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| <a href="#libvips-region.synopsis" class="shortcut">Top</a> |
| | |
| <a href="#libvips-region.description" class="shortcut">Description</a> |
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| <div class="refentry" title="region"> |
| <a name="libvips-region"></a><div class="titlepage"></div> |
| <div class="refnamediv"><table width="100%"><tr> |
| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="libvips-region.top_of_page"></a>region</span></h2> |
| <p>region — small, rectangular parts of images</p> |
| </td> |
| <td valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsect1" title="Stability Level"> |
| <a name="libvips-region.stability-level"></a><h2>Stability Level</h2> |
| Stable, unless otherwise indicated |
| </div> |
| <div class="refsynopsisdiv" title="Synopsis"> |
| <a name="libvips-region.synopsis"></a><h2>Synopsis</h2> |
| <pre class="synopsis"> |
| #include <vips/vips.h> |
| |
| <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION">REGION</a>; |
| <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="returnvalue">REGION</span></a> * <a class="link" href="libvips-region.html#im-region-create" title="im_region_create ()">im_region_create</a> (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="libvips-region.html#im-region-free" title="im_region_free ()">im_region_free</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-region.html#im-region-buffer" title="im_region_buffer ()">im_region_buffer</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-region.html#im-region-image" title="im_region_image ()">im_region_image</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-region.html#im-region-region" title="im_region_region ()">im_region_region</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *to</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>, |
| <em class="parameter"><code><span class="type">int</span> x</code></em>, |
| <em class="parameter"><code><span class="type">int</span> y</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-region.html#im-region-equalsregion" title="im_region_equalsregion ()">im_region_equalsregion</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg1</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg2</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-region.html#im-region-position" title="im_region_position ()">im_region_position</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg1</code></em>, |
| <em class="parameter"><code><span class="type">int</span> x</code></em>, |
| <em class="parameter"><code><span class="type">int</span> y</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="libvips-region.html#im-region-paint" title="im_region_paint ()">im_region_paint</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>, |
| <em class="parameter"><code><span class="type">int</span> value</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="libvips-region.html#im-region-black" title="im_region_black ()">im_region_black</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="libvips-region.html#im-region-copy" title="im_region_copy ()">im_region_copy</a> (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *dest</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>, |
| <em class="parameter"><code><span class="type">int</span> x</code></em>, |
| <em class="parameter"><code><span class="type">int</span> y</code></em>); |
| #define <a class="link" href="libvips-region.html#IM-REGION-LSKIP:CAPS" title="IM_REGION_LSKIP()">IM_REGION_LSKIP</a> (R) |
| #define <a class="link" href="libvips-region.html#IM-REGION-N-ELEMENTS:CAPS" title="IM_REGION_N_ELEMENTS()">IM_REGION_N_ELEMENTS</a> (R) |
| #define <a class="link" href="libvips-region.html#IM-REGION-SIZEOF-LINE:CAPS" title="IM_REGION_SIZEOF_LINE()">IM_REGION_SIZEOF_LINE</a> (R) |
| #define <a class="link" href="libvips-region.html#IM-REGION-ADDR:CAPS" title="IM_REGION_ADDR()">IM_REGION_ADDR</a> (B, |
| X, |
| Y) |
| #define <a class="link" href="libvips-region.html#IM-REGION-ADDR-TOPLEFT:CAPS" title="IM_REGION_ADDR_TOPLEFT()">IM_REGION_ADDR_TOPLEFT</a> (B) |
| </pre> |
| </div> |
| <div class="refsect1" title="Description"> |
| <a name="libvips-region.description"></a><h2>Description</h2> |
| <p> |
| A <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> is a small part of an image and some pixels. You use regions to |
| read pixels out of images without having to have the whole image in memory |
| at once. |
| </p> |
| <p> |
| A region can be a memory buffer, part of a memory-mapped file, part of some |
| other image, or part of some other region. |
| </p> |
| <p> |
| Regions must be created, used and freed all within the same thread, since |
| they can reference private per-thread caches. VIPS sanity-checks region |
| ownership in various places, so you are likely to see <code class="function">g_assert()</code> errors if |
| you don't follow this rule. |
| </p> |
| <p> |
| There |
| is API to transfer ownership of regions between threads, but hopefully this |
| is only needed within VIPS, so we don't expose it. Hopefully. |
| </p> |
| </div> |
| <div class="refsect1" title="Details"> |
| <a name="libvips-region.details"></a><h2>Details</h2> |
| <div class="refsect2" title="REGION"> |
| <a name="REGION:CAPS"></a><h3>REGION</h3> |
| <pre class="programlisting">typedef struct { |
| /* Users may read these two fields. |
| */ |
| IMAGE *im; /* Link back to parent image */ |
| Rect valid; /* Area of parent we can see */ |
| |
| /* The rest of REGION is private. |
| */ |
| } REGION; |
| </pre> |
| <p> |
| A small part of an <span class="type">IMAGE</span>. <em class="parameter"><code>valid</code></em> holds the left/top/width/height of the |
