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diff --git a/manuals/chickadee/Scripts.html b/manuals/chickadee/Scripts.html deleted file mode 100644 index b62bb2d..0000000 --- a/manuals/chickadee/Scripts.html +++ /dev/null @@ -1,212 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> -<html> -<!-- 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 -or any later version published by the Free Software Foundation; -with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. -A copy of the license is included in the section entitled "GNU -Free Documentation License". - -A copy of the license is also available from the Free Software -Foundation Web site at http://www.gnu.org/licenses/fdl.html. - - -* Chickadee: (chickadee). Game programming toolkit for Guile. - -The document was typeset with -http://www.texinfo.org/ (GNU 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" /> -<title>Scripts (The Chickadee Game Toolkit)</title> - -<meta name="description" content="Scripts (The Chickadee Game Toolkit)" /> -<meta name="keywords" content="Scripts (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="Scripting.html" rel="up" title="Scripting" /> -<link href="Tweening.html" rel="next" title="Tweening" /> -<link href="Agendas.html" rel="prev" title="Agendas" /> -<style type="text/css"> -<!-- -a.summary-letter {text-decoration: none} -blockquote.indentedblock {margin-right: 0em} -div.display {margin-left: 3.2em} -div.example {margin-left: 3.2em} -div.lisp {margin-left: 3.2em} -kbd {font-style: oblique} -pre.display {font-family: inherit} -pre.format {font-family: inherit} -pre.menu-comment {font-family: serif} -pre.menu-preformatted {font-family: serif} -span.nolinebreak {white-space: nowrap} -span.roman {font-family: initial; font-weight: normal} -span.sansserif {font-family: sans-serif; font-weight: normal} -ul.no-bullet {list-style: none} -@media (min-width: 1140px) { - body { - margin-left: 14rem; - margin-right: 4rem; - max-width: 52rem; - } -} - -@media (min-width: 800px) and (max-width: 1140px) { - body { - margin-left: 6rem; - margin-right: 4rem; - max-width: 52rem; - } -} - -@media (max-width: 800px) { - body { - margin: 1rem; - } -} - ---> -</style> -<link rel="stylesheet" type="text/css" href="https://dthompson.us/css/dthompson.css" /> - - -</head> - -<body lang="en"> -<span id="Scripts"></span><div class="header"> -<p> -Next: <a href="Tweening.html" accesskey="n" rel="next">Tweening</a>, Previous: <a href="Agendas.html" accesskey="p" rel="prev">Agendas</a>, Up: <a href="Scripting.html" accesskey="u" rel="up">Scripting</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 /> -<span id="Scripts-1"></span><h4 class="subsection">5.5.2 Scripts</h4> - -<p>Now that we can schedule tasks, let’s take things to the next level. -It sure would be great if we could make procedures that described a -series of actions that happened over time, especially if we could do -so without contorting our code into a nest of callback procedures. -This is where scripts come in. With scripts we can write code in a -linear way, in a manner that appears to be synchronous, but with the -ability to suspend periodically in order to let other scripts have a -turn and prevent blocking the game loop. Building on top of the -scheduling that agendas provide, here is a script that models a child -trying to get their mother’s attention: -</p> -<div class="lisp"> -<pre class="lisp"><span class="syntax-open">(</span><span class="syntax-symbol">script</span> - <span class="syntax-open">(</span><span class="syntax-symbol">while</span> <span class="syntax-symbol">#t</span> - <span class="syntax-open">(</span><span class="syntax-symbol">display</span> <span class="syntax-string">"mom!"</span><span class="syntax-close">)</span> - <span class="syntax-open">(</span><span class="syntax-symbol">newline</span><span class="syntax-close">)</span> - <span class="syntax-open">(</span><span class="syntax-symbol">sleep</span> <span class="syntax-symbol">60</span><span class="syntax-close">)</span><span class="syntax-close">)</span><span class="syntax-close">)</span> <span class="syntax-comment">; where 60 = 1 second of real time -</span></pre></div> - -<p>This code runs in an endless loop, but the <code>sleep</code> procedure -suspends the script and schedules it to be run later by the agenda. -So, after each iteration of the loop, control is returned back to the -game loop and the program is not stuck spinning in a loop that will -never exit. Pretty neat, eh? -</p> -<p>Scripts can suspend to any capable handler, not just the agenda. -The <code>yield</code> procedure will suspend the current script and pass -its “continuation” to a handler procedure. This handler