widget/gonk/libui/VelocityControl.cpp@6474c204b198 (annotated)
widget/gonk/libui/VelocityControl.cpp
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* |
| michael@0 | 2 | * Copyright (C) 2012 The Android Open Source Project |
| michael@0 | 3 | * |
| michael@0 | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| michael@0 | 5 | * you may not use this file except in compliance with the License. |
| michael@0 | 6 | * You may obtain a copy of the License at |
| michael@0 | 7 | * |
| michael@0 | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| michael@0 | 9 | * |
| michael@0 | 10 | * Unless required by applicable law or agreed to in writing, software |
| michael@0 | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| michael@0 | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| michael@0 | 13 | * See the License for the specific language governing permissions and |
| michael@0 | 14 | * limitations under the License. |
| michael@0 | 15 | */ |
| michael@0 | 16 | |
| michael@0 | 17 | #define LOG_TAG "VelocityControl" |
| michael@0 | 18 | //#define LOG_NDEBUG 0 |
| michael@0 | 19 | |
| michael@0 | 20 | // Log debug messages about acceleration. |
| michael@0 | 21 | #define DEBUG_ACCELERATION 0 |
| michael@0 | 22 | |
| michael@0 | 23 | #include <math.h> |
| michael@0 | 24 | #include <limits.h> |
| michael@0 | 25 | |
| michael@0 | 26 | #include "VelocityControl.h" |
| michael@0 | 27 | #include <utils/BitSet.h> |
| michael@0 | 28 | #include <utils/Timers.h> |
| michael@0 | 29 | |
| michael@0 | 30 | namespace android { |
| michael@0 | 31 | |
| michael@0 | 32 | // --- VelocityControl --- |
| michael@0 | 33 | |
| michael@0 | 34 | const nsecs_t VelocityControl::STOP_TIME; |
| michael@0 | 35 | |
| michael@0 | 36 | VelocityControl::VelocityControl() { |
| michael@0 | 37 | reset(); |
| michael@0 | 38 | } |
| michael@0 | 39 | |
| michael@0 | 40 | void VelocityControl::setParameters(const VelocityControlParameters& parameters) { |
| michael@0 | 41 | mParameters = parameters; |
| michael@0 | 42 | reset(); |
| michael@0 | 43 | } |
| michael@0 | 44 | |
| michael@0 | 45 | void VelocityControl::reset() { |
| michael@0 | 46 | mLastMovementTime = LLONG_MIN; |
| michael@0 | 47 | mRawPosition.x = 0; |
| michael@0 | 48 | mRawPosition.y = 0; |
| michael@0 | 49 | mVelocityTracker.clear(); |
| michael@0 | 50 | } |
| michael@0 | 51 | |
| michael@0 | 52 | void VelocityControl::move(nsecs_t eventTime, float* deltaX, float* deltaY) { |
| michael@0 | 53 | if ((deltaX && *deltaX) || (deltaY && *deltaY)) { |
| michael@0 | 54 | if (eventTime >= mLastMovementTime + STOP_TIME) { |
| michael@0 | 55 | #if DEBUG_ACCELERATION |
| michael@0 | 56 | ALOGD("VelocityControl: stopped, last movement was %0.3fms ago", |
| michael@0 | 57 | (eventTime - mLastMovementTime) * 0.000001f); |
| michael@0 | 58 | #endif |
| michael@0 | 59 | reset(); |
| michael@0 | 60 | } |
| michael@0 | 61 | |
| michael@0 | 62 | mLastMovementTime = eventTime; |
| michael@0 | 63 | if (deltaX) { |
| michael@0 | 64 | mRawPosition.x += *deltaX; |
| michael@0 | 65 | } |
| michael@0 | 66 | if (deltaY) { |
| michael@0 | 67 | mRawPosition.y += *deltaY; |
| michael@0 | 68 | } |
| michael@0 | 69 | mVelocityTracker.addMovement(eventTime, BitSet32(BitSet32::valueForBit(0)), &mRawPosition); |
| michael@0 | 70 | |
| michael@0 | 71 | float vx, vy; |
| michael@0 | 72 | float scale = mParameters.scale; |
| michael@0 | 73 | if (mVelocityTracker.getVelocity(0, &vx, &vy)) { |
| michael@0 | 74 | float speed = hypotf(vx, vy) * scale; |
| michael@0 | 75 | if (speed >= mParameters.highThreshold) { |
| michael@0 | 76 | // Apply full acceleration above the high speed threshold. |
| michael@0 | 77 | scale *= mParameters.acceleration; |
| michael@0 | 78 | } else if (speed > mParameters.lowThreshold) { |
| michael@0 | 79 | // Linearly interpolate the acceleration to apply between the low and high |
| michael@0 | 80 | // speed thresholds. |
| michael@0 | 81 | scale *= 1 + (speed - mParameters.lowThreshold) |
| michael@0 | 82 | / (mParameters.highThreshold - mParameters.lowThreshold) |
| michael@0 | 83 | * (mParameters.acceleration - 1); |
| michael@0 | 84 | } |
| michael@0 | 85 | |
| michael@0 | 86 | #if DEBUG_ACCELERATION |
| michael@0 | 87 | ALOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): " |
| michael@0 | 88 | "vx=%0.3f, vy=%0.3f, speed=%0.3f, accel=%0.3f", |
| michael@0 | 89 | mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold, |
| michael@0 | 90 | mParameters.acceleration, |
| michael@0 | 91 | vx, vy, speed, scale / mParameters.scale); |
| michael@0 | 92 | #endif |
| michael@0 | 93 | } else { |
| michael@0 | 94 | #if DEBUG_ACCELERATION |
| michael@0 | 95 | ALOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): unknown velocity", |
| michael@0 | 96 | mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold, |
| michael@0 | 97 | mParameters.acceleration); |
| michael@0 | 98 | #endif |
| michael@0 | 99 | } |
| michael@0 | 100 | |
| michael@0 | 101 | if (deltaX) { |
| michael@0 | 102 | *deltaX *= scale; |
| michael@0 | 103 | } |
| michael@0 | 104 | if (deltaY) { |
| michael@0 | 105 | *deltaY *= scale; |
| michael@0 | 106 | } |
| michael@0 | 107 | } |
| michael@0 | 108 | } |
| michael@0 | 109 | |
| michael@0 | 110 | } // namespace android |
