//this would theoretically be the amount of rgb every pixel would need to change to register as dropping alpha

let threshold = 30;

//this will hold every pixel in state

let pixelValues = [];

let currentr = 0;

let currentg = 0;

let currentb = 0;

let priorr = 0;

let priorg = 0;

let priorb = 0;

let currenta = 0;

let priora = 0;

​

//in setup initialize all alpha values to 255, as i am collecting data from pixel array don't touch alpha values, when i detect a change put down the alpha values

​

//let acounter = 255;

​

function setup() {

  createCanvas(640, 480);

  pixelDensity(1);

  video = createCapture(VIDEO);

  video.size(width,height);

  video.hide();

  frameRate(60);

}

​

function draw() {

  image(video,0,0,width,height);

  video.loadPixels();

  loadPixels();

  for (let y=0; y<height; y++){

    for (let x=0; x<width; x++){

      /* so far:

      put the video up there

      load up the pixels

      for every pixel store in state the current rgb value

      if it's different from the previous rgb value 

      turn alpha all the way down

      */

      let i = (x + y * width) * 4;

      currentr = video.pixels[i];

      currentg = video.pixels[i+1];

      currentb = video.pixels[i+2];

      currenta = video.pixels[i+3];

      //entire thing one interdependent using boolean logic

      /*

      if ((currentr != priorr && ((currentr >= (priorr + threshold)) || 

                                 (currentr <= (priorr - threshold)))) || 

          (currentg != priorg && ((currentg >= (priorg + threshold)) || 

                                 (currentg <= (priorg - threshold)))) ||

          (currentb != priorb && ((currentb >= (priorb + threshold)) || 

                                 (currentb <= (priorb - threshold)))))

        {

        video.pixels[i+3] -= 255;

      }

      */

      /*

      //each one an individual check with threshold

      if (currentr != priorr && ((currentr >= (priorr + threshold)) || 

                                 (currentr <= (priorr - threshold)))) {

        video.pixels[i+3] -= 200;

      } else if (currentg != priorg && ((currentg >= (priorg + threshold))                                    || (currentg <= (priorg - threshold)))) {

        video.pixels[i+3] -= 200;

      } else if (currentb != priorb && ((currentb >= (priorb + threshold)) || (currentb <= (priorb - threshold))))

        {

        video.pixels[i+3] -= 200;

      }

      */

      //just checking if they're at all different

      if (video.pixels[i] != pixelValues[i]) {

        video.pixels[i+3] -= 255;

      }

      if (video.pixels[i+1] != pixelValues[i+1]) {

        video.pixels[i+3] -= 255;

      }

      if (video.pixels[i+2] != pixelValues[i+2]) {

        video.pixels[i+3] -= 255;

      }

      pixelValues[i] = currentr;

      pixelValues[i+1] = currentg;

      pixelValues[i+2] = currentb;

      pixelValues[i+3] = currenta;

    }

  }

  updatePixels();

  video.updatePixels();

  //console.log(pixels[4246]);

}

​

/*

what do i want to do

i want the video to be slowly erased based on the person's movements

so if they hold very still maybe they dont fade

but if they move they fade (the alpha goes down)

so in pseudocode... if the pixel's rgb values change significantly every time 

the loop runs, the alpha goes down maybe ten or 20

what's my threshold? let's say 30?

*/