#include <stdlib.h></stdlib.h>

#include <math.h></math.h>

#include <helianthus.h></helianthus.h>

int seed;

double t;

const double segmentLength = 5;

const double segmentWidth = 0.05;

const double minWidth = 0.5;

const double branchesPerSegment = 0.2;

const double leafSize = 200;

const double leafPerBranch = 1;

const double leafThreshold = 1 + 200/5*0.05/4*0.5;

double randomRange(double min, double max)

  { return randomFloat()*(max - min) + min; }

double randomIncrement(double deviation)

  { return randomRange(-deviation, deviation); }

double randomAmplifier(double deviation)

  { return randomRange(1 - deviation, 1 + deviation); }

void leaf(double x, double y, double size) {

  double r = 0.5*size;//*randomAmplifier(0.5);

  saveState();

  noStroke();

  circle(x, y, r);

  restoreState();

}

void branch(double x, double y, double angle, double width) {

  double da = sin(t*randomRange(0.5, 1) + randomIncrement(PI));

  saveState();

  while(TRUE) {

    double length = segmentLength * randomAmplifier(0.1);

    double s = sin(angle/180*PI);

    double c = cos(angle/180*PI);

    double nx = x + c*length;

    double ny = y + s*length;

    double nw = width - segmentWidth;

    strokeWidth(width);

    line(x, y, nx, ny);

    if (width > leafThreshold && nw <= leafThreshold && randomFloat() < leafPerBranch && y > leafSize/2) {

      double dl = randomRange(0, length);

      leaf(x + c*dl, y + s*dl, leafSize);

    }

    if (width < minWidth || ny < 0)

      break;

    x = nx;

    y = ny;

    s += randomRange(0, 0.2);

    c += randomIncrement(0.15);

    angle = atan2(s, c)/PI*180;

    width -= segmentWidth;

    translate(x, y);

    rotate(da*pow(minWidth/width, 2));

    translate(-x, -y);

    if (randomFloat() < branchesPerSegment) {

      double k = randomRange(0.1, 0.3);

      double w = sqrt(width*width*k);

      if (w > minWidth) {

        width = sqrt(width*width*(1-k));

        double a = randomNumber(0, 1) ? angle - 90 + randomRange(0, 45)

                                      : angle + 90 - randomRange(0, 45);

        branch(x, y, a, w);

      }

    }

  }

  restoreState();

}

void tree(int seed, double x, double y, double width) {

  srand(seed);

  double angle = 90 + randomIncrement(30);

  width *= randomAmplifier(0.5);

  int s = randomNumber(0, 1000000);

  saveState();

  noStroke();

  srand(s);

  branch(x, y, angle, width);

  restoreState();

  saveState();

  noFill();

  srand(s);

  branch(x, y, angle, width);

  restoreState();

}

void init() {

  seed = randomNumber(0, 1000000);

}

void draw() {

  double w = windowGetWidth();

  double h = windowGetHeight();

  t += windowGetFrameTime();

  if (keyWentDown("space")) seed = randomNumber(0, 1000000);

  saveState();

  translate(w/2, h*0.9);

  scale(1, -1);

  fill(colorByName("green"));

  stroke(colorByName("black"));

  tree(seed, 0, 0, 20);

  restoreState();

}

int main() {

  windowSetVariableFrameRate();

  windowSetResizable(TRUE);

  windowSetInit(&init);

  windowSetDraw(&draw);

  windowRun();

}