60 lines
2.4 KiB
Lua
60 lines
2.4 KiB
Lua
--[[
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Copyright (c) 2014, Robert 'Bobby' Zenz
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice, this
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list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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--]]
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--- Various mathematical functions for interpolating values.
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interpolate = {}
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--- Performs a cosine interpolation with the given offset between the given
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-- min and max values.
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--
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-- @param offset The offset to get, should be between 0 and 1.
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-- @param min Optional. The minimum value of the range, defaults to 0.
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-- @param max Optional. The maximum value of the range, defaults to 1.
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-- @return The interpolated value at the given offset.
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function interpolate.cosine(offset, min, max)
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local value = (1 - math.cos(offset * math.pi)) / 2
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if min ~= nil and max ~= nil then
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return min * (1 - value) + max * value
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else
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return value
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end
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end
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--- Performs a linear interpolation with the given offset between the given
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-- min and max values.
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--
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-- @param offset The offset to get, should be between 0 and 1.
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-- @param min Optional. The minimum value of the range, defaults to 0.
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-- @param max Optional. The maximum value of the range, defaults to 1.
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-- @return The interpolated value at the given offset.
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function interpolate.linear(offset, min, max)
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return min * (1 - offset) + max * offset
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end
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