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Direktori : /usr/share/doc/libcairo-perl/examples/ |
Current File : //usr/share/doc/libcairo-perl/examples/simple.pl |
#!/usr/bin/perl # # $Id$ # use strict; use warnings; use Cairo; use constant { IMG_WIDTH => 640, IMG_HEIGHT => 480, M_PI => 3.14159265, }; die "png backend not supported" unless (Cairo::HAS_PNG_FUNCTIONS); $0 =~ /(.*)\.pl/; my $png = "$1.png"; my $surf = Cairo::ImageSurface->create ('argb32', IMG_WIDTH, IMG_HEIGHT); my $cr = Cairo::Context->create ($surf); $cr->rectangle (0, 0, IMG_WIDTH, IMG_HEIGHT); $cr->set_source_rgba (1, 1, 1, 0.5); $cr->fill; # black $cr->save; $cr->set_source_rgba (0, 0, 0, 0.5); $cr->translate (IMG_WIDTH / 2, IMG_HEIGHT - (IMG_HEIGHT / 4)); do_star (); $cr->restore; # red $cr->save; $cr->set_source_rgba (1, 0, 0, 0.5); $cr->translate (IMG_WIDTH / 2, IMG_HEIGHT / 4); do_star (); $cr->restore; # green $cr->save; $cr->set_source_rgba (0, 1, 0, 0.5); $cr->translate (IMG_WIDTH / 4, IMG_HEIGHT / 2); do_star (); $cr->restore; # blue $cr->save; $cr->set_source_rgba (0, 0, 1, 0.5); $cr->translate (IMG_WIDTH - (IMG_WIDTH / 4), IMG_HEIGHT / 2); do_star (); $cr->restore; $cr->show_page; $surf->write_to_png ($png); sub do_star { my $mx = IMG_WIDTH / 3.0; my $count = 100; foreach (0..$count-1) { $cr->new_path; $cr->move_to (0, 0); $cr->rel_line_to (-$mx, 0); $cr->stroke; $cr->rotate ((M_PI * 2) / $count); } }