blob: f8a685de34aff3ed415cd91f354d213918f67102 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Copyright (C) 2013, 2014 David Thompson davet@gnu.org
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.
The document was typeset with
http://www.texinfo.org/ (GNU Texinfo).
-->
<!-- Created by GNU Texinfo 6.0, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Sly: The Game Loop</title>
<meta name="description" content="Sly: The Game Loop">
<meta name="keywords" content="Sly: The Game Loop">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta charset="UTF-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Index.html#Index" rel="index" title="Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Booting.html#Booting" rel="up" title="Booting">
<link href="Math.html#Math" rel="next" title="Math">
<link href="Window-Creation.html#Window-Creation" rel="prev" title="Window Creation">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {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}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space: nowrap}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: serif; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>
</head>
<body lang="en">
<a name="The-Game-Loop"></a>
<div class="header">
<p>
Previous: <a href="Window-Creation.html#Window-Creation" accesskey="p" rel="prev">Window Creation</a>, Up: <a href="Booting.html#Booting" accesskey="u" rel="up">Booting</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Index.html#Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="The-Game-Loop-1"></a>
<h4 class="subsection">4.1.2 The Game Loop</h4>
<dl>
<dt><a name="index-draw_002dhook"></a>Scheme Variable: <strong>draw-hook</strong></dt>
<dd><p>This hook is run every time the game loop wants to render. Procedures
added to this hook should accept two arguments: <code>dt</code>, the time in
seconds since the last render call; and <code>alpha</code>, a number in the
range [0,1] that indicates how far in between two discrete updates of
the game state the loop is in. The <code>alpha</code> value is important
for smoothing animated values to avoid the “temporal aliasing”
effect that causes choppy looking animations.
</p></dd></dl>
<dl>
<dt><a name="index-after_002dgame_002dloop_002derror_002dhook"></a>Scheme Variable: <strong>after-game-loop-error-hook</strong></dt>
<dd><p>This hook is run every time the game loop catches an error.
Procedures added to this hook should accept no arguments.
</p></dd></dl>
<dl>
<dt><a name="index-run_002dgame_002dloop"></a>Scheme Procedure: <strong>run-game-loop</strong> <em>[<var>#:frame-rate</var>] [<var>#:tick-rate</var>] [<var>#:max-ticks-per-frame</var>]</em></dt>
<dd><p>Start the game loop. <code>frame-rate</code> specifies the optimal number
of frames to draw per second. <code>tick-rate</code> specifies the optimal
game logic updates per second. Both <code>frame-rate</code> and
<code>tick-rate</code> are 60 by default. <code>max-ticks-per-frame</code> is the
maximum number of times the game loop will update game state in a
single frame. When this upper bound is reached due to poor
performance, the game will start to slow down instead of becoming
completely unresponsive and possibly crashing.
</p></dd></dl>
<dl>
<dt><a name="index-stop_002dgame_002dloop"></a>Scheme Procedure: <strong>stop-game-loop</strong></dt>
<dd><p>Abort the game loop.
</p></dd></dl>
</body>
</html>
|
