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Diffstat (limited to 'manuals/chickadee/Path-Finding.html')
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1 files changed, 33 insertions, 33 deletions
diff --git a/manuals/chickadee/Path-Finding.html b/manuals/chickadee/Path-Finding.html index 40dc80e..150ef88 100644 --- a/manuals/chickadee/Path-Finding.html +++ b/manuals/chickadee/Path-Finding.html @@ -1,6 +1,6 @@ <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> -<!-- Copyright (C) 2017-2021 David Thompson davet@gnu.org +<!-- Copyright (C) 2017-2023 David Thompson dthompson2@worcester.edu Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 @@ -17,25 +17,25 @@ Foundation Web site at http://www.gnu.org/licenses/fdl.html. The document was typeset with http://www.texinfo.org/ (GNU Texinfo). - --> -<!-- Created by GNU Texinfo 6.7, http://www.gnu.org/software/texinfo/ --> + --> +<!-- Created by GNU Texinfo 6.7, http://www.gnu.org/software/texinfo/ --> <head> -<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Path Finding (The Chickadee Game Toolkit)</title> -<meta name="description" content="Path Finding (The Chickadee Game Toolkit)"> -<meta name="keywords" content="Path Finding (The Chickadee Game Toolkit)"> -<meta name="resource-type" content="document"> -<meta name="distribution" content="global"> -<meta name="Generator" content="makeinfo"> -<link href="index.html" rel="start" title="Top"> -<link href="Index.html" rel="index" title="Index"> -<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> -<link href="Data-Structures.html" rel="up" title="Data Structures"> -<link href="Copying-This-Manual.html" rel="next" title="Copying This Manual"> -<link href="Grids.html" rel="prev" title="Grids"> +<meta name="description" content="Path Finding (The Chickadee Game Toolkit)" /> +<meta name="keywords" content="Path Finding (The Chickadee Game Toolkit)" /> +<meta name="resource-type" content="document" /> +<meta name="distribution" content="global" /> +<meta name="Generator" content="makeinfo" /> +<link href="index.html" rel="start" title="Top" /> +<link href="Index.html" rel="index" title="Index" /> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents" /> +<link href="Data-Structures.html" rel="up" title="Data Structures" /> +<link href="Copying-This-Manual.html" rel="next" title="Copying This Manual" /> +<link href="Grids.html" rel="prev" title="Grids" /> <style type="text/css"> -<!-- +<!-- a.summary-letter {text-decoration: none} blockquote.indentedblock {margin-right: 0em} div.display {margin-left: 3.2em} @@ -72,9 +72,9 @@ ul.no-bullet {list-style: none} } } ---> +--> </style> -<link rel="stylesheet" type="text/css" href="https://dthompson.us/css/dthompson.css"> +<link rel="stylesheet" type="text/css" href="https://dthompson.us/css/dthompson.css" /> </head> @@ -84,7 +84,7 @@ ul.no-bullet {list-style: none} <p> Previous: <a href="Grids.html" accesskey="p" rel="prev">Grids</a>, Up: <a href="Data-Structures.html" accesskey="u" rel="up">Data Structures</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Index.html" title="Index" rel="index">Index</a>]</p> </div> -<hr> +<hr /> <span id="Path-Finding-1"></span><h4 class="subsection">5.6.6 Path Finding</h4> <p>Most game worlds have maps. Often, these games have a need to move @@ -101,19 +101,19 @@ map implementation! <p>The example below defines a very simple town map and finds the quickest way to get from the town common to the school. </p> -<div class="example"> -<pre class="example">(define world-map - '((town-common . (town-hall library)) - (town-hall . (town-common school)) - (library . (town-common cafe)) - (school . (town-hall cafe)) - (cafe . (library school)))) -(define (neighbors building) - (assq-ref town-map building)) -(define (cost a b) 1) -(define (distance a b) 1) -(define pf (make-path-finder)) -(a* pf 'town-common 'school neighbors cost distance) +<div class="lisp"> +<pre class="lisp"><span class="syntax-open">(</span><span class="syntax-special">define</span> <span class="syntax-symbol">world-map</span> + <span class="syntax-symbol">'</span><span class="syntax-open">(</span><span class="syntax-open">(</span><span class="syntax-symbol">town-common</span> <span class="syntax-symbol">.