| area of pixels that are available from the region. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-region.html#IM-REGION-ADDR:CAPS" title="IM_REGION_ADDR()"><code class="function">IM_REGION_ADDR()</code></a>, <a class="link" href="libvips-region.html#im-region-create" title="im_region_create ()"><code class="function">im_region_create()</code></a>, <a class="link" href="libvips-generate.html#im-prepare" title="im_prepare ()"><code class="function">im_prepare()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><span class="type">IMAGE</span> *<em class="structfield"><code><a name="REGION--CAPS.im"></a>im</code></em>;</span></p></td> |
| <td>the <span class="type">IMAGE</span> that this region is defined on |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> <em class="structfield"><code><a name="REGION--CAPS.valid"></a>valid</code></em>;</span></p></td> |
| <td>the <a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> of pixels that this region represents |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_create ()"> |
| <a name="im-region-create"></a><h3>im_region_create ()</h3> |
| <pre class="programlisting"><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="returnvalue">REGION</span></a> * im_region_create (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>);</pre> |
| <p> |
| Create a region. <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> s start out empty, you need to call <a class="link" href="libvips-generate.html#im-prepare" title="im_prepare ()"><code class="function">im_prepare()</code></a> to |
| fill them with pixels. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-generate.html#im-prepare" title="im_prepare ()"><code class="function">im_prepare()</code></a>, <a class="link" href="libvips-region.html#im-region-free" title="im_region_free ()"><code class="function">im_region_free()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to create this region on |
| </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_free ()"> |
| <a name="im-region-free"></a><h3>im_region_free ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> im_region_free (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>);</pre> |
| <p> |
| Free a region and any resources it holds. |
| </p> |
| <p> |
| If <em class="parameter"><code>im</code></em> has previously been closed, then freeing the last <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> on <em class="parameter"><code>in</code></em> can |
| cause <em class="parameter"><code>im</code></em> to finally be freed as well. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td> |
| <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> to free |
| </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_buffer ()"> |
| <a name="im-region-buffer"></a><h3>im_region_buffer ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_region_buffer (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>);</pre> |
| <p> |
| The region is transformed so that at least <em class="parameter"><code>r</code></em> pixels are available as a |
| memory buffer. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td>region to operate upon |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>r</code></em> :</span></p></td> |
| <td> |
| <a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> of pixels you need to be able to address |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, or -1 for error. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_image ()"> |
| <a name="im-region-image"></a><h3>im_region_image ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_region_image (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>);</pre> |
| <p> |
| The region is transformed so that at least <em class="parameter"><code>r</code></em> pixels are available directly |
| from the image. The image needs to be a memory buffer or represent a file |
| on disc that has been mapped or can be mapped. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td>region to operate upon |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>r</code></em> :</span></p></td> |
| <td> |
| <a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> of pixels you need to be able to address |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, or -1 for error. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_region ()"> |
| <a name="im-region-region"></a><h3>im_region_region ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_region_region (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *to</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>, |
| <em class="parameter"><code><span class="type">int</span> x</code></em>, |
| <em class="parameter"><code><span class="type">int</span> y</code></em>);</pre> |
| <p> |
| Make <a class="link" href="libvips-region.html#IM-REGION-ADDR:CAPS" title="IM_REGION_ADDR()"><code class="function">IM_REGION_ADDR()</code></a> on <em class="parameter"><code>reg</code></em> go to <em class="parameter"><code>dest</code></em> instead. |
| </p> |
| <p> |
| <em class="parameter"><code>r</code></em> is the part of <em class="parameter"><code>reg</code></em> which you want to be able to address (this |
| effectively becomes the valid field), (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>) is the top LH corner of the |
| corresponding area in <em class="parameter"><code>dest</code></em>. |
| </p> |
| <p> |
| Performs all clipping necessary to ensure that <em class="parameter"><code>reg->valid</code></em> is indeed |
| valid. |
| </p> |
| <p> |
| If the region we attach to is modified, we can be left with dangling |
| pointers! If the region we attach to is on another image, the two images |
| must have |
| the same sizeof( pel ). |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td>region to operate upon |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>dest</code></em> :</span></p></td> |
| <td>region to connect to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>r</code></em> :</span></p></td> |
| <td> |
| <a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> of pixels you need to be able to address |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td> |
