Module: Magick::RVG::Transformable

Included in:
Magick::RVG, Group, Image, Shape, Use
Defined in:
lib/rvg/transformable.rb

Overview

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)

Instance Method Summary collapse

Instance Method Details

#matrix(sx, rx, ry, sy, tx, ty) {|_self| ... } ⇒ Object

Applies the transformation matrix [sx, rx, ry, sy, tx, ty]

Yields:

  • (_self)

Yield Parameters:


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# File 'lib/rvg/transformable.rb', line 46

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

#rotate(angle, *args) {|_self| ... } ⇒ Object

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].

Yields:

  • (_self)

Yield Parameters:


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# File 'lib/rvg/transformable.rb', line 87

def rotate(angle, *args)
    begin
        case args.length
            when 0
                @transforms << [:rotate, [Float(angle)]]
            when 2
                cx, cy = Float(args[0]), Float(args[1])
                @transforms << [:translate, [cx, cy]]
                @transforms << [:rotate, [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].collect {|a| a.class}.join(', ')})"
    end
    yield(self) if block_given?
    self
end

#scale(sx, sy = nil) {|_self| ... } ⇒ Object

Multiply the x-coordinates by sx and the y-coordinates by sy. If sy is omitted it defaults to sx.

Yields:

  • (_self)

Yield Parameters:


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# File 'lib/rvg/transformable.rb', line 72

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

#skewX(angle) {|_self| ... } ⇒ Object

Skew the X-axis by angle degrees.

Yields:

  • (_self)

Yield Parameters:


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# File 'lib/rvg/transformable.rb', line 108

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

#skewY(angle) {|_self| ... } ⇒ Object

Skew the Y-axis by angle degrees.

Yields:

  • (_self)

Yield Parameters:


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# File 'lib/rvg/transformable.rb', line 119

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

#translate(tx, ty = nil) {|_self| ... } ⇒ Object

Add tx to all x-coordinates and ty to all y-coordinates. If ty is omitted it defaults to tx.

Yields:

  • (_self)

Yield Parameters:


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# File 'lib/rvg/transformable.rb', line 59

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