Actually, both OpenGL and DirectX specify a matrix layout where the base vectors and the translational
part is consecutive in memory.
OpenGL uses post-multiplication of column-vectors and stores the matrix in column-major storage format:
| X1 Y1 Z1 T1 | | a |
| X2 Y2 Z2 T2 | | b |
| X3 Y3 Z3 T3 | | c |
| 0 0 0 1 | | 1 |
DirectX on the other hand uses row-major storage format but also pre-multiplication of
row-vectors
| a b c 1 | | X1 X2 X3 0 |
| Y1 Y2 Y3 0 |
| Z1 Z2 Z3 0 |
| T1 T2 T3 1 |
So a matrix is stored the same way in both frameworks and both times the translational part is consecutive,
which is not the format that Assimp uses.
The columns of the matrix are the images of the standard base vectors rather than the base vectors themselves. Added some
description of the row-major storage format.
Some are doxy comments, some are just trivial source comment typos.
Found using `codespell -q 3 --skip="./contrib" -I ../assimp-whitelist.txt`
whereby whitelist contained:
```
childs
iff
lod
nto
ot
whitespaces
```
check on doc/CMakeLists since is already checked on main CMakeLists.
At same time, Doxygen becomes required as no documentation can be built
without it.
Output directory now uses the user defined HTML_OUTPUT instead of
forced dir.
- Added included GNUInstallDirs on same UNIX check, avoiding duplication
of checks
Current documentation lacks a proper directory handling and switch for
Unix like systems.
The option BUILD_DOCS are added as disable by default, even so the
Doxyfile file is generated for a manual build.
Option HTML_OUTPUT are made cached to be properly replaced, as usually
done by some Linux distributions
Microsoft CHM option is enabled if MSVC is detected.
- pull in IOhannes' patch to set the gcc default visibility for all symbols to NO and to mark ASSIMP_API with __attribute__ ((visibility("default"))).
- drop unneeded ASSIMP_API from most internal classes in /code, we just need to keep some exports on Windows to keep AssimpView alive.
git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@1066 67173fc5-114c-0410-ac8e-9d2fd5bffc1f