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# encoding: utf-8
#
# transformation_stack.rb : Stores the transformations that have been applied to the document
#
# Copyright 2015, Roger Nesbitt. All Rights Reserved.
#
# This is free software. Please see the LICENSE and COPYING files for details.
#
require 'matrix'
module Prawn
module TransformationStack
def add_to_transformation_stack(a, b, c, d, e, f)
@transformation_stack ||= [[]]
@transformation_stack.last.push([a, b, c, d, e, f].map(&:to_f))
end
def save_transformation_stack
@transformation_stack ||= [[]]
@transformation_stack.push(@transformation_stack.last.dup)
end
def restore_transformation_stack
@transformation_stack.pop if @transformation_stack
end
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
end
end
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