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diff --git a/manuals/chickadee/Bezier-Curves.html b/manuals/chickadee/Bezier-Curves.html new file mode 100644 index 0000000..6a49b59 --- /dev/null +++ b/manuals/chickadee/Bezier-Curves.html @@ -0,0 +1,174 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 2017 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 6.5, http://www.gnu.org/software/texinfo/ --> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<title>Bezier Curves (The Chickadee Game Toolkit)</title> + +<meta name="description" content="Bezier Curves (The Chickadee Game Toolkit)"> +<meta name="keywords" content="Bezier Curves (The Chickadee Game Toolkit)"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<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="Math.html#Math" rel="up" title="Math"> +<link href="Path-Finding.html#Path-Finding" rel="next" title="Path Finding"> +<link href="Easings.html#Easings" rel="prev" title="Easings"> +<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.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"> +<a name="Bezier-Curves"></a> +<div class="header"> +<p> +Next: <a href="Path-Finding.html#Path-Finding" accesskey="n" rel="next">Path Finding</a>, Previous: <a href="Easings.html#Easings" accesskey="p" rel="prev">Easings</a>, Up: <a href="Math.html#Math" accesskey="u" rel="up">Math</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="Bezier-Curves-1"></a> +<h4 class="subsection">2.2.8 Bezier Curves</h4> + +<p>The <code>(chickadee math bezier)</code> module provides an API for +describing cubic Bezier curves in 2D space. These curves are notably +used in font description, vector graphics programs, and when it comes +to games: path building. With Bezier curves, it’s somewhat easy to +create a smooth looking path for an enemy to move along, for example. +Bezier curves become particularly interesting when they are chained +together to form a Bezier “path”, where the end point of one curve +becomes the starting point of the next. +</p> +<p>Currently, the rendering of Bezier curves is rather crude and provided +mostly for visualizing and debugging curves that would be unseen in +the final game. See See <a href="Lines-and-Shapes.html#Lines-and-Shapes">Lines and Shapes</a> for more information. +</p> +<dl> +<dt><a name="index-make_002dbezier_002dcurve"></a>Procedure: <strong>make-bezier-curve</strong> <em><var>p0</var> <var>p1</var> <var>p2</var> <var>p3</var></em></dt> +<dd><p>Return a new Bezier curve object whose starting point is <var>p0</var>, +ending point is <var>p3</var>, and control points are <var>p1</var> and +<var>p2</var>. All points are 2D vectors. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dcurve_003f"></a>Procedure: <strong>bezier-curve?</strong> <em><var>obj</var></em></dt> +<dd><p>Return <code>#t</code> if <var>obj</var> is a Bezier curve. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dcurve_002dp0"></a>Procedure: <strong>bezier-curve-p0</strong> <em><var>bezier</var></em></dt> +<dd><p>Return the starting point of <var>bezier</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dcurve_002dp1"></a>Procedure: <strong>bezier-curve-p1</strong> <em><var>bezier</var></em></dt> +<dd><p>Return the first control point of <var>bezier</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dcurve_002dp2"></a>Procedure: <strong>bezier-curve-p2</strong> <em><var>bezier</var></em></dt> +<dd><p>Return the second control point of <var>bezier</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dcurve_002dp3"></a>Procedure: <strong>bezier-curve-p3</strong> <em><var>bezier</var></em></dt> +<dd><p>Return the end point of <var>bezier</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dpath"></a>Procedure: <strong>bezier-path</strong> <em>. <var>control-points</var></em></dt> +<dd><p>Return a list of connected bezier curves defined by +<var>control-points</var>. The first curve is defined by the first 4 +arguments and every additional curve thereafter requires 3 additional +arguments. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dcurve_002dpoint_002dat"></a>Procedure: <strong>bezier-curve-point-at</strong> <em><var>bezier</var> <var>t</var></em></dt> +<dd><p>Return the coordinates for <var>bezier</var> at <var>t</var> (a value in the +range [0, 1] representing how far from the start of the curve to +check) as a 2D vector. +</p></dd></dl> + +<dl> +<dt><a name="index-bezier_002dcurve_002dpoint_002dat_0021"></a>Procedure: <strong>bezier-curve-point-at!</strong> <em><var>dest</var> <var>bezier</var> <var>t</var></em></dt> +<dd><p>Modify the 2D vector <var>dest</var> in-place to contain the coordinates +for <var>bezier</var> at <var>t</var>. +</p></dd></dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Path-Finding.html#Path-Finding" accesskey="n" rel="next">Path Finding</a>, Previous: <a href="Easings.html#Easings" accesskey="p" rel="prev">Easings</a>, Up: <a href="Math.html#Math" accesskey="u" rel="up">Math</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> + + + +</body> +</html> |