Introduce PathInterpolator to native animators
For interpolators defined with a path, PathInterpolator is more accurate
and likely less costly for longer animations than what are currently
using as a substiute - LUTInterpolator.
Test: manual test and added a unit test
BUG: 32830741
Change-Id: I867c7a28e4261392cce9c45a2992ab4fd120c496
diff --git a/libs/hwui/Android.mk b/libs/hwui/Android.mk
index 8dc502a..1315056 100644
--- a/libs/hwui/Android.mk
+++ b/libs/hwui/Android.mk
@@ -294,6 +294,7 @@
tests/unit/MeshStateTests.cpp \
tests/unit/OffscreenBufferPoolTests.cpp \
tests/unit/OpDumperTests.cpp \
+ tests/unit/PathInterpolatorTests.cpp \
tests/unit/RenderNodeDrawableTests.cpp \
tests/unit/RecordingCanvasTests.cpp \
tests/unit/RenderNodeTests.cpp \
diff --git a/libs/hwui/Interpolator.cpp b/libs/hwui/Interpolator.cpp
index cc47f00..ae9ee6e 100644
--- a/libs/hwui/Interpolator.cpp
+++ b/libs/hwui/Interpolator.cpp
@@ -88,6 +88,39 @@
return t * t * ((mTension + 1) * t + mTension) + 1.0f;
}
+float PathInterpolator::interpolate(float t) {
+ if (t <= 0) {
+ return 0;
+ } else if (t >= 1) {
+ return 1;
+ }
+ // Do a binary search for the correct x to interpolate between.
+ size_t startIndex = 0;
+ size_t endIndex = mX.size() - 1;
+
+ while (endIndex > startIndex + 1) {
+ int midIndex = (startIndex + endIndex) / 2;
+ if (t < mX[midIndex]) {
+ endIndex = midIndex;
+ } else {
+ startIndex = midIndex;
+ }
+ }
+
+ float xRange = mX[endIndex] - mX[startIndex];
+ if (xRange == 0) {
+ return mY[startIndex];
+ }
+
+ float tInRange = t - mX[startIndex];
+ float fraction = tInRange / xRange;
+
+ float startY = mY[startIndex];
+ float endY = mY[endIndex];
+ return startY + (fraction * (endY - startY));
+
+}
+
LUTInterpolator::LUTInterpolator(float* values, size_t size)
: mValues(values)
, mSize(size) {
diff --git a/libs/hwui/Interpolator.h b/libs/hwui/Interpolator.h
index 6512008..224cee7 100644
--- a/libs/hwui/Interpolator.h
+++ b/libs/hwui/Interpolator.h
@@ -20,6 +20,7 @@
#include <memory>
#include <cutils/compiler.h>
+#include <vector>
namespace android {
namespace uirenderer {
@@ -100,6 +101,16 @@
const float mTension;
};
+class ANDROID_API PathInterpolator : public Interpolator {
+public:
+ explicit PathInterpolator(std::vector<float>&& x, std::vector<float>&& y)
+ : mX (x), mY(y) {}
+ virtual float interpolate(float input) override;
+private:
+ std::vector<float> mX;
+ std::vector<float> mY;
+};
+
class ANDROID_API LUTInterpolator : public Interpolator {
public:
LUTInterpolator(float* values, size_t size);
diff --git a/libs/hwui/tests/unit/PathInterpolatorTests.cpp b/libs/hwui/tests/unit/PathInterpolatorTests.cpp
new file mode 100644
index 0000000..d7cb23a
--- /dev/null
+++ b/libs/hwui/tests/unit/PathInterpolatorTests.cpp
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2016 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 <gtest/gtest.h>
+
+#include <Interpolator.h>
+
+namespace android {
+namespace uirenderer {
+
+struct TestData {
+ const std::vector<float> x;
+ const std::vector<float> y;
+ const std::vector<float> inFraction;
+ const std::vector<float> outFraction;
+};
+
+const static TestData sTestDataSet[] = {
+ {
+ // Straight line as a path.
