Re: Argh: Why are arrows clipped to the graph?

[Ethan M. <merritt@u.washington.edu>]

On Wednesday 09 November 2005 03:59 pm, Harald Harders wrote:
> 
> Why do so many routines have clipping? In my opinion we have about four
> things that have to be clipped, in most terminals:
> 
> points
	gadgets.c:170:clip_point(unsigned int x, unsigned int y)
> lines
	gadgets.c:192:draw_clip_line(int x1, int y1, int x2, int y2)
> filled polygons
	We don't have this one
> text
	term.c:941:write_multiline()

> Since arrows are produced by lines and filled polygons in most terminals,
> clipping would be done automatically by the routines producing the lines
> and the polygons. As a positive side effect, only the part of the arrow
> head would be cut off that is outside the canvas.

Guess what?  That is exactly the change I made to do_arrow() which you
have been complaining about.  It now uses the routine draw_clip_line()
to draw all the lines in the arrow, which means that they get clipped
automatically.

What you are now finding is that this generic clipping doesn't always
work the way you would like, because the individual terminal drivers
are not consistent.

I'm glad we are now in agreement :-)




-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195