Timer.html 2.9 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109
  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <meta charset="utf-8" />
  5. <base href="../../../" />
  6. <script src="page.js"></script>
  7. <link type="text/css" rel="stylesheet" href="page.css" />
  8. </head>
  9. <body>
  10. <h1>[name]</h1>
  11. <p class="desc">
  12. This class is an alternative to [page:Clock] with a different API design and behavior.
  13. The goal is to avoid the conceptual flaws that became apparent in [page:Clock] over time.
  14. <ul>
  15. <li>[name] has an [page:.update]() method that updates its internal state. That makes it possible to call [page:.getDelta]() and [page:.getElapsed]() multiple times per simulation step without getting different values.</li>
  16. <li>The class uses the Page Visibility API to avoid large time delta values when the app is inactive (e.g. tab switched or browser hidden).</li>
  17. </ul>
  18. </p>
  19. <h2>Import</h2>
  20. <p>
  21. [name] is an add-on, and must be imported explicitly.
  22. See [link:#manual/introduction/Installation Installation / Addons].
  23. </p>
  24. <code>
  25. import { Timer } from 'three/addons/misc/Timer.js';
  26. </code>
  27. <h2>Code Example</h2>
  28. <code>
  29. const timer = new Timer();
  30. function animate( timestamp ) {
  31. requestAnimationFrame( animate );
  32. // timestamp is optional
  33. timer.update( timestamp );
  34. const delta = timer.getDelta();
  35. // do something with delta
  36. renderer.render( scene, camera );
  37. }
  38. </code>
  39. <h2>Examples</h2>
  40. <p>
  41. [example:webgl_morphtargets_sphere WebGL / morphtargets / sphere]
  42. </p>
  43. <h2>Constructor</h2>
  44. <h3>Timer()</h3>
  45. <h2>Methods</h2>
  46. <h3>[method:Number getDelta]()</h3>
  47. <p>
  48. Returns the time delta in seconds.
  49. </p>
  50. <h3>[method:Number getElapsed]()</h3>
  51. <p>
  52. Returns the elapsed time in seconds.
  53. </p>
  54. <h3>[method:this setTimescale]( [param:Number timescale] )</h3>
  55. <p>
  56. Sets a time scale that scales the time delta in [page:.update]().
  57. </p>
  58. <h3>[method:this reset]()</h3>
  59. <p>
  60. Resets the time computation for the current simulation step.
  61. </p>
  62. <h3>[method:this dispose]()</h3>
  63. <p>
  64. Can be used to free all internal resources. Usually called when the timer instance isn't required anymore.
  65. </p>
  66. <h3>[method:this update]( [param:Number timestamp] )</h3>
  67. <p>
  68. timestamp -- (optional) The current time in milliseconds. Can be obtained from the
  69. [link:https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame requestAnimationFrame]
  70. callback argument. If not provided, the current time will be determined with
  71. [link:https://developer.mozilla.org/en-US/docs/Web/API/Performance/now performance.now].<br /><br />
  72. Updates the internal state of the timer. This method should be called once per simulation step
  73. and before you perform queries against the timer (e.g. via [page:.getDelta]()).
  74. </p>
  75. <h2>Source</h2>
  76. <p>
  77. [link:https://github.com/mrdoob/three.js/blob/master/examples/jsm/misc/Timer.js examples/jsm/misc/Timer.js]
  78. </p>
  79. </body>
  80. </html>