circuitpython/shared-module/rainbowio/__init__.c
2021-07-12 14:40:01 -04:00

43 lines
1.7 KiB
C

/*
* This file is part of the CircuitPython project, https://github.com/adafruit/circuitpython
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Kattni Rembor
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "shared-bindings/rainbowio/__init__.h"
const int32_t colorwheel(float pos) {
if (pos > 255) {
pos = pos - ((uint32_t)(pos / 256) * 256);
}
if (pos < 85) {
return (uint8_t)(255 - (pos * 3)) << 16 | (uint8_t)(pos * 3) << 8;
} else if (pos < 170) {
pos -= 85;
return (uint8_t)(255 - (pos * 3)) << 8 | (uint8_t)(pos * 3);
} else {
pos -= 170;
return (uint8_t)(pos * 3) << 16 | (uint8_t)(255 - (pos * 3));
}
}