48 lines
1.7 KiB
C
48 lines
1.7 KiB
C
/*
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* This file is part of the CircuitPython project, https://github.com/adafruit/circuitpython
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2021 Kattni Rembor
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "shared-bindings/rainbowio/__init__.h"
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int32_t colorwheel(mp_float_t pos) {
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pos = pos - ((uint32_t)(pos / 256) * 256);
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int shift1, shift2;
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if (pos < 85) {
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shift1 = 8;
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shift2 = 16;
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} else if (pos < 170) {
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pos -= 85;
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shift1 = 0;
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shift2 = 8;
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} else {
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pos -= 170;
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shift1 = 16;
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shift2 = 0;
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}
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int p = (int)(pos * 3);
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p = (p < 256) ? p : 255;
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return (p << shift1) | ((255 - p) << shift2);
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}
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