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package Imager::Transform;
use strict;
use Imager;
use Imager::Expr::Assem;
use vars qw($VERSION);
$VERSION = "1.005";
my %funcs =
(
mandel=>
{
desc=>"Mandelbrot set",
type=>'assem',
assem=><<EOS,
# x treated as in range minx..maxx
# y treated as in range miny..maxy
var nx:n ; var ny:n
var diffx:n ; var diffy:n
# conx/y are x/y adjusted to min..max ranges
var conx:n ; var cony:n
diffx = subtract maxx minx
conx = div x w
conx = mult conx diffx
conx = add conx minx
diffy = subtract maxy miny
cony = div y h
cony = mult cony diffy
cony = add cony miny
nx = 0
ny = 0
var count:n
count = 0
loop:
# calculate (nx,ny)**2 +(x,y)->
# (nx*nx-ny*ny+x, 2.nx.ny+y)
var wx:n ; var wy:n ; var work:n
wx = mult nx nx
wy = mult ny ny
wx = subtract wx wy
ny = mult ny nx
ny = mult ny 2
nx = wx
nx = add nx conx
ny = add ny cony
work = distance nx ny 0 0
work = gt work 2
jumpnz work docol
count = add count 1
work = lt count maxcount
jumpnz work loop
jumpnz insideangle doinang
var workp:p
workp = rgb 0 0 0
ret workp
doinang:
var ang:n
ang = atan2 ny nx
ang = mult ang 360
ang = div ang pi
workp = hsv ang 255 0.5
ret workp
docol:
var outvalue:n
outvalue = mult outsidevaluestep count
outvalue = add outvalue outsidevalue
outvalue = mod outvalue 1.01
jumpnz outsideangle do_outang
work = mult count huestep
work = add work huebase
work = mod work 360
workp = hsv work 1 outvalue
ret workp
do_outang:
ang = atan2 ny nx
ang = mult ang 360
ang = div ang pi
ang = add ang outsidebase
workp = hsv ang outsidesat outvalue
ret workp
EOS
constants=>
{
minx=>{ default=>-2, desc=>'Left of rendered area', },
miny=>{ default=>-1.5, desc=>'Top of rendered area', },
maxx=>{ default=>1, desc=>'Right of rendered area', },
maxy=>{ default=>1.5, desc=>'Bottom of rendered area', },
maxcount=>{ default=>100, desc=>'Maximum iterations', },
huestep=>{ default=>21.1, desc=>'Hue step for number of iterations', },
huebase=>{ default=>0, desc=>'Base hue for number of iterations', },
insideangle=>
{
default=>0,
desc=>'Non-zero to use angle of final as hue for inside',
},
insidebase=>
{
default=>0,
desc=>'Base angle for inside colours if insideangle is non-zero',
},
outsideangle=>
{
default=>0,
desc=>'Non-zero to use angle of final as hue for outside',
},
outsidebase=>
{
default=>0,
desc=>'Base angle if outsideangle is true',
},
outsidevalue=>
{
default=>1,
desc=>'Brightness for outside pixels',
},
outsidevaluestep=>
{
default=>0,
desc=>'Brightness step for each count for outside pixels',
},
outsidesat=>
{
default=>1,
desc=>'Saturation for outside pixels',
},
},
inputs=>[],
},
julia=>
{
desc=>"Julia set",
type=>'assem',
assem=><<EOS,
# print x
# x treated as in range minx..maxx
# y treated as in range miny..maxy
var nx:n ; var ny:n
var diffx:n ; var diffy:n
# conx/y are x/y adjusted to min..max ranges
var conx:n ; var cony:n
diffx = subtract maxx minx
conx = div x w
conx = mult conx diffx
conx = add conx minx
diffy = subtract maxy miny
cony = div y h
cony = mult cony diffy
cony = add cony miny
nx = conx
ny = cony
var count:n
count = 0
loop:
# calculate (nx,ny)**2 +(x,y)->
# (nx*nx-ny*ny+x, 2.nx.ny+y)
var wx:n ; var wy:n ; var work:n
wx = mult nx nx
wy = mult ny ny
wx = subtract wx wy
ny = mult ny nx
ny = mult ny 2
nx = wx
nx = add nx zx
ny = add ny zy
work = distance nx ny 0 0
work = gt work 2
jumpnz work docol
count = add count 1
work = lt count maxcount
jumpnz work loop
jumpnz insideangle doinang
var workp:p
workp = rgb 0 0 0
ret workp
doinang:
var ang:n
ang = atan2 ny nx
ang = mult ang 360
ang = div ang pi
workp = hsv ang 255 0.5
ret workp
docol:
var outvalue:n
outvalue = mult outsidevaluestep count
outvalue = add outvalue outsidevalue
outvalue = mod outvalue 1.01
jumpnz outsideangle do_outang
work = mult count huestep
work = add work huebase
work = mod work 360
