master c609865258 3/3: Accumulate deltas in pinch events that were skipped

[Po Lu]

branch: master
commit c609865258dbd16caf84e96c63db11a52c1d1cb5
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Accumulate deltas in pinch events that were skipped
    
    * src/keyboard.c (kbd_buffer_get_event): Accumulate relative deltas
    inside skipped events when coalescing them.
---
 src/keyboard.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/keyboard.c b/src/keyboard.c
index 304dff4a91..8b85911cc4 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -65,6 +65,7 @@ along with GNU Emacs.  If not, see 
<https://www.gnu.org/licenses/>.  */
 #include <sys/types.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <math.h>
 
 #include <ignore-value.h>
 
@@ -4037,6 +4038,8 @@ kbd_buffer_get_event (KBOARD **kbp,
             and build a real event from the queue entry.  */
          if (NILP (obj))
            {
+             double pinch_dx, pinch_dy, pinch_angle;
+
              /* Pinch events are often sent in rapid succession, so
                 large amounts of such events have the potential to
                 queue up inside the keyboard buffer.  In that case,
@@ -4048,11 +4051,16 @@ kbd_buffer_get_event (KBOARD **kbp,
                     These events should always be sent so that we
                     never miss a sequence starting, and they don't
                     have the potential to queue up.  */
-                 && (XFLOAT_DATA (XCAR (event->ie.arg)) != 0.0
+                 && ((pinch_dx
+                      = XFLOAT_DATA (XCAR (event->ie.arg))) != 0.0
                      || XFLOAT_DATA (XCAR (XCDR (event->ie.arg))) != 0.0
-                     || XFLOAT_DATA (XCAR (XCDR (XCDR (event->ie.arg)))) != 
1.0))
+                     || XFLOAT_DATA (Fnth (make_fixnum (3), event->ie.arg)) != 
0.0))
                {
                  union buffered_input_event *maybe_event = next_kbd_event 
(event);
+
+                 pinch_dy = XFLOAT_DATA (XCAR (XCDR (event->ie.arg)));
+                 pinch_angle = XFLOAT_DATA (Fnth (make_fixnum (3), 
event->ie.arg));
+
                  while (maybe_event != kbd_store_ptr
                         && maybe_event->ie.kind == PINCH_EVENT
                         /* Make sure we never miss an event that has
@@ -4066,9 +4074,21 @@ kbd_buffer_get_event (KBOARD **kbp,
                            of a new pinch gesture sequence.  */
                         && (XFLOAT_DATA (XCAR (maybe_event->ie.arg)) != 0.0
                             || XFLOAT_DATA (XCAR (XCDR (maybe_event->ie.arg))) 
!= 0.0
-                            || XFLOAT_DATA (XCAR (XCDR (XCDR 
(maybe_event->ie.arg)))) != 1.0))
+                            || XFLOAT_DATA (Fnth (make_fixnum (3),
+                                                  maybe_event->ie.arg)) != 
0.0))
                    {
                      event = maybe_event;
+                     /* Add up relative deltas inside events we skip.  */
+                     pinch_dx += XFLOAT_DATA (XCAR (maybe_event->ie.arg));
+                     pinch_dy += XFLOAT_DATA (XCAR (XCDR 
(maybe_event->ie.arg)));
+                     pinch_angle += XFLOAT_DATA (Fnth (make_fixnum (3),
+                                                       maybe_event->ie.arg));
+
+                     XSETCAR (maybe_event->ie.arg, make_float (pinch_dx));
+                     XSETCAR (XCDR (maybe_event->ie.arg), make_float 
(pinch_dy));
+                     XSETCAR (Fnthcdr (make_fixnum (3),
+                                       maybe_event->ie.arg),
+                              make_float (fmod (pinch_angle, 360.0)));
                      maybe_event = next_kbd_event (event);
                    }
                }