xserver: Branch 'master'

[Keith Packard]

 dix/ptrveloc.c     |   28 +++++++++++++++++++++++++++-
 include/ptrveloc.h |    3 ++-
 2 files changed, 29 insertions(+), 2 deletions(-)

New commits:
commit 1763550d0181ac1c775b9ddf490114eff2fbe67e
Author: Simon Thum <simon.thum at gmx.de>
Date:   Fri Jan 1 19:58:05 2010 +0100

    dix: add smooth limited pointer acceleration profile
    
    This profile is inspired by the accel code removed from the wacom driver.
    It ascends from zero to acceleration, maxing out at threshold. This means you
    can control the slope using threshold, which wasn't possible in wacom.
    For sanity's sake, threshold should grow with acceleration.
    
    Works best with adaptive deceleration, since otherwise it only generates
    acceleration above 1, causing seldom pixel skips.
    
    Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
    Signed-off-by: Keith Packard <keithp at keithp.com>

diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c
index 6fb9e21..c2f4378 100644
--- a/dix/ptrveloc.c
+++ b/dix/ptrveloc.c
@@ -868,6 +868,31 @@ SmoothLinearProfile(
 }
 
 
+/**
+ * From 0 to threshold, the response graduates smoothly from min_accel to
+ * acceleration. Beyond threshold it is exactly the specified acceleration.
+ */
+static float
+SmoothLimitedProfile(
+    DeviceIntPtr dev,
+    DeviceVelocityPtr vel,
+    float velocity,
+    float threshold,
+    float acc)
+{
+    float res;
+
+    if(velocity >= threshold || threshold == 0.0f)
+	return acc;
+
+    velocity /= threshold; /* should be [0..1[ now */
+
+    res = CalcPenumbralGradient(velocity) * (acc - vel->min_acceleration);
+
+    return vel->min_acceleration + res;
+}
+
+
 static float
 LinearProfile(
     DeviceIntPtr dev,
@@ -879,7 +904,6 @@ LinearProfile(
     return acc * velocity;
 }
 
-
 static float
 NoProfile(
     DeviceIntPtr dev,
@@ -911,6 +935,8 @@ GetAccelerationProfile(
             return PowerProfile;
         case AccelProfileLinear:
             return LinearProfile;
+        case AccelProfileSmoothLimited:
+            return SmoothLimitedProfile;
         case AccelProfileNone:
             return NoProfile;
         default:
diff --git a/include/ptrveloc.h b/include/ptrveloc.h
index 2a4b40b..676c464 100644
--- a/include/ptrveloc.h
+++ b/include/ptrveloc.h
@@ -37,7 +37,8 @@
 #define AccelProfileSimple 4
 #define AccelProfilePower 5
 #define AccelProfileLinear 6
-#define AccelProfileLAST AccelProfileLinear
+#define AccelProfileSmoothLimited 7
+#define AccelProfileLAST AccelProfileSmoothLimited
 
 /* fwd */
 struct _DeviceVelocityRec;