diff options
Diffstat (limited to 'users/vitoni/utils.c')
| -rw-r--r-- | users/vitoni/utils.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/users/vitoni/utils.c b/users/vitoni/utils.c new file mode 100644 index 0000000000..fb011570e4 --- /dev/null +++ b/users/vitoni/utils.c @@ -0,0 +1,129 @@ +// Copyright 2021 Victor Toni (@vitoni) +// SPDX-License-Identifier: GPL-2.0-or-later + +#include "utils.h" + +#include <lib/lib8tion/lib8tion.h> + +/** +* @brief Changes `*value` to `new_value`. +* @param[in,out] value Pointer to variable to be changed. +* @param[in] new_value Value to be changed. +* @param[in,out] changed Flag indicating `*value` and `new_value` were different. +*/ +void update_value(uint8_t *value, const uint8_t new_value, bool *changed) { + if (new_value != (*value)) { + (*changed) = true; + (*value) = new_value; + } +} + +/** +* @brief Checks whether a value is in the given range. +* @param[in] value Value to be checked. +* @param[in] range_min Lower bound of range (inclusive). +* @param[in] range_max Upper bound of range (inclusive). +* @return `true` if (range_min <= value <= range_max), `false` otherwise +*/ +bool in_range(const uint8_t value, const uint8_t range_min, const uint8_t range_max) { + return range_min <= value && value <= range_max; +} + +/** +* @brief Calculates the sine value based on sin8() and scales it to the given range (unsigned). +* +* Table of values for unscaled sin8() eg. a theta of 0 results to 128 and a theta of 255 (240+15) results to 125. + 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 + +---------------------------------------------------------------- + 0: 128 131 134 137 140 143 146 149 152 155 158 161 164 167 170 173 + 16: 177 179 182 184 187 189 192 194 197 200 202 205 207 210 212 215 + 32: 218 219 221 223 224 226 228 229 231 233 234 236 238 239 241 243 + 48: 245 245 246 246 247 248 248 249 250 250 251 251 252 253 253 254 + 64: 255 254 253 253 252 251 251 250 250 249 248 248 247 246 246 245 + 80: 245 243 241 239 238 236 234 233 231 229 228 226 224 223 221 219 + 96: 218 215 212 210 207 205 202 200 197 194 192 189 187 184 182 179 + 112: 177 173 170 167 164 161 158 155 152 149 146 143 140 137 134 131 + 128: 128 125 122 119 116 113 110 107 104 101 98 95 92 89 86 83 + 144: 79 77 74 72 69 67 64 62 59 56 54 51 49 46 44 41 + 160: 38 37 35 33 32 30 28 27 25 23 22 20 18 17 15 13 + 176: 11 11 10 10 9 8 8 7 6 6 5 5 4 3 3 2 + 192: 1 2 3 3 4 5 5 6 6 7 8 8 9 10 10 11 + 208: 11 13 15 17 18 20 22 23 25 27 28 30 32 33 35 37 + 224: 38 41 44 46 49 51 54 56 59 62 64 67 69 72 74 77 + 240: 79 83 86 89 92 95 98 101 104 107 110 113 116 119 122 125 +* +* @param[in] theta Angle (a full circle mapped to 0-255) used as input for sine calculation. +* @param[in] range_min Lower bound of range (inclusive). +* @param[in] range_max Upper bound of range (inclusive). +* @return Calculated sine value mapped to the given range. +*/ +uint8_t scaled_sin(const uint8_t theta, const uint8_t range_min, const uint8_t range_max) { + const uint8_t range = range_max - range_min; + return scale8(sin8(theta), range) + range_min; +} + +/** +* @brief Increases the given value until reaching range_max. +* The increments occur following an upwards sine wave (scaled from range_min to range_max). +* @param[in] theta Angle (a full circle mapped to 0-255) used as input for sine calculation. +* @param[in] range_min Lower bound of range (inclusive). +* @param[in] range_max Upper bound of range (inclusive). +* @param[in] max_delta Maximum delta between value and range_max (due to values being integers and eventually not fully matching). +* @param[in,out] value Reference of variable to be increased +* @return `true` if value and range_max are within a delta of 3 (chosen by fair dice rolling), `false` otherwise +* @see scaled_sin() +*/ +bool scaled_sin_up(const uint8_t theta, const uint8_t range_min, const uint8_t range_max, const uint8_t max_delta, uint8_t *value) { + // ensure upper range bound + if (range_max <= (*value)) { + (*value) = range_max; + return true; + } + + const uint8_t new_value = scaled_sin(theta, range_min, range_max); + if (in_range(new_value, range_min, range_max) && (*value) < new_value) { + (*value) = new_value; + + return range_max == (*value); + } + + const uint8_t delta = range_max - (*value); + if (delta <= max_delta) { + (*value) = range_max; + } + + return delta <= max_delta; +} + +/** +* @brief Decreases the given value until reaching range_min. +* The decrements occur following an downwards sinus wave (scaled from range_min to range_max). +* @param[in] theta Angle (a full circle mapped to 0-255) used as input for sinus calculation. +* @param[in] range_min Lower bound of range (inclusive). +* @param[in] range_max Upper bound of range (inclusive). +* @param[in] max_delta Maximum delta between value and range_min (due to values being integers and eventually not fully matching). +* @param[in,out] value Reference of variable to be decreased +* @return `true` if value and range_max are within a delta of 3 (chosen by fair dice rolling), `false` otherwise +* @see scaled_sin() +*/ +bool scaled_sin_down(const uint8_t theta, const uint8_t range_min, const uint8_t range_max, const uint8_t max_delta, uint8_t *value) { + // ensure lower range bound + if ((*value) <= range_min) { + (*value) = range_min; + return true; + } + + const uint8_t new_value = scaled_sin(theta, range_min, range_max); + if (in_range(new_value, range_min, range_max) && new_value < (*value)) { + (*value) = new_value; + + return range_min == (*value); + } + + const uint8_t delta = (*value) - range_min; + if (delta <= max_delta) { + (*value) = range_min; + } + + return delta <= max_delta; +} |