| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "SkiaInterpolator.h" |
| |
| #include "include/core/SkScalar.h" |
| #include "include/core/SkTypes.h" |
| #include "include/private/SkFixed.h" |
| #include "src/core/SkTSearch.h" |
| |
| #include <log/log.h> |
| |
| typedef int Dot14; |
| #define Dot14_ONE (1 << 14) |
| #define Dot14_HALF (1 << 13) |
| |
| #define Dot14ToFloat(x) ((x) / 16384.f) |
| |
| static inline Dot14 Dot14Mul(Dot14 a, Dot14 b) { |
| return (a * b + Dot14_HALF) >> 14; |
| } |
| |
| static inline Dot14 eval_cubic(Dot14 t, Dot14 A, Dot14 B, Dot14 C) { |
| return Dot14Mul(Dot14Mul(Dot14Mul(C, t) + B, t) + A, t); |
| } |
| |
| static inline Dot14 pin_and_convert(float x) { |
| if (x <= 0) { |
| return 0; |
| } |
| if (x >= SK_Scalar1) { |
| return Dot14_ONE; |
| } |
| return SkScalarToFixed(x) >> 2; |
| } |
| |
| static float SkUnitCubicInterp(float value, float bx, float by, float cx, float cy) { |
| // pin to the unit-square, and convert to 2.14 |
| Dot14 x = pin_and_convert(value); |
| |
| if (x == 0) return 0; |
| if (x == Dot14_ONE) return SK_Scalar1; |
| |
| Dot14 b = pin_and_convert(bx); |
| Dot14 c = pin_and_convert(cx); |
| |
| // Now compute our coefficients from the control points |
| // t -> 3b |
| // t^2 -> 3c - 6b |
| // t^3 -> 3b - 3c + 1 |
| Dot14 A = 3 * b; |
| Dot14 B = 3 * (c - 2 * b); |
| Dot14 C = 3 * (b - c) + Dot14_ONE; |
| |
| // Now search for a t value given x |
| Dot14 t = Dot14_HALF; |
| Dot14 dt = Dot14_HALF; |
| for (int i = 0; i < 13; i++) { |
| dt >>= 1; |
| Dot14 guess = eval_cubic(t, A, B, C); |
| if (x < guess) { |
| t -= dt; |
| } else { |
| t += dt; |
| } |
| } |
| |
| // Now we have t, so compute the coeff for Y and evaluate |
| b = pin_and_convert(by); |
| c = pin_and_convert(cy); |
| A = 3 * b; |
| B = 3 * (c - 2 * b); |
| C = 3 * (b - c) + Dot14_ONE; |
| return SkFixedToScalar(eval_cubic(t, A, B, C) << 2); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| SkiaInterpolatorBase::SkiaInterpolatorBase() { |
| fStorage = nullptr; |
| fTimes = nullptr; |
| } |
| |
| SkiaInterpolatorBase::~SkiaInterpolatorBase() { |
| if (fStorage) { |
| free(fStorage); |
| } |
| } |
| |
| void SkiaInterpolatorBase::reset(int elemCount, int frameCount) { |
| fFlags = 0; |
| fElemCount = static_cast<uint8_t>(elemCount); |
| fFrameCount = static_cast<int16_t>(frameCount); |
| fRepeat = SK_Scalar1; |
| if (fStorage) { |
| free(fStorage); |
| fStorage = nullptr; |
| fTimes = nullptr; |
| } |
| } |
| |
| /* Each value[] run is formatted as: |
| <time (in msec)> |
| <blend> |
| <data[fElemCount]> |
| |
| Totaling fElemCount+2 entries per keyframe |
| */ |
| |
| bool SkiaInterpolatorBase::getDuration(SkMSec* startTime, SkMSec* endTime) const { |
| if (fFrameCount == 0) { |
| return false; |
| } |
| |
| if (startTime) { |
| *startTime = fTimes[0].fTime; |
| } |
| if (endTime) { |
| *endTime = fTimes[fFrameCount - 1].fTime; |
| } |
| return true; |
| } |
| |
| float SkiaInterpolatorBase::ComputeRelativeT(SkMSec time, SkMSec prevTime, SkMSec nextTime, |
| const float blend[4]) { |
| SkASSERT(time > prevTime && time < nextTime); |
| |
| float t = (float)(time - prevTime) / (float)(nextTime - prevTime); |
| return blend ? SkUnitCubicInterp(t, blend[0], blend[1], blend[2], blend[3]) : t; |
| } |
| |
| SkiaInterpolatorBase::Result SkiaInterpolatorBase::timeToT(SkMSec time, float* T, int* indexPtr, |
| bool* exactPtr) const { |
| SkASSERT(fFrameCount > 0); |
| Result result = kNormal_Result; |
| if (fRepeat != SK_Scalar1) { |
| SkMSec startTime = 0, endTime = 0; // initialize to avoid warning |
