1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
# frozen_string_literal: true
require 'matrix'
module Prawn
# Stores the transformations that have been applied to the document.
# @private
module TransformationStack
# rubocop: disable Metrics/ParameterLists, Naming/MethodParameterName
# 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]
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
# Save transformation stack.
#
# @return [void]
def save_transformation_stack
@transformation_stack ||= [[]]
@transformation_stack.push(@transformation_stack.last.dup)
end
# Restore previous transformation.
#
# Effectively pops the last transformation off of the transformation stack.
#
# @return [void]
def restore_transformation_stack
@transformation_stack&.pop
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)]
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
# rubocop: enable Metrics/ParameterLists, Naming/MethodParameterName
end
end
|
