shithub: puzzles

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js: Move much of the handling of device pixel ratios to the mid-end

Now that the mid-end knows how to do it, we can remove some complexity
from the front end.

--- a/emcc.c

+++ b/emcc.c

@@ -82,7 +82,6 @@

 extern void js_canvas_make_statusbar(void);

 extern void js_canvas_set_statusbar(const char *text);

 extern void js_canvas_set_size(int w, int h);

-extern void js_canvas_set_nominal_size();

 extern double js_get_device_pixel_ratio();

 extern void js_dialog_init(const char *title);

@@ -184,42 +183,31 @@

  */

 static int canvas_w, canvas_h;

-/* 

- * Called when we resize as a result of changing puzzle settings.

- * "initial" is true if this is the first call, or the first call

- * since a midend_reset_tilesize().  In that case, we might want to

- * adjust the size to compensate for the device pixel ratio.

+/*

+ * Called when we resize as a result of changing puzzle settings

+ * or device pixel ratio.

  */

-static void resize(bool initial)

+static void resize()

 {

     int w, h;

-    double dpr;

     w = h = INT_MAX;

-    midend_size(me, &w, &h, false, 1.0);

-    if (initial) {

-        dpr = js_get_device_pixel_ratio();

-        if (dpr != 1.0) {

-            /*

-             * The default w and h are probably in units of

-             * sensible-sized pixels (~0.25 mm).  Scale them to the

-             * actual device pixels and then ask for a size near

-             * that.

-             */

-            w *= dpr;

-            h *= dpr;

-            midend_size(me, &w, &h, true, 1.0);

-        }

-    }

+    midend_size(me, &w, &h, false, js_get_device_pixel_ratio());

     js_canvas_set_size(w, h);

-    js_canvas_set_nominal_size();

     canvas_w = w;

     canvas_h = h;

 }

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

-void rescale_puzzle(int w, int h)

+void rescale_puzzle()

 {

-    midend_size(me, &w, &h, true, 1.0);

+    resize();

+    midend_force_redraw(me);

+}

+

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

+void resize_puzzle(int w, int h)

+{

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

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

         js_canvas_set_size(w, h);

         canvas_w = w;

@@ -228,18 +216,11 @@

     }

 }

-/* 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 */

 void restore_puzzle_size(int w, int h)

 {

     midend_reset_tilesize(me);

-    resize(true);

+    resize();

     midend_force_redraw(me);

 }

@@ -734,7 +715,7 @@

              */

             select_appropriate_preset();

             midend_new_game(me);

-            resize(false);

+            resize();

             midend_redraw(me);

             free_cfg(cfg);

             js_dialog_cleanup();

@@ -791,7 +772,7 @@

                 assert(i < npresets);

                 midend_set_params(me, presets[i]);

                 midend_new_game(me);

-                resize(false);

+                resize();

                 midend_redraw(me);

                 update_undo_redo();

                 js_focus_canvas();

@@ -915,7 +896,7 @@

         js_error_box(err);

     } else {

         select_appropriate_preset();

-        resize(false);

+        resize();

         midend_redraw(me);

         update_permalinks();

         update_undo_redo();

@@ -957,7 +938,7 @@

      * canvas size appropriately.

      */

     midend_new_game(me);

-    resize(true);

+    resize();

     /*

      * Create a status bar, if needed.

--- a/emcclib.js

+++ b/emcclib.js

@@ -559,22 +559,6 @@

     },

     /*

-     * void js_canvas_set_nominal_size();

-     *

-     * Set the nominal size of the puzzle to the current canvas size

-     * scaled to CSS pixels.  This should be called whenever the

-     * canvas size is changed other than in response to a change of

-     * device pixel ratio.  This nominal size will then be used at

-     * every change of device pixel ratio to calculate the new

-     * physical size of the canvas.

-     */

-    js_canvas_set_nominal_size: function() {

-        var dpr = window.devicePixelRatio || 1;

-        nominal_width = onscreen_canvas.width / dpr;

-        nominal_height = onscreen_canvas.height / dpr;

-    },

-

-    /*

      * double js_get_device_pixel_ratio();

      *

      * Return the current device pixel ratio.

--- a/emccpre.js

+++ b/emccpre.js

@@ -30,12 +30,6 @@

 // by js_canvas_end_draw.

 var update_xmin, update_xmax, update_ymin, update_ymax;

-// Nominal size of the canvas in CSS pixels.  This is set when the

-// canvas is explicitly resized, and used as the basis of calls to

-// midend_size whenever the device pixel ratio changes.  That way

-// changes of zoom levels in browsers will generally be reversible.

-var nominal_width, nominal_height;

-

 // Module object for Emscripten. We fill in these parameters to ensure

 // that Module.run() won't be called until we're ready (we want to do

 // our own init stuff first), and that when main() returns nothing

@@ -540,8 +534,7 @@

      * <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 rescale_puzzle = Module.cwrap('rescale_puzzle', 'void', []);

     var mql = null;

     var update_pixel_ratio = function() {

         var dpr = window.devicePixelRatio;

@@ -549,7 +542,7 @@

             mql.removeListener(update_pixel_ratio);

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

         mql.addListener(update_pixel_ratio);

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

+        rescale_puzzle();

     }

     Module.onRuntimeInitialized = function() {