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<center><h1>FreeType-2.1.10 API Reference</h1></center>

<center><h1>
Scanline Converter
</h1></center>
<h2>Synopsis</h2>
<table align=center cellspacing=5 cellpadding=0 border=0>
<tr><td></td><td><a href="#FT_Raster">FT_Raster</a></td><td></td><td><a href="#FT_Raster_RenderFunc">FT_Raster_RenderFunc</a></td></tr>
<tr><td></td><td><a href="#FT_Span">FT_Span</a></td><td></td><td><a href="#FT_Raster_Funcs">FT_Raster_Funcs</a></td></tr>
<tr><td></td><td><a href="#FT_SpanFunc">FT_SpanFunc</a></td><td></td><td><a href="#FT_Incremental">FT_Incremental</a></td></tr>
<tr><td></td><td><a href="#FT_Raster_BitTest_Func">FT_Raster_BitTest_Func</a></td><td></td><td><a href="#FT_Incremental_Metrics">FT_Incremental_Metrics</a></td></tr>
<tr><td></td><td><a href="#FT_Raster_BitSet_Func">FT_Raster_BitSet_Func</a></td><td></td><td><a href="#FT_Incremental_GetGlyphDataFunc">FT_Incremental_GetGlyphDataFunc</a></td></tr>
<tr><td></td><td><a href="#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_XXX</a></td><td></td><td><a href="#FT_Incremental_FreeGlyphDataFunc">FT_Incremental_FreeGlyphDataFunc</a></td></tr>
<tr><td></td><td><a href="#FT_Raster_Params">FT_Raster_Params</a></td><td></td><td><a href="#FT_Incremental_GetGlyphMetricsFunc">FT_Incremental_GetGlyphMetricsFunc</a></td></tr>
<tr><td></td><td><a href="#FT_Raster_NewFunc">FT_Raster_NewFunc</a></td><td></td><td><a href="#FT_Incremental_FuncsRec">FT_Incremental_FuncsRec</a></td></tr>
<tr><td></td><td><a href="#FT_Raster_DoneFunc">FT_Raster_DoneFunc</a></td><td></td><td><a href="#FT_Incremental_InterfaceRec">FT_Incremental_InterfaceRec</a></td></tr>
<tr><td></td><td><a href="#FT_Raster_ResetFunc">FT_Raster_ResetFunc</a></td><td></td><td><a href="#FT_PARAM_TAG_INCREMENTAL">FT_PARAM_TAG_INCREMENTAL</a></td></tr>
<tr><td></td><td><a href="#FT_Raster_SetModeFunc">FT_Raster_SetModeFunc</a></td><td></td><td></td></tr>
</table><br><br>

<table align=center width="87%"><tr><td>
<p>This section contains technical definitions.</p>
</td></tr></table><br>
<table align=center width="75%"><tr><td>
<h4><a name="FT_Raster">FT_Raster</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_RasterRec_*  <b>FT_Raster</b>;

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A handle (pointer) to a raster object. Each object can be used independently to convert an outline into a bitmap or pixmap.</p>
</td></tr></table><br>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="FT_Span">FT_Span</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">struct</span>  FT_Span_
  {
    <span class="keyword">short</span>           x;
    <span class="keyword">unsigned</span> <span class="keyword">short</span>  len;
    <span class="keyword">unsigned</span> <span class="keyword">char</span>   coverage;

  } <b>FT_Span</b>;

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A structure used to model a single span of gray (or black) pixels when rendering a monochrome or anti-aliased bitmap.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>fields</b></em></td></tr><tr><td>
<table cellpadding=3>
<tr valign=top><td><b>x</b></td><td>
<p>The span's horizontal start position.</p>
</td></tr>
<tr valign=top><td><b>len</b></td><td>
<p>The span's length in pixels.</p>
</td></tr>
<tr valign=top><td><b>coverage</b></td><td>
<p>The span color/coverage, ranging from 0 (background) to 255 (foreground). Only used for anti-aliased rendering.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>note</b></em></td></tr><tr><td>
<p>This structure is used by the span drawing callback type named FT_SpanFunc which takes the y-coordinate of the span as a a parameter.</p>
<p>The coverage value is always between 0 and 255, even if the number of gray levels have been set through FT_Set_Gray_Levels().</p>
</td></tr></table>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="FT_SpanFunc">FT_SpanFunc</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">void</span>
  (*<b>FT_SpanFunc</b>)( <span class="keyword">int</span>       y,
                  <span class="keyword">int</span>       count,
                  <a href="ft2-raster.html#FT_Span">FT_Span</a>*  spans,
                  <span class="keyword">void</span>*     user );

