int lim = 3;

void fliesen(int a, int b, int t) {
  int i, j, x, y;
  background(0);
  x = a / t;
  y = b / t;
  if (t >= lim) {
    stroke(100, 100, 100);
    fill(0, 255, 0);
    for (i=0; i<x; i++) {
      for (j=0; j<y; j++) {
        rect(i*t, j*t, t, t);
      }
    }
  } 
  else {
    noStroke();
    fill(255, 0, 0);
    rect(0, 0, a, b);
  }
  //println(a + " " + b + " " + t);
}

void balken(int a, int b, int t) {
  int i, x, y;
  background(255);
  x = a / t;
  y = b / t;

  stroke(200, 200, 200);
  line(a, 0, a, width);
  line(b, 0, b, width);

  stroke(100, 100, 100);
  fill(255, 0, 0);
  rect(0, 20, a, 10);
  rect(0, 60, b, 10);

  textFont(font, 12); 
  fill(0, 0, 0);
  text(a, 10, 15);
  text(b, 10, 55);

  if (t >= lim) {
    text(t, 10, 95);
    fill(0, 255, 0);
    for (i=0; i<x; i++)
      rect(i*t, 30, t, 10);
    for (i=0; i<y; i++)
      rect(i*t, 70, t, 10);
  }
}

void schwingung(int a, int b, int t) {
  int x;
  background(255);
  textFont(font, 12); 
  fill(0, 0, 0);
  int y_axis = height/2;
  stroke(200, 200, 200);
  line(0, y_axis, width, y_axis);

  for (x = 0; x <= width; x = x + a) {
    stroke(0, 150, 150);
    drawSinus(x, y_axis, a, a/2);
    stroke(200, 200, 200);
    line(x+a, 0, x+a, width);
  }
  
  for (x = 0; x <= width; x = x + b) {
    stroke(150, 0, 150);
    drawSinus(x, y_axis, b, b/2);
    stroke(200, 200, 200);
    line(x+b, 0, x+b, width);
  }

  if (t >= lim) {
    stroke(0, 0, 0);
    for (x = 0; x <= width; x = x + t)
      drawSinus(x, y_axis, t, t/2);
    text("a="+a+", b="+b+", ggt="+t, 10, height-15);
  } else {
    text("a="+a+", b="+b, 10, height-15);
  }
}

void drawSinus(int startX, int startY, int wlen, int amp) {
  int x, y;
  for (x = 0; x <= wlen ; x = x + 1) {
    y = -int(amp * cos(6.28 * float(x)/wlen));
    point(startX+x, startY+y);
  }
}