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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);
   $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.

_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 :)

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/