workp = hsv work 1 outvalue
ret workp
do_outang:
ang = atan2 ny nx
ang = mult ang 360
ang = div ang pi
ang = add ang outsidebase
workp = hsv ang outsidesat outvalue
ret workp
EOS
constants=>
{
zx=>{default=>0.7, desc=>'Real part of initial Z', },
zy=>{default=>0.2, desc=>'Imaginary part of initial Z', },
minx=>{ default=>-1.5, desc=>'Left of rendered area', },
miny=>{ default=>-1.5, desc=>'Top of rendered area', },
maxx=>{ default=>1.5, desc=>'Right of rendered area', },
maxy=>{ default=>1.5, desc=>'Bottom of rendered area', },
maxcount=>{ default=>100, desc=>'Maximum iterations', },
huestep=>{ default=>21.1, desc=>'Hue step for number of iterations', },
huebase=>{ default=>0, desc=>'Base hue for number of iterations', },
insideangle=>
{
default=>0,
desc=>'Non-zero to use angle of final as hue for inside',
},
insidebase=>
{
default=>0,
desc=>'Base angle for inside colours if insideangle is non-zero',
},
outsideangle=>
{
default=>0,
desc=>'Non-zero to use angle of final as hue for outside',
},
outsidebase=>
{
default=>0,
desc=>'Base angle if outsideangle is true',
},
outsidevalue=>
{
default=>1,
desc=>'Brightness for outside pixels',
},
outsidevaluestep=>
{
default=>0,
desc=>'Brightness step for each count for outside pixels',
},
outsidesat=>
{
default=>1,
desc=>'Saturation for outside pixels',
},
},
inputs=>[],
},
circleripple=>
{
type=>'rpnexpr',
desc=>'Adds a circular ripple effect',
rpnexpr=><<'EOS',
x y cx cy distance !dist
@dist freq / sin !scale
@scale depth * @dist + !adj
y cy - x cx - atan2 !ang
cx @ang cos @adj * + cy @ang sin @adj * + getp1 @scale shadow + shadow 1 + / *
EOS
constants=>
{
freq=> { desc=>'Frequency of ripples', default=>5 },
depth=> { desc=>'Depth of ripples', default=>10 },
shadow=> { desc=>'Fraction of shadow', default=>20 },
},
inputs=>
[
{ desc=>'Image to ripple' }
],
},
spiral=>
{
type=>'rpnexpr',
desc=>'Render a colorful spiral',
rpnexpr=><<'EOS',
x y cx cy distance !d y cy - x cx - atan2 !a
@d spacing / @a + pi 2 * % !a2
@a 180 * pi / 1 @a2 sin 1 + 2 / hsv
EOS
constants=>
{
spacing=>{ desc=>'Spacing between arms', default=>10 },
},
inputs=>[],
},
diagripple=>
{
type=>'rpnexpr',
desc=>'Adds diagonal ripples to an image',
rpnexpr=><<'EOS',
x y + !dist @dist freq / sin !scale
@scale depth * !adj
x @adj + y @adj + getp1 @scale shadow + shadow 1 + / *
EOS
constants=>
{
freq=>{ desc=>'Frequency of ripples', default=>5, },
depth=>{desc=>'Depth of ripples', default=>3,},
shadow=>
{
desc=>'Fraction of brightness to remove for shadows',
default=>20,
},
},
inputs=>
[
{ desc=>'Image to add ripples to' }
],
},
twist=>
{
type=>'rpnexpr',
desc=>'Twist an image',
rpnexpr=><<'EOS',
x y cx cy distance !dist
y cy - x cx - atan2 @dist twist / + !ang
cx @ang cos @dist * + cy @ang sin @dist * + getp1
EOS
constants=>
{
twist=>{ desc=>'Amount of twist', default=>2.5, },
},
inputs=>
[
{ desc=>'Image to twist' },
],
},
# any other functions can wait until Imager::Expr::Infix supports
# jumps
);
sub new {
my ($class, $name) = @_;
exists $funcs{$name} or return;
bless { func=>$funcs{$name}, name=>$name }, $class;
}
sub inputs {
my ($self) = @_;
return @{$self->{func}{inputs}}
}
sub constants {
my $self = shift;
if (@_) {
return @{$self->{func}{constants}}{@_};
}
else {
return keys %{$self->{func}{constants}};
}
}
sub transform {
my ($self, $opts, $constants, @in) = @_;
my $func = $self->{func};
my %opts = %$opts;
$opts{$func->{type}} = $func->{$func->{type}};
my %con = %$constants;
for my $name (keys %{$func->{'constants'}}) {
unless (exists $con{$name}) {
if (exists $func->{'constants'}{$name}{default}) {
$con{$name} = $func->{'constants'}{$name}{default};
}
else {
$self->{error} = "No value or default for constant $name";
return;
}
}
}
$opts{'constants'} = \%con;
unless (@in == @{$func->{'inputs'}}) {
$self->{error} = @in." input images given, ".
