esp_color_correction.cpp

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#include "esp_color_correction.h"
#include "light_color_values.h"
#include "esphome/core/log.h"
 
namespace esphome::light {
 
void ESPColorCorrection::calculate_gamma_table(float gamma) {
  for (uint16_t i = 0; i < 256; i++) {
    // corrected = val ^ gamma
    auto corrected = to_uint8_scale(gamma_correct(i / 255.0f, gamma));
    this->gamma_table_[i] = corrected;
  }
  if (gamma == 0.0f) {
    for (uint16_t i = 0; i < 256; i++)
      this->gamma_reverse_table_[i] = i;
    return;
  }
  for (uint16_t i = 0; i < 256; i++) {
    // val = corrected ^ (1/gamma)
    auto uncorrected = to_uint8_scale(powf(i / 255.0f, 1.0f / gamma));
    this->gamma_reverse_table_[i] = uncorrected;
  }
}
 
}  // namespace esphome::light