</span> <span class="syntax-open">(</span><span class="syntax-symbol">town-hall</span> <span class="syntax-special">library</span><span class="syntax-close">)</span><span class="syntax-close">)</span> + <span class="syntax-open">(</span><span class="syntax-symbol">town-hall</span> <span class="syntax-symbol">.</span> <span class="syntax-open">(</span><span class="syntax-symbol">town-common</span> <span class="syntax-symbol">school</span><span class="syntax-close">)</span><span class="syntax-close">)</span> + <span class="syntax-open">(</span><span class="syntax-special">library</span> <span class="syntax-symbol">.</span> <span class="syntax-open">(</span><span class="syntax-symbol">town-common</span> <span class="syntax-symbol">cafe</span><span class="syntax-close">)</span><span class="syntax-close">)</span> + <span class="syntax-open">(</span><span class="syntax-symbol">school</span> <span class="syntax-symbol">.</span> <span class="syntax-open">(</span><span class="syntax-symbol">town-hall</span> <span class="syntax-symbol">cafe</span><span class="syntax-close">)</span><span class="syntax-close">)</span> + <span class="syntax-open">(</span><span class="syntax-symbol">cafe</span> <span class="syntax-symbol">.</span> <span class="syntax-open">(</span><span class="syntax-special">library</span> <span class="syntax-symbol">school</span><span class="syntax-close">)</span><span class="syntax-close">)</span><span class="syntax-close">)</span><span class="syntax-close">)</span> +<span class="syntax-open">(</span><span class="syntax-special">define</span> <span class="syntax-open">(</span><span class="syntax-symbol">neighbors</span> <span class="syntax-symbol">building</span><span class="syntax-close">)</span> + <span class="syntax-open">(</span><span class="syntax-symbol">assq-ref</span> <span class="syntax-symbol">town-map</span> <span class="syntax-symbol">building</span><span class="syntax-close">)</span><span class="syntax-close">)</span> +<span class="syntax-open">(</span><span class="syntax-special">define</span> <span class="syntax-open">(</span><span class="syntax-symbol">cost</span> <span class="syntax-symbol">a</span> <span class="syntax-symbol">b</span><span class="syntax-close">)</span> <span class="syntax-symbol">1</span><span class="syntax-close">)</span> +<span class="syntax-open">(</span><span class="syntax-special">define</span> <span class="syntax-open">(</span><span class="syntax-symbol">distance</span> <span class="syntax-symbol">a</span> <span class="syntax-symbol">b</span><span class="syntax-close">)</span> <span class="syntax-symbol">1</span><span class="syntax-close">)</span> +<span class="syntax-open">(</span><span class="syntax-special">define</span> <span class="syntax-symbol">pf</span> <span class="syntax-open">(</span><span class="syntax-symbol">make-path-finder</span><span class="syntax-close">)</span><span class="syntax-close">)</span> +<span class="syntax-open">(</span><span class="syntax-symbol">a*</span> <span class="syntax-symbol">pf</span> <span class="syntax-symbol">'town-common</span> <span class="syntax-symbol">'school</span> <span class="syntax-symbol">neighbors</span> <span class="syntax-symbol">cost</span> <span class="syntax-symbol">distance</span><span class="syntax-close">)</span> </pre></div> <p>In this case, the <code>a*</code> procedure will return the list @@ -159,7 +159,7 @@ number. <var>distance</var> is a procedure that accepts two nodes and returns an approximate distance between them. </p></dd></dl> -<hr> +<hr /> <div class="header"> <p> Previous: <a href="Grids.html" accesskey="p" rel="prev">Grids</a>, Up: <a href="Data-Structures.html" accesskey="u" rel="up">Data Structures</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Index.html" title="Index" rel="index">Index</a>]</p> |