js: Make update_pixel_ratio() more robust

With very small tile sizes, js_canvas_find_font_midpoint() can throw an
exception.  When it was called from update_pixel_ratio(), this prevented
the new MediaQueryList from being created, which meant that the puzzle
stopped noticing changes of device pixel ratio.

Now update_pixel_ratio() establishes a new MediaQueryList before calling
rescale_puzzle(), so the exception can't break it.  Catching the
exception properly would be even better, of course.

1 files changed, 1 insertions, 1 deletions

diff --git a/emccpre.js b/emccpre.js
index e91a215..6af3350 100644
--- a/emccpre.js
+++ b/emccpre.js
@@ -547,9 +547,9 @@ function initPuzzle() {
         var dpr = window.devicePixelRatio;
         if (mql !== null)
             mql.removeListener(update_pixel_ratio);
-        rescale_puzzle(nominal_width * dpr, nominal_height * dpr);
         mql = window.matchMedia(`(resolution: ${dpr}dppx)`);
         mql.addListener(update_pixel_ratio);
+        rescale_puzzle(nominal_width * dpr, nominal_height * dpr);
     }
 
     Module.onRuntimeInitialized = function() {