+ {0.0f, 1.0f},
+ {0.0f, 1.0f},
+ {0.0f, 0.2f, 0.4f, 0.6f, 0.8f, 1.0f},
+ {0.0f, 0.2f, 0.4f, 0.6f, 0.8f, 1.0f},
+ },
+
+ {
+ {
+ 0.0f, 0.5f, 0.5178955f, 0.5341797f, 0.5489991f, 0.5625f, 0.5748291f,
+ 0.5861328f, 0.60625005f, 0.62402344f, 0.640625f, 0.675f, 0.6951172f,
+ 0.71875f, 0.7470703f, 0.78125f, 0.82246095f, 0.84606934f, 0.871875f,
+ 0.9000244f, 0.93066406f, 0.96394044f, 1.0f
+ },
+ {
+ 0.0f, 0.0f, 0.0028686523f, 0.011230469f, 0.024719238f, 0.04296875f,
+ 0.06561279f, 0.092285156f, 0.15625f, 0.2319336f, 0.31640625f, 0.5f,
+ 0.5932617f, 0.68359375f, 0.7680664f, 0.84375f, 0.90771484f, 0.9343872f,
+ 0.95703125f, 0.97528076f, 0.98876953f, 0.99713135f, 1.0f
+ },
+ {
+ 0.0f, 0.03375840187072754f, 0.13503384590148926f, 0.23630905151367188f,
+ 0.336834192276001f, 0.4508626461029053f, 0.564141035079956f,
+ 0.6781694889068604f, 0.7921979427337646f, 0.9054763317108154f, 1.0f
+ },
+ {
+ 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0459827296435833f,
+ 0.5146934390068054f, 0.8607426285743713f, 0.9776809215545654f, 1.0f
+
+ }
+
+ },
+ {
+ {
+ 0.0f, 0.017895509f, 0.034179688f, 0.048999026f, 0.0625f, 0.0748291f,
+ 0.08613282f, 0.10625f, 0.12402344f, 0.140625f, 0.17500001f, 0.19511719f,
+ 0.21875f, 0.24707031f, 0.28125f, 0.32246095f, 0.34606934f, 0.371875f,
+ 0.4000244f, 0.43066406f, 0.46394044f, 0.5f, 1.0f
+ },
+ {
+ 0.0f, 0.0028686523f, 0.011230469f, 0.024719238f, 0.04296875f, 0.06561279f,
+ 0.092285156f, 0.15625f, 0.2319336f, 0.31640625f, 0.5f, 0.5932617f,
+ 0.68359375f, 0.7680664f, 0.84375f, 0.90771484f, 0.9343872f, 0.95703125f,
+ 0.97528076f, 0.98876953f, 0.99713135f, 1.0f, 1.0f
+ },
+ {
+ 0.0f, 0.102020263671875f, 0.20330810546875f, 0.3165740966796875f,
+ 0.43060302734375f, 0.5318756103515625f, 0.6331634521484375f,
+ 0.746429443359375f, 0.84771728515625f, 0.9617462158203125f, 1.0f
+ },
+ {
+ 0.0f, 0.14280107617378235f, 0.6245699524879456f, 0.8985776901245117f,
+ 0.9887426495552063f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f
+ }
+ },
+
+
+};
+
+static std::vector<float> getX(const TestData& data) {
+ return data.x;
+}
+
+static std::vector<float> getY(const TestData& data) {
+ return data.y;
+}
+
+TEST(Interpolator, pathInterpolation) {
+ for (const TestData& data: sTestDataSet) {
+ PathInterpolator interpolator(getX(data), getY(data));
+ for (size_t i = 0; i < data.inFraction.size(); i++) {
+ EXPECT_FLOAT_EQ(data.outFraction[i], interpolator.interpolate(data.inFraction[i]));
+ }
+ }
+}
+
+}
+}