procedure -could do anything. Perhaps the handler stashes the continuation -somewhere where it will be resumed when the user presses a specific -key on the keyboard, or maybe it will be resumed when the player picks -up an item off of the dungeon floor; the sky is the limit. -</p> -<p>Sometimes it is necessary to abruptly terminate a script after it has -been started. For example, when an enemy is defeated their AI routine -needs to be shut down. When a script is spawned, a handle to that -script is returned that can be used to cancel it when desired. -</p> -<div class="lisp"> -<pre class="lisp"><span class="syntax-open">(</span><span class="syntax-special">define</span> <span class="syntax-symbol">script</span> <span class="syntax-open">(</span><span class="syntax-symbol">script</span> <span class="syntax-open">(</span><span class="syntax-symbol">while</span> <span class="syntax-symbol">#t</span> <span class="syntax-open">(</span><span class="syntax-symbol">display</span> <span class="syntax-string">"hey\n"</span><span class="syntax-close">)</span> <span class="syntax-open">(</span><span class="syntax-symbol">sleep</span> <span class="syntax-symbol">60</span><span class="syntax-close">)</span><span class="syntax-close">)</span><span class="syntax-close">)</span><span class="syntax-close">)</span> -<span class="syntax-comment">;; sometime later -</span><span class="syntax-open">(</span><span class="syntax-symbol">cancel-script</span> <span class="syntax-symbol">script</span><span class="syntax-close">)</span> -</pre></div> - -<dl> -<dt id="index-spawn_002dscript">Procedure: <strong>spawn-script</strong> <em>thunk</em></dt> -<dd><p>Apply <var>thunk</var> as a script and return a handle to it. -</p></dd></dl> - -<dl> -<dt id="index-script">Syntax: <strong>script</strong> <em>body …</em></dt> -<dd><p>Evaluate <var>body</var> as a script and return a handle to it. -</p></dd></dl> - -<dl> -<dt id="index-script_003f">Procedure: <strong>script?</strong> <em>obj</em></dt> -<dd><p>Return <code>#t</code> if <var>obj</var> is a script handle. -</p></dd></dl> - -<dl> -<dt id="index-script_002dcancelled_003f">Procedure: <strong>script-cancelled?</strong> <em>obj</em></dt> -<dd><p>Return <code>#t</code> if <var>obj</var> has been cancelled. -</p></dd></dl> - -<dl> -<dt id="index-script_002drunning_003f">Procedure: <strong>script-running?</strong> <em>obj</em></dt> -<dd><p>Return <code>#t</code> if <var>obj</var> has not yet terminated or been -cancelled. -</p></dd></dl> - -<dl> -<dt id="index-script_002dcomplete_003f">Procedure: <strong>script-complete?</strong> <em>obj</em></dt> -<dd><p>Return <code>#t</code> if <var>obj</var> has terminated. -</p></dd></dl> - -<dl> -<dt id="index-cancel_002dscript">Procedure: <strong>cancel-script</strong> <em>co</em></dt> -<dd><p>Prevent further execution of the script <var>co</var>. -</p></dd></dl> - -<dl> -<dt id="index-yield">Procedure: <strong>yield</strong> <em>handler</em></dt> -<dd><p>Suspend the current script and pass its continuation to the -procedure <var>handler</var>. -</p></dd></dl> - -<dl> -<dt id="index-join">Procedure: <strong>join</strong> <em>script</em></dt> -<dd><p>Suspend the current script until <var>script</var> has terminated. -</p></dd></dl> - -<dl> -<dt id="index-sleep">Procedure: <strong>sleep</strong> <em>duration</em></dt> -<dd><p>Wait <var>duration</var> before resuming the current script. -</p></dd></dl> - -<dl> -<dt id="index-wait_002duntil">Syntax: <strong>wait-until</strong> <em>condition</em></dt> -<dd><p>Wait until <var>condition</var> is met before resuming the current script. -</p> -<div class="lisp"> -<pre class="lisp"><span class="syntax-open">(</span><span class="syntax-symbol">script</span> - <span class="syntax-open">(</span><span class="syntax-symbol">wait-until</span> <span class="syntax-open">(</span><span class="syntax-symbol">key-pressed?</span> <span class="syntax-symbol">'z</span><span class="syntax-close">)</span><span class="syntax-close">)</span> - <span class="syntax-open">(</span><span class="syntax-symbol">display</span> <span class="syntax-string">"you pressed the Z key!\n"</span><span class="syntax-close">)</span><span class="syntax-close">)</span> -</pre></div> - -</dd></dl> - -<dl> -<dt id="index-forever">Syntax: <strong>forever</strong> <em>body …</em></dt> -<dd><p>Evaluate <var>body</var> in an endless loop. -</p></dd></dl> - -<hr /> -<div class="header"> -<p> -Next: <a href="Tweening.html" accesskey="n" rel="next">Tweening</a>, Previous: <a href="Agendas.html" accesskey="p" rel="prev">Agendas</a>, Up: <a href="Scripting.html" accesskey="u" rel="up">Scripting</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> - - - -</body> -</html> |