| this->getDuration(&startTime, &endTime); |
| SkMSec totalTime = endTime - startTime; |
| SkMSec offsetTime = time - startTime; |
| endTime = SkScalarFloorToInt(fRepeat * totalTime); |
| if (offsetTime >= endTime) { |
| float fraction = SkScalarFraction(fRepeat); |
| offsetTime = fraction == 0 && fRepeat > 0 |
| ? totalTime |
| : (SkMSec)SkScalarFloorToInt(fraction * totalTime); |
| result = kFreezeEnd_Result; |
| } else { |
| int mirror = fFlags & kMirror; |
| offsetTime = offsetTime % (totalTime << mirror); |
| if (offsetTime > totalTime) { // can only be true if fMirror is true |
| offsetTime = (totalTime << 1) - offsetTime; |
| } |
| } |
| time = offsetTime + startTime; |
| } |
| |
| int index = SkTSearch<SkMSec>(&fTimes[0].fTime, fFrameCount, time, sizeof(SkTimeCode)); |
| |
| bool exact = true; |
| |
| if (index < 0) { |
| index = ~index; |
| if (index == 0) { |
| result = kFreezeStart_Result; |
| } else if (index == fFrameCount) { |
| if (fFlags & kReset) { |
| index = 0; |
| } else { |
| index -= 1; |
| } |
| result = kFreezeEnd_Result; |
| } else { |
| exact = false; |
| } |
| } |
| SkASSERT(index < fFrameCount); |
| const SkTimeCode* nextTime = &fTimes[index]; |
| SkMSec nextT = nextTime[0].fTime; |
| if (exact) { |
| *T = 0; |
| } else { |
| SkMSec prevT = nextTime[-1].fTime; |
| *T = ComputeRelativeT(time, prevT, nextT, nextTime[-1].fBlend); |
| } |
| *indexPtr = index; |
| *exactPtr = exact; |
| return result; |
| } |
| |
| SkiaInterpolator::SkiaInterpolator() { |
| INHERITED::reset(0, 0); |
| fValues = nullptr; |
| } |
| |
| SkiaInterpolator::SkiaInterpolator(int elemCount, int frameCount) { |
| SkASSERT(elemCount > 0); |
| this->reset(elemCount, frameCount); |
| } |
| |
| void SkiaInterpolator::reset(int elemCount, int frameCount) { |
| INHERITED::reset(elemCount, frameCount); |
| size_t numBytes = (sizeof(float) * elemCount + sizeof(SkTimeCode)) * frameCount; |
| fStorage = malloc(numBytes); |
| LOG_ALWAYS_FATAL_IF(!fStorage, "Failed to allocate %zu bytes in %s", |
| numBytes, __func__); |
| fTimes = (SkTimeCode*)fStorage; |
| fValues = (float*)((char*)fStorage + sizeof(SkTimeCode) * frameCount); |
| } |
| |
| #define SK_Fixed1Third (SK_Fixed1 / 3) |
| #define SK_Fixed2Third (SK_Fixed1 * 2 / 3) |
| |
| static const float gIdentityBlend[4] = {0.33333333f, 0.33333333f, 0.66666667f, 0.66666667f}; |
| |
| bool SkiaInterpolator::setKeyFrame(int index, SkMSec time, const float values[], |
| const float blend[4]) { |
| SkASSERT(values != nullptr); |
| |
| if (blend == nullptr) { |
| blend = gIdentityBlend; |
| } |
| |
| bool success = ~index == SkTSearch<SkMSec>(&fTimes->fTime, index, time, sizeof(SkTimeCode)); |
| SkASSERT(success); |
| if (success) { |
| SkTimeCode* timeCode = &fTimes[index]; |
| timeCode->fTime = time; |
| memcpy(timeCode->fBlend, blend, sizeof(timeCode->fBlend)); |
| float* dst = &fValues[fElemCount * index]; |
| memcpy(dst, values, fElemCount * sizeof(float)); |
| } |
| return success; |
| } |
| |
| SkiaInterpolator::Result SkiaInterpolator::timeToValues(SkMSec time, float values[]) const { |
| float T; |
| int index; |
| bool exact; |
| Result result = timeToT(time, &T, &index, &exact); |
| if (values) { |
| const float* nextSrc = &fValues[index * fElemCount]; |
| |
| if (exact) { |
| memcpy(values, nextSrc, fElemCount * sizeof(float)); |
| } else { |
| SkASSERT(index > 0); |
| |
| const float* prevSrc = nextSrc - fElemCount; |
| |
| for (int i = fElemCount - 1; i >= 0; --i) { |
| values[i] = SkScalarInterp(prevSrc[i], nextSrc[i], T); |
| } |
| } |
| } |
| return result; |
| } |