Graphics::Primitive::Driver(3p)

NAME
Graphics::Primitive::Driver - Role for driver implementations

DESCRIPTION
What good is a library agnostic intermediary representation of graphical components if you can't feed them to a library specific implementation that turns them into drawings? Psht, none!

To write a driver for Graphics::Primitive implement this role.

SYNOPSIS
  my $c = Graphics::Primitive::Component->new({
    origin => Geometry::Primitive::Point->new({
        x => $x, y => $y
    }),
    width => 500, height => 350
  });

CANVASES
When a path is added to the internal list via do, it is stored in the paths attribute as a hashref. The hashref has two keys: path and op. The path is, well, the path. The op is the operation provided to do. As canvases are just lists of paths you should consult the next section as well.

PATHS AND HINTING
Paths are lists of primitives. Primitives are all descendants of Geometry::Shape and therefore have point_start and point_end. These two attributes allow the chaining of primitives. To draw a path you should iterate over the primitives, drawing each.

When you pull each path from the arrayref you should pull it's accompanying hints via get_hint (the indexes match). The hint may provide you with additional information:

  PRIMITIVE HINTS

contiguous
    True if this primitive is contiguous with the previous one. Example: Used to determine if a new sub-path is needed for the Cairo driver.

  OPERATION HINTS

preserve

WARNING
Only this class or the driver itself should call methods starting with an underscore, as this interface may change.

METHODS

_do_stroke ($strokeop)
    Perform a stroke.

_do_fill ($fillop)
    Perform a fill.

_draw_arc ($arc)
    Draw an arc.

_draw_canvas ($canvas)
    Draw a canvas.

_draw_component ($comp)
    Draw a component.

_draw_line ($line)
    Draw a line.

_draw_rectangle ($rect)
    Draw a rectangle.

_draw_textbox
    Draw a textbox.

_resize ($width, $height)
    Resize the current working surface to the size specified.

_finish_page
    Finish the current 'page' and start a new one. Some drivers that are not paginated may need to emulate this behaviour.

data
    Retrieve the results of this driver's operations.

draw
    Draws the given Graphics::Primitive::Component. If the component is a container then all components therein are drawn, recursively.

get_text_bounding_box
    Given a Font and a string, returns a bounding box of the rendered text.

finalize
    Finalize the supplied component and any child components, recursively.

prepare
    Prepare the supplied component and any child components, recursively.

write
    Write out the results of this driver's operations to the specified file.

AUTHOR
Cory Watson, "<gphat@cpan.org>"

COPYRIGHT & LICENSE
Copyright 2008-2010 by Cory G Watson.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.