Added options into osgprerender for controlling how to do the pre rendering i.e.
--fbo, --pbuffer, --fb --window, and also added the option for controlling the
window size with --width and --height.
"On fixing the pointer access I discovered that reading osga archives
containing ive files went into a cpu loop. This turned out to be a
problem with proxy_streambuf on Solaris. Public methods in the Solaris
streambuf standard library implementation rely on the gptr() being set,
which proxy_streambuf was not doing. So I have modified
proxy_streambuf to set the input sequence pointers, and have also
aligned it more with the standard library streambuf implementation
where all input is through underflow(), not uflow() which merely calls
underflow() and advances the pointer."
From Robert Osfield, change from using pointer cast and assignment to using
a templated _write and _read method to avoid pointer aliasing to 2/4/8
byte boundaries that some computer system may produce. These changes
where inspried by Colin McDonalds change to using memcpy, these
changes weren't merged as memcpy is not as clear in naming as _read,
_write and memcpy will incurr a function call just for copy a
uint.
"Some makedefs fixes for Solaris:
For multithreaded applications the -mt option must be specified on both
the compile and link steps, to ensure correct behaviour. According to
the Sun compiler documentation it sets REENTRANT flags in the system
header files, and links the -lthread library in the correct order.
When compiling shared libraries the -KPIC option should be specified.
Although Solaris will handle shared libraries without
position-independent code there is a performance penalty. The linker
reference manual says: 'If a shared object is built from code that is
not position-independent, the text segment will usually require a large
number of relocations to be performed at runtime. Although the runtime
linker is equipped to handle this, the system overhead this creates can
cause serious performance degradation'."
