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

#include <helianthus.h></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();

}