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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /gfx/layers/AxisPhysicsMSDModel.h
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/layers/AxisPhysicsMSDModel.h')
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diff --git a/gfx/layers/AxisPhysicsMSDModel.h b/gfx/layers/AxisPhysicsMSDModel.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_layers_AxisPhysicsMSDModel_h
+#define mozilla_layers_AxisPhysicsMSDModel_h
+
+#include "AxisPhysicsModel.h"
+
+namespace mozilla {
+namespace layers {
+
+/**
+ * AxisPhysicsMSDModel encapsulates a 1-dimensional MSD (Mass-Spring-Damper)
+ * model. A unit mass is assumed.
+ */
+class AxisPhysicsMSDModel : public AxisPhysicsModel {
+ public:
+ AxisPhysicsMSDModel(double aInitialPosition, double aInitialDestination,
+ double aInitialVelocity, double aSpringConstant,
+ double aDampingRatio);
+
+ virtual ~AxisPhysicsMSDModel();
+
+ /**
+ * Gets the raw destination of this axis at this moment.
+ */
+ double GetDestination() const;
+
+ /**
+ * Sets the raw destination of this axis at this moment.
+ */
+ void SetDestination(double aDestination);
+
+ /**
+ * Returns true when the position is close to the destination and the
+ * velocity is low.
+ */
+ bool IsFinished(double aSmallestVisibleIncrement) const;
+
+ protected:
+ double Acceleration(const State& aState) override;
+
+ private:
+ /**
+ * mDestination represents the target position and the resting position of
+ * the simulated spring.
+ */
+ double mDestination;
+
+ /**
+ * Greater values of mSpringConstant result in a stiffer / stronger spring.
+ */
+ double mSpringConstant;
+
+ /**
+ * mSpringConstantSqrtTimesTwo is calculated from mSpringConstant to reduce
+ * calculations performed in the inner loop.
+ */
+ double mSpringConstantSqrtXTwo;
+
+ /**
+ * Damping Ratio: http://en.wikipedia.org/wiki/Damping_ratio
+ *
+ * When mDampingRatio < 1.0, this is an under damped system.
+ * - Overshoots destination and oscillates with the amplitude gradually
+ * decreasing to zero.
+ *
+ * When mDampingRatio == 1.0, this is a critically damped system.
+ * - Reaches destination as quickly as possible without oscillating.
+ *
+ * When mDampingRatio > 1.0, this is an over damped system.
+ * - Reaches destination (exponentially decays) without oscillating.
+ */
+ double mDampingRatio;
+};
+
+} // namespace layers
+} // namespace mozilla
+
+#endif