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| author | David Thompson <dthompson@vistahigherlearning.com> | 2019-06-04 20:49:16 -0400 |
|---|---|---|
| committer | David Thompson <dthompson@vistahigherlearning.com> | 2019-06-04 20:49:16 -0400 |
| commit | 279f17ac0e1b3d019c2b294098e834d249376686 (patch) | |
| tree | 47be849d3b35635d167e00cd8448815a75167a23 /manuals/chickadee/Fonts.html | |
| parent | 7b808b9268ec735a7a176d10bf1887b3fa66d13e (diff) | |
Update chickadee manual.
Diffstat (limited to 'manuals/chickadee/Fonts.html')
| -rw-r--r-- | manuals/chickadee/Fonts.html | 84 |
1 files changed, 30 insertions, 54 deletions
diff --git a/manuals/chickadee/Fonts.html b/manuals/chickadee/Fonts.html index a4ed5c6..d65d67c 100644 --- a/manuals/chickadee/Fonts.html +++ b/manuals/chickadee/Fonts.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 David Thompson davet@gnu.org +<!-- Copyright (C) 2017, 2018, 2019 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 @@ -13,6 +13,8 @@ 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). --> @@ -30,7 +32,7 @@ http://www.texinfo.org/ (GNU Texinfo). <link href="Index.html#Index" rel="index" title="Index"> <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> <link href="Graphics.html#Graphics" rel="up" title="Graphics"> -<link href="Blending-and-Depth-Testing.html#Blending-and-Depth-Testing" rel="next" title="Blending and Depth Testing"> +<link href="Particles.html#Particles" rel="next" title="Particles"> <link href="Lines-and-Shapes.html#Lines-and-Shapes" rel="prev" title="Lines and Shapes"> <style type="text/css"> <!-- @@ -90,91 +92,70 @@ ul.no-bullet {list-style: none} <a name="Fonts"></a> <div class="header"> <p> -Next: <a href="Blending-and-Depth-Testing.html#Blending-and-Depth-Testing" accesskey="n" rel="next">Blending and Depth Testing</a>, Previous: <a href="Lines-and-Shapes.html#Lines-and-Shapes" accesskey="p" rel="prev">Lines and Shapes</a>, Up: <a href="Graphics.html#Graphics" accesskey="u" rel="up">Graphics</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="Particles.html#Particles" accesskey="n" rel="next">Particles</a>, Previous: <a href="Lines-and-Shapes.html#Lines-and-Shapes" accesskey="p" rel="prev">Lines and Shapes</a>, Up: <a href="Graphics.html#Graphics" accesskey="u" rel="up">Graphics</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="Fonts-1"></a> -<h4 class="subsection">2.3.6 Fonts</h4> - -<p>Unlike the traditional TrueType font format that many are accustomed -to, Chickadee loads and renders bitmap fonts in the -<a href="http://www.angelcode.com/products/bmfont/doc/file_format.html">Angel Code format</a>. But why use this seemingly obscure format? It’s -easy to find TTFs but not easy to find FNTs (the canonical file -extension used for Angel Code fonts) and bitmap fonts don’t scale -well. The reason is efficiency. -</p> -<p>If all of the glyphs of a font are pre-rendered and packed into an -image file then it becomes possible to use a texture atlas -(see <a href="Textures.html#Textures">Textures</a>) and a sprite batch (see <a href="Sprites.html#Sprites">Sprites</a>) when -rendering, which is a more efficient way to render fonts than using, -say, <a href="https://www.libsdl.org/projects/SDL_ttf/">SDL_ttf</a> or other -solutions that involve using the FreeType library directly. -</p> -<p>Now what about scaling? In libraries that use TTF fonts, one must -choose the size that the glyphs will be rasterized at up front. To -use <code>n</code> sizes of the same font, one must load <code>n</code> variants -of that font. If the size of the text is dynamic, some kind of -texture scaling algorithm must be used and the text will inevitably -look blurry. At first glance, using bitmap fonts seem to have an even -worse issue. Instead of just loading the same font <code>n</code> times at -different sizes, one would need to generate <code>n</code> image files for -each font size needed. This is where the “signed distance field” -rendering technique comes in. Introduced by -<a href="http://www.valvesoftware.com/.../2007/SIGGRAPH2007_AlphaTestedMagnification.pdf">Valve</a> in 2007, signed distance field fonts can be efficiently stored -in a bitmap and be rendered at arbitrary scale factors with good -results. +<h4 