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Shift mapping math out of floating point

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This commit is contained in:
Adam Martini 2020-06-23 12:54:06 -07:00
parent 0aeb49d28a
commit 663af3dfb3
1 changed files with 4 additions and 4 deletions
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8
src/lv_misc/lv_math.c
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@ -239,12 +239,12 @@ int64_t _lv_pow(int64_t base, int8_t exp)
* @param in min output range * @param in min output range
* @param out max output range * @param out max output range
*/ */
LV_ATTRIBUTE_FAST_MEM int16_t _lv_map(int16_t x, float min_in, float max_in, float min, float max) LV_ATTRIBUTE_FAST_MEM int16_t _lv_map(int16_t x, int16_t min_in, int16_t max_in, int16_t min, int16_t max)
{ {
float slope = (max - min) / (max_in - min_in); uint32_t slope = ((uint32_t)(max - min) * 1000) / (uint32_t)(max_in - min_in); /** times 1000 to avoid rounding errors*/
float bias = min - slope * min_in; uint32_t bias = min - (slope * min_in) / 1000;
return bias + slope * x; return bias + (slope * x) / 1000;
} }
/********************** /**********************