#include <math.h>
#include <helianthus.h>


#define WIDTH    285.0
#define HEIGHT   200.0
#define RES       10.0
#define THIKNESS   0.25
#define ALPHA      0.50

#define DIAMETER  10.0


int cols;
int rows;
double border;


Framebuffer framebuffer;
Animation fbAnim;



void generate() {
  double d = DIAMETER;
  double r = d/2.0;

  saveState();
  target(framebuffer);
  clear();

  zoom(RES);
  translate(WIDTH/2.0, HEIGHT/2.0);
  noFill();
  double c = 1 - ALPHA;
  stroke(colorByRGBA(c, c, c, 1));
  strokeWidth(THIKNESS);

  translate(-(cols-1)*d, -(rows-1)*d);

  double xx = (cols-1)*d*2;
  double yy = (rows-1)*d*2;
  circle( 0,  0, r);
  circle( 0, yy, r);
  circle(xx,  0, r);
  circle(xx, yy, r);

  for(int y = 0; y < rows; ++y) {
    double py = y*d*2 - r;
    for(int x = 1; x < (cols-1)*4; ++x) {
      arc(x*r-d, py, d, d, -120,   0);
      arc(x*r  , py, d, d,   60, 180);
    }
    arc(-r  , py, d, d,  90, 150);
    arc(0   , py, d, d,  60, 120);
    arc(xx-d, py, d, d,-120, -60);
    arc(xx-r, py, d, d, -90, -30);
  }

  for(int x = 0; x < cols; ++x) {
    double px = x*d*2 - r;
    for(int y = 1; y < (rows-1)*4; ++y) {
      arc(px, y*r-d, d, d, -30,  90);
      arc(px, y*r  , d, d, 150, 270);
    }
    arc(px, -r  , d, d, 180, 240);
    arc(px, 0   , d, d, 150, 210);
    arc(px, yy-d, d, d, -30,  30);
    arc(px, yy-r, d, d,   0,  60);
  }

  viewportSave("data/output/generated-round-grid.png");
  restoreState();
}


void init() {
  double border = 2*THIKNESS;
  cols = ((int)floor((WIDTH - 2*border)/DIAMETER + 0.001) + 1)/2;
  rows = ((int)floor((HEIGHT - 2*border)/DIAMETER + 0.001) + 1)/2;

  int w = ceil(WIDTH*RES - 0.001);
  int h = ceil(HEIGHT*RES - 0.001);
  framebuffer = createFramebuffer(w, h);
  fbAnim = createAnimationFromFramebuffer(framebuffer);

  generate();
}


void draw() {
  double w = windowGetWidth();
  double h = windowGetHeight();

  if (keyWentDown("space")) generate();

  saveState();
  translate(w/2, h/2);
  zoom(w/WIDTH);
  fill(COLOR_WHITE);
  noStroke();
  rectTextured(fbAnim, -WIDTH/2.0, -HEIGHT/2.0, WIDTH, HEIGHT);
  restoreState();
}


int main() {
  windowSetVariableFrameRate();
  windowSetResizable(TRUE);
  windowSetInit(&init);
  windowSetDraw(&draw);
  windowRun();
}