nerdcruft/libcruft-util
1
0
Fork 0
Code Issues Releases Activity

quaternion: fix incorrect factorisation in as_matrix

Browse Source 
One of the terms in m[0][0] and m[1][1] was incorrectly negated from an
incomplete factorisation when I transcribed the formula.

Also reintroduces the axis-rotation tests which inadvertantly had zero
magnitudes.
This commit is contained in:
Danny Robson 2016-09-14 16:48:31 +10:00
parent 798d3aac5a
commit c917f264c4
2 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
quaternion.cpp
View File

@ -111,8 +111,8 @@ quaternion<S, T>::as_matrix (void) const
const T yy = this->y * this->y, yz = this->y * this->z, zz = this->z * this->z;
return { {
{ 1 - 2 * (yy - zz), 2 * (xy - wz), 2 * (xz + wy), 0 },
{ 2 * (xy + wz), 1 - 2 * (xx - zz), 2 * (yz - wx), 0 },
{ 1 - 2 * (yy + zz), 2 * (xy - wz), 2 * (xz + wy), 0 },
{ 2 * (xy + wz), 1 - 2 * (xx + zz), 2 * (yz - wx), 0 },
{ 2 * (xz - wy), 2 * (yz + wx), 1 - 2 * (xx + yy), 0 },
{ 0, 0, 0, 1 }
} };

4
test/quaternion.cpp
View File

@ -68,9 +68,9 @@ main (void)
float mag;
util::vector3f axis;
} ROTATIONS[] = {
{ 0.f, { 1.f, 0.f, 0.f } },
{ 1.f, { 1.f, 0.f, 0.f } },
{ 1.f, { 0.f, 1.f, 0.f } },
{ 0.f, { 0.f, 0.f, 1.f } },
{ 1.f, { 0.f, 0.f, 1.f } },
};
for (size_t i = 0; i < elems (ROTATIONS); ++i) {