Cody Boone Ferguson
22e483723c
Instead of code blocks the bug / (mis)features statuses are quoted rather than in a code block. In the case that there is more than one a line break was added at the end of all but the last one. A bug status was renamed to be slightly more correct (maybe more than one was renamed for the same purpose but at least one was). The bug statuses in the quotes are now bold to let them stand out better.
172 lines
4.0 KiB
Markdown
172 lines
4.0 KiB
Markdown
## To build:
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``` <!---sh-->
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make
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```
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If you wish to change the size (see the [Author's remarks](#authors-remarks)
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below) you can do so with the `SIZE` variable. For instance you can do:
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``` <!---sh-->
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make clobber SIZE=50,50 all
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```
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but you can also do this directly with the [endoh4.sh](%%REPO_URL%%/2013/endoh4/endoh4.sh) script as
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described below.
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### Bugs and (Mis)features:
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The current status of this entry is:
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> **STATUS: INABIAF - please DO NOT fix**
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For more detailed information see [2013/endoh4 in bugs.html](../../bugs.html#2013_endoh4).
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## To use:
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``` <!---sh-->
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./endoh4 < file
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./endoh4.sh file
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```
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The second form is preferable as it will temporarily make the cursor invisible
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as recommended by the author. If no file is specified in the `./endoh4.sh` command
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line it will feed to the program [endoh4.c](%%REPO_URL%%/2013/endoh4/endoh4.c).
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## Try:
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``` <!---sh-->
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./endoh4.sh cube.txt
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```
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Hit ctrl-c to end the program.
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The author recommends the use of xterm.
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For an example, if you are a football/soccer fan, try:
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``` <!---sh-->
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./endoh4.sh solids/archimedian-solid/a11-truncated-icosahedron.txt
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```
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You can provide more than one file:
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``` <!---sh-->
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./endoh4.sh solids/archimedian-solid/a11-truncated-icosahedron.txt cube.txt
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```
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Hit ctrl-c/intr to go to the next file.
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If you wish to change the size to `50,50` without passing any arg:
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``` <!---sh-->
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SIZE=50,50 ./endoh4.sh
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```
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Not specifying a file feeds [endoh4.c](%%REPO_URL%%/2013/endoh4/endoh4.c) to the program.
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## Judges' remarks:
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This program is formatted as the net for a tetrahedron (hint: try feeding the
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program it's own source code like `./endoh4.sh`). When it runs there is an
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animation for the computation to work out the convex hull.
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## Author's remarks:
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### Spec
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This is a convex polyhedron viewer, which:
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1. reads three-dimensional vertices (3N float values) from `stdin`,
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2. calculates a convex hull of them, and
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3. renders it.
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This simple spec involves many details.
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* 3D convex hull calculation
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* recursive gift wrapping algorithm
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* automatic merging of (almost) co-planar faces (i.e., faces are not
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triangulated)
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* random perturbation for robustness
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* 3D rendering
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* perspective projection
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* ASCII line drawing: `"',;;;,;'"`
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* camera in a spherical spiral orbit
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(Note that this program does not use `math.h`.)
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### Portability
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I think it conforms with both C89 and C99. I confirmed that it worked on gcc,
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clang, and tcc. It should not trigger warnings with `-pedantic` and `-Wextra`.
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### Tips
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You may want to use `tput` to hide the terminal cursor.
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``` <!---sh-->
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tput civis
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./endoh4 < cube.txt
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tput cnorm
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```
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or
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``` <!---sh-->
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./endoh4.sh cube.txt
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```
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### Bonuses
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You can change the screen size. Let the aspect ratio be about 3:1.
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``` <!---sh-->
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cc -DS=120,40 -o endoh4 endoh4.c
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```
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The shape of this code is the geometric net of a regular tetrahedron.
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So, try:
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``` <!---sh-->
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./endoh4 < endoh4.c # or ./endoh4.sh
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```
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The `solids` directory includes various solid data:
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- [Platonic solids](http://en.wikipedia.org/wiki/Platonic_solid)
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- [Archimedean solids](http://en.wikipedia.org/wiki/Archimedean_solid)
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- [Prisms](http://en.wikipedia.org/wiki/Prism_%28geometry%29)
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- [Antiprisms](http://en.wikipedia.org/wiki/Antiprism)
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- [Bipyramids](http://en.wikipedia.org/wiki/Bipyramid)
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- [Trapezohedrons](http://en.wikipedia.org/wiki/Trapezohedron)
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- [Johnson solids](http://en.wikipedia.org/wiki/Johnson_solid)
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I created the files by using the POV-Ray scripts
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([1](http://en.wikipedia.org/wiki/File:Poly.pov) and
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[2](http://en.wikipedia.org/wiki/User:AndrewKepert/poly.pov) in Wikipedia.
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They are copyrighted in CC BY-SA 3.0 by "User:Cyp" and "User:AndrewKepert".
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<!--
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Copyright © 1984-2024 by Landon Curt Noll. All Rights Reserved.
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You are free to share and adapt this file under the terms of this license:
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Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
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For more information, see:
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https://creativecommons.org/licenses/by-sa/4.0/
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-->
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