diff options
Diffstat (limited to 'redist/linmath.c')
| -rw-r--r-- | redist/linmath.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/redist/linmath.c b/redist/linmath.c index eefcd5f..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. @@ -215,7 +237,7 @@ void quatfrommatrix( FLT * q, const FLT * matrix44 ) q[1] = (matrix44[9] - matrix44[6]) / S; q[2] = (matrix44[2] - matrix44[8]) / S; q[3] = (matrix44[4] - matrix44[1]) / S; - } else if ((matrix44[0] > matrix44[5])&(matrix44[0] > matrix44[10])) { + } else if ((matrix44[0] > matrix44[5])&&(matrix44[0] > matrix44[10])) { FLT S = FLT_SQRT(1.0 + matrix44[0] - matrix44[5] - matrix44[10]) * 2.; // S=4*qx q[0] = (matrix44[9] - matrix44[6]) / S; q[1] = 0.25f * S; |