Modified: trunk/Source/WebCore/ChangeLog (116010 => 116011)
--- trunk/Source/WebCore/ChangeLog 2012-05-03 21:10:34 UTC (rev 116010)
+++ trunk/Source/WebCore/ChangeLog 2012-05-03 21:17:15 UTC (rev 116011)
@@ -1,3 +1,23 @@
+2012-05-03 W. James MacLean <wjmacl...@chromium.org>
+
+ [chromium] Revise touchpad fling curve to use exponential curve, to improve feel and small fling performance.
+ https://bugs.webkit.org/show_bug.cgi?id=85530
+
+ Reviewed by Kenneth Russell.
+
+ Existing unit tests updated for new curve.
+
+ Modifies TouchpadFLingGestureCurve to use an exponential, rather than polynomial, curve.
+ This change appears to improve the overall feel of touchpad fling, and substantially
+ improves small-fling performance.
+
+ * platform/TouchpadFlingPlatformGestureCurve.cpp:
+ (WebCore::TouchpadFlingPlatformGestureCurve::create):
+ (WebCore):
+ (WebCore::position):
+ (WebCore::velocity):
+ (WebCore::TouchpadFlingPlatformGestureCurve::TouchpadFlingPlatformGestureCurve):
+
2012-04-23 Levi Weintraub <le...@chromium.org> and Emil A Eklund <e...@chromium.org>
[meta] Switch away from integers representing pixels for layout/event handling/rendering
Modified: trunk/Source/WebCore/platform/TouchpadFlingPlatformGestureCurve.cpp (116010 => 116011)
--- trunk/Source/WebCore/platform/TouchpadFlingPlatformGestureCurve.cpp 2012-05-03 21:10:34 UTC (rev 116010)
+++ trunk/Source/WebCore/platform/TouchpadFlingPlatformGestureCurve.cpp 2012-05-03 21:17:15 UTC (rev 116011)
@@ -56,9 +56,11 @@
PassOwnPtr<PlatformGestureCurve> TouchpadFlingPlatformGestureCurve::create(const FloatPoint& velocity, IntPoint cumulativeScroll)
{
// The default parameters listed below are a matched set, and should not be changed independently of one another.
- return create(velocity, 1.5395e+01, 2.0466e+04, -2.9899e+04, 2.0577e+04, -5.4966e+03, 1.128445, cumulativeScroll);
+ return create(velocity, -5.70762e+03, 1.72e+02, 3.7e+00, 0, 0, 1.3, cumulativeScroll);
}
+// FIXME: need to remove p3, p4 here and below as they are not used in the exponential curve, but leave in for now to facilitate
+// the in-flight patch for https://bugs.webkit.org/show_bug.cgi?id=81663 .
PassOwnPtr<PlatformGestureCurve> TouchpadFlingPlatformGestureCurve::create(const FloatPoint& velocity, float p0, float p1, float p2, float p3, float p4, float curveDuration, IntPoint cumulativeScroll)
{
return adoptPtr(new TouchpadFlingPlatformGestureCurve(velocity, p0, p1, p2, p3, p4, curveDuration, cumulativeScroll));
@@ -66,12 +68,12 @@
inline double position(double t, float* p)
{
- return p[0] + t * (p[1] + t * (p[2] + t * (p[3] + t * p[4])));
+ return p[0] * exp(-p[2] * t) - p[1] * t - p[0];
}
inline double velocity(double t, float* p)
{
- return p[1] + t * (2 * p[2] + t * (3 * p[3] + t * 4 * p[4]));
+ return -p[0] * p[2] * exp(-p[2] * t) - p[1];
}
TouchpadFlingPlatformGestureCurve::TouchpadFlingPlatformGestureCurve(const FloatPoint& initialVelocity, float p0, float p1, float p2, float p3, float p4, float curveDuration, const IntPoint& cumulativeScroll)
@@ -79,19 +81,20 @@
, m_curveDuration(curveDuration)
{
ASSERT(initialVelocity != FloatPoint::zero());
- m_coeffs[0] = p0;
- m_coeffs[1] = p1;
- m_coeffs[2] = p2;
- m_coeffs[3] = p3;
- m_coeffs[4] = p4;
+ m_coeffs[0] = p0; // alpha
+ m_coeffs[1] = p1; // beta
+ m_coeffs[2] = p2; // gamma
+ m_coeffs[3] = p3; // not used
+ m_coeffs[4] = p4; // not used
+
float maxInitialVelocity = max(fabs(initialVelocity.x()), fabs(initialVelocity.y()));
// Force maxInitialVelocity to lie in the range v(0) to v(curveDuration), and assume that
// the curve parameters define a monotonically decreasing velocity, or else bisection search may
// fail.
- if (maxInitialVelocity > m_coeffs[1])
- maxInitialVelocity = m_coeffs[1];
+ if (maxInitialVelocity > velocity(0, m_coeffs))
+ maxInitialVelocity = velocity(0, m_coeffs);
if (maxInitialVelocity < velocity(m_curveDuration, m_coeffs))
maxInitialVelocity = velocity(m_curveDuration, m_coeffs);
Modified: trunk/Source/WebKit/chromium/ChangeLog (116010 => 116011)
--- trunk/Source/WebKit/chromium/ChangeLog 2012-05-03 21:10:34 UTC (rev 116010)
+++ trunk/Source/WebKit/chromium/ChangeLog 2012-05-03 21:17:15 UTC (rev 116011)
@@ -1,3 +1,12 @@
+2012-05-03 W. James MacLean <wjmacl...@chromium.org>
+
+ [chromium] Revise touchpad fling curve to use exponential curve, to improve feel and small fling performance.
+ https://bugs.webkit.org/show_bug.cgi?id=85530
+
+ Reviewed by Kenneth Russell.
+
+ * tests/PlatformGestureCurveTest.cpp:
+
2012-05-03 Dimitri Glazkov <dglaz...@chromium.org>
[Chromium] Use correct define in the features.gypi
Modified: trunk/Source/WebKit/chromium/tests/PlatformGestureCurveTest.cpp (116010 => 116011)
--- trunk/Source/WebKit/chromium/tests/PlatformGestureCurveTest.cpp 2012-05-03 21:10:34 UTC (rev 116010)
+++ trunk/Source/WebKit/chromium/tests/PlatformGestureCurveTest.cpp 2012-05-03 21:17:15 UTC (rev 116011)
@@ -110,7 +110,7 @@
EXPECT_TRUE(animation->animate(0.45)); // Use non-uniform tick spacing.
EXPECT_TRUE(animation->animate(1));
EXPECT_FALSE(animation->animate(1.5));
- EXPECT_NEAR(target.cumulativeDelta().x(), 1094, 1);
+ EXPECT_NEAR(target.cumulativeDelta().x(), 1193, 1);
EXPECT_EQ(target.cumulativeDelta().y(), 0);
}
