Rename hint.txt and hint.text to README.md

2013/endoh4/README.md

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+# Most solid
+
+Yusuke Endoh  
+<mame@ruby-lang.org>  
+<https://github.com/mame/>  
+
+
+## Judges' comments:
+### To build:
+
+    make endoh4
+
+### To run:
+
+    ./endoh4
+
+### Try:
+
+NOTE: The author recommends the use of xterm.
+
+    ./endoh4 < cube.txt
+
+For example, if you are a soccer fan, try:
+
+    make all
+    ./endoh4 < solids/archimedian-solid/a11-truncated-icosahedron.txt
+
+### Selected Judges Remarks:
+
+This program is formatted as the net for a tetrahedron. (hint, try feeding the
+program it's own source code).  When it runs there is an animation for the
+computation to work out the convex hull.
+
+## Author's comments:
+### Spec
+
+This is a convex polyhedron viewer, which:
+
+1. reads three-dimentional vertices (3N float values) from stdin,
+2. calculates a convex hull of them, and
+3. renders it.
+
+This simple spec involves many details.
+
+* 3D convex hull calculation
+  * recursive gift wrapping algorithm
+  * automatical merging of (almost) co-planar faces
+    (i.e., faces are not triangulated)
+  * random perturbation for robustness
+* 3D rendering
+  * perspective projection
+  * ASCII line drawing: `"',;;;,;'"`
+  * camera in a spherical spiral orbit
+
+(Note that this program does not use `math.h`.)
+
+### Portability
+
+I think it conforms with both C89 and C99.
+I confirmed that it worked on gcc, clang, and tcc.
+It should not be warned with -pedantic and -Wextra.
+
+### Tips
+
+You may want to use `tput` to hide a terminal cursor.
+
+    tput civis
+    ./endoh4 < cube.txt
+    tput cnorm
+
+### Bonuses
+
+You can change the screen size.  Let the aspect ratio be about 3:1.
+
+    gcc -DS=120,40 -o endoh4 endoh4.c
+
+The shape of this code is the geometric net of a regular tetrahedron.
+  So, try:
+
+    ./endoh4 < endoh4.c
+
+The solids.tbz2 file includes various solid data:
+[Platonic solids](http://en.wikipedia.org/wiki/Platonic_solid),
+[Archimedean solids](http://en.wikipedia.org/wiki/Archimedean_solid),
+[Prisms](http://en.wikipedia.org/wiki/Prism_%28geometry%29),
+[Antiprisms](http://en.wikipedia.org/wiki/Antiprism),
+[Bipyramids](http://en.wikipedia.org/wiki/Bipyramid),
+[Trapezohedrons](http://en.wikipedia.org/wiki/Trapezohedron), and
+[Johnson solids](http://en.wikipedia.org/wiki/Johnson_solid).
+
+I created the files by using the POV-Ray scripts
+([1](http://en.wikipedia.org/wiki/File:Poly.pov) and
+ [2](http://en.wikipedia.org/wiki/User:AndrewKepert/poly.pov))
+in Wikipedia.
+They are copyrighted in CC BY-SA 3.0
+by "User:Cyp" and "User:AndrewKepert".
+
+--------------------------------------------------------------------------------
+<!--
+(c) Copyright 1984-2015, [Leo Broukhis, Simon Cooper, Landon Curt Noll][judges] - All rights reserved
+This work is licensed under a [Creative Commons Attribution-ShareAlike 3.0 Unported License][cc].
+
+[judges]: http://www.ioccc.org/judges.html
+[cc]: http://creativecommons.org/licenses/by-sa/3.0/
+-->