods could let me know if I am barking up an entirely impossible tree, that may save me from wandering in the wilderness. The archives seem very silent on this topic.

Thanks!

Since I discovered lilypond postscript units are staff-spaces and not points, and that the postscript coordinate origin is at the reference point of the ground in question, a better example of showing an arrow is:

0 0 20 4 0.3 1.2 1.2 arrow

So, in short, I need to understand if it is possible to pass parameters (seven in this case) to a postscript procedure in the context of a markup _expression_.

Andrew

On 13 March 2015 at 16:04:30, Andrew Bernard (address@hidden) wrote:

Greetings list,

I want to make many different types of arrows using PostScript. The following function from the Adobe Blue Book works very nicely for what I need. It’s quite general.

The question is, how do I incorporate something of this level of complexity this into a form where it can be invoked with \postscript in a \markup block?

%!PS-Adobe-3.0

/arrowdict 14 dict def arrowdict begin

/mtrx matrix def end

/arrow

{ arrowdict begin

/headlength exch def /halfheadthickness exch 2 div def /halfthickness exch 2 div def

/tipy exch def /tipx exch def

/taily exch def /tailx exch def

/dx tipx tailx sub def

/dy tipy taily sub def

/arrowlength dx dx mul dy dy mul add

sqrt def

/angle dy dx atan def

/base arrowlength headlength sub def

/savematrix mtrx currentmatrix def

tailx taily translate angle rotate

0 halfthickness neg moveto

base halfthickness neg lineto base halfheadthickness neg lineto arrowlength 0 lineto

base halfheadthickness lineto base halfthickness lineto

0 halfthickness lineto

closepath

savematrix setmatrix end

} def

An example of use in raw PostScript:

newpath

318 340 72 340 10 30 72 arrow

fill

Andrew