git.r.bdr.sh - rbdr/canvas/blob - src/lib/components/sensor.svelte

   1 <script>
   2         import { browser } from '$app/environment';
   3         import { maxSize } from '$lib/config';
   4         import { modulo } from '$lib/math';
   5         import { canvas } from '$lib/stores/canvas';
   6         import { sensor } from '$lib/stores/widgets';
   7
   8         const kSensorSize = 2;
   9
  10         let left;
  11         let right;
  12         let top;
  13         let bottom;
  14
  15         let timer;
  16         const fetchItems = function fetchItems(left, top, right, bottom) {
  17                 clearTimeout(timer);
  18                 timer = setTimeout(() => {
  19                         sensor.set({ left, top, right, bottom });
  20                 }, 50);
  21         };
  22
  23         $: {
  24                 if (browser) {
  25                         left = modulo($canvas.x - window.screen.width * kSensorSize, maxSize);
  26                         top = modulo($canvas.y - window.screen.height * kSensorSize, maxSize);
  27                         right = left + 2 * window.screen.width * kSensorSize;
  28                         bottom = top + 2 * window.screen.height * kSensorSize;
  29
  30                         fetchItems(left, top, right, bottom);
  31                 }
  32         }
  33 </script>