class RVG::Pattern < Object

Table of Contents

class methods

instance methods

shared methods

In addition to the methods listed above, this class also implements the styles method, the shape methods and the transform methods.

class methods

new

RVG::Pattern.new(width=0, height=0, x=0, y=0) [ { |pattern| drawing method calls } ] -> aPattern

Description

Creates a pattern that can be used with the :fill and :stroke styles.

Define the pattern in the associated block. The pattern can be composed of shapes, text, raster images, groups, and RVG objects. You can use the use method to include graphic objects in the pattern.

Arguments

width, height
These arguments define the pattern viewport.
x, y
Specify the starting offset of the pattern. The pattern will be repeated at x+m*width and y+n*height offsets.

Example

pattern example

instance methods

g

pattern.g [{|grp| ...}] -> aGroup

Description

Calls RVG::Group.new to construct a group and adds it to the pattern. Yields to a block if one is present, passing the new group as an argument.

Returns

Returns the new group, so RVG::Group methods can be chained to this method.

image

pattern.image(raster_image, width=nil, height=nil, x=0, y=0) -> anImage

Description

Calls RVG::Image.new to construct an image and adds it to the pattern.

Returns

Returns the new image, so RVG::Image methods can be chained to this method.

preserve_aspect_ratio

pattern.preserve_aspect_ratio(align, meet_or_slice='meet') [{|self| ...}] -> self

Description

If you use the viewbox method and the user coordinate system does not scale uniformly to the default coordinate system, use the preserve_aspect_ratio method to specify whether or not the content is stretched to fit. If not, you can specify how to fit the content into the space.

Preserve_aspect_ratio yields to a block if one is present, passing self as an argument.

Arguments

align
When the value of the meet_or_slice argument is 'meet' or 'slice', this argument controls the placement of the content within the viewport. The align argument is the concatenation of an x-aligment and a y-alignment. The values are shown in these lists:
x-alignment
xMin
align the minimum x value of the content with the left corner of the viewport.
xMid
vertically center the content within the viewport.
xMax
align the maximum x value of the content with the right corner of the viewport.
y-alignment
YMin
align the minimum y value of the content with the top of the viewport.
YMid
horizontally center the content within the viewport.
YMax
align the maximum y value of the content with the bottom of the viewport
meet_or_slice
This argument can have one of these three values:
'none'
The content is scaled as necessary so that it fits exactly within the viewport. The aspect ratio is not maintained.
'meet'
The content is scaled as necessary so that the larger dimension exactly fits the viewport. There may be some unused space in the viewport. The aspect ratio is maintained.
'slice'
The content is scaled as necessary so that the smaller dimension exactly fits the viewport. Some of the content in the larger dimension may be cut off. The aspect ratio is maintained.

Example

See the RVG class example.

Returns

Self, so other RVG::Pattern methods can be chained to this method.

See Also

viewbox

rvg

pattern.rvg(width, height, x=0, y=0) [{|new_rvg| ...}] -> aPattern

Description

This method constructs a new RVG object and adds it to the pattern. Each nested RVG object can use the viewbox method to define its own coordinate system. The rvg method yields to a block, passing the nested RVG object as an argument. Within the block, any drawing objects added to the nested RVG object are rendered within the nested RVG object's viewport.

Arguments

width, height
Specifies the viewport width and height. The units are in the user coordinate system of the parent container.
x, y
The x- and y-axis offsets of the viewport upper-left corner. The units are in the user coordinate system of the parent container.

Example

See the example for preserve_aspect_ratio in class RVG.

Returns

The RVG object, so other RVG methods can be chained to this method.

text

pattern.text(x=0, y=0, text=nil) [{|aText| ...}] -> aText

Description

Calls RVG::Text.new to construct a text object and adds it to the pattern. Yields to a block if one is present, passing the new text object as an argument.

Returns

The RVG::Text object, so other RVG::Text methods can be chained to this method.

use

pattern.use(obj, x=0, y=0, width=nil, height=nil) -> aUse

Description

Calls RVG::Use.new to constructs a use object and adds it to the pattern.

When the referenced argument is an RVG object, width and height can be used to specify the width and height of the viewport. If present and non-nil, these arguments override any width and height specified when the RVG object was created. You must specify the viewport size either when creating the RVG object or when referencing it with use.

Examples

See RVG::Use.new

Returns

The RVG::Use object, so other RVG::Use methods can be chained to this method.

viewbox

pattern.viewbox(min_x, min_y, width, height) [{|self| ...}] -> rvg

Description

The area of the pattern is called the viewport. By default the origin of the coordinate system for an pattern is (0,0). The user coordinates are pixels and the width and height are established by the width and height arguments to RVG::Pattern.new.

Use the viewbox method to superimpose a user coordinate system on the viewport. The viewbox method lets you set up a coordinate system using the units of your choice.

The viewbox method yields to a block if one is present, passing self as an argument.

Arguments

min_x, min_y
The minimum x-coordinate and y-coordinate of the user coordinate system.
width, height
The width and height of the user coordinate system.

Example

See the example for the RVG class.

Returns

Self, so other RVG::Pattern methods may be chained to viewbox.

See Also

preserve_aspect_ratio