Merge lp:~alan-griffiths/miral/an-alternative-touch-resize-algorithm into lp:miral

[Alan Griffiths]

Copy the touch resize logic used by mir_proving_server

An experiment - I don't have a good approach to touch resize yet.

Seeking on whether this is an improvement.

Unmerged revisions

183. By Alan Griffiths on 2016-06-02

Delete debug code

182. By Alan Griffiths on 2016-06-02

Try the touch resize logic used by mir_proving_server

=== modified file 'miral-shell/canonical_window_manager.cpp'
--- miral-shell/canonical_window_manager.cpp	2016-06-02 16:19:39 +0000
+++ miral-shell/canonical_window_manager.cpp	2016-06-02 16:19:39 +0000
@@ -630,20 +630,46 @@
         }
     }
 
+    int touch_pinch_size = 0;
+    Displacement pinch_delta;
+
+    for (auto i = 0U; i != count; ++i)
+    {
+        for (auto j = 0U; j != i; ++j)
+        {
+            int dx = mir_touch_event_axis_value(event, i, mir_touch_axis_x) -
+                     mir_touch_event_axis_value(event, j, mir_touch_axis_x);
+
+            int dy = mir_touch_event_axis_value(event, i, mir_touch_axis_y) -
+                     mir_touch_event_axis_value(event, j, mir_touch_axis_y);
+
+            int size = dx*dx + dy*dy;
+
+            if (touch_pinch_size < size)
+            {
+                touch_pinch_size = size;
+                pinch_delta = Displacement{dx, dy};
+            }
+        }
+    }
+
     bool consumes_event = false;
     if (is_drag)
     {
-        switch (count)
+        if (count == 3)
         {
-        case 4:
-            resize(cursor);
-            consumes_event = true;
-            break;
-
-        case 3:
             drag(cursor);
+
+            if (auto window = tools->active_window())
+            {
+                auto const numerator = sqrtf(touch_pinch_size) - sqrtf(old_touch_pinch_size);
+                auto const denominator = sqrtf(pinch_delta.length_squared());
+                auto const displacement = (numerator / denominator) * pinch_delta;
+                auto const new_size = as_displacement(window.size()) + displacement;
+
+                apply_resize(tools->info_for(window), window.top_left(), as_size(new_size));
+            }
             consumes_event = true;
-            break;
         }
     }
     else
@@ -653,6 +679,7 @@
     }
 
     old_cursor = cursor;
+    old_touch_pinch_size = touch_pinch_size;
     return consumes_event;
 }
 

=== modified file 'miral-shell/canonical_window_manager.h'
--- miral-shell/canonical_window_manager.h	2016-06-02 10:03:55 +0000
+++ miral-shell/canonical_window_manager.h	2016-06-02 16:19:39 +0000
@@ -108,6 +108,7 @@
     bool resizing = false;
     bool left_resize = false;
     bool top_resize  = false;
+    long long old_touch_pinch_size = 0;
 };
 
 #endif /* MIRAL_SHELL_CANONICAL_WINDOW_MANAGER_H_ */