diff GD/Polygon.pm @ 0:e94de0ea3351 draft default tip

Uploaded

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GD/Polygon.pm	Wed Sep 11 09:08:15 2013 -0400
@@ -0,0 +1,183 @@
+package GD::Polygon;
+
+use strict;
+use Carp 'carp';
+use GD;
+
+# old documentation error
+*GD::Polygon::delete = \&deletePt;
+
+=head1 NAME
+
+GD::Polygon - Polygon class for the GD image library
+
+=head1 SYNOPSIS
+
+See L<GD>
+
+=head1 DESCRIPTION
+
+See L<GD>
+
+=head1 AUTHOR
+
+The GD.pm interface is copyright 1995-2005, Lincoln D. Stein.  It is
+distributed under the same terms as Perl itself.  See the "Artistic
+License" in the Perl source code distribution for licensing terms.
+
+The latest versions of GD.pm are available on CPAN:
+
+  http://www.cpan.org
+
+=head1 SEE ALSO
+
+L<GD>
+L<GD::Polyline>,
+L<GD::SVG>,
+L<GD::Simple>,
+L<Image::Magick>
+
+=cut
+
+### The polygon object ###
+# create a new polygon
+sub new {
+    my $class = shift;
+    return bless { 'length'=>0,'points'=>[] },$class;
+}
+
+# automatic destruction of the polygon
+sub DESTROY {
+    my $self = shift;
+    undef $self->{'points'};
+}
+
+sub clear {
+  my $self = shift;
+  $self->{'points'} = [];
+}
+
+# add an x,y vertex to the polygon
+sub addPt {
+    my($self,$x,$y) = @_;
+    push(@{$self->{'points'}},[$x,$y]);
+    $self->{'length'}++;
+}
+
+# get a vertex
+sub getPt {
+    my($self,$index) = @_;
+    return () unless ($index>=0) && ($index<$self->{'length'});
+    return @{$self->{'points'}->[$index]};
+}
+
+# change the value of a vertex
+sub setPt {
+    my($self,$index,$x,$y) = @_;
+    unless (($index>=0) && ($index<$self->{'length'})) {
+	carp "Attempt to set an undefined polygon vertex";
+	return undef;
+    }
+    @{$self->{'points'}->[$index]} = ($x,$y);
+    1;
+}
+
+# return the total number of vertices
+sub length {
+    my $self = shift;
+    return $self->{'length'};
+}
+
+# return the array of vertices.
+# each vertex is an two-member (x,y) array
+sub vertices {
+    my $self = shift;
+    return @{$self->{'points'}};
+}
+
+# return the bounding box of the polygon
+# (smallest rectangle that contains it)
+sub bounds {
+    my $self = shift;
+    my($top,$bottom,$left,$right) = @_;
+    $top =    99999999;
+    $bottom =-99999999;
+    $left =   99999999;
+    $right = -99999999;
+    my $v;
+    foreach $v ($self->vertices) {
+	$left = $v->[0] if $left > $v->[0];
+	$right = $v->[0] if $right < $v->[0];
+	$top = $v->[1] if $top > $v->[1];
+	$bottom = $v->[1] if $bottom < $v->[1];
+    }
+    return ($left,$top,$right,$bottom);
+}
+
+# delete a vertex, returning it, just for fun
+sub deletePt {
+     my($self,$index) = @_;
+     unless (($index>=0) && ($index<@{$self->{'points'}})) {
+ 	carp "Attempt to delete an undefined polygon vertex";
+ 	return undef;
+     }
+      my($vertex) = splice(@{$self->{'points'}},$index,1);
+     $self->{'length'}--;
+      return @$vertex;
+  }
+
+# translate the polygon in space by deltaX and deltaY
+sub offset {
+    my($self,$dh,$dv) = @_;
+    my $size = $self->length;
+    my($i);
+    for ($i=0;$i<$size;$i++) {
+	my($x,$y)=$self->getPt($i);
+	$self->setPt($i,$x+$dh,$y+$dv);
+    }
+}
+
+# map the polygon from sourceRect to destRect,
+# translating and resizing it if necessary
+sub map {
+    my($self,$srcL,$srcT,$srcR,$srcB,$destL,$destT,$destR,$destB) = @_;
+    my($factorV) = ($destB-$destT)/($srcB-$srcT);
+    my($factorH) = ($destR-$destL)/($srcR-$srcL);
+    my($vertices) = $self->length;
+    my($i);
+    for ($i=0;$i<$vertices;$i++) {
+	my($x,$y) = $self->getPt($i);
+	$x = int($destL + ($x - $srcL) * $factorH);
+	$y = int($destT + ($y - $srcT) * $factorV);
+	$self->setPt($i,$x,$y);
+    }
+}
+
+# These routines added by Winfriend Koenig.
+sub toPt {
+    my($self, $dx, $dy) = @_;
+    unless ($self->length > 0) {
+	$self->addPt($dx,$dy);
+	return;
+    }
+    my ($x, $y) = $self->getPt($self->length-1);
+    $self->addPt($x+$dx,$y+$dy);
+}
+
+sub transform($$$$$$$) {
+    # see PostScript Ref. page 154
+    my($self, $a, $b, $c, $d, $tx, $ty) = @_;
+    my $size = $self->length;
+    for (my $i=0;$i<$size;$i++) {
+	my($x,$y)=$self->getPt($i);
+	$self->setPt($i, $a*$x+$c*$y+$tx, $b*$x+$d*$y+$ty);
+    }
+}
+
+sub scale {
+    my($self, $sx, $sy, $cx, $cy) = @_;
+    $self->offset(-$cx,-$cy) if defined $cx or defined $cy;
+    $self->transform($sx,0,0,$sy,$cx,$cy);
+}
+
+1;