HSV to RGB 255 - Smooth

/* 

This sketch shows how to equalize the primary and secondary color region widths of the spectrum.

it works only for colorMode(HSB) and its equivalent, colorMode(HSB, 360, 255, 255).

For a formula that smooths the color regions of colorMode(HSB) or its equivalent 

colorMode(HSB, 360, 255, 255), see this sketch:

https://https://openprocessing.org/sketch/2345954

*/

​

​

let hu = 0;

OPC.slider('fvalue', 6); // this slider sets spectrum linearity correction

​

function setup() {

  createCanvas(windowWidth, windowWidth*.75);

  colorMode(HSB, 255); 

  background(255);

}

​

function draw() {

  for (let t=0; t<765; t+=10){

    //let hu = hsv2Rgb(t/765, 1, 1)

    hu = t/765*255;

    let h = hu + fvalue * sin(3 * hu / 40.53);    // linearity corrected for 256 degrees

    fill(h, 255, 255);

    rect(t*1.53, 0, 16, height);

  }

}

​

let lapse = 0;    // mouse timer

function mousePressed(){

// prevents mouse press from registering twice

  if (millis() - lapse > 400){

    save("img_" + month() + '-' + day() + '_' + hour() + '-' + minute() + '-' + second() +      ".jpg");

    lapse = millis();

  }

}