64 lines
1.4 KiB
Perl
64 lines
1.4 KiB
Perl
#! /usr/bin/perl
|
|
use strict;
|
|
use Image::Imlib2;
|
|
|
|
sub my_draw_line
|
|
{
|
|
my ( $img, $x0, $y0, $x1, $y1) = @_;
|
|
|
|
my $steep = (abs($y1 - $y0) > abs($x1 - $x0));
|
|
if ( $steep ) {
|
|
( $y0, $x0 ) = ( $x0, $y0);
|
|
( $y1, $x1 ) = ( $x1, $y1 );
|
|
}
|
|
if ( $x0 > $x1 ) {
|
|
( $x1, $x0 ) = ( $x0, $x1 );
|
|
( $y1, $y0 ) = ( $y0, $y1 );
|
|
}
|
|
my $deltax = $x1 - $x0;
|
|
my $deltay = abs($y1 - $y0);
|
|
my $error = $deltax / 2;
|
|
my $ystep;
|
|
my $y = $y0;
|
|
my $x;
|
|
$ystep = ( $y0 < $y1 ) ? 1 : -1;
|
|
for( $x = $x0; $x <= $x1; $x += 1 ) {
|
|
if ( $steep ) {
|
|
$img->draw_point($y, $x);
|
|
} else {
|
|
$img->draw_point($x, $y);
|
|
}
|
|
$error -= $deltay;
|
|
if ( $error < 0 ) {
|
|
$y += $ystep;
|
|
$error += $deltax;
|
|
}
|
|
}
|
|
}
|
|
|
|
# test
|
|
my $img = Image::Imlib2->new(160, 160);
|
|
$img->set_color(255, 255, 255, 255); # white
|
|
$img->fill_rectangle(0,0,160,160);
|
|
|
|
$img->set_color(0,0,0,255); # black
|
|
my_draw_line($img, 10, 80, 80, 160);
|
|
my_draw_line($img, 80, 160, 160, 80);
|
|
my_draw_line($img, 160, 80, 80, 10);
|
|
my_draw_line($img, 80, 10, 10, 80);
|
|
|
|
$img->save("test0.png");
|
|
|
|
# let's try the same using its internal algo
|
|
$img->set_color(255, 255, 255, 255); # white
|
|
$img->fill_rectangle(0,0,160,160);
|
|
$img->set_color(0,0,0,255); # black
|
|
$img->draw_line(10, 80, 80, 160);
|
|
$img->draw_line(80, 160, 160, 80);
|
|
$img->draw_line(160, 80, 80, 10);
|
|
$img->draw_line(80, 10, 10, 80);
|
|
|
|
$img->save("test1.png");
|
|
|
|
exit 0;
|