[PATCH] dix: Save touchpoint last coordinates before transform. #49347

[Yuly Novikov]

A touchpoint used to store the entire valuators structure,
and coordinates there were stored post-transformation,
which resulted in Coordinate Transformation Matrix
being applied multiple times to the last coordinates,
in the case when only pressure changes in the last touch event.

This commit gets rid of the valuators, as only X and Y coordinates
are actually used, and stores only the relevant values.
The variable name was changed to indicate
that the values are stored before transformation,
to avoid confusion with last.valuators, which are after transformation.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=49347

Signed-off-by: Yuly Novikov <ynovikov at chromium.org>
---
 dix/devices.c      |    2 --
 dix/getevents.c    |   19 ++++++-------------
 dix/touch.c        |    1 -
 include/inputstr.h |    3 +--
 4 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/dix/devices.c b/dix/devices.c
index 613323f..d23b1b4 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -967,8 +967,6 @@ CloseDevice(DeviceIntPtr dev)
     free(dev->deviceGrab.sync.event);
     free(dev->config_info);     /* Allocated in xf86ActivateDevice. */
     free(dev->last.scroll);
-    for (j = 0; j < dev->last.num_touches; j++)
-        free(dev->last.touches[j].valuators);
     free(dev->last.touches);
     dev->config_info = NULL;
     dixFreePrivates(dev->devPrivates, PRIVATE_DEVICE);
diff --git a/dix/getevents.c b/dix/getevents.c
index 8b4379d..fe60ac3 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -1951,32 +1951,25 @@ GetTouchEvents(InternalEvent *events, DeviceIntPtr dev, uint32_t ddx_touchid,
     default:
         return 0;
     }
-    if (t->mode == XIDirectTouch && !(flags & TOUCH_CLIENT_ID)) {
-        if (!valuator_mask_isset(&mask, 0))
-            valuator_mask_set_double(&mask, 0,
-                                     valuator_mask_get_double(touchpoint.ti->
-                                                              valuators, 0));
-        if (!valuator_mask_isset(&mask, 1))
-            valuator_mask_set_double(&mask, 1,
-                                     valuator_mask_get_double(touchpoint.ti->
-                                                              valuators, 1));
-    }
 
     /* Get our screen event co-ordinates (root_x/root_y/event_x/event_y):
      * these come from the touchpoint in Absolute mode, or the sprite in
      * Relative. */
     if (t->mode == XIDirectTouch) {
-        transformAbsolute(dev, &mask);
 
         if (!(flags & TOUCH_CLIENT_ID)) {
-            for (i = 0; i < valuator_mask_size(&mask); i++) {
+            for (i = 0; i < 2; i++) {
                 double val;
 
                 if (valuator_mask_fetch_double(&mask, i, &val))
-                    valuator_mask_set_double(touchpoint.ti->valuators, i, val);
+                    touchpoint.ti->last_raw_axes[i] = val;
+                else
+                    valuator_mask_set_double(&mask, i,
+                                             touchpoint.ti->last_raw_axes[i]);
             }
         }
 
+        transformAbsolute(dev, &mask);
         clipAbsolute(dev, &mask);
     }
     else {
diff --git a/dix/touch.c b/dix/touch.c
index 5f77be5..5074ec7 100644
--- a/dix/touch.c
+++ b/dix/touch.c
@@ -226,7 +226,6 @@ void
 TouchInitDDXTouchPoint(DeviceIntPtr dev, DDXTouchPointInfoPtr ddxtouch)
 {
     memset(ddxtouch, 0, sizeof(*ddxtouch));
-    ddxtouch->valuators = valuator_mask_new(dev->valuator->numAxes);
 }
 
 Bool
diff --git a/include/inputstr.h b/include/inputstr.h
index 5a38924..c06f9fe 100644
--- a/include/inputstr.h
+++ b/include/inputstr.h
@@ -330,8 +330,7 @@ typedef struct _DDXTouchPointInfo {
     Bool active;                /* whether or not the touch is active */
     uint32_t ddx_id;            /* touch ID given by the DDX */
     Bool emulate_pointer;
-
-    ValuatorMask *valuators;    /* last recorded axis values */
+    double last_raw_axes[2];    /* last X/Y axis valuator data as posted */
 } DDXTouchPointInfoRec;
 
 typedef struct _TouchClassRec {
-- 
1.7.7.3