// Generate an LED gamma-correction table for Arduino sketches.
// Written in Processing (www.processing.org), NOT for Arduino!
// Copy-and-paste the program's output into an Arduino sketch.

// NOTE: For ESPs a 'gamma' variable is always declared in an ESP tool source code.
float     GammaVal  = 2;  // Correction factor (1.5 - 3.0 for LEDs)
uint16_t  max_in    = 255,  // Top end of INPUT range (number of elements in the table)
          max_out   = 255,  // Top end of OUTPUT range 
          newLn     = 16;   // Create new line after this number of elements

/* for gamma = 2.0 the formular is quiet simple as:
int x = readAnalogInput();  /// 0 - 255
int brightness = (x*x)/255.0;
*/

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.print("Creating gamma correction table for LEDs! Used gamma: ");
  Serial.println(GammaVal);

  Serial.print("const uint8_t PROGMEM gamma[] = {");
  for(int i=0; i <= max_in; i++) {
    if(i > 0) Serial.print(',');
    if((i % newLn) == 0) Serial.print("\n ");
    
    uint16_t v = (uint16_t)(pow((float)i / (float)max_in, GammaVal) * max_out + 0.5);
    Serial.printf("%3u", v);
  }
  Serial.println(" };");
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}