From de3e0e6cb80c3b1319b2f598e1c9fbae058d33aa Mon Sep 17 00:00:00 2001
From: pleroy <pascal.h.leroy@gmail.com>
Date: Sun, 10 Oct 2021 11:59:44 +0200
Subject: [PATCH 1/2] Implementation and tests.
---
physics/discrete_trajectory_segment.hpp | 4 +++
physics/discrete_trajectory_segment_body.hpp | 20 ++++++++++---
physics/discrete_trajectory_segment_test.cpp | 30 ++++++++++++++++++++
3 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/physics/discrete_trajectory_segment.hpp b/physics/discrete_trajectory_segment.hpp
index 9bd0c46633..9e04548d99 100644
--- a/physics/discrete_trajectory_segment.hpp
+++ b/physics/discrete_trajectory_segment.hpp
@@ -67,9 +67,13 @@ class DiscreteTrajectorySegment {
absl::Status Append(Instant const& t,
DegreesOfFreedom<Frame> const& degrees_of_freedom);
+ // Removes all points with a time greater than or equal to |t| (1st overload)
+ // or starting at |begin| (2nd overload).
void ForgetAfter(Instant const& t);
void ForgetAfter(typename Timeline::const_iterator begin);
+ // Removes all points with a time strictly less than |t| (1st overload) or
+ // ending at |end| (2nd overload).
void ForgetBefore(Instant const& t);
void ForgetBefore(typename Timeline::const_iterator end);
diff --git a/physics/discrete_trajectory_segment_body.hpp b/physics/discrete_trajectory_segment_body.hpp
index 849f6ad37c..32d970365d 100644
--- a/physics/discrete_trajectory_segment_body.hpp
+++ b/physics/discrete_trajectory_segment_body.hpp
@@ -111,18 +111,30 @@ absl::Status DiscreteTrajectorySegment<Frame>::Append(
}
template<typename Frame>
-void DiscreteTrajectorySegment<Frame>::ForgetAfter(Instant const& t) {}
+void DiscreteTrajectorySegment<Frame>::ForgetAfter(Instant const& t) {
+ ForgetAfter(timeline_.lower_bound(t));
+ // TODO(phl): Downsampling.
+}
template<typename Frame>
void DiscreteTrajectorySegment<Frame>::ForgetAfter(
- typename Timeline::const_iterator const begin) {}
+ typename Timeline::const_iterator const begin) {
+ timeline_.erase(begin, timeline_.end());
+ // TODO(phl): Downsampling.
+}
template<typename Frame>
-void DiscreteTrajectorySegment<Frame>::ForgetBefore(Instant const& t) {}
+void DiscreteTrajectorySegment<Frame>::ForgetBefore(Instant const& t) {
+ ForgetBefore(timeline_.lower_bound(t));
+ // TODO(phl): Downsampling.
+}
template<typename Frame>
void DiscreteTrajectorySegment<Frame>::ForgetBefore(
- typename Timeline::const_iterator const end) {}
+ typename Timeline::const_iterator const end) {
+ timeline_.erase(timeline_.begin(), end);
+ // TODO(phl): Downsampling.
+}
template<typename Frame>
typename DiscreteTrajectorySegment<Frame>::Timeline::const_iterator
diff --git a/physics/discrete_trajectory_segment_test.cpp b/physics/discrete_trajectory_segment_test.cpp
index e997f04461..500ade8532 100644
--- a/physics/discrete_trajectory_segment_test.cpp
+++ b/physics/discrete_trajectory_segment_test.cpp
@@ -106,5 +106,35 @@ TEST_F(DiscreteTrajectorySegmentTest, EmptySize) {
EXPECT_EQ(5, segment_->size());
}
+TEST_F(DiscreteTrajectorySegmentTest, ForgetAfterExisting) {
+ segment_.ForgetAfter(t0_ + 5 * Second);
+ EXPECT_EQ(t0_ + 3 * Second, segment_.rend()->first);
+}
+
+TEST_F(DiscreteTrajectorySegmentTest, ForgetAfterNonexisting) {
+ segment_.ForgetAfter(t0_ + 6 * Second);
+ EXPECT_EQ(t0_ + 5 * Second, segment_.rend()->first);
+}
+
+TEST_F(DiscreteTrajectorySegmentTest, ForgetAfterPastTheEnd) {
+ segment_.ForgetAfter(t0_ + 29 * Second);
+ EXPECT_EQ(t0_ + 11 * Second, segment_.rend()->first);
+}
+
+TEST_F(DiscreteTrajectorySegmentTest, ForgetBeforeExisting) {
+ segment_.ForgetBefore(t0_ + 7 * Second);
+ EXPECT_EQ(t0_ + 7 * Second, segment_.begin()->first);
+}
+
+TEST_F(DiscreteTrajectorySegmentTest, ForgetBeforeNonexisting) {
+ segment_.ForgetBefore(t0_ + 6 * Second);
+ EXPECT_EQ(t0_ + 7 * Second, segment_.begin()->first);
+}
+
+TEST_F(DiscreteTrajectorySegmentTest, ForgetBeforeTheBeginning) {
+ segment_.ForgetBefore(t0_ + 1 * Second);
+ EXPECT_EQ(t0_ + 2 * Second, segment_.begin()->first);
+}
+
} // namespace physics
} // namespace principia
From 25f4121e49de63ee591797b32e0a7f76fbec8334 Mon Sep 17 00:00:00 2001
From: pleroy <pascal.h.leroy@gmail.com>
Date: Sun, 10 Oct 2021 12:10:41 +0200
Subject: [PATCH 2/2] Tests passing.
