libcruft-util/test/vector.cpp

116 lines
2.9 KiB
C++

#include "vector.hpp"
#include "maths.hpp"
#include "tap.hpp"
using util::vector;
using util::vector2f;
void
test_polar (util::TAP::logger &tap)
{
static const struct {
util::vector2f polar;
util::vector2f cartesian;
const char *desc;
} TESTS[] {
{
{ 0.f, 0.f },
{ 0.f, 0.f },
"all zeroes"
},
{
{ 1.f, 0.f },
{ 1.f, 0.f },
"unit length, unrotated"
},
{
{ 1.f, PI<float> / 2.f },
{ 0.f, 1.f },
"unit length, rotated"
},
{
{ 1.f, 2 * PI<float> },
{ 1.f, 0.f },
"full rotation, unit length"
}
};
for (const auto &t: TESTS) {
// Compare the difference of cartesian representations. Don't use
// direct equality comparisons here as the numeric stability can be
// poor and we have nice whole numbers to start with.
auto in_cart = t.cartesian;
auto to_cart = util::polar_to_cartesian (t.polar);
tap.expect_lt ((in_cart - to_cart).magnitude (), 0.00001f, t.desc);
// Compare polar representations. Make sure to normalise them first.
auto in_polar = t.polar;
auto to_polar = util::cartesian_to_polar (t.cartesian);
in_polar[1] = std::fmod (in_polar[1], 2 * PI<float>);
to_polar[1] = std::fmod (to_polar[1], 2 * PI<float>);
tap.expect_eq (in_polar, to_polar, t.desc);
}
}
void
test_euler (util::TAP::logger &tap)
{
static const struct {
util::vector3f dir;
util::vector2f euler;
const char *name;
} TESTS[] = {
// y-axis
{ { 0, 0, -1 }, { 0.5f, 0.5f }, "forward" },
{ { -1, 0, 0 }, { 0.5f, -1.0f }, "left" },
{ { 0, 0, 1 }, { 0.5f, -0.5f }, "back" },
{ { 1, 0, 0 }, { 0.5f, 0.0f }, "right" },
// x-axis
{ { 0, 1, 0 }, { 0, 0 }, "up" },
{ { 0, -1, 0 }, { 1, 0 }, "down" },
};
// check that simple axis rotations look correct
for (auto i: TESTS) {
tap.expect_eq (util::to_euler (i.dir),
i.euler * PI<float>,
"to euler, %s", i.name);
}
// check error in round trip through euler angles
for (auto i: TESTS) {
auto trip = util::from_euler (util::to_euler (i.dir));
auto diff = i.dir - trip;
auto norm = diff.magnitude ();
// trig functions reduce precision above almost_equal levels, so we
// hard code a fairly low bound here instead.
tap.expect_lt (norm, 1e-7, "euler round-trip error, %s", i.name);
}
}
int
main ()
{
util::TAP::logger tap;
test_polar (tap);
test_euler (tap);
tap.expect (!util::vector3f::ZERO.is_normalised (), "zero isn't normalised");
tap.expect (!util::vector3f::UNIT.is_normalised (), "unit is normalised");
return tap.status ();
}