Hi,
I have been playing with the osg::Vec classes, and also read a 2 year old
thread about this here
on the forum (not allowed to link to it because I don't have 2 posts already).
I too find the current implementation rather inconsistent and limited so I've
made
a concise c++03 implementation that I hope will be aproved. It should be much
easier
to maintain as it is much less code, and each function is defined only once
(has no
overloaded "similar" functions either). I suppose Matrix{f,d} and other classes
should be updated later to use the new template classes Vec2t<T>, Vec3t<T>,
Vec4t<T>.
FULLY HARMONISED WITH TEMPLATES.
All Vec types have equal interface and can fully intermix in expressions. Most
arguments
are templated, so no unneccesary conversions or temporaries are made, which
should speed up code.
Also Vec4{*}::asRGBA() works for any type.
SMART RETURN TYPES
Expressions returns the "natural" Vec type, e.g. Vec3i ^ Vec3d => Vec3d,
whereas Vec3s ^ Vec3i => Vec3i,
although the Vec3 ^ function is defined only once! Automatic conversion to
other Vec classes is
enabled by default in order to compile the current OSG source, but I highly
recommend that this
feature is turned off by default in the future (#define
OSG_NO_VEC_AUTO_CONVERSION) and force
explicit conversions.
NOTE: Expressions involving integer types only (char, short, int and unsigned
types) always return
int for implementation simplicity. E.g.: -Vec3us() => Vec3i, Vec3ub + Vec3s =>
Vec3i.
EXTENSIONS
I have not added excessive new functionality, but did add a few:
* Explicit constructors that also accept number array (e.g float[]).
* Partial set() functions, which set some of the components, e.g.:
Code:
osg::Vec4 color1, color2;
color2.set<0,1,2>( color1.rgb() );
* normalized() const. returns unity vector.
* equivalent(u,v) implemented for Vecs.
NOTE: In partial set<>() above, the indices 0,1,2 are actually compile-time
checked to be < 4
and unequal to each other! The rgb() function returns a Vec3, which brings us
to the next point.
SWIZZLE FUNCTIONS
>From a set of macros, a complete set of very convenient swizzle functions are
>generated,
e.g. v.wyxx(), v.xy(), v.bgr(), etc. This could potentially slow down
compilation or create bigger
executables. However, I have not seen any of those effects with neither VC nor
GCC.
FILES AND IMPLEMENTATION
The implementation is done in files Vec2, Vec3, Vec4 and VecFwd. The remaining
osg/Vec{*}
files are needed for backward compability only, and osg/Export, osg/Config and
osg/Math
are included only so the test can be compiled standalone.
NB: Code which predeclares class Vec2i; class Vec3f, etc. must #include <
osg/VecFwd > instead.
Thank you!
Cheers,
Tyge
ps: I have contributed a few lines of code earlier.
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=63672#63672
Attachments:
http://forum.openscenegraph.org//files/osg_vec_850.zip
_______________________________________________
osg-submissions mailing list
[email protected]
http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
