module Magick::RVG::Transformable
Transformations are operations on the coordinate system. All the transformations defined within a container (an RVG
object or a group) are applied before drawing any shapes or text. All transformations are applied in the order they were defined. Note: This means that
g.translate(10,20).scale(2)
is not the same as
g.scale(2).translate(10,20)
Public Class Methods
# File lib/rvg/transformable.rb, line 34 def initialize(*_args) super() @transforms = Transforms.new end
Public Instance Methods
Applies the transformation matrix [sx, rx, ry, sy, tx, ty]
# File lib/rvg/transformable.rb, line 42 def matrix(sx, rx, ry, sy, tx, ty) begin @transforms << [:affine, [Float(sx), Float(rx), Float(ry), Float(sy), Float(tx), Float(ty)]] rescue ArgumentError raise ArgumentError, "arguments must be convertable to float (got #{sx.class}, #{rx.class}, #{ry.class}, #{sy.class}, #{sx.class}, #{sx.class}, #{tx.class}, #{ty.class})" end yield(self) if block_given? self end
This method can take either of two argument lists:
- rotate(angle)
-
rotate by
angle
degrees - rotate(angle, cx, cy)
-
rotate by
angle
degrees about the point [cx
,cy
].
# File lib/rvg/transformable.rb, line 83 def rotate(angle, *args) begin case args.length when 0 @transforms << [:rotate, [Float(angle)]] when 2 cx = Float(args[0]) cy = Float(args[1]) @transforms << [:translate, [cx, cy]] @transforms << [:rotate, [Float(angle)]] @transforms << [:translate, [-cx, -cy]] else raise ArgumentError, "wrong number of arguments (#{args.length} for 1 or 3)" end rescue ArgumentError raise ArgumentError, "arguments must be convertable to float (got #{[angle, *args].map(&:class).join(', ')})" end yield(self) if block_given? self end
Multiply the x-coordinates by sx
and the y-coordinates by sy
. If sy
is omitted it defaults to sx
.
# File lib/rvg/transformable.rb, line 68 def scale(sx, sy = nil) sy ||= sx begin @transforms << [:scale, [Float(sx), Float(sy)]] rescue ArgumentError raise ArgumentError, "arguments must be convertable to float (got #{sx.class}, #{sy.class})" end yield(self) if block_given? self end
Skew the X-axis by angle
degrees.
# File lib/rvg/transformable.rb, line 105 def skewX(angle) begin @transforms << [:skewx, [Float(angle)]] rescue ArgumentError raise ArgumentError, "argument must be convertable to float (got #{angle.class})" end yield(self) if block_given? self end
Skew the Y-axis by angle
degrees.
# File lib/rvg/transformable.rb, line 116 def skewY(angle) begin @transforms << [:skewy, [Float(angle)]] rescue ArgumentError raise ArgumentError, "argument must be convertable to float (got #{angle.class})" end yield(self) if block_given? self end
Add tx
to all x-coordinates and ty
to all y-coordinates. If ty
is omitted it defaults to tx
.
# File lib/rvg/transformable.rb, line 55 def translate(tx, ty = nil) ty ||= tx begin @transforms << [:translate, [Float(tx), Float(ty)]] rescue ArgumentError raise ArgumentError, "arguments must be convertable to float (got #{tx.class}, #{ty.class})" end yield(self) if block_given? self end
Private Instance Methods
Apply transforms in the same order they were specified!
# File lib/rvg/transformable.rb, line 30 def add_transform_primitives(gc) @transforms.each { |transform| gc.__send__(transform[0], *transform[1]) } end