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diff --git a/manuals/chickadee/Rectangles.html b/manuals/chickadee/Rectangles.html index 6d0c9e8..edaf4e6 100644 --- a/manuals/chickadee/Rectangles.html +++ b/manuals/chickadee/Rectangles.html @@ -16,22 +16,22 @@ 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 6.3, http://www.gnu.org/software/texinfo/ --> +<!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ --> <head> -<title>The Chickadee Game Toolkit: Rectangles</title> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<title>Rectangles (The Chickadee Game Toolkit)</title> -<meta name="description" content="The Chickadee Game Toolkit: Rectangles"> -<meta name="keywords" content="The Chickadee Game Toolkit: Rectangles"> +<meta name="description" content="Rectangles (The Chickadee Game Toolkit)"> +<meta name="keywords" content="Rectangles (The Chickadee Game Toolkit)"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="makeinfo"> -<meta http-equiv="Content-Type" content="text/html; 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="Math.html#Math" rel="up" title="Math"> -<link href="Graphics.html#Graphics" rel="next" title="Graphics"> -<link href="Matrices.html#Matrices" rel="prev" title="Matrices"> +<link href="Grid.html#Grid" rel="next" title="Grid"> +<link href="Vectors.html#Vectors" rel="prev" title="Vectors"> <style type="text/css"> <!-- a.summary-letter {text-decoration: none} @@ -90,12 +90,247 @@ ul.no-bullet {list-style: none} <a name="Rectangles"></a> <div class="header"> <p> -Previous: <a href="Matrices.html#Matrices" accesskey="p" rel="prev">Matrices</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> +Next: <a href="Grid.html#Grid" accesskey="n" rel="next">Grid</a>, Previous: <a href="Vectors.html#Vectors" accesskey="p" rel="prev">Vectors</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="Rectangles-1"></a> -<h4 class="subsection">2.3.3 Rectangles</h4> +<h4 class="subsection">2.2.3 Rectangles</h4> + +<p>The <code>(chickadee math rect)</code> module provides an API for +manipulating axis-aligned bounding boxes (AABBs). AABBs are often +used for collision detection in games. Common use-cases are defining +“hitboxes” in platformers or using them for the “broad phase” of a +collision detection algorithm that uses a more complex (and thus +slower) method of determining the actual collisions. +</p> +<p>Like some of the other math modules, there exists a collection of +functions that do in-place modification of rectangles for use in +performance critical code paths. +</p> +<dl> +<dt><a name="index-make_002drect"></a>Procedure: <strong>make-rect</strong> <em><var>x</var> <var>y</var> <var>width</var> <var>height</var></em></dt> +<dd><p>Create a new rectangle that is <var>width</var> by <var>height</var> in size and +whose bottom-left corner is located at (<var>x</var>, <var>y</var>). +</p></dd></dl> + +<dl> +<dt><a name="index-rect_003f"></a>Procedure: <strong>rect?</strong> <em><var>obj</var></em></dt> +<dd><p>Return <code>#t</code> if <var>obj</var> is a rectangle. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dwithin_003f"></a>Procedure: <strong>rect-within?</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Return <code>#t</code> if <var>rect2</var> is completely within <var>rect1</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dintersects_003f"></a>Procedure: <strong>rect-intersects?</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Return <code>#t</code> if <var>rect2</var> overlaps <var>rect1</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dcontains_003f"></a>Procedure: <strong>rect-contains?</strong> <em><var>rect</var> <var>x</var> <var>y</var></em></dt> +<dd><p>Return <code>#t</code> if the coordinates (<var>x</var>, <var>y</var>) are within +<var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dcontains_002dvec2_003f"></a>Procedure: <strong>rect-contains-vec2?