#include <math.h>

#include <helianthus.h>

#define WIDTH  1024

#define HEIGHT  768

#define SIZE    100

#define COUNT   100

typedef struct {

  double x, y, s, r, rk;

} Rect;

Framebuffer fb;

Animation anim;

Rect rects[COUNT];

int id;

void generateRect(Rect *r) {

  r->x = randomFloat();

  r->y = randomFloat();

  r->s = randomFloat();

  r->r = randomFloat();

  r->rk = randomFloat()*2 - 1;

}

void drawRect(Rect *r, double a) {

  a = (1 - cos(a*PI))/2;

  double s = r->s * a * SIZE * ((mouseX() - WIDTH / 2) + (mouseY() - HEIGHT / 2))/100;

  double rot = a*r->rk*180 + r->r*360;

  saveState();

  //stroke(colorByRGBA(0, 0, 0, a));

  fill(colorByHSVA(r->x*360, 1, 1, a));

  translate(r->x*WIDTH, r->y*HEIGHT);

  rotate(rot);

  rect(-s/2, -s/2, s, s);

  restoreState();

}

void init() {

  fb = createFramebuffer(WIDTH, HEIGHT);

  anim = createAnimationFromFramebuffer(fb);

  for(int i = 0; i < COUNT; ++i)

    generateRect(&rects[i]);

  saveState();

  target(fb);

  clear();

  restoreState();

}

void draw() {

  saveState();

  noStroke();

  rectTextured(anim, 0, 0, WIDTH, HEIGHT);

  for(int i = 0; i < COUNT; ++i)

    drawRect(&rects[(id + i)%COUNT], 1.0 - (double)i/COUNT);

  target(fb);

  drawRect(&rects[id], 1.0);

  generateRect(&rects[id]);

  id = (id + 1)%COUNT;

  restoreState();

}

int main() {

  windowSetVariableFrameRate();

  windowSetSize(WIDTH, HEIGHT);

  windowSetInit(&init);

  windowSetDraw(&draw);

  windowRun();

}