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comparison: widget/gonk/libui/VelocityControl.cpp
widget/gonk/libui/VelocityControl.cpp
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
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| -1:000000000000 | 0:3ce2e215b89b |
|---|---|
| 1 /* | |
| 2 * Copyright (C) 2012 The Android Open Source Project | |
| 3 * | |
| 4 * Licensed under the Apache License, Version 2.0 (the "License"); | |
| 5 * you may not use this file except in compliance with the License. | |
| 6 * You may obtain a copy of the License at | |
| 7 * | |
| 8 * http://www.apache.org/licenses/LICENSE-2.0 | |
| 9 * | |
| 10 * Unless required by applicable law or agreed to in writing, software | |
| 11 * distributed under the License is distributed on an "AS IS" BASIS, | |
| 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 13 * See the License for the specific language governing permissions and | |
| 14 * limitations under the License. | |
| 15 */ | |
| 16 | |
| 17 #define LOG_TAG "VelocityControl" | |
| 18 //#define LOG_NDEBUG 0 | |
| 19 | |
| 20 // Log debug messages about acceleration. | |
| 21 #define DEBUG_ACCELERATION 0 | |
| 22 | |
| 23 #include <math.h> | |
| 24 #include <limits.h> | |
| 25 | |
| 26 #include "VelocityControl.h" | |
| 27 #include <utils/BitSet.h> | |
| 28 #include <utils/Timers.h> | |
| 29 | |
| 30 namespace android { | |
| 31 | |
| 32 // --- VelocityControl --- | |
| 33 | |
| 34 const nsecs_t VelocityControl::STOP_TIME; | |
| 35 | |
| 36 VelocityControl::VelocityControl() { | |
| 37 reset(); | |
| 38 } | |
| 39 | |
| 40 void VelocityControl::setParameters(const VelocityControlParameters& parameters) { | |
| 41 mParameters = parameters; | |
| 42 reset(); | |
| 43 } | |
| 44 | |
| 45 void VelocityControl::reset() { | |
| 46 mLastMovementTime = LLONG_MIN; | |
| 47 mRawPosition.x = 0; | |
| 48 mRawPosition.y = 0; | |
| 49 mVelocityTracker.clear(); | |
| 50 } | |
| 51 | |
| 52 void VelocityControl::move(nsecs_t eventTime, float* deltaX, float* deltaY) { | |
| 53 if ((deltaX && *deltaX) || (deltaY && *deltaY)) { | |
| 54 if (eventTime >= mLastMovementTime + STOP_TIME) { | |
| 55 #if DEBUG_ACCELERATION | |
| 56 ALOGD("VelocityControl: stopped, last movement was %0.3fms ago", | |
| 57 (eventTime - mLastMovementTime) * 0.000001f); | |
| 58 #endif | |
| 59 reset(); | |
| 60 } | |
| 61 | |
| 62 mLastMovementTime = eventTime; | |
| 63 if (deltaX) { | |
| 64 mRawPosition.x += *deltaX; | |
| 65 } | |
| 66 if (deltaY) { | |
| 67 mRawPosition.y += *deltaY; | |
| 68 } | |
| 69 mVelocityTracker.addMovement(eventTime, BitSet32(BitSet32::valueForBit(0)), &mRawPosition); | |
| 70 | |
| 71 float vx, vy; | |
| 72 float scale = mParameters.scale; | |
| 73 if (mVelocityTracker.getVelocity(0, &vx, &vy)) { | |
| 74 float speed = hypotf(vx, vy) * scale; | |
| 75 if (speed >= mParameters.highThreshold) { | |
| 76 // Apply full acceleration above the high speed threshold. | |
| 77 scale *= mParameters.acceleration; | |
| 78 } else if (speed > mParameters.lowThreshold) { | |
| 79 // Linearly interpolate the acceleration to apply between the low and high | |
| 80 // speed thresholds. | |
| 81 scale *= 1 + (speed - mParameters.lowThreshold) | |
| 82 / (mParameters.highThreshold - mParameters.lowThreshold) | |
| 83 * (mParameters.acceleration - 1); | |
| 84 } | |
| 85 | |
| 86 #if DEBUG_ACCELERATION | |
| 87 ALOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): " | |
| 88 "vx=%0.3f, vy=%0.3f, speed=%0.3f, accel=%0.3f", | |
| 89 mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold, | |
| 90 mParameters.acceleration, | |
| 91 vx, vy, speed, scale / mParameters.scale); | |
| 92 #endif | |
| 93 } else { | |
| 94 #if DEBUG_ACCELERATION | |
| 95 ALOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): unknown velocity", | |
| 96 mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold, | |
| 97 mParameters.acceleration); | |
| 98 #endif | |
| 99 } | |
| 100 | |
| 101 if (deltaX) { | |
| 102 *deltaX *= scale; | |
| 103 } | |
| 104 if (deltaY) { | |
| 105 *deltaY *= scale; | |
| 106 } | |
| 107 } | |
| 108 } | |
| 109 | |
| 110 } // namespace android |
