All platforms
=============

      ==> The removal of LZW compression from recent versions of the TIFF
      	  library makes TIFF generation in render fail.  You can find an
	  older version of the TIFF library that still supports LZW compression
	  or you can live with the much larger uncompressed files.

	  I am undecided what the long term fix should be --
	  live with ridiculously large TIFF files? require people to find
	  an old version of libtiff with LZW support? switch entirely to
	  PNG images?

	- ISOLATE (object code 15) not yet implemented for quadric surfaces
	- Linear depth-cueing code (FOG 0) is not correct for parts of the 
	  scene behind a transparent object. This problem arises because a 
	  linear fog model does not correspond to reality. 
	  It would be possible to handle transparency correctly for an 
	  exponential fog model, but doesn't seem worth the effort right now.
	- Z-clipped objects cast un-clipped shadows.
	- The mixed Fortran/C calls to local() generate an interesting 
	  variety of compiler warnings because of inadequte type-casting
	  on the Fortran side.  
	- General quadric surfaces (other than ellipsoids) may cast spurious
	  shadows, and always fail to shadow themselves.
	- Explicit vertex colors take precedence over material colors;
	  (That's a feature, not a bug)
	- Labels with TeX-like escape sequences are always treated as Left-Align.
	- Angstrom symbol only loaded into Times/Helvetica fonts.
	- the calls in local.c to time() behave very oddly under linux and DU;
	  the first call always returns 0, so two in a row are needed
	- ribbon coloring scheme 6 doesn't work

Tru64 unix 5.1
==============
	- The new fortran compiler is not fully compatible with older
	  Compaq f77 compilers.  I think I have worked around this in the code,
	  but I may have missed something.

AIX 
===
	File indirection in render doesn't work, because opening Fortran
	LUN 6 clobbers C I/O in local.c
	Work-around : 
		Patch file render_patch.aix modifies render to use
		LUNs 5,4,3,2,1 for file indirection rather than 6,7,...
	dispose='delete' not permitted in open statement
	Work-around :
		None; temp files accumulate until deleted

linux (g77 compiler)
====================
	The g77 compiler does not support file open options 
	CARRIAGECONTROL='LIST' or DISPOSE='DELETE'.
	Work-around :
		'make linux' deletes these specifications from the source
		files; unfortunately, this means that temporary files do not
		automatically get deleted from the system temp directory.

	Optimization bug in quadric.f can cause render to fail on certain
	input.  g77 -w -malign-double quadric.f   seems to fix this.
	Separate optimization bug, also in quadric.f, can cause the
	impingement test in qinp() to give different result than the one
	in render(). This causes render to exit with an error message.

	g77 on top of gcc-2.96 (Mandrake 8.0) has been reported to produce 
	incorrect code in render;  the same report says that gcc-2.95 is OK.   
	I still recommend using a real Fortran compiler, rather than g77.

Windows
=======
	I am relying entirely on instructions kindly provided by 
	Suhaib Siddiqi, and have not tested the installation procedure at all.
	In particular the Makefile is probably out of date.

