Modified: trunk/Source/WebCore/ChangeLog (111482 => 111483)
--- trunk/Source/WebCore/ChangeLog 2012-03-21 02:00:19 UTC (rev 111482)
+++ trunk/Source/WebCore/ChangeLog 2012-03-21 02:06:12 UTC (rev 111483)
@@ -1,3 +1,20 @@
+2012-03-20 W. James MacLean <[email protected]>
+
+ [chromium] Convert TouchFlingPlatformGestureCurve to a 2-D Bezier for better control of curve shape.
+ https://bugs.webkit.org/show_bug.cgi?id=81713
+
+ Reviewed by Dirk Pranke.
+
+ Exisiting unit test revised to cover this change.
+
+ Change the fling gesture animation curve to use a 2-D Bezier to obtain greater control
+ over the shape of the curve. Also, change time scaling code to be logarithmic for more
+ natural feel.
+
+ * platform/TouchFlingPlatformGestureCurve.cpp:
+ (WebCore::TouchFlingPlatformGestureCurve::TouchFlingPlatformGestureCurve):
+ (WebCore::TouchFlingPlatformGestureCurve::apply):
+
2012-03-18 Tim Horton <[email protected]>
Infinite repaint loop with SVGImageCache and deferred repaint timers
Modified: trunk/Source/WebCore/platform/TouchFlingPlatformGestureCurve.cpp (111482 => 111483)
--- trunk/Source/WebCore/platform/TouchFlingPlatformGestureCurve.cpp 2012-03-21 02:00:19 UTC (rev 111482)
+++ trunk/Source/WebCore/platform/TouchFlingPlatformGestureCurve.cpp 2012-03-21 02:06:12 UTC (rev 111483)
@@ -27,6 +27,7 @@
#include "TouchFlingPlatformGestureCurve.h"
#include "PlatformGestureCurveTarget.h"
+#include "UnitBezier.h"
#include <math.h>
namespace WebCore {
@@ -40,7 +41,7 @@
TouchFlingPlatformGestureCurve::TouchFlingPlatformGestureCurve(const FloatPoint& velocity)
: m_velocity(velocity)
- , m_timeScaleFactor(1000 / max(1.f, max(fabs(velocity.x()), fabs(velocity.y()))))
+ , m_timeScaleFactor(3 / log10(max(10.f, max(fabs(velocity.x()), fabs(velocity.y())))))
{
ASSERT(velocity != FloatPoint::zero());
}
@@ -51,26 +52,21 @@
bool TouchFlingPlatformGestureCurve::apply(double time, PlatformGestureCurveTarget* target)
{
- // Here we implement a cubic bezier curve with parameters [p0 p1 p2 p3] = [1 (3 + 1/tau) 0 0] which gives
- // v(0) = 1, a(0) = v(0)/tau, v(1) = 0, a(1) = 0. The curve is scaled by the initial
- // velocity, and the time parameter is re-scaled so that larger initial velocities
- // lead to longer initial animations. This should allow the animation to smoothly
- // continue the velocity at the end of the GestureScroll, and smoothly come to a rest
- // at the end. Finally, we have integrated the curve so we can deal with displacement
- // as a function of time, and not velocity.
+ // Use 2-D Bezier curve with a "stretched-italic-s" curve.
+ // We scale time logarithmically as this (subjectively) feels better.
time *= m_timeScaleFactor;
- static double tau = 0.25;
- static double p1 = 3.0 + 1 / tau;
- // Note: "displacement" below is the integral of the cubic bezier curve defined by [p0 p1 p2 p3].
+ static UnitBezier flingBezier(0.3333, 0.6666, 0.6666, 1);
float displacement;
if (time < 0)
displacement = 0;
- else if (time < 1)
- displacement = time * (time * (time * (time * 0.25 * (3 * p1 - 1.0) + (1 - 2 * p1)) + 1.5 * (p1 - 1)) + 1) / m_timeScaleFactor;
- else
- displacement = (1 + (p1 - 1) * 1.5 + (1 - 2 * p1) + (3 * p1 - 1) * 0.25) / m_timeScaleFactor;
+ else if (time < 1) {
+ // Below, s is the curve parameter for the 2-D Bezier curve (time(s), displacement(s)).
+ double s = flingBezier.solveCurveX(time, 1.e-3);
+ displacement = flingBezier.sampleCurveY(s);
+ } else
+ displacement = 1;
// Keep track of integer portion of scroll thus far, and prepare increment.
IntPoint scroll(displacement * m_velocity.x(), displacement * m_velocity.y());
Modified: trunk/Source/WebKit/chromium/ChangeLog (111482 => 111483)
--- trunk/Source/WebKit/chromium/ChangeLog 2012-03-21 02:00:19 UTC (rev 111482)
+++ trunk/Source/WebKit/chromium/ChangeLog 2012-03-21 02:06:12 UTC (rev 111483)
@@ -1,3 +1,12 @@
+2012-03-20 W. James MacLean <[email protected]>
+
+ [chromium] Convert TouchFlingPlatformGestureCurve to a 2-D Bezier for better control of curve shape.
+ https://bugs.webkit.org/show_bug.cgi?id=81713
+
+ Reviewed by Dirk Pranke.
+
+ * tests/PlatformGestureCurveTest.cpp:
+
2012-03-20 Dana Jansens <[email protected]>
[chromium] Allow us to disable overdraw metrics when tracing is off
Modified: trunk/Source/WebKit/chromium/tests/PlatformGestureCurveTest.cpp (111482 => 111483)
--- trunk/Source/WebKit/chromium/tests/PlatformGestureCurveTest.cpp 2012-03-21 02:00:19 UTC (rev 111482)
+++ trunk/Source/WebKit/chromium/tests/PlatformGestureCurveTest.cpp 2012-03-21 02:06:12 UTC (rev 111483)
@@ -100,7 +100,7 @@
TEST(PlatformGestureCurve, flingCurveTouch)
{
double initialVelocity = 1000;
- const double touchFlingCurveAreaFactor = 2; // Depends on value of tau in TouchFlingPlatformGestureCurve.
+ const double touchFlingCurveAreaFactor = 1; // Depends on parameterization in TouchFlingPlatformGestureCurve.
MockPlatformGestureCurveTarget target;
OwnPtr<ActivePlatformGestureAnimation> animation = ActivePlatformGestureAnimation::create(TouchFlingPlatformGestureCurve::create(FloatPoint(initialVelocity, 0)), &target);
