Cory G Watson > Graphics-Primitive > Graphics::Primitive::Driver

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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.

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