summaryrefslogtreecommitdiff
path: root/Build/source/libs/gd/libgd-src/docs/naturaldocs/html/files/preamble-txt.html
blob: 2ef6ae2844d35fce26800a74c2ad3578326e905f (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
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd">

<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>About LibGD 2.3.1</title><link rel="stylesheet" type="text/css" href="../styles/main.css"><script language=JavaScript src="../javascript/main.js"></script><script language=JavaScript src="../javascript/prettify.js"></script><script language=JavaScript src="../javascript/searchdata.js"></script></head><body class="ContentPage" onLoad="NDOnLoad();prettyPrint();"><script language=JavaScript><!--
if (browserType) {document.write("<div class=" + browserType + ">");if (browserVer) {document.write("<div class=" + browserVer + ">"); }}// --></script>

<!--  Generated by Natural Docs, version 1.51 -->
<!--  http://www.naturaldocs.org  -->

<!-- saved from url=(0026)http://www.naturaldocs.org -->




<div id=Content><div class="CSection"><div class=CTopic id=MainTopic><h1 class=CTitle><a name="About_LibGD_2.3.1"></a>About LibGD 2.3.1</h1><div class=CBody><h4 class=CHeading>What is gd?</h4><p>gd is a graphics library.&nbsp; It allows your code to quickly draw images complete with lines, arcs, text, multiple colors, cut and paste from other images, and flood fills, and write out the result as a PNG or JPEG file.&nbsp; This is particularly useful in World Wide Web applications, where PNG and JPEG are two of the formats accepted for inline images by most browsers.</p><p>gd is not a paint program.&nbsp; If you are looking for a paint program, you are looking in the wrong place.&nbsp; If you are not a programmer, you are looking in the wrong place, unless you are installing a required library in order to run an application.</p><p>gd does not provide for every possible desirable graphics operation.&nbsp; It is not necessary or desirable for gd to become a kitchen-sink graphics package, but version 2.0 does include most frequently requested features, including both truecolor and palette images, resampling (smooth resizing of truecolor images) and so forth.</p><h4 class=CHeading>gd basics: using gd in your program</h4><p>gd lets you create PNG or JPEG images on the fly.&nbsp; To use gd in your program, include the file gd.h, and link with the gd library and the other required libraries; the syntax for most Unix flavors is:</p><blockquote><pre>-lgd -lpng -lz -ljpeg -lfreetype -lm</pre></blockquote><p>Assuming that all of these libraries are available.</p><p>If you want to use the provided simple fonts, include gdfontt.h, gdfonts.h, gdfontmb.h, gdfontl.h and/or gdfontg.h.&nbsp; For more impressive results, install FreeType 2.x and use the gdImageStringFT function.&nbsp; If you are not using the provided Makefile and/or a library-based approach, be sure to include the source modules as well in your project.</p><p>Here is a short example program.&nbsp; (For a more advanced example, see gddemo.c, included in the distribution. gddemo.c is NOT the same program; it demonstrates additional features!)</p><blockquote><pre>/* Bring in gd library functions */
#include &quot;gd.h&quot;

/* Bring in standard I/O so we can output the PNG to a file */
#include &lt;stdio.h&gt;

int main() {
  /* Declare the image */
  gdImagePtr im;
  /* Declare output files */
  FILE *pngout, *jpegout;
  /* Declare color indexes */
  int black;
  int white;

  /* Allocate the image: 64 pixels across by 64 pixels tall */
  im = gdImageCreate(64, 64);

  /* Allocate the color black (red, green and blue all minimum).
    Since this is the first color in a new image, it will
    be the background color. */
  black = gdImageColorAllocate(im, 0, 0, 0);

  /* Allocate the color white (red, green and blue all maximum). */
  white = gdImageColorAllocate(im, 255, 255, 255);

  /* Draw a line from the upper left to the lower right,
    using white color index. */
  gdImageLine(im, 0, 0, 63, 63, white);

  /* Open a file for writing. &quot;wb&quot; means &quot;write binary&quot;, important
    under MSDOS, harmless under Unix. */
  pngout = fopen(&quot;test.png&quot;, &quot;wb&quot;);

  /* Do the same for a JPEG-format file. */
  jpegout = fopen(&quot;test.jpg&quot;, &quot;wb&quot;);

  /* Output the image to the disk file in PNG format. */
  gdImagePng(im, pngout);

  /* Output the same image in JPEG format, using the default
    JPEG quality setting. */
  gdImageJpeg(im, jpegout, -1);

  /* Close the files. */
  fclose(pngout);
  fclose(jpegout);

  /* Destroy the image in memory. */
  gdImageDestroy(im);
}</pre></blockquote></div></div></div>

</div><!--Content-->


<div id=Footer><a href="http://www.naturaldocs.org">Generated by Natural Docs</a></div><!--Footer-->


