NoisyCrosses

// Create a symmetrical diamond shaped (sideways square) snowflake.
// Create 1/8th of the shape and reflect that for the remaining 7/8ths.
// Make it a repeatable function with a parameter for the center XY.
// New pattern generated on key press.
// Animated GIF generated and saved on form unload.
// ToDo: Store as class? Then it would be copyable.


// Save as animated GIF
// Requires gifAnimation Processing Library
// http://www.extrapixel.ch/processing/gifAnimation/
import gifAnimation.*;
GifMaker gifExport;
boolean saveToGif = true;

// The time between GIF frames
int frameDelay = 1000;

// No of cells between the centre and edge DIAGONALLY
// It's kind of confusing, but it makes sense in the code
// Works nicely between 4 to 6
int triangleRadius = 8;
int triangleDiameter = (triangleRadius*4) - 1;

// This specifies how much the shape should resemble a "star"
//   == 1 makes a cross
//   == 2 makes a square diamond
//   >= 2 makes a star
float starness = 2.7;

// Cell will be drawn if the RNG is below 1
// So a value of 3 will draw about 1/3 of the cells
float randomUpperLimit = 1.8;

// The dimensions of each cell
int cellW = 7;
int cellH = cellW;

// The ideal pixel size for the canvas
int yPixelIdeal = 256;
int xPixelIdeal = int(yPixelIdeal * 1);

// Has to be an odd number to make sure we have a central pixel
int xCells = (xPixelIdeal / cellW) + 1;
int yCells = (yPixelIdeal / cellH) + 1;

// Find central cell
int centreCellX = (xCells - 1) / 2;
int centreCellY = (yCells - 1) / 2;

//////////////////////////////////////////////////////////////////////

void setup(){
  size(xCells*cellW,yCells*cellH);
  background(0);
  if (saveToGif) {
    gifExport = new GifMaker(this, System.currentTimeMillis() + ".gif");
    gifExport.setRepeat(0);
  }
  keyPressed();
}

//////////////////////////////////////////////////////////////////////

void draw() {}

void keyPressed(){
  background(0);
  
  // Draw one in each corner of the canvas
  newPattern(triangleRadius*2          , triangleRadius*2);
  newPattern(triangleRadius*2          , yCells-1-triangleRadius*2);
  newPattern(xCells-1-triangleRadius*2 , triangleRadius*2);
  newPattern(xCells-1-triangleRadius*2 , yCells-1-triangleRadius*2);
  
  // Draw one in the centre
  newPattern(centreCellX , centreCellY);
  
  addToGif();
}

void stop() {
  if (saveToGif) {
    gifExport.setDelay(frameDelay);
    gifExport.finish();
  }
}

//////////////////////////////////////////////////////////////////////

void addToGif() {
  if (saveToGif) {
    gifExport.setDelay(frameDelay);
    gifExport.addFrame();
  }
}

//////////////////////////////////////////////////////////////////////

void newPattern(int centreCellX, int centreCellY) {
  for(int i=0;i<triangleRadius;i++){
    for(int j=0;j<( (triangleRadius*2) - (starness*i) );j++){
      
      //// Colours /////////////////////////////////
      // White
      //   fill(255);
      // Grey
         fill(255-i*60, 255-i*60, 255-i*60);
      // Dark red
      //   fill(210-(150/triangleRadius)*i, 20, 0);
      // Cross red (makes a more pronounced "cross" effect)
      //   fill(220-(220/triangleRadius)*i, 0, 0);
      // Red cross
      //   fill(255-i*60, 0, 0);
      // Dark blue
      //   fill(0, 0, 255-(255/triangleRadius)*i );
      // Lighter blue
      //   fill(0, 0, random(100,255));
      // Blue cross
      //   fill(0, 0, 255-i*60);
      // Green cross
      //   fill(0, 255-i*60, 0);
      // Yellow cross
      //   fill(255-i*60, 255-i*60, 0);
      // Completely random (stained glass window / rag rug effect)
      // (Warning: kinda lame)
      //   fill(random(255), random(255), random(255));
      //   fill(random(255), random(255), random(255), 110+(100/triangleRadius)*i);
      //   fill(random(255)-i*60, random(255)-i*60, random(255)-i*60);
      //////////////////////////////////////////////
      
      // Split the square into eighths, and have each square in each eighth behave the same
      if (random(randomUpperLimit)<1) {
        rect( (centreCellX+i)*cellW, (centreCellY+j+i)*cellH, cellW, cellH);
        rect( (centreCellX-i)*cellW, (centreCellY+j+i)*cellH, cellW, cellH);
        rect( (centreCellX+i)*cellW, (centreCellY-j-i)*cellH, cellW, cellH);
        rect( (centreCellX-i)*cellW, (centreCellY-j-i)*cellH, cellW, cellH);
        rect( (centreCellX+j+i)*cellW, (centreCellY+i)*cellH, cellW, cellH);
        rect( (centreCellX-j-i)*cellW, (centreCellY+i)*cellH, cellW, cellH);
        rect( (centreCellX+j+i)*cellW, (centreCellY-i)*cellH, cellW, cellH);
        rect( (centreCellX-j-i)*cellW, (centreCellY-i)*cellH, cellW, cellH);
      }
    }
  }
}

//////////////////////////////////////////////////////////////////////