CountColor(3pm) User Contributed Perl Documentation CountColor(3pm)NAME
Imager::CountColor - demonstrates writing a simple function using Imager.
SYNOPSIS
use Imager;
use Imager::CountColor;
my $im = Imager->new(...); # some Imager image
...; # some sort of manipulation
print count_color($im, $color_object);
DESCRIPTION
This module is a simple demonstration of how to create an XS module that works with Imager objects.
You may want to copy the source for this module as a start.
SEE ALSO
Imager, Imager::Filter::DynTest
AUTHOR
Tony Cook <tonyc@cpan.org>
perl v5.14.2 2012-03-18 CountColor(3pm)
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Imager::Matrix2d(3pm) User Contributed Perl Documentation Imager::Matrix2d(3pm)NAME
Imager::Matrix2d - simple wrapper for matrix construction
SYNOPSIS
use Imager::Matrix2d;
$m1 = Imager::Matrix2d->identity;
$m2 = Imager::Matrix2d->rotate(radians=>$angle, x=>$cx, y=>$cy);
$m3 = Imager::Matrix2d->translate(x=>$dx, y=>$dy);
$m4 = Imager::Matrix2d->shear(x=>$sx, y=>$sy);
$m5 = Imager::Matrix2d->reflect(axis=>$axis);
$m6 = Imager::Matrix2d->scale(x=>$xratio, y=>$yratio);
$m8 = Imager::Matric2d->matrix($v11, $v12, $v13,
$v21, $v22, $v23,
$v31, $v32, $v33);
$m6 = $m1 * $m2;
$m7 = $m1 + $m2;
use Imager::Matrix2d qw(:handy);
# various m2d_* functions imported
# where m2d_(.*) calls Imager::Matrix2d->$1()
DESCRIPTION
This class provides a simple wrapper around a reference to an array of 9 co-efficients, treated as a matrix:
[ 0, 1, 2,
3, 4, 5,
6, 7, 8 ]
Most of the methods in this class are constructors. The others are overloaded operators.
Note that since Imager represents images with y increasing from top to bottom, rotation angles are clockwise, rather than counter-
clockwise.
identity()
Returns the identity matrix.
rotate(radians=>$angle)
rotate(degrees=>$angle)
Creates a matrix that rotates around the origin, or around the point (x,y) if the 'x' and 'y' parameters are provided.
translate(x=>$dx, y=>$dy)
translate(x=>$dx)
translate(y=>$dy)
Translates by the specify amounts.
shear(x=>$sx, y=>$sy)
shear(x=>$sx)
shear(y=>$sy)
Shear by the given amounts.
reflect(axis=>$axis)
Reflect around the given axis, either 'x' or 'y'.
reflect(radians=>$angle)
reflect(degrees=>$angle)
Reflect around a line drawn at the given angle from the origin.
scale(x=>$xratio, y=>$yratio)
Scales at the given ratios.
You can also specify a center for the scaling with the "cx" and "cy" parameters.
matrix($v11, $v12, $v13, $v21, $v22, $v23, $v31, $v32, $v33)
Create a matrix with custom co-efficients.
_mult()
Implements the overloaded '*' operator. Internal use.
Currently both the left and right-hand sides of the operator must be an Imager::Matrix2d.
_add()
Implements the overloaded binary '+' operator.
Currently both the left and right sides of the operator must be Imager::Matrix2d objects.
_string()
Implements the overloaded stringification operator.
This returns a string containing 3 lines of text with no terminating newline.
I tried to make it fairly nicely formatted. You might disagree :)
_eq Implement the overloaded equality operator.
Provided for older perls that don't handle magic auto generation of eq from "".
The following functions are shortcuts to the various constructors.
These are not methods.
You can import these methods with:
use Imager::Matrix2d ':handy';
m2d_identity
m2d_rotate()
m2d_translate()
m2d_shear()
m2d_reflect()
m2d_scale()
AUTHOR
Tony Cook <tony@develop-help.com>
BUGS
Needs a way to invert a matrix.
SEE ALSO Imager(3), Imager::Font(3)
http://imager.perl.org/
perl v5.14.2 2011-11-25 Imager::Matrix2d(3pm)