<div id=Menu><div class=MEntry><div class=MFile id=MSelected>About LibGD 2.<wbr>3.0-dev</div></div><div class=MEntry><div class=MGroup><a href="javascript:ToggleMenu('MGroupContent1')">Image Formats</a><div class=MGroupContent id=MGroupContent1><div class=MEntry><div class=MFile><a href="gd_bmp-c.html">BMP IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_gd-c.html">GD IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_gd2-c.html">GD2 IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_gif_in-c.html">GIF Input</a></div></div><div class=MEntry><div class=MFile><a href="gd_gif_out-c.html">GIF Output</a></div></div><div class=MEntry><div class=MFile><a href="gd_jpeg-c.html">JPEG IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_png-c.html">PNG IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_tga-c.html">TGA Input</a></div></div><div class=MEntry><div class=MFile><a href="gd_tiff-c.html">TIFF IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_wbmp-c.html">WBMP IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_webp-c.html">WebP IO</a></div></div><div class=MEntry><div class=MFile><a href="gd_xbm-c.html">XBM IO</a></div></div><div class=MEntry><div class=MFile><a href="gdxpm-c.html">XPM Input</a></div></div></div></div></div><div class=MEntry><div class=MFile><a href="gd_topal-c.html">Color Quantization</a></div></div><div class=MEntry><div class=MFile><a href="gd_crop-c.html">Cropping</a></div></div><div class=MEntry><div class=MFile><a href="gdft-c.html">FreeType font rendering</a></div></div><div class=MEntry><div class=MFile><a href="gd-c.html">gd.c</a></div></div><div class=MEntry><div class=MFile><a href="gd-h.html">gd.h</a></div></div><div class=MEntry><div class=MFile><a href="gd_filename-c.html">gd_filename.c</a></div></div><div class=MEntry><div class=MFile><a href="gd_interpolation-c.html">gd_interpolation.c</a></div></div><div class=MEntry><div class=MFile><a href="gd_io-h.html">gd_io.h</a></div></div><div class=MEntry><div class=MFile><a href="gd_io_dp-c.html">gd_io_dp.c</a></div></div><div class=MEntry><div class=MFile><a href="gd_ss-c.html">gd_ss.c</a></div></div><div class=MEntry><div class=MFile><a href="gd_version-c.html">gd_version.c</a></div></div><div class=MEntry><div class=MFile><a href="gd_color_map-c.html">gdColorMapLookup</a></div></div><div class=MEntry><div class=MFile><a href="gdhelpers-c.html">gdFree</a></div></div><div class=MEntry><div class=MFile><a href="gdfx-c.html">gdfx.c</a></div></div><div class=MEntry><div class=MFile><a href="gd_color_match-c.html">gdImageColorMatch</a></div></div><div class=MEntry><div class=MFile><a href="gd_nnquant-c.html">gdImageNeuQuant</a></div></div><div class=MEntry><div class=MFile><a href="gd_io_file-c.html">gdNewFileCtx</a></div></div><div class=MEntry><div class=MFile><a href="gd_io_ss-c.html">gdNewSSCtx</a></div></div><div class=MEntry><div class=MFile><a href="gd_filter-c.html">Image Filters</a></div></div><div class=MEntry><div class=MFile><a href="license-txt.html">License</a></div></div><div class=MEntry><div class=MFile><a href="gd_matrix-c.html">Matrix</a></div></div><div class=MEntry><div class=MFile><a href="gd_transform-c.html">Transformations</a></div></div><div class=MEntry><div class=MGroup><a href="javascript:ToggleMenu('MGroupContent2')">Built-in Fonts</a><div class=MGroupContent id=MGroupContent2><div class=MEntry><div class=MFile><a href="gdfontg-c.html">Giant Font</a></div></div><div class=MEntry><div class=MFile><a href="gdfontl-c.html">Large Font</a></div></div><div class=MEntry><div class=MFile><a href="gdfontmb-c.html">Medium Bold Font</a></div></div><div class=MEntry><div class=MFile><a href="gdfonts-c.html">Small Font</a></div></div><div class=MEntry><div class=MFile><a href="gdfontt-c.html">Tiny Font</a></div></div></div></div></div><div class=MEntry><div class=MGroup><a href="javascript:ToggleMenu('MGroupContent3')">Index</a><div class=MGroupContent id=MGroupContent3><div class=MEntry><div class=MIndex><a href="../index/Constants.html">Constants</a></div></div><div class=MEntry><div class=MIndex><a href="../index/General.html">Everything</a></div></div><div class=MEntry><div class=MIndex><a href="../index/Files.html">Files</a></div></div><div class=MEntry><div class=MIndex><a href="../index/Functions.html">Functions</a></div></div><div class=MEntry><div class=MIndex><a href="../index/Macros.html">Macros</a></div></div><div class=MEntry><div class=MIndex><a href="../index/Types.html">Types</a></div></div></div></div></div><script type="text/javascript"><!--
var searchPanel = new SearchPanel("searchPanel", "HTML", "../search");
--></script><div id=MSearchPanel class=MSearchPanelInactive><input type=text id=MSearchField value=Search onFocus="searchPanel.OnSearchFieldFocus(true)" onBlur="searchPanel.OnSearchFieldFocus(false)" onKeyUp="searchPanel.OnSearchFieldChange()"><select id=MSearchType onFocus="searchPanel.OnSearchTypeFocus(true)" onBlur="searchPanel.OnSearchTypeFocus(false)" onChange="searchPanel.OnSearchTypeChange()"><option  id=MSearchEverything selected value="General">Everything</option><option value="Constants">Constants</option><option value="Files">Files</option><option value="Functions">Functions</option><option value="Macros">Macros</option><option value="Types">Types</option></select></div><script language=JavaScript><!--
HideAllBut([], 4);// --></script></div><!--Menu-->



<!--START_ND_TOOLTIPS-->
<!--END_ND_TOOLTIPS-->




<div id=MSearchResultsWindow><iframe src="" frameborder=0 name=MSearchResults id=MSearchResults></iframe><a href="javascript:searchPanel.CloseResultsWindow()" id=MSearchResultsWindowClose>Close</a></div>


<script language=JavaScript><!--
if (browserType) {if (browserVer) {document.write("</div>"); }document.write("</div>");}// --></script></body></html>