Distance calculation

distance calculation

// "noop" baseline to compare against
start = performance.now();
for (x = 0; x < 1000; x++) {
  for (y = 0; y < 1000; y++) {
  }
}
finish = performance.now();
console.debug("Baseline: " + (finish - start) + "ms");

// Math.sqrt and Math.pow
start = performance.now();
for (x = 0; x < 1000; x++) {
  for (y = 0; y < 1000; y++) {
    Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
  }
}
finish = performance.now();
console.debug("Math.sqrt & Math.pow: " + (finish - start) + "ms");

// Math.sqrt and manual squaring
start = performance.now();
for (x = 0; x < 1000; x++) {
  for (y = 0; y < 1000; y++) {
    Math.sqrt(x*x + y*y);
  }
}
finish = performance.now();
console.debug("Math.sqrt & manual squaring: " + (finish - start) + "ms");

// Math.hypot
start = performance.now();
for (x = 0; x < 1000; x++) {
  for (y = 0; y < 1000; y++) {
    Math.hypot(x, y);
  }
}
finish = performance.now();
console.debug("Math.hypot: " + (finish - start) + "ms");

// without sqrt (not necessary for when comparing distances))
start = performance.now();
for (x = 0; x < 1000; x++) {
  for (y = 0; y < 1000; y++) {
    x*x + y*y;
  }
}
finish = performance.now();
console.debug("Manual squaring and addition: " + (finish - start) + "ms");

// index hypot results and using index
start = performance.now();
t = [];
for (x = 0; x < 1000; x++) {
  t[x] = [];
  for (y = 0; y < 1000; y++) {
    t[x][y] = Math.hypot(x, y);
  }
}
finish = performance.now();
console.debug("Indexed hypot generation: " + (finish - start) + "ms");
start = performance.now();
for (x = 0; x < 1000; x++) {
  for (y = 0; y < 1000; y++) {
    t[x][y];
  }
}
finish = performance.now();
console.debug("Using indexed hypot: " + (finish - start) + "ms");