image = new SimpleImage("abby.jpg");

maxNumberOfVertices = 20;
numberOfVertices = 3;
maxIterations = 10000;  // number of points plotted
dim = getMinDimension(); // dim is minimum of image height, width
magnification = 0.9; // fraction of dim / 2 used for plot
plotRatio = 0.5; // fraction of distance from curr. pt. to vertex
xUnit = magnification * (dim / 2);
yUnit = xUnit; // number of pixels for 1 unit of distance

color = new Array(maxNumberOfVertices); // color for each vertex
for (rep = 0; rep < maxNumberOfVertices; rep++){
  color[rep] = new Array(3);
}
color[0] = [58, 178, 58]; // each color is an array of 3 integers
color[1] = [255, 195, 155]; // in [0, 255] for red, green, and blue
color[2] = [255, 188, 255];
color[3] = [255, 111, 255];
color[4] = [138, 111, 226];
color[5] = [100, 55, 180];
color[6] = [0, 155, 255];
color[7] = [0, 255, 255];
color[8] = [155, 155, 155];
color[9] = [255, 155, 255];
color[10] = [200, 055, 155];
color[11] = [55, 55, 255];
color[12] = [55, 255, 155];
color[13] = [0, 0, 55];
color[14] = [0, 0, 55];
color[15] = [0, 0, 255];
color[16] = [0, 255, 0];
color[17] = [255, 0, 155];
color[18] = [55, 155, 155];
color[19] = [55, 55, 255];

function setVerticies()
{
  vertex = new Array(numberOfVertices); // array for vertex coords
  for (rep = 0; rep < numberOfVertices; rep++){
    vertex[rep] = new Array(2); // array of 2 coordinates per vertex
  }
  vertex[0][0] = 0.0;        // x = x'cosT - y'sinT
  vertex[0][1] = 1.0;        // y = x'sinT + y'cosT
  angle = 2.0 * Math.PI / numberOfVertices;
  theta = angle; // rotate vertex[0] theta to obtain other vertices
  for (rep = 1; rep < numberOfVertices; rep++){
    vertex[rep][0] = vertex[0][0] * Math.cos(theta) - 
                     vertex[0][1] * Math.sin(theta);
    vertex[rep][1] = vertex[0][0] * Math.sin(theta) + 
                     vertex[0][1] * Math.cos(theta);
    theta += angle;
  }
    
  currVx = vertex[0][0];   // inital point for start of game
  currVy = vertex[0][1];
  nextVx = currVx;
  nextVy = currVy;
}

function getMinDimension()
{
  if (image.height < image.width) // use min of height and width
    return image.height;          // for image dimension in order
  return image.width;             // to fit within the given image
}

function convertImageToWhite()
{
  for (pixel: image) { // set RGB value to 255 for all pixels
    pixel.setRed(255);
    pixel.setGreen(255);
    pixel.setBlue(255);
  }
}

function getNextCoordinate(next, vert, plotRatio)
{ // add to the current coordinate the plotRatio
  // of the distance to the chosen vertex
  return next + (vert - next) * plotRatio;
}
function drawPixel(pix, col)
{
/* create math fucntions for calculating color based on col
  red = Math.floor( 3.5 * pix.getX() * (1+col)  % 256 );
  green = Math.floor( 6.5 * pix.getX() * (1+col)  % 256 );
  blue = Math.floor( 8.5 * pix.getX() * (1+col)  % 256 );
  pix.setRed(red);
  pix.setGreen(green); 
  pix.setBlue(blue);
*/
  pix.setRed(color[col][0]);
  pix.setGreen(color[col][1]); // use preset color values
  pix.setBlue(color[col][2]);
}

function convertCoordToXPixel( coord )
{
// convert coord to pixel value for creative displays
  return image.width / 2 + 1.5*Math.sqrt(coord*coord)*xUnit*coord;
//  return image.width / 2 + xUnit * coord; // traditional
}

function convertCoordToYPixel( coord )
{
// convert coord to pixel value for creative displays
  return image.height / 2 - 1.1*Math.sin(1.2*Math.PI*coord) *
                                               yUnit * coord;
//  return image.height / 2 - yUnit * coord; // traditional
}

convertImageToWhite();
setVerticies();

for (rep = 0; rep < maxIterations; rep++) {
  vert = Math.floor( Math.random() * numberOfVertices );
  currVx = getNextCoordinate(currVx, vertex[vert][0], plotRatio);
  currVy = getNextCoordinate(currVy, vertex[vert][1], plotRatio);
  pixelX = Math.floor( convertCoordToXPixel(currVx) );
  pixelY = Math.floor( convertCoordToYPixel(currVy) );
  if (pixelX >= 0 && pixelX < image.width &&
      pixelY >= 0 && pixelY < image.height )
  {
    pixel = image.getPixel(pixelX, pixelY );
    drawPixel(pixel, vert);
  }  
}

print(image);