let img;

let morphs = [];
// The order of the morphs, being mapped to the grayscale
const orderedMorphs = [5,6,0,4,1,2,3];
let count = 7;
let size = 10;
let countH = 800;
let countV = 520;

// Load the image and symbols
function preload() {
  img = loadImage('/assets/mona-lisa.jpg');
  for (let i = 0; i < count; i++)
    morphs[i] = loadSVG(`/assets/morphs/${i}.svg`);
}

function setup() {
  pixelDensity(1);

  // Display the image
  img.resize(0, countH);
  img.filter(GRAY);
  createCanvas(countV, countH);
  image(img, 0, 0);

  describe('Mona lisa - by Davincci');
  
  // Load the pixels of the canvas
  // This is a 1D array of integers with the rgba values of the pixels
  loadPixels();
  let i = 0;
  let j = 0;
  // Create an array containing only the grayscale of every pixel
  let pixels1d = [];
  // Since the picture is gray, the first 3 values (rgb) for every picture are similar
  // We need the value at indexes 0,4,7,...
  for (let i = 0; i < pixels.length; i += 4) 
    pixels1d.push(pixels[i]);
  
  // Combine every 10 values into one by calculating their average
  // Put the result in a 2D array, the rows are the pixel-rows of the image
  // The columns are grayscale averages of every 10 pixel-columns of the picture
  let averages = new Array(countH);
  for (let i = 0; i < averages.length; i++)
    averages[i] = new Array(countV/10);

  let sum = 0;
  for(let k = 0; k < pixels1d.length; k++) {
    sum += pixels1d[k];
    if (j%10 == 0) {
      averages[i][Math.floor(j/10)] = sum/10;
      sum = 0;
    }
    j++;
    if (k%countV == 0 && k>0) {
      i++;
      j = 0;
    }
  }

  // Combine every 10 rows into one row by calculating the average of the values of every column
  // Put the result into a new array 'average2'
  let sums = new Array(countV/10).fill(0);
  let averages2 = new Array(countH/10);
  for (let i = 0; i < averages2.length; i++)
    averages2[i] = new Array(countV/10);

  for (let i = 0; i < averages.length; i++) {
    for (let j = 0; j < averages2[0].length; j++) {
      sums[j] += averages[i][j];
      if (i%10 == 0) {
        averages2[i/10][j] = Math.round(sums[j]/10);
        sums[j] = 0;
      }
    }
  }

  // Find the min and max value in averages2
  let minGray = Infinity;
  let maxGray = -Infinity;

  for (let i = 0; i < averages2.length; i++) {
    for (let j = 0; j < averages2[i].length; j++) {
      let val = averages2[i][j];
      if (val < minGray) minGray = val;
      if (val > maxGray) maxGray = val;
    }
  }

  // Scale all values of averages2 between minGray and maxGray
  for (let i = 0; i < averages2.length; i++) {
    for (let j = 0; j < averages2[i].length; j++) {
      // Scale between 0.0 - 1.0
      let normalized = (averages2[i][j] - minGray) / (maxGray - minGray);
      // Map to 0 - 6 (the morph indexes)
      averages2[i][j] = Math.round(normalized * 6)%7;
    }
  }

  let svgCanvas = createGraphics(countV*2,countH,SVG);
  svgCanvas.image(img, 0, 0);

  for (let i = 0; i < countH/10; i++) {
    for (let j = 0; j < countV/10; j++) {
      svgCanvas.image(morphs[orderedMorphs[averages2[i][j]]], j*size+countV+size, i*size, size, size);
    }
  }
  svgCanvas.save("morphed-mona-lisa.svg");
}