Attachment 65371 Details for Bug 53037 – 0001-dix-work-around-scaling-issues-during-WarpPointer-53.patch

[patch] 0001-dix-work-around-scaling-issues-during-WarpPointer-53.patch

0001-dix-work-around-scaling-issues-during-WarpPointer-53.patch (text/plain), 2.86 KB, created by Peter Hutterer on 2012-08-10 07:43:25 UTC

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Creator: Peter Hutterer

Created: 2012-08-10 07:43:25 UTC

Size: 2.86 KB

patch

obsolete

>From cfced5a235480eba14ae0e169b91b3cfa64e78dc Mon Sep 17 00:00:00 2001
>From: Peter Hutterer <peter.hutterer@who-t.net>
>Date: Wed, 8 Aug 2012 11:34:32 +1000
>Subject: [PATCH] dix: work around scaling issues during WarpPointer (#53037)
>
>In WarpPointer calls, we get input in screen coordinates. They must be
>scaled to device coordinates, and then back to screen coordinates for screen
>crossing and root coordinates in events.
>
>The rounding errors introduced (and clipping in core/XI 1.x events) can lead
>to the actual position being different to the requested input coordinates.
>e.g. 200 scales to 199.9999, truncated to 199 in the event.
>
>Avoid this by simply overwriting the scaled screen coordinates with the
>input coordinates for the POINTER_SCREEN case.
>
>X.Org Bug 53037 <http://bugs.freedesktop.org/show_bug.cgi?id=53037>
>
>Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
>---
> dix/getevents.c | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
>diff --git a/dix/getevents.c b/dix/getevents.c
>index b3bb162..b10be6e 100644
>--- a/dix/getevents.c
>+++ b/dix/getevents.c
>@@ -1327,6 +1327,7 @@ fill_pointer_events(InternalEvent *events, DeviceIntPtr pDev, int type,
>     RawDeviceEvent *raw;
>     double screenx = 0.0, screeny = 0.0;        /* desktop coordinate system */
>     double devx = 0.0, devy = 0.0;      /* desktop-wide in device coords */
>+    int sx, sy;                                 /* for POINTER_SCREEN */
>     ValuatorMask mask;
>     ScreenPtr scr;
> 
>@@ -1369,8 +1370,11 @@ fill_pointer_events(InternalEvent *events, DeviceIntPtr pDev, int type,
>     /* valuators are in driver-native format (rel or abs) */
> 
>     if (flags & POINTER_ABSOLUTE) {
>-        if (flags & POINTER_SCREEN)     /* valuators are in screen coords */
>+        if (flags & POINTER_SCREEN) {    /* valuators are in screen coords */
>+            sx = valuator_mask_get(&mask, 0);
>+            sy = valuator_mask_get(&mask, 1);
>             scale_from_screen(pDev, &mask);
>+        }
> 
>         transformAbsolute(pDev, &mask);
>         clipAbsolute(pDev, &mask);
>@@ -1386,8 +1390,21 @@ fill_pointer_events(InternalEvent *events, DeviceIntPtr pDev, int type,
>         moveRelative(pDev, &mask);
>     }
> 
>+
>     /* valuators are in device coordinate system in absolute coordinates */
>     scale_to_desktop(pDev, &mask, &devx, &devy, &screenx, &screeny);
>+
>+    /* #53037 XWarpPointer's scaling back and forth between screen and
>+       device may leave us with rounding errors. End result is that the
>+       pointer doesn't end up on the pixel it should.
>+       Avoid this by forcing screenx/screeny back to what the input
>+       coordinates were.
>+     */
>+    if (flags & POINTER_SCREEN) {
>+        screenx = sx;
>+        screeny = sy;
>+    }
>+
>     scr = positionSprite(pDev, (flags & POINTER_ABSOLUTE) ? Absolute : Relative,
>                          &mask, &devx, &devy, &screenx, &screeny);
> 
>-- 
>1.7.11.2
>

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