class="subsection">2.3.5 Fonts</h4> + +<p>Printing text to the screen is quite easy: </p> -<p>While Chickadee does not yet offer a tool for converting TTF fonts -into FNT fonts, tools such as -<a href="https://github.com/libgdx/libgdx/wiki/Hiero">Hiero</a> may be used -in the meantime. +<div class="example"> +<pre class="example">(draw-text "Hello, world" (vec2 100.0 100.0)) +</pre></div> + +<p>Chickadee loads and renders bitmap fonts in the +<a href="http://www.angelcode.com/products/bmfont/doc/file_format.html">Angel Code format</a>. A default font named “Good Neighbors” is +built-in to Chickadee and is used for all text rendering operations +where a font is not specified, as is the case in the above example. </p> <p>The following procedures can be found in the <code>(chickadee render -font)</code> module. +font)</code> module: </p> <dl> -<dt><a name="index-load_002dfont"></a>Procedure: <strong>load-font</strong> <em><var>file</var></em></dt> -<dd><p>Load the Angel Code formatted XML document in <var>file</var> and return a -new font object. +<dt><a name="index-load_002dfont"></a>Procedure: <strong>load-font</strong> <em>file</em></dt> +<dd><p>Load the Angel Code font (in either XML or FNT format) in <var>file</var> +and return a new font object. </p></dd></dl> <dl> -<dt><a name="index-font_003f"></a>Procedure: <strong>font?</strong> <em><var>obj</var></em></dt> +<dt><a name="index-font_003f"></a>Procedure: <strong>font?</strong> <em>obj</em></dt> <dd><p>Return <code>#t</code> if <var>obj</var> is a font object. </p></dd></dl> <dl> -<dt><a name="index-font_002dface"></a>Procedure: <strong>font-face</strong> <em><var>font</var></em></dt> +<dt><a name="index-font_002dface"></a>Procedure: <strong>font-face</strong> <em>font</em></dt> <dd><p>Return the name of <var>font</var>. </p></dd></dl> <dl> -<dt><a name="index-font_002dline_002dheight"></a>Procedure: <strong>font-line-height</strong> <em><var>font</var></em></dt> +<dt><a name="index-font_002dline_002dheight"></a>Procedure: <strong>font-line-height</strong> <em>font</em></dt> <dd><p>Return the line height of <var>font</var>. </p></dd></dl> <dl> -<dt><a name="index-font_002dline_002dheight-1"></a>Procedure: <strong>font-line-height</strong> <em><var>font</var></em></dt> +<dt><a name="index-font_002dline_002dheight-1"></a>Procedure: <strong>font-line-height</strong> <em>font</em></dt> <dd><p>Return the line height of <var>font</var>. </p></dd></dl> <dl> -<dt><a name="index-font_002dbold_003f"></a>Procedure: <strong>font-bold?</strong> <em><var>font</var></em></dt> +<dt><a name="index-font_002dbold_003f"></a>Procedure: <strong>font-bold?</strong> <em>font</em></dt> <dd><p>Return <code>#t</code> if <var>font</var> is a bold font. </p></dd></dl> <dl> -<dt><a name="index-font_002ditalic_003f"></a>Procedure: <strong>font-italic?</strong> <em><var>font</var></em></dt> +<dt><a name="index-font_002ditalic_003f"></a>Procedure: <strong>font-italic?</strong> <em>font</em></dt> <dd><p>Return <code>#t</code> if <var>font</var> is an italicized font. </p></dd></dl> <dl> -<dt><a name="index-draw_002dtext"></a>Procedure: <strong>draw-text</strong> <em><var>font</var> <var>text</var> <var>position</var></em></dt> -<dd><p>[#:origin] [#:scale] [#:rotation] [#:blend-mode] +<dt><a name="index-draw_002dtext"></a>Procedure: <strong>draw-text</strong> <em>text position</em></dt> +<dd><p>[#:font] [#:origin] [#:scale] [#:rotation] [#:blend-mode] [#:start 0] [#:end <code>(string-length text)</code>] </p> <p>Draw the string <var>text</var> with the first character starting at -<var>position</var> using <var>font</var>. +<var>position</var> using <var>font</var>. If <var>font</var> is not specified, a +built-in font is used. </p> <div class="example"> <pre class="example">(draw-text font "Hello, world!" (vec2 128.0 128.0)) @@ -187,11 +168,6 @@ arguments. the other arguments. </p></dd></dl> -<hr> -<div class="header"> -<p> -Next: <a href="Blending-and-Depth-Testing.html#Blending-and-Depth-Testing" accesskey="n" rel="next">Blending and Depth Testing</a>, Previous: <a href="Lines-and-Shapes.html#Lines-and-Shapes" accesskey="p" rel="prev">Lines and Shapes</a>, Up: <a href="Graphics.html#Graphics" accesskey="u" rel="up">Graphics</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> |