Fix box layouting to take small floating point differences into account

When fitting or splitting boxes their width/height is often compared to
other widths/heights. Due to small floating point differences a box that
fits might be treated as one that doesn't fit.

This can be fixed by using a special float comparision method in such
cases.

CHANGELOG.md

@@ -7,6 +7,7 @@
  the document's root page tree node
 * HexaPDF::Type::Page#perform_validation to only do the validation if the page
  is part of the document's page tree
+* Box layouting to take small floating point differences into account
 
 
 ## 0.24.1 - 2022-08-11

lib/hexapdf/layout/box.rb

@@ -34,6 +34,7 @@
 # commercial licenses are available at <https://gettalong.at/hexapdf/>.
 #++
 require 'hexapdf/layout/style'
+require 'geom2d/utils'
 
 module HexaPDF
  module Layout
@@ -76,6 +77,8 @@ module Layout
  # which should just draw the content.
  class Box
 
+ include Geom2D::Utils
+
  # Creates a new Box object, using the provided block as drawing block (see ::new).
  #
  # If +content_box+ is +true+, the width and height are taken to mean the content width and
@@ -183,7 +186,9 @@ def fit(available_width, available_height, _frame)
  def split(available_width, available_height, frame)
  if @fit_successful
  [self, nil]
- elsif (style.position != :flow && (@width > available_width || @height > available_height)) ||
+ elsif (style.position != :flow &&
+ (float_compare(@width, available_width) > 0 ||
+ float_compare(@height, available_height) > 0)) ||
  content_height == 0 || content_width == 0
  [nil, self]
  else

lib/hexapdf/layout/image_box.rb

@@ -98,7 +98,8 @@ def fit(available_width, available_height, _frame)
  @height = image_height * ratio + rh
  end
 
- @width <= available_width && @height <= available_height
+ @fit_successful = float_compare(@width, available_width) <= 0 &&
+ float_compare(@height, available_height) <= 0
  end
 
  private