#define FT_Raster_Span_Func   <b>FT_SpanFunc</b>

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A function used as a call-back by the anti-aliased renderer in order to let client applications draw themselves the gray pixel spans on each scan line.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<table cellpadding=3>
<tr valign=top><td><b>y</b></td><td>
<p>The scanline's y-coordinate.</p>
</td></tr>
<tr valign=top><td><b>count</b></td><td>
<p>The number of spans to draw on this scanline.</p>
</td></tr>
<tr valign=top><td><b>spans</b></td><td>
<p>A table of `count' spans to draw on the scanline.</p>
</td></tr>
<tr valign=top><td><b>user</b></td><td>
<p>User-supplied data that is passed to the callback.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>note</b></em></td></tr><tr><td>
<p>This callback allows client applications to directly render the gray spans of the anti-aliased bitmap to any kind of surfaces.</p>
<p>This can be used to write anti-aliased outlines directly to a given background bitmap, and even perform translucency.</p>
<p>Note that the `count' field cannot be greater than a fixed value defined by the FT_MAX_GRAY_SPANS configuration macro in ftoption.h. By default, this value is set to 32, which means that if there are more than 32 spans on a given scanline, the callback will be called several times with the same `y' parameter in order to draw all callbacks.</p>
<p>Otherwise, the callback is only called once per scan-line, and only for those scanlines that do have `gray' pixels on them.</p>
</td></tr></table>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="FT_Raster_BitTest_Func">FT_Raster_BitTest_Func</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">int</span>
  (*<b>FT_Raster_BitTest_Func</b>)( <span class="keyword">int</span>    y,
                             <span class="keyword">int</span>    x,
                             <span class="keyword">void</span>*  user );

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>THIS TYPE IS DEPRECATED. DO NOT USE IT.</p>
<p>A function used as a call-back by the monochrome scan-converter to test whether a given target pixel is already set to the drawing `color'. These tests are crucial to implement drop-out control per-se the TrueType spec.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<table cellpadding=3>
<tr valign=top><td><b>y</b></td><td>
<p>The pixel's y-coordinate.</p>
</td></tr>
<tr valign=top><td><b>x</b></td><td>
<p>The pixel's x-coordinate.</p>
</td></tr>
<tr valign=top><td><b>user</b></td><td>
<p>User-supplied data that is passed to the callback.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>return</b></em></td></tr><tr><td>
<p>1 if the pixel is `set', 0 otherwise.</p>
</td></tr></table>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="FT_Raster_BitSet_Func">FT_Raster_BitSet_Func</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">void</span>
  (*<b>FT_Raster_BitSet_Func</b>)( <span class="keyword">int</span>    y,
                            <span class="keyword">int</span>    x,
                            <span class="keyword">void</span>*  user );

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>THIS TYPE IS DEPRECATED. DO NOT USE IT.</p>
<p>A function used as a call-back by the monochrome scan-converter to set an individual target pixel. This is crucial to implement drop-out control according to the TrueType specification.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<table cellpadding=3>
<tr valign=top><td><b>y</b></td><td>
<p>The pixel's y-coordinate.</p>
</td></tr>
<tr valign=top><td><b>x</b></td><td>
<p>The pixel's x-coordinate.</p>
</td></tr>
<tr valign=top><td><b>user</b></td><td>
<p>User-supplied data that is passed to the callback.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>return</b></em></td></tr><tr><td>
<p>1 if the pixel is `set', 0 otherwise.</p>
</td></tr></table>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_XXX</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

#define <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_DEFAULT</a>  0x0
#define <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_AA</a>       0x1
#define <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_DIRECT</a>   0x2
#define <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_CLIP</a>     0x4

  /* deprecated */
#define ft_raster_flag_default  <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_DEFAULT</a>
#define ft_raster_flag_aa       <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_AA</a>
#define ft_raster_flag_direct   <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_DIRECT</a>
#define ft_raster_flag_clip     <a href="ft2-raster.html#FT_RASTER_FLAG_XXX">FT_RASTER_FLAG_CLIP</a>

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A list of bit flag constants as used in the `flags' field of a <a href="ft2-raster.html#FT_Raster_Params">FT_Raster_Params</a> structure.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>values</b></em></td></tr><tr><td>
<table cellpadding=3>
<tr valign=top><td><b>FT_RASTER_FLAG_DEFAULT</b></td><td>
<p>This value is 0.</p>
</td></tr>
<tr valign=top><td><b>FT_RASTER_FLAG_AA</b></td><td>
<p>This flag is set to indicate that an anti-aliased glyph image should be generated. Otherwise, it will be monochrome (1-bit).</p>
</td></tr>
<tr valign=top><td><b>FT_RASTER_FLAG_DIRECT</b></td><td>
<p>This flag is set to indicate direct rendering. In this mode, client applications must provide their own span callback. This lets them directly draw or compose over an existing bitmap. If this bit is not set, the target pixmap's buffer <i>must</i> be zeroed before rendering.</p>
<p>Note that for now, direct rendering is only possible with anti-aliased glyphs.</p>
</td></tr>
<tr valign=top><td><b>FT_RASTER_FLAG_CLIP</b></td><td>
<p>This flag is only used in direct rendering mode. If set, the output will be clipped to a box specified in the "clip_box" field of the FT_Raster_Params structure.</p>
<p>Note that by default, the glyph bitmap is clipped to the target pixmap, except in direct rendering mode where all spans are generated if no clipping box is set.</p>
</td></tr>
</table>
</td></tr></table>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="FT_Raster_Params">FT_Raster_Params</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>
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