@{$func->{'inputs'}}." supplied";
return;
}
my $out = Imager::transform2(\%opts, @in);
unless ($out) {
$self->{error} = $Imager::ERRSTR;
return;
}
return $out;
}
sub errstr {
return $_[0]{error};
}
sub list {
return keys %funcs;
}
sub describe {
my ($class, $name) = @_;
my $func;
if (ref $class && !$name) {
$func = $class->{func};
$name = $class->{name}
}
else {
$func = $funcs{$name}
or return undef;
}
my $desc = <<EOS;
Function : $name
Description: $func->{desc}
EOS
if ($func->{'inputs'} && @{$func->{'inputs'}}) {
$desc .= "Input images:\n";
my $i = 1;
for my $in (@{$func->{'inputs'}}) {
$desc .= " $i: $in->{desc}\n";
}
}
else {
$desc .= "There are no input images\n";
}
if ($func->{'constants'} && keys %{$func->{'constants'}}) {
$desc .= "Input constants:\n";
for my $key (keys %{$func->{'constants'}}) {
$desc .= " $key: $func->{'constants'}{$key}{desc}\n";
$desc .= " Default: $func->{'constants'}{$key}{default}\n";
}
}
else {
$desc .= "There are no constants\n";
}
return $desc;
}
1;
__END__
=head1 NAME
Imager::Transform - a library of register machine image transformations
=head1 SYNOPSIS
# get a list of transformations
my @funcs = Imager::Transform->list;
# create a transformation object
my $tran = Imager::Transform->new($name);
# describe it
print $tran->describe;
# a list of constant names
my @constants = $tran->constants;
# information about some of the constants
my @info = $tran->constants(@constants);
=head1 DESCRIPTION
This module provides a library of transformations that use the Imager
transform2() function.
The aim is to provide a place to collect these transformations.
At some point there might be an interface to add new functions, but
there's not a whole lot of point to that.
The interface is a little sparse as yet.
=head1 METHODS
=over 4
=item my @names = Imager::Transform->list
Returns a list of the transformations.
=item my $desc = Imager::Transform->describe($name);
=item my $desc = $tran->describe()
Describes a transformation specified either by name (as a class
method) or by reference (as an instance method).
The class method returns undef if there is no such transformation.
=item my $tran = Imager::Transform->new($name)
Create a new transformation object. Returns undef if there is no such
transformation.
=item my @inputs = $tran->inputs;
=item my $inputs = $tran->inputs;
Returns a list of input image descriptions, or the number of them,
depending on content.
The list contains hash references, which current contain only one
member, C<desc>, a description of the use of the input image.
=item $tran->constants
Returns a list of names of constants that can be set for the
transformation.
=item $tran->constants($name, $name, ...)
Returns a hashref for each named constant, which contains the default
in key C<default> and a description in key C<desc>.
=item my $out = $tran->transform(\%opts, \%constants, @imgs)
Perform the image transformation.
Returns the new image on success, or undef on failure, in which case
you can use $tran->errstr to get an error message.
=item $tran->errstr
The error message, if any from the last image transformation.
=back
=head1 BUGS
Needs more transformations.
=head1 SEE ALSO
Imager(3), F<transform.perl>
=cut
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