Index: webkit/child/touch_fling_gesture_curve.cc |
diff --git a/webkit/child/touch_fling_gesture_curve.cc b/webkit/child/touch_fling_gesture_curve.cc |
deleted file mode 100644 |
index 274dcaa355b1a53e173a14766db48e2096cffdfd..0000000000000000000000000000000000000000 |
--- a/webkit/child/touch_fling_gesture_curve.cc |
+++ /dev/null |
@@ -1,163 +0,0 @@ |
-// Copyright (c) 2012 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "webkit/child/touch_fling_gesture_curve.h" |
- |
-#include <cmath> |
- |
-#include "base/debug/trace_event.h" |
-#include "base/logging.h" |
-#include "third_party/WebKit/public/platform/WebFloatPoint.h" |
-#include "third_party/WebKit/public/platform/WebFloatSize.h" |
-#include "third_party/WebKit/public/platform/WebGestureCurve.h" |
-#include "third_party/WebKit/public/platform/WebGestureCurveTarget.h" |
-#include "third_party/WebKit/public/platform/WebSize.h" |
- |
-using WebKit::WebFloatPoint; |
-using WebKit::WebFloatSize; |
-using WebKit::WebGestureCurve; |
-using WebKit::WebGestureCurveTarget; |
-using WebKit::WebSize; |
- |
-namespace { |
- |
-const char* kCurveName = "TouchFlingGestureCurve"; |
- |
-inline double position(double t, float* p) { |
- return p[0] * exp(-p[2] * t) - p[1] * t - p[0]; |
-} |
- |
-inline double velocity(double t, float* p) { |
- return -p[0] * p[2] * exp(-p[2] * t) - p[1]; |
-} |
- |
-inline double timeAtVelocity(double v, float* p) { |
- DCHECK(p[0]); |
- DCHECK(p[2]); |
- return -log((v + p[1]) / (-p[0] * p[2])) / p[2]; |
-} |
- |
-} // namespace |
- |
- |
-namespace webkit_glue { |
- |
-// This curve implementation is based on the notion of a single, absolute |
-// curve, which starts at a large velocity and smoothly decreases to |
-// zero. For a given input velocity, we find where on the curve this |
-// velocity occurs, and start the animation at this point---denoted by |
-// (time_offset_, position_offset_). |
-// |
-// This has the effect of automatically determining an animation duration |
-// that scales with input velocity, as faster initial velocities start |
-// earlier on the curve and thus take longer to reach the end. No |
-// complicated time scaling is required. |
-// |
-// Since the starting velocity is implicitly determined by our starting |
-// point, we only store the relative magnitude and direction of both |
-// initial x- and y-velocities, and use this to scale the computed |
-// displacement at any point in time. This guarantees that fling |
-// trajectories are straight lines when viewed in x-y space. Initial |
-// velocities that lie outside the max velocity are constrained to start |
-// at zero (and thus are implicitly scaled). |
-// |
-// The curve is modelled as a 4th order polynomial, starting at t = 0, |
-// and ending at t = curve_duration_. Attempts to generate |
-// position/velocity estimates outside this range are undefined. |
- |
-WebGestureCurve* TouchFlingGestureCurve::Create( |
- const WebFloatPoint& initial_velocity, |
- float p0, |
- float p1, |
- float p2, |
- const WebSize& cumulative_scroll) { |
- return new TouchFlingGestureCurve(initial_velocity, p0, p1, p2, |
- cumulative_scroll); |
-} |
- |
-TouchFlingGestureCurve::TouchFlingGestureCurve( |
- const WebFloatPoint& initial_velocity, |
- float alpha, |
- float beta, |
- float gamma, |
- const WebSize& cumulative_scroll) |
- : cumulative_scroll_(WebFloatSize(cumulative_scroll.width, |
- cumulative_scroll.height)) { |
- DCHECK(initial_velocity != WebFloatPoint()); |
- |
- coefficients_[0] = alpha; |
- coefficients_[1] = beta; |
- coefficients_[2] = gamma; |
- |
- // Curve ends when velocity reaches zero. |
- curve_duration_ = timeAtVelocity(0, coefficients_); |
- DCHECK(curve_duration_ > 0); |
- |
- float max_start_velocity = std::max(fabs(initial_velocity.x), |
- fabs(initial_velocity.y)); |
- |
- // Force max_start_velocity to lie in the range v(0) to v(curve_duration), |
- // and assume that the curve parameters define a monotonically decreasing |
- // velocity, or else bisection search may fail. |
- if (max_start_velocity > velocity(0, coefficients_)) |
- max_start_velocity = velocity(0, coefficients_); |
- |
- if (max_start_velocity < 0) |
- max_start_velocity = 0; |
- |
- // We keep track of relative magnitudes and directions of the |
- // velocity/displacement components here. |
- displacement_ratio_ = WebFloatPoint(initial_velocity.x / max_start_velocity, |
- initial_velocity.y / max_start_velocity); |
- |
- // Compute time-offset for start velocity. |
- time_offset_ = timeAtVelocity(max_start_velocity, coefficients_); |
- |
- // Compute curve position at offset time |
- position_offset_ = position(time_offset_, coefficients_); |
- TRACE_EVENT_ASYNC_BEGIN1("input", "GestureAnimation", this, "curve", |
- kCurveName); |
-} |
- |
-TouchFlingGestureCurve::~TouchFlingGestureCurve() { |
- TRACE_EVENT_ASYNC_END0("input", "GestureAnimation", this); |
-} |
- |
-bool TouchFlingGestureCurve::apply(double time, WebGestureCurveTarget* target) { |
- float displacement; |
- float speed; |
- if (time < 0) { |
- displacement = 0.f; |
- speed = 0.f; |
- } else if (time + time_offset_ < curve_duration_) { |
- displacement = |
- position(time + time_offset_, coefficients_) - position_offset_; |
- speed = velocity(time + time_offset_, coefficients_); |
- } else { |
- displacement = position(curve_duration_, coefficients_) - position_offset_; |
- speed = 0.f; |
- } |
- |
- // Keep track of integer portion of scroll thus far, and prepare increment. |
- WebFloatSize scroll(displacement * displacement_ratio_.x, |
- displacement * displacement_ratio_.y); |
- WebFloatSize scroll_increment(scroll.width - cumulative_scroll_.width, |
- scroll.height - cumulative_scroll_.height); |
- WebFloatSize scroll_velocity(speed * displacement_ratio_.x, |
- speed * displacement_ratio_.y); |
- cumulative_scroll_ = scroll; |
- |
- if (time + time_offset_ < curve_duration_ || |
- scroll_increment != WebFloatSize()) { |
- target->notifyCurrentFlingVelocity(scroll_velocity); |
- // scrollBy() could delete this curve if the animation is over, so don't |
- // touch any member variables after making that call. |
- target->scrollBy(scroll_increment); |
- return true; |
- } |
- |
- return false; |
-} |
- |
-} // namespace webkit_glue |