module Prawn::TransformationStack

Stores the transformations that have been applied to the document. @private

Public Instance Methods

add_to_transformation_stack (a, b, c, d, e, f)

Source

# File lib/prawn/transformation_stack.rb, line 20
def add_to_transformation_stack(a, b, c, d, e, f)
  @transformation_stack ||= [[]]
  @transformation_stack.last.push([a, b, c, d, e, f].map { |i| Float(i) })
end

Add transformation to the stack.

@param a [Number] @param b [Number] @param c [Number] @param d [Number] @param e [Number] @param f [Number] @return [void]

current_transformation_matrix_with_translation (x = 0, y = 0)

Source

# File lib/prawn/transformation_stack.rb, line 48
def current_transformation_matrix_with_translation(x = 0, y = 0)
  transformations = (@transformation_stack || [[]]).last

  matrix = Matrix.identity(3)

  transformations.each do |a, b, c, d, e, f|
    matrix *= Matrix[[a, c, e], [b, d, f], [0, 0, 1]]
  end

  matrix *= Matrix[[1, 0, x], [0, 1, y], [0, 0, 1]]

  matrix.to_a[0..1].transpose.flatten
end

Get current transformation matrix. It’s a result of multiplication of the whole transformation stack with additional translation.

@param x [Number] @param y [Number] @return [Array(Number, Number, Number, Number, Number, Number)]

restore_transformation_stack ()

Source

# File lib/prawn/transformation_stack.rb, line 38
def restore_transformation_stack
  @transformation_stack&.pop
end

Restore previous transformation.

Effectively pops the last transformation off of the transformation stack.

@return [void]

save_transformation_stack ()

Source

# File lib/prawn/transformation_stack.rb, line 28
def save_transformation_stack
  @transformation_stack ||= [[]]
  @transformation_stack.push(@transformation_stack.last.dup)
end

Save transformation stack.

@return [void]