shithub: puzzles

Info  •  Files  •  Log  •  Branches

js: Distinguish manual resizes from device pixel ratio changes

This adds a new callback, rescale_puzzle(), that's called when the
device pixel ratio changes.  This means that resize_puzzle() can safely
set the nominal canvas size, which means that manual resizing of the
puzzle now sticks.

Still missing: paying attention to the device pixel ratio when choosing
the initial (or reset) size.

--- a/cmake/platforms/emscripten.cmake

+++ b/cmake/platforms/emscripten.cmake

@@ -26,6 +26,8 @@

   # Callbacks when the resizing controls are used

   _resize_puzzle

   _restore_puzzle_size

+  # Callback when device pixel ratio changes

+  _rescale_puzzle

   # Main program, run at initialisation time

   _main)

--- a/emcc.c

+++ b/emcc.c

@@ -195,8 +195,8 @@

     canvas_h = h;

 }

-/* Called from JS when the user uses the resize handle */

-void resize_puzzle(int w, int h)

+/* Called from JS when the device pixel ratio changes */

+void rescale_puzzle(int w, int h)

 {

     midend_size(me, &w, &h, true);

     if (canvas_w != w || canvas_h != h) { 

@@ -205,6 +205,13 @@

         canvas_h = h;

         midend_force_redraw(me);

     }

+}

+

+/* Called from JS when the user uses the resize handle */

+void resize_puzzle(int w, int h)

+{

+    rescale_puzzle(w, h);

+    js_canvas_set_nominal_size();

 }

 /* Called from JS when the user uses the restore button */

--- a/emccpre.js

+++ b/emccpre.js

@@ -535,12 +535,14 @@

      * <https://developer.mozilla.org/en-US/docs/Web/API/Window/

      * devicePixelRatio> (CC0) to work on older browsers.

      */

+    var rescale_puzzle = Module.cwrap('rescale_puzzle',

+                                      'void', ['number', 'number']);

     var mql = null;

     var update_pixel_ratio = function() {

         var dpr = window.devicePixelRatio;

         if (mql !== null)

             mql.removeListener(update_pixel_ratio);

-        resize_puzzle(nominal_width * dpr, nominal_height * dpr);

+        rescale_puzzle(nominal_width * dpr, nominal_height * dpr);

         mql = window.matchMedia(`(resolution: ${dpr}dppx)`);

         mql.addListener(update_pixel_ratio);

     }