aboutsummaryrefslogtreecommitdiff
path: root/freetype/docs/reference/ft2-gasp_table.html
blob: 3b56119a10a8070dc069b699826a6e87b54b7b5e (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
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>FreeType-2.5.5 API Reference</title>
<style type="text/css">
  a:link { color: #0000EF; }
  a:visited { color: #51188E; }
  a:hover { color: #FF0000; }

  body { font-family: Verdana, Geneva, Arial, Helvetica, serif;
         color: #000000;
         background: #FFFFFF;
         width: 87%;
         margin: auto; }

  div.section { width: 75%;
                margin: auto; }
  div.section hr { margin: 4ex 0 1ex 0; }
  div.section h4 { background-color: #EEEEFF;
                   font-size: medium;
                   font-style: oblique;
                   font-weight: bold;
                   margin: 3ex 0 1.5ex 9%;
                   padding: 0.3ex 0 0.3ex 1%; }
  div.section p { margin: 1.5ex 0 1.5ex 10%; }
  div.section pre { margin: 3ex 0 3ex 9%;
                    background-color: #D6E8FF;
                    padding: 2ex 0 2ex 1%; }
  div.section table.fields { width: 90%;
                             margin: 1.5ex 0 1.5ex 10%; }
  div.section table.toc { width: 95%;
                          margin: 1.5ex 0 1.5ex 5%; }
  div.timestamp { text-align: center;
                  font-size: 69%;
                  margin: 1.5ex 0 1.5ex 0; }

  h1 { text-align: center; }
  h3 { font-size: medium;
       margin: 4ex 0 1.5ex 0; }

  p { text-align: justify; }

  pre.colored { color: blue; }

  span.keyword { font-family: monospace;
                 text-align: left;
                 white-space: pre;
                 color: darkblue; }

  table.fields td.val { font-weight: bold;
                        text-align: right;
                        width: 30%;
                        vertical-align: baseline;
                        padding: 1ex 1em 1ex 0; }
  table.fields td.desc { vertical-align: baseline;
                         padding: 1ex 0 1ex 1em; }
  table.fields td.desc p:first-child { margin: 0; }
  table.fields td.desc p { margin: 1.5ex 0 0 0; }
  table.index { margin: 6ex auto 6ex auto;
                border: 0;
                border-collapse: separate;
                border-spacing: 1em 0.3ex; }
  table.index tr { padding: 0; }
  table.index td { padding: 0; }
  table.index-toc-link { width: 100%;
                         border: 0;
                         border-spacing: 0;
                         margin: 1ex 0 1ex 0; }
  table.index-toc-link td.left { padding: 0 0.5em 0 0.5em;
                                 font-size: 83%;
                                 text-align: left; }
  table.index-toc-link td.middle { padding: 0 0.5em 0 0.5em;
                                   font-size: 83%;
                                   text-align: center; }
  table.index-toc-link td.right { padding: 0 0.5em 0 0.5em;
                                  font-size: 83%;
                                  text-align: right; }
  table.synopsis { margin: 6ex auto 6ex auto;
                   border: 0;
                   border-collapse: separate;
                   border-spacing: 2em 0.6ex; }
  table.synopsis tr { padding: 0; }
  table.synopsis td { padding: 0; }
  table.toc td.link { width: 30%;
                      text-align: right;
                      vertical-align: baseline;
                      padding: 1ex 1em 1ex 0; }
  table.toc td.desc { vertical-align: baseline;
                      padding: 1ex 0 1ex 1em;
                      text-align: left; }
  table.toc td.desc p:first-child { margin: 0;
                                    text-align: left; }
  table.toc td.desc p { margin: 1.5ex 0 0 0;
                        text-align: left; }

</style>
</head>
<body>

<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table>
<h1>FreeType-2.5.5 API Reference</h1>

<h1>Gasp Table</h1>
<h2>Synopsis</h2>
<table class="synopsis">
<tr><td><a href="#FT_GASP_XXX">FT_GASP_XXX</a></td><td><a href="#FT_Get_Gasp">FT_Get_Gasp</a></td><td></td><td></td><td></td><td></td></tr>
</table>


<p>The function <a href="ft2-gasp_table.html#FT_Get_Gasp">FT_Get_Gasp</a> can be used to query a TrueType or OpenType font for specific entries in its &lsquo;gasp&rsquo; table, if any. This is mainly useful when implementing native TrueType hinting with the bytecode interpreter to duplicate the Windows text rendering results.</p>

