This is the second optimization. With that we don't have to iterate over the
umbrella's components.
The table below summarizes the mean CPU time in ns from the brenchmark results
on an Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz processor:
| Naive implementation | First Optimization | Second Optimization
------------------------------------------------------------------------
Min. | 26.0 | 28.00 | 26.0
1st Qu.| 78.0 | 48.75 | 39.0
Median | 132.0 | 57.00 | 41.0
Mean | 130.1 | 61.20 | 41.6
3rd Qu.| 182.2 | 76.00 | 47.0
Max. | 234.0 | 98.00 | 54.0
If v is the null vector, then alpha * v is still the null vector for any alpha
as a real number. That means that the null vector doesn't cross any section.
This is a first optimization of the algorithm. The struct for the neighbor
umbrella has only one member, but new members will be added in the next
optimization.
The table below summarizes the mean CPU time in ns from the brenchmark results
on an Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz processor:
Cases | Naive implementation | First Optimization
--------------------------------------------------
Min. | 26.0 | 28.00
1st Qu.| 78.0 | 48.75
Median | 132.0 | 57.00
Mean | 130.1 | 61.20
3rd Qu.| 182.2 | 76.00
Max. | 234.0 | 98.00
This optimization reduces the mean time for the worst case (Max. line) by more
than 50%.
- Change the order of the icosahedron triangles so that there's a uniform way of
finding the opposite triangle. The order visually still makes sense.
- Change test to accommodate the order change.
Avoid warnings like:
[2130/2168] Compiling libraries/AP_Math/tests/test_math.cpp
../../libraries/AP_Math/tests/test_math.cpp: In member function ‘virtual void MathTest_IsZero_Test::TestBody()’:
../../libraries/AP_Math/tests/test_math.cpp:73:196: warning: converting ‘false’ to pointer type for argument 1 of ‘char
testing::internal::IsNullLiteralHelper(testing::internal::Secret*)’ [-Wconversion-null]
../../libraries/AP_Math/tests/test_math.cpp:74:199: warning: converting ‘false’ to pointer type for argument 1 of ‘char
testing::internal::IsNullLiteralHelper(testing::internal::Secret*)’ [-Wconversion-null]
Use EXPECT_TRUE() and EXPECT_FALSE() from gtest instead.
The new function can deal with a variable number of function parameters.
Additionally, I renamed the functions to norm(), because this is the
standard name used in several other projects.
When using wrap_180_cd() we are adding a small float (180 * 100) to a
possibly big number. This may lose float precision as illustrated by the
unit test failing:
OUT: ../../libraries/AP_Math/tests/test_math.cpp:195: Failure
OUT: Value of: wrap_180_cd(-3600000000.f)
OUT: Actual: -80
OUT: Expected: 0.f
OUT: Which is: 0
These functions (or variants thereof) now have unit tests:
- is_zero()
- is_equal()
- sq()
- pythagorous()
- constrain()
- wrap_180()
- wrap_360()
Some tests in wrap_180_cd are failing: -180 should be wrapped to 180,
not -180.
Gustavo Jose de Sousa
dgrat
Ricardo de Almeida Gonzaga
Lucas De Marchi
Andrew Tridgell
Michael du Breuil
Tom Pittenger
Daniel Frenzel
Peter Barker