54 lines
1.8 KiB
Markdown
54 lines
1.8 KiB
Markdown
# Ease
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A generic implementation of standard easing functions for use in animation or
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robotics.
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For examples of "standard" easing algorithms (in this case used in CSS
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animations) take a look at [easings.net](http://easings.net)
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## Installation
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[Available in Hex](https://hex.pm/packages/ease), the package can be installed
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by adding `ease` to your list of dependencies in `mix.exs`:
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```elixir
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def deps do
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[{:ease, "~> 0.1.0"}]
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end
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```
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Documentation can be found at [https://hexdocs.pm/ease](https://hexdocs.pm/ease).
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## Usage
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You can use an easing function directly from within your own loop, provided
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that you can supply the four arguments needed;
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* `current_time` - the elapsed "time" in the loop, ie if your `duration` is
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ten, and you want to find the position for half way through the duration
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then you set it to `5`. Units are arbitrary (steps, ms, whatever).
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* `start_value` - the initial value or position at `current_time` of zero.
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* `change_in_value`- how much the `start_value` should be changed by the end
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of the animation, ie the expected final value minus the `start_value`.
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* `duration` - the duration of the animation, in the same units as `current_time`.
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Given a quadratic ease-in of `1..10`, over 1 unit of time, where would we be
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when half-way through:
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iex> Ease.ease_in_quad(0.5, 1, 10, 1)
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3.25
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Plot the `{x, y}` positions for a circular ease-in:
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iex> ys = 1..10
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...> xs = Ease.map(ys, :ease_in_circular)
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...> Enum.zip(xs, ys)
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[{1.0, 1}, {1.0557280900008417, 2}, {1.2250356126078779, 3},
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{1.5147186257614298, 4}, {1.9377422517014504, 5}, {2.5166852264521173, 6},
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{3.291796067500631, 7}, {4.34314575050762, 8}, {5.876894374382339, 9},
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{10.0, 10}]
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# License
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Source code is licensed under the terms of the MIT license, the text of which
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is included in the `LICENSE` file in this distribution.
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