</strong> <em><var>rect</var> <var>v</var></em></dt> +<dd><p>Return <code>#t</code> if the 2D vector <var>v</var> is within the bounds of +<var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dx"></a>Procedure: <strong>rect-x</strong> <em><var>rect</var></em></dt> +<dd><p>Return the X coordinate of the lower-left corner of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dy"></a>Procedure: <strong>rect-y</strong> <em><var>rect</var></em></dt> +<dd><p>Return the Y coordinate of the lower-left corner of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dleft"></a>Procedure: <strong>rect-left</strong> <em><var>rect</var></em></dt> +<dd><p>Return the left-most X coordinate of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dright"></a>Procedure: <strong>rect-right</strong> <em><var>rect</var></em></dt> +<dd><p>Return the right-most X coordinate of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dbottom"></a>Procedure: <strong>rect-bottom</strong> <em><var>rect</var></em></dt> +<dd><p>Return the bottom-most Y coordinate of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dtop"></a>Procedure: <strong>rect-top</strong> <em><var>rect</var></em></dt> +<dd><p>Return the top-most Y coordinate of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dcenter_002dx"></a>Procedure: <strong>rect-center-x</strong> <em><var>rect</var></em></dt> +<dd><p>Return the X coordinate of the center of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dcenter_002dy"></a>Procedure: <strong>rect-center-y</strong> <em><var>rect</var></em></dt> +<dd><p>Return the Y coordinate of the center of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dwidth"></a>Procedure: <strong>rect-width</strong> <em><var>rect</var></em></dt> +<dd><p>Return the width of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dheight"></a>Procedure: <strong>rect-height</strong> <em><var>rect</var></em></dt> +<dd><p>Return the height of <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002darea"></a>Procedure: <strong>rect-area</strong> <em><var>rect</var></em></dt> +<dd><p>Return the surface area covered by <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dclamp_002dx"></a>Procedure: <strong>rect-clamp-x</strong> <em><var>rect</var> <var>x</var></em></dt> +<dd><p>Restrict <var>x</var> to the portion of the X axis covered by <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dclamp_002dy"></a>Procedure: <strong>rect-clamp-y</strong> <em><var>rect</var> <var>y</var></em></dt> +<dd><p>Restrict <var>y</var> to the portion of the Y axis covered by <var>rect</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dclamp"></a>Procedure: <strong>rect-clamp</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Return a new rect that adjusts the location of <var>rect1</var> so that it +is completely within <var>rect2</var>. An exception is thrown in the case +that <var>rect1</var> cannot fit completely within <var>rect2</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dmove"></a>Procedure: <strong>rect-move</strong> <em><var>rect</var> <var>x</var> <var>y</var></em></dt> +<dd><p>Return a new rectangle based on <var>rect</var> but moved to the +coordinates (<var>x</var>, <var>y</var>). +</p></dd></dl> +<dl> +<dt><a name="index-rect_002dmove_002dvec2"></a>Procedure: <strong>rect-move-vec2</strong> <em><var>rect</var> <var>v</var></em></dt> +<dd><p>Return a new rectangle based on <var>rect</var> but moved to the +coordinates in the 2D vector <var>v</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dmove_002dby"></a>Procedure: <strong>rect-move-by</strong> <em><var>rect</var> <var>x</var> <var>y</var></em></dt> +<dd><p>Return a new rectangle based on <var>rect</var> but moved by (<var>x</var>, +<var>y</var>) units relative to its current location. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dmove_002dby_002dvec2"></a>Procedure: <strong>rect-move-by-vec2</strong> <em><var>rect</var> <var>v</var></em></dt> +<dd><p>Return a new rectangle based on <var>rect</var> but moved by the 2D vector +<var>v</var> relative to its current location. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dinflate"></a>Procedure: <strong>rect-inflate</strong> <em><var>rect</var> <var>width</var> <var>height</var></em></dt> +<dd><p>Return a new rectangle based on <var>rect</var>, but expanded by +<var>width</var> units on the X axis and <var>height</var> units on the Y axis, +while keeping the rectangle centered on the same point. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dunion"></a>Procedure: <strong>rect-union</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Return a new rectangle that completely covers the area of <var>rect1</var> +and <var>rect2</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dclip"></a>Procedure: <strong>rect-clip</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Return a new rectangle that is the overlapping region of <var>rect1</var> +and <var>rect2</var>. If the two rectangles do not overlap, a rectangle of +0 width and 0 height is returned. +</p></dd></dl> + +<dl> +<dt><a name="index-set_002drect_002dx_0021"></a>Procedure: <strong>set-rect-x!</strong> <em><var>rect</var> <var>x</var></em></dt> +<dd><p>Set the left X coordinate of <var>rect</var> to <var>x</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-set_002drect_002dy_0021"></a>Procedure: <strong>set-rect-y!</strong> <em><var>rect</var> <var>y</var></em></dt> +<dd><p>Set the bottom Y coordinate of <var>rect</var> to <var>y</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-set_002drect_002dwidth_0021"></a>Procedure: <strong>set-rect-width!</strong> <em><var>rect</var> <var>width</var></em></dt> +<dd><p>Set the width of <var>rect</var> to <var>width</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-set_002drect_002dheight_0021"></a>Procedure: <strong>set-rect-height!</strong> <em><var>rect</var> <var>height</var></em></dt> +<dd><p>Set the height of <var>rect</var> to <var>height</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dmove_0021"></a>Procedure: <strong>rect-move!</strong> <em><var>rect</var> <var>x</var> <var>y</var></em></dt> +<dd><p>Move <var>rect</var> to (<var>x</var>, <var>y</var>) in-place. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dmove_002dvec2_0021"></a>Procedure: <strong>rect-move-vec2!</strong> <em><var>rect</var> <var>v</var></em></dt> +<dd><p>Move <var>rect</var> to the 2D vector <var>v</var> in-place. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dmove_002dby_0021"></a>Procedure: <strong>rect-move-by!</strong> <em><var>rect</var> <var>x</var> <var>y</var></em></dt> +<dd><p>Move <var>rect</var> by (<var>x</var>, <var>y</var>) in-place. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dmove_002dby_002dvec2_0021"></a>Procedure: <strong>rect-move-by-vec2!</strong> <em><var>rect</var> <var>v</var></em></dt> +<dd><p>Move <var>rect</var> by the 2D vector <var>v</var> in-place. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dinflate_0021"></a>Procedure: <strong>rect-inflate!</strong> <em><var>rect</var> <var>width</var> <var>height</var></em></dt> +<dd><p>Expand <var>rect</var> by <var>width</var> and <var>height</var> in-place. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dunion_0021"></a>Procedure: <strong>rect-union!</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Modify <var>rect1</var> in-place to completely cover the area of both +<var>rect1</var> and <var>rect2</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dclip_0021"></a>Procedure: <strong>rect-clip!</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Modify <var>rect1</var> in-place to be the overlapping region of +<var>rect1</var> and <var>rect2</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-rect_002dclamp_0021"></a>Procedure: <strong>rect-clamp!</strong> <em><var>rect1</var> <var>rect2</var></em></dt> +<dd><p>Adjust the location of <var>rect1</var> in-place so that its bounds are +completely within <var>rect2</var>. An exception is thrown in the case +that <var>rect1</var> cannot fit completely within <var>rect2</var>. +</p></dd></dl> + +<dl> +<dt><a name="index-vec2_002dclamp_002dto_002drect_0021"></a>Procedure: <strong>vec2-clamp-to-rect!</strong> <em><var>v</var> <var>rect</var></em></dt> +<dd><p>Restrict the coordinates of the 2D vector <var>v</var> so that they are +within the bounds of <var>rect</var>. <var>v</var> is modified in-place. +</p></dd></dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Grid.html#Grid" accesskey="n" rel="next">Grid</a>, Previous: <a href="Vectors.html#Vectors" accesskey="p" rel="prev">Vectors</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> |