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# coding: utf-8
# Copyright 2019 DragonRuby LLC
# MIT License
# geometry_docs.rb has been released under MIT (*only this file*).
module GeometryDocs
def docs_method_sort_order
[:docs_class, :docs_scale_rect]
end
def docs_class
<<-S
* DOCS: ~Geometry~
The Geometry module contains methods for calculations that are frequently used in game development.
S
end
def docs_scale_rect
<<-S
* DOCS: ~GTK::Geometry#scale_rect~
Given an array with 4 elements representing a rect [x, y, w, h], this function returns a scaled rect. It accepts three arguments:
~ratio~: the ratio by which to scale the rect. A ratio of 2 will double the dimensions of the rect while a ratio of 0.5 will halve its dimensions.
~anchor_x~ and ~anchor_y~ specify the point within the rect from which to resize it. Setting both to 0 will affect the width and height of the rect, leaving x and y unchanged. Setting both to 0.5 will scale all sides of the rect proportionally from the center.
The ~scale_rect~ method can be applied directly to a sprite or other primitives. See CHEATSHEET: How to Scale a Sprite.
#+begin_src ruby
def tick args
# x, y, w, h
my_rect = [100, 100, 200, 200]
# halve the dimensions of the rect:
# ratio, anchor_x, anchor_y
new_rect = my_rect.scale_rect(0.5, 0.5, 0.5)
puts new_rect # => [150.0, 150.0, 100.0, 100.0]
end
#+end_src
S
end
end
module Geometry
extend Docs
extend GeometryDocs
end
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