Imager::Fill(3) general fill types

SYNOPSIS


use Imager;
use Imager::Fill;
my $fill1 = Imager::Fill->new(solid=>$color, combine=>$combine);
my $fill2 = Imager::Fill->new(hatch=>'vline2', fg=>$color1, bg=>$color2,
dx=>$dx, dy=>$dy);
my $fill3 = Imager::Fill->new(fountain=>$type, ...);
my $fill4 = Imager::Fill->new(image=>$img, ...);
my $fill5 = Imager::Fill->new(type => "opacity", other => $fill,
opacity => ...);

DESCRIPTION

Creates fill objects for use by most filled area drawing functions.

All fills are created with the new method.

new
  my $fill = Imager::Fill->new(...);

The parameters depend on the type of fill being created. See below for details.

The currently available fills are:

  • solid
  • hatch
  • fountain (similar to gradients in paint software)
  • image - fill with an image, possibly transformed
  • opacity - a lower opacity version of some other fill

Common options

combine
The way in which the fill data is combined with the underlying image. See ``Combine Types'' in Imager::Draw.

In general colors can be specified as Imager::Color or Imager::Color::Float objects. The fill object will typically store both types and convert from one to the other. If a fill takes 2 color objects they should have the same type.

Solid fills

  my $fill = Imager::Fill->new(solid=>$color, combine =>$combine)

Creates a solid fill, the only required parameter is "solid" which should be the color to fill with.

A translucent red fill:

  my $red = Imager::Fill->new(solid => "FF000080", combine => "normal");

Hatched fills

  my $fill = Imager::Fill->new(hatch=>$type, fg=>$fgcolor, bg=>$bgcolor,
                               dx=>$dx, $dy=>$dy);

Creates a hatched fill. You can specify the following keywords:

  • "hatch" - The type of hatch to perform, this can either be the numeric index of the hatch (not recommended), the symbolic name of the hatch, or an array of 8 integers which specify the pattern of the hatch.

    Hatches are represented as cells 8x8 arrays of bits, which limits their complexity.

    Current hatch names are:

  • "check1x1", "check2x2", "check4x4" - checkerboards at various sizes
  • "vline1", "vline2", "vline4" - 1, 2, or 4 vertical lines per cell
  • "hline1", "hline2", "hline4" - 1, 2, or 4 horizontal lines per cell
  • "slash1", "slash2" - 1 or 2 / lines per cell.
  • "slosh1", "slosh2" - 1 or 2 \ lines per cell
  • "grid1", "grid2", "grid4" - 1, 2, or 4 vertical and horizontal lines per cell
  • "dots1", "dots4", "dots16" - 1, 4 or 16 dots per cell
  • "stipple", "stipple2" - see the samples
  • "weave" - I hope this one is obvious.
  • "cross1", "cross2" - 2 densities of crosshatch
  • "vlozenge", "hlozenge" - something like lozenge tiles
  • "scalesdown", "scalesup", "scalesleft", "scalesright" - Vaguely like fish scales in each direction.
  • "tile_L" - L-shaped tiles
  • "fg", "bg" - The "fg" color is rendered where bits are set in the hatch, and the "bg" where they are clear. If you use a transparent "fg" or "bg", and set combine, you can overlay the hatch onto an existing image.

    "fg" defaults to black, "bg" to white.

  • "dx", "dy" - An offset into the hatch cell. Both default to zero.

A blue and white 4-pixel check pattern:

  my $fill = Imager::Fill->new(hatch => "check2x2", fg => "blue");

You can call Imager::Fill->hatches for a list of hatch names.

Fountain fills

  my $fill = Imager::Fill->new(fountain=>$ftype, 
       xa=>$xa, ya=>$ya, xb=>$xb, yb=>$yb, 
       segments=>$segments, repeat=>$repeat, combine=>$combine, 
       super_sample=>$super_sample, ssample_param=>$ssample_param);

This fills the given region with a fountain fill. This is exactly the same fill as the "fountain" filter, but is restricted to the shape you are drawing, and the fountain parameter supplies the fill type, and is required.

A radial fill from white to transparent centered on (50, 50) with a 50 pixel radius:

  use Imager::Fountain;
  my $segs = Imager::Fountain->simple(colors => [ "FFFFFF", "FFFFFF00" ],
                                      positions => [ 0, 1 ]);
  my $fill = Imager::Fill->new(fountain => "radial", segments => $segs,
                               xa => 50, ya => 50, xb => 0, yb => 50,
                               combine => "normal");

Image Fills

  my $fill = Imager::Fill->new(image=>$src, xoff=>$xoff, yoff=>$yoff,
                               matrix=>$matrix, combine => $combine);

Fills the given image with a tiled version of the given image. The first non-zero value of "xoff" or "yoff" will provide an offset along the given axis between rows or columns of tiles respectively.

The matrix parameter performs a co-ordinate transformation from the co-ordinates in the target image to the fill image co-ordinates. Linear interpolation is used to determine the fill pixel. You can use the Imager::Matrix2d class to create transformation matrices.

The matrix parameter will significantly slow down the fill.

  # some image to act as a texture
  my $txim = Imager->new(...);
  # simple tiling
  my $fill = Imager::Fill->new(image => $txim);
  # tile with a vertical offset
  my $fill = Imager::Fill->new(image => $txim, yoff => 10);
  # tile with a horizontal offset
  my $fill = Imager::Fill->new(image => $txim, xoff => 10);
  # rotated
  use Imager::Matrix2d;
  my $fill = Imager::Fill->new(image => $txim,
                matrix => Imager::Matrix2d->rotate(degrees => 20));

Opacity modification fill

  my $fill = Imager::Fill->new(type => "opacity",
      other => $fill, opacity => 0.25);

This can be used to make a fill that is a more translucent or opaque version of an existing fill. This is intended for use where you receive a fill object as a parameter and need to change the opacity.

Parameters:

  • type => ``opacity'' - Required
  • other - the fill to produce a modified version of. This must be an Imager::Fill object. Required.
  • opacity - multiplier for the source fill opacity. Default: 0.5.

The source fills combine mode is used.

  my $hatch = Imager::Fill->new(hatch => "check4x4", combine => "normal");
  my $fill = Imager::Fill->new(type => "opacity", other => $hatch);

OTHER METHODS

Imager::Fill->hatches
A list of all defined hatch names.
Imager::Fill->combines
A list of all combine types.

FUTURE PLANS

I'm planning on adding the following types of fills:
  • "checkerboard" - combines 2 other fills in a checkerboard
  • "combine" - combines 2 other fills using the levels of an image
  • "regmach" - uses the transform2() register machine to create fills

AUTHOR

Tony Cook <[email protected]>