---
physics/discrete_trajectory_segment_test.cpp | 32 ++++++++++++--------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/physics/discrete_trajectory_segment_test.cpp b/physics/discrete_trajectory_segment_test.cpp
index 500ade8532..9c70435125 100644
--- a/physics/discrete_trajectory_segment_test.cpp
+++ b/physics/discrete_trajectory_segment_test.cpp
@@ -36,6 +36,14 @@ class DiscreteTrajectorySegmentTest : public ::testing::Test {
segment_->Append(t0_ + 11 * Second, unmoving_origin_);
}
+ void ForgetAfter(Instant const& t) {
+ segment_->ForgetAfter(t);
+ }
+
+ void ForgetBefore(Instant const& t) {
+ segment_->ForgetBefore(t);
+ }
+
DiscreteTrajectorySegment<World>* segment_;
internal_discrete_trajectory_types::Segments<World> segments_;
Instant const t0_;
@@ -107,33 +115,33 @@ TEST_F(DiscreteTrajectorySegmentTest, EmptySize) {
}
TEST_F(DiscreteTrajectorySegmentTest, ForgetAfterExisting) {
- segment_.ForgetAfter(t0_ + 5 * Second);
- EXPECT_EQ(t0_ + 3 * Second, segment_.rend()->first);
+ ForgetAfter(t0_ + 5 * Second);
+ EXPECT_EQ(t0_ + 3 * Second, segment_->rbegin()->first);
}
TEST_F(DiscreteTrajectorySegmentTest, ForgetAfterNonexisting) {
- segment_.ForgetAfter(t0_ + 6 * Second);
- EXPECT_EQ(t0_ + 5 * Second, segment_.rend()->first);
+ ForgetAfter(t0_ + 6 * Second);
+ EXPECT_EQ(t0_ + 5 * Second, segment_->rbegin()->first);
}
TEST_F(DiscreteTrajectorySegmentTest, ForgetAfterPastTheEnd) {
- segment_.ForgetAfter(t0_ + 29 * Second);
- EXPECT_EQ(t0_ + 11 * Second, segment_.rend()->first);
+ ForgetAfter(t0_ + 29 * Second);
+ EXPECT_EQ(t0_ + 11 * Second, segment_->rbegin()->first);
}
TEST_F(DiscreteTrajectorySegmentTest, ForgetBeforeExisting) {
- segment_.ForgetBefore(t0_ + 7 * Second);
- EXPECT_EQ(t0_ + 7 * Second, segment_.begin()->first);
+ ForgetBefore(t0_ + 7 * Second);
+ EXPECT_EQ(t0_ + 7 * Second, segment_->begin()->first);
}
TEST_F(DiscreteTrajectorySegmentTest, ForgetBeforeNonexisting) {
- segment_.ForgetBefore(t0_ + 6 * Second);
- EXPECT_EQ(t0_ + 7 * Second, segment_.begin()->first);
+ ForgetBefore(t0_ + 6 * Second);
+ EXPECT_EQ(t0_ + 7 * Second, segment_->begin()->first);
}
TEST_F(DiscreteTrajectorySegmentTest, ForgetBeforeTheBeginning) {
- segment_.ForgetBefore(t0_ + 1 * Second);
- EXPECT_EQ(t0_ + 2 * Second, segment_.begin()->first);
+ ForgetBefore(t0_ + 1 * Second);
+ EXPECT_EQ(t0_ + 2 * Second, segment_->begin()->first);
}
} // namespace physics