King_DuckZ/vectorwrapper
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Implement 2D and 3D cross product.

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2D cross product is defined as equivalent to:
res = cross(a.xy0(), b.xy0()).z()
This commit is contained in:
King_DuckZ 2017-02-01 01:51:52 +00:00
parent fc7b666429
commit aaa8e75dc1
2 changed files with 51 additions and 1 deletions
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18
include/vectorwrapper/vectorops.hpp
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@ -26,6 +26,11 @@ namespace vwr {
template <typename V1, typename V2, size_type S>
typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type dot ( const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight );
template <typename V1, typename V2>
typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type cross ( const Vec<V1, 2>& parLeft, const Vec<V2, 2>& parRight );
template <typename V1, typename V2>
Vec<typename std::common_type<V1, V2>::type> cross ( const Vec<V1, 3>& parLeft, const Vec<V2, 3>& parRight );
template <typename V1, typename V2, size_type S>
inline typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type dot (const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight) {
auto retval = parLeft.x() * parRight.x();
@ -34,6 +39,19 @@ namespace vwr {
}
return retval;
}
template <typename V1, typename V2>
inline typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type cross (const Vec<V1, 2>& parLeft, const Vec<V2, 2>& parRight) {
return parLeft.x() * parRight.y() - parLeft.y() * parRight.x();
}
template <typename V1, typename V2>
inline Vec<typename std::common_type<V1, V2>::type> cross (const Vec<V1, 3>& parLeft, const Vec<V2, 3>& parRight) {
return Vec<typename std::common_type<V1, V2>::type>(
parLeft.y() * parRight.z() - parLeft.z() * parRight.y(),
parLeft.z() * parRight.x() - parLeft.x() * parRight.z(),
parLeft.x() * parRight.y() - parLeft.y() * parRight.x()
);
}
} //namespace vwr
#endif

34
test/unit/test_ops.cpp
View file

@ -23,7 +23,7 @@ namespace vwr {
typedef vwr::Vec<UnorderedVector> uvec3i;
TEST(vwr, ops) {
TEST(vwr, dot) {
using namespace vwr;
ivec3 a(1);
@ -43,3 +43,35 @@ TEST(vwr, ops) {
EXPECT_EQ(7*5+2*2+9*8, dot(a, c));
EXPECT_EQ(7*6+2*9+9*3, dot(b, c));
}
TEST(vwr, cross2D) {
using namespace vwr;
ivec2 a(53, 97);
ivec2 b(71, -30);
EXPECT_EQ(-8477, cross(a, b));
a /= 4;
b /= -2;
EXPECT_EQ(1035, cross(a, b));
}
TEST(vwr, cross3D) {
using namespace vwr;
ivec3 a(5, 7, 13);
ivec3 b(17, 19, 23);
ivec3 res(-86, 106, -24);
EXPECT_EQ(res, cross(a, b));
a.x() *= 10;
a.y() *= -8;
a.z() *= 37;
b *= -99;
res.x() = 1032273;
res.y() = -695673;
res.z() = -188298;
EXPECT_EQ(res, cross(a, b));
}