diff options
Diffstat (limited to 'redist/linmath.c')
| -rw-r--r-- | redist/linmath.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/redist/linmath.c b/redist/linmath.c index 1724a13..caff1de 100644 --- a/redist/linmath.c +++ b/redist/linmath.c @@ -82,6 +82,28 @@ FLT anglebetween3d( FLT * a, FLT * b ) return FLT_ACOS(dot); } +// algorithm found here: http://inside.mines.edu/fs_home/gmurray/ArbitraryAxisRotation/ +void rotatearoundaxis(FLT *outvec3, FLT *invec3, FLT *axis, FLT angle) +{ + // TODO: this really should be external. + normalize3d(axis, axis); + + FLT s = FLT_SIN(angle); + FLT c = FLT_COS(angle); + + FLT u=axis[0]; + FLT v=axis[1]; + FLT w=axis[2]; + + FLT x=invec3[0]; + FLT y=invec3[1]; + FLT z=invec3[2]; + + outvec3[0] = u*(u*x + v*y + w*z)*(1-c) + x*c + (-w*y + v*z)*s; + outvec3[1] = v*(u*x + v*y + w*z)*(1-c) + y*c + ( w*x - u*z)*s; + outvec3[2] = w*(u*x + v*y + w*z)*(1-c) + z*c + (-v*x + u*y)*s; +} + /////////////////////////////////////QUATERNIONS////////////////////////////////////////// //Originally from Mercury (Copyright (C) 2009 by Joshua Allen, Charles Lohr, Adam Lowman) //Under the mit/X11 license. |