| Subject: | lines3d: patch to trim miter |
I produce hires line graphs with lines3d, and realized that simple miter calculation is not enough. I've created a patch to trim miters. License as perl itself. Here is a little test script, that produces ugly peaks without my patch.
#! /usr/bin/perl -w
#
use GD::Graph::lines3d;
use GD::Graph::lines;
my $data = [
["1st","2nd","3rd","4th","5th","6th","7th", "8th", "9th", "10", "11st","12nd","13rd","14th","15th","16th","17th", "18th", "19th"],
[ 1, 2, 5, 6, 3, 1.5, 1, 3, 4, 0, 1, 2, 5, 6, 3, 1.5, 1, 3, 4],
[ -1, 4.5, 6, 0, 5, 1.5, 1, 3, 4, 7, -1, 4.5, 6, 5.7, 5, 1.5, 1, 3, 4]
];
my $graph = GD::Graph::lines3d->new(1200,900);
$graph->set(
transparent => 0,
line_type_scale => 1,
bgclr => 'white',
gfclr => 'lgray',
line_width => 40,
line_depth => 10,
'3d_shading' => 1,
skip_undef => 1,
scale => 4,
trim_miter => 1,
long_ticks => 1,
);
my $gd = $graph->plot($data) or die $graph->error;
binmode STDOUT;
print $gd->png;
close STDOUT;
--- GD-Graph3d-0.63/lib/GD/Graph/lines3d.pm.orig 2002-12-06 21:14:55.000000000 +0100
+++ GD-Graph3d-0.63/lib/GD/Graph/lines3d.pm 2005-03-03 16:08:02.570748909 +0100
@@ -47,6 +47,7 @@
# The depth of the line in their extrusion
line_depth => 10,
+ trim_miter => 0,
);
sub initialise()
@@ -83,6 +84,12 @@
delete $args{$_};
next;
};
+ /^trim_miter$/ and do
+ {
+ $s->{trim_miter} = $args{$_};
+ delete $args{$_};
+ next;
+ };
}
return $s->SUPER::set(%args);
@@ -238,7 +245,7 @@
} # end if
# Draw the line segment
- $self->draw_line( $points_cache[$i - 1][$j],
+ my $poly_style = $self->draw_line( $points_cache[$i - 1][$j],
$points_cache[$i][$j],
$points_cache[$i + 1][$j],
$type,
@@ -256,6 +263,12 @@
} else {
$g->filledPolygon( $poly, $dsci );
} # end if
+
+ # Hmm, the if's in draw_line are much more elaborated
+ # than the one above. A direct copy does not look too bad.
+ # FIXME, 2005-03-003, jw@suse.de
+ $g->filledPolygon( $poly, $poly_style );
+
$g->polygon( $poly, $self->{fgci} );
} # end if
@@ -426,6 +439,23 @@
$this->{face}[2] = ($bn - $bt) / ($mt - $mn);
} # end if
$this->{face}[3] = $mt * $this->{face}[2] + $bt;
+ if ($self->{trim_miter})
+ {
+ if (($mt > 1) && ($mn < -1))
+ {
+ $this->{trim23}[2] = $xe + $lwxoff + $lwyoff;
+ $this->{trim23}[3] = $ye + $lwyoff - $lwxoff;
+ $this->{face}[2] = $xe + $lwxo2 - $lwyo2;
+ $this->{face}[3] = $ye + $lwyo2 + $lwxo2;
+ }
+ elsif (($mt < -1) && ($mn > 1))
+ {
+ $this->{trim01}[0] = $xe - $lwxoff + $lwyoff;
+ $this->{trim01}[1] = $ye - $lwyoff - $lwxoff;
+ $this->{face}[0] = $xe - $lwxo2 - $lwyo2;
+ $this->{face}[1] = $ye - $lwyo2 + $lwxo2;
+ }
+ }
} # end if
@@ -462,6 +492,19 @@
} # end if
$self->{graph}->polygon( $poly, $self->{fgci} );
+ if ($this->{trim01})
+ {
+ ## upper trim caps are always visible. lower trim caps never.
+ $poly = new GD::Polygon;
+ my $ld = $self->{line_depth};
+ $poly->addPt($this->{trim01}[0] , $this->{trim01}[1] );
+ $poly->addPt($this->{trim01}[0] + $ld, $this->{trim01}[1] - $ld);
+ $poly->addPt($this->{face}[0] + $ld, $this->{face}[1] - $ld);
+ $poly->addPt($this->{face}[0] , $this->{face}[1] );
+ $self->{graph}->filledPolygon( $poly, $style );
+ $self->{graph}->polygon( $poly, $self->{fgci} );
+ }
+
# *** This paints dashed and dotted patterns on the faces of
# the polygons. They don't look very good though. Would it
# be better to extrude the style as well as the lines?
@@ -472,13 +515,18 @@
# Make the face polygon
$poly = new GD::Polygon;
$poly->addPt( $prev->{face}[0], $prev->{face}[1] );
+ $poly->addPt( $this->{trim01}[0], $this->{trim01}[1] ) if $this->{trim01};
$poly->addPt( $this->{face}[0], $this->{face}[1] );
$poly->addPt( $this->{face}[2], $this->{face}[3] );
+ $poly->addPt( $this->{trim23}[2], $this->{trim23}[3] ) if $this->{trim23};
$poly->addPt( $prev->{face}[2], $prev->{face}[3] );
$self->{graph}->filledPolygon( $poly, $style );
$self->{graph}->polygon( $poly, $self->{fgci} );
+# $self->{graph}->arc($xe,$ye, 10,10, 0, 360, 1); # show centers for debugging.
+ return $style;
+
} # end draw line
# ----------------------------------------------------------
--- GD-Graph3d-0.63/lib/GD/Graph3d.pm.orig 2002-12-06 21:14:16.000000000 +0100
+++ GD-Graph3d-0.63/lib/GD/Graph3d.pm 2005-03-03 16:18:17.138907917 +0100
@@ -106,6 +106,14 @@
users. You can disable the shading of lines and axes by specifiying a false
value for this option.
+=item trim_miter
+
+By default this is set to '0'. If line_width is large, typical zig-zag data
+lines may appear to exaggerated, due to the width of the lines.
+When trim_miter is set to '1', then acute-angled segments are cut back
+(with an additional small rectangle on top) to extend only half a line_width
+beyond the data points.
+
=back
=back