From a7fa84cb35d176b92f0de731caa85585d9019e45 Mon Sep 17 00:00:00 2001
From: John Honniball <coredump@virginmedia.com>
Date: Sat, 22 Aug 2020 14:15:37 +0100
Subject: [PATCH] Update library tester. Add guidelines for arcs, add a
 rectangle and a rounded rectangle.

---
 TODO.md   | 11 ++++++++++-
 libtest.c | 23 ++++++++++++++++++++---
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/TODO.md b/TODO.md
index f304c69..64392f2 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,7 +1,8 @@
 # Things To Do
 
 ## HPGL library
-* Add support for non-ISO paper sizes (i.e. U.S. paper sizes, origami square paper)
+* Add support for non-ISO paper sizes (i.e. U.S. paper sizes,
+origami square paper, postcard sizes, photographic sizes).
 * Add support for plot scaling. We should be able to plot directly
 in millimetres (and possibly in inches) as well as in device
 coordinates and maybe in other units.
@@ -30,6 +31,11 @@ lines in reverse directions.
 * Remove 'openlinesequence()', 'linesegmentto()' and 'closelinesequence()'
 from the library. They were a bit of a kludge anyway, and inconvenient
 for the user.
+* Optimise HPGL by not emitting 'PU;PA' in response to a 'moveto()'
+if the pen is already at that location. Will probably reduce the number
+of zero line segments that we get in 'hp2xx'.
+* Change 'rectangle()' to call 'moveto()'/'lineto()'. Let those
+functions handle optimisation.
 * Draw circles using Arc Absolute 'AA;' and choose arc starting-point
 that's closest to current pen position.
 * Add support for the front-panel LCD on the HP 7550A. Use the 'WD'
@@ -45,6 +51,9 @@ arc tolerance of 72 chords. Make this a settable parameter somehow.
 comma-separated list of pens. Plot programs could then call for the
 next (or previous) pen and make simple multi-colour plots.
 Plots that might benefit from that: dala2, morphpoly, sutpent.
+* Can we tell 'hp2xx' about pen width via the HPGL? If we can, we'd
+be able to get previews with bold or fine pens.
+* Should we set pen speeds separately for each pen?
 * Eliminate 'hpglout()' if at all possible. It breaks the abstraction
 that the library tries to maintain.
 * Support non-HPGL output. Maybe PostScript, BMC plotter commands,
diff --git a/libtest.c b/libtest.c
index 6b90e98..c5f8ca6 100644
--- a/libtest.c
+++ b/libtest.c
@@ -84,6 +84,8 @@ int main(int argc, char * const argv[])
 void lineTest(const double xc, const double yc, const double wd, const double ht, const PlotInfo_t *const info)
 {
    const double len = wd / 16.0;
+   double hside = wd * 0.8;
+   double vside = ht * 0.8;
    
    moveto(xc - len, yc);
    lineto(xc + len, yc);
@@ -91,6 +93,13 @@ void lineTest(const double xc, const double yc, const double wd, const double ht
    moveto(xc, yc - len);
    lineto(xc, yc + len);
    
+   rectangle(xc - hside, yc - vside, xc + hside, yc + vside);
+   
+   hside = wd * 0.7;
+   vside = ht * 0.7;
+   
+   roundrect(xc - hside, yc - vside, xc + hside, yc + vside, wd / 8);
+   
    hlabel(xc - (wd / 2.0), yc - (ht / 2.0), 5.0, info->plotterName);
    hlabel(xc + (wd / 2.0), yc - (ht / 2.0), 5.0, info->paperName);
 }
@@ -116,10 +125,18 @@ void arcTest(const double xc, const double yc, const double wd, const double ht,
    double angle;
    int i;
    
-   moveto(xc - (wd / 2.0), yc);
-   lineto(xc, yc);
-   lineto(xc, yc + (wd / 2.0));
+   moveto(xc - radius, yc);
+   lineto(xc + radius, yc);
+
+   moveto(xc + radius, yc - radius);
+   lineto(xc - radius, yc + radius);
+
+   moveto(xc, yc + radius);
+   lineto(xc, yc - radius);
    
+   moveto(xc - radius, yc - radius);
+   lineto(xc + radius, yc + radius);
+
    for (i = 0; i < 7; i++) {
       radius = (wd / 16.0) * (i + 1);
       angle = 45.0 * (i + 1);