<div class="section">
<h3 id="FT_GASP_XXX">FT_GASP_XXX</h3>
<p>Defined in FT_GASP_H (ftgasp.h).</p>
<pre>
#define <a href="ft2-gasp_table.html#FT_GASP_NO_TABLE">FT_GASP_NO_TABLE</a>               -1
#define <a href="ft2-gasp_table.html#FT_GASP_DO_GRIDFIT">FT_GASP_DO_GRIDFIT</a>           0x01
#define <a href="ft2-gasp_table.html#FT_GASP_DO_GRAY">FT_GASP_DO_GRAY</a>              0x02
#define <a href="ft2-gasp_table.html#FT_GASP_SYMMETRIC_SMOOTHING">FT_GASP_SYMMETRIC_SMOOTHING</a>  0x08
#define <a href="ft2-gasp_table.html#FT_GASP_SYMMETRIC_GRIDFIT">FT_GASP_SYMMETRIC_GRIDFIT</a>    0x10
</pre>

<p>A list of values and/or bit-flags returned by the <a href="ft2-gasp_table.html#FT_Get_Gasp">FT_Get_Gasp</a> function.</p>

<h4>values</h4>
<table class="fields">
<tr><td class="val" id="FT_GASP_NO_TABLE">FT_GASP_NO_TABLE</td><td class="desc">
<p>This special value means that there is no GASP table in this face. It is up to the client to decide what to do.</p>
</td></tr>
<tr><td class="val" id="FT_GASP_DO_GRIDFIT">FT_GASP_DO_GRIDFIT</td><td class="desc">
<p>Grid-fitting and hinting should be performed at the specified ppem. This <b>really</b> means TrueType bytecode interpretation. If this bit is not set, no hinting gets applied.</p>
</td></tr>
<tr><td class="val" id="FT_GASP_DO_GRAY">FT_GASP_DO_GRAY</td><td class="desc">
<p>Anti-aliased rendering should be performed at the specified ppem. If not set, do monochrome rendering.</p>
</td></tr>
<tr><td class="val" id="FT_GASP_SYMMETRIC_SMOOTHING">FT_GASP_SYMMETRIC_SMOOTHING</td><td class="desc">
<p>If set, smoothing along multiple axes must be used with ClearType.</p>
</td></tr>
<tr><td class="val" id="FT_GASP_SYMMETRIC_GRIDFIT">FT_GASP_SYMMETRIC_GRIDFIT</td><td class="desc">
<p>Grid-fitting must be used with ClearType's symmetric smoothing.</p>
</td></tr>
</table>

<h4>note</h4>
<p>The bit-flags &lsquo;FT_GASP_DO_GRIDFIT&rsquo; and &lsquo;FT_GASP_DO_GRAY&rsquo; are to be used for standard font rasterization only. Independently of that, &lsquo;FT_GASP_SYMMETRIC_SMOOTHING&rsquo; and &lsquo;FT_GASP_SYMMETRIC_GRIDFIT&rsquo; are to be used if ClearType is enabled (and &lsquo;FT_GASP_DO_GRIDFIT&rsquo; and &lsquo;FT_GASP_DO_GRAY&rsquo; are consequently ignored).</p>
<p>&lsquo;ClearType&rsquo; is Microsoft's implementation of LCD rendering, partly protected by patents.</p>

<h4>since</h4>
<p>2.3.0</p>

<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>

<div class="section">
<h3 id="FT_Get_Gasp">FT_Get_Gasp</h3>
<p>Defined in FT_GASP_H (ftgasp.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Int">FT_Int</a> )
  <b>FT_Get_Gasp</b>( <a href="ft2-base_interface.html#FT_Face">FT_Face</a>  face,
               <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a>  ppem );
</pre>

<p>Read the &lsquo;gasp&rsquo; table from a TrueType or OpenType font file and return the entry corresponding to a given character pixel size.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="face">face</td><td class="desc">
<p>The source face handle.</p>
</td></tr>
<tr><td class="val" id="ppem">ppem</td><td class="desc">
<p>The vertical character pixel size.</p>
</td></tr>
</table>

<h4>return</h4>
<p>Bit flags (see <a href="ft2-gasp_table.html#FT_GASP_XXX">FT_GASP_XXX</a>), or <a href="ft2-gasp_table.html#FT_GASP_XXX">FT_GASP_NO_TABLE</a> if there is no &lsquo;gasp&rsquo; table in the face.</p>

<h4>since</h4>
<p>2.3.0</p>

<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>

</body>
</html>