| <td>postion of <em class="parameter"><code>r</code></em> in <em class="parameter"><code>dest</code></em> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td> |
| <td>postion of <em class="parameter"><code>r</code></em> in <em class="parameter"><code>dest</code></em> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, or -1 for error. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_equalsregion ()"> |
| <a name="im-region-equalsregion"></a><h3>im_region_equalsregion ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_region_equalsregion (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg1</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg2</code></em>);</pre> |
| <p> |
| Do two regions point to the same piece of image? ie. |
| </p> |
| <p> |
| </p> |
| <div class="informalexample"><pre class="programlisting"> |
| IM_REGION_ADDR( reg1, x, y ) == IM_REGION_ADDR( reg2, x, y ) && |
| *IM_REGION_ADDR( reg1, x, y ) == |
| *IM_REGION_ADDR( reg2, x, y ) for all x, y, reg1, reg2. |
| </pre></div> |
| <p> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg1</code></em> :</span></p></td> |
| <td>region to test |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg2</code></em> :</span></p></td> |
| <td>region to test |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> non-zero on equality. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_position ()"> |
| <a name="im-region-position"></a><h3>im_region_position ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_region_position (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg1</code></em>, |
| <em class="parameter"><code><span class="type">int</span> x</code></em>, |
| <em class="parameter"><code><span class="type">int</span> y</code></em>);</pre> |
| <p> |
| Set the position of a region. This only affects reg->valid, ie. the way |
| pixels are addressed, not reg->data, the pixels which are addressed. Clip |
| against the size of the image. Do not allow negative positions, or |
| positions outside the image. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td>region to operate upon |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td> |
| <td>position to move to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td> |
| <td>position to move to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, or -1 for error. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_paint ()"> |
| <a name="im-region-paint"></a><h3>im_region_paint ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> im_region_paint (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>, |
| <em class="parameter"><code><span class="type">int</span> value</code></em>);</pre> |
| <p> |
| Paints <em class="parameter"><code>value</code></em> into <em class="parameter"><code>reg</code></em> covering rectangle <em class="parameter"><code>r</code></em>. <em class="parameter"><code>value</code></em> is passed to |
| <code class="function">memset()</code>, so it usually needs to be 0 or 255. <em class="parameter"><code>r</code></em> is clipped against |
| <em class="parameter"><code>reg->valid</code></em>. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-region.html#im-region-black" title="im_region_black ()"><code class="function">im_region_black()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td>region to operate upon |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>r</code></em> :</span></p></td> |
| <td>area to paint |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>value to paint |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_black ()"> |
| <a name="im-region-black"></a><h3>im_region_black ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> im_region_black (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>);</pre> |
| <p> |
| Paints 0 into the valid part of <em class="parameter"><code>reg</code></em>. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-region.html#im-region-paint" title="im_region_paint ()"><code class="function">im_region_paint()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody><tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td>region to operate upon |
| </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_region_copy ()"> |
| <a name="im-region-copy"></a><h3>im_region_copy ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> im_region_copy (<em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *reg</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> *dest</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> *r</code></em>, |
| <em class="parameter"><code><span class="type">int</span> x</code></em>, |
| <em class="parameter"><code><span class="type">int</span> y</code></em>);</pre> |
| <p> |
| Copy from one region to another. Copy area <em class="parameter"><code>r</code></em> from inside <em class="parameter"><code>reg</code></em> to <em class="parameter"><code>dest</code></em>, |
| positioning the area of pixels at <em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>. The two regions must have pixels |
| which are the same size. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-region.html#im-region-paint" title="im_region_paint ()"><code class="function">im_region_paint()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>reg</code></em> :</span></p></td> |
| <td>source region |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>dest</code></em> :</span></p></td> |
| <td>destination region |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>r</code></em> :</span></p></td> |
| <td> |
| <a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> of pixels you need to copy |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td> |
| <td>postion of <em class="parameter"><code>r</code></em> in <em class="parameter"><code>dest</code></em> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td> |
| <td>postion of <em class="parameter"><code>r</code></em> in <em class="parameter"><code>dest</code></em> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_REGION_LSKIP()"> |
| <a name="IM-REGION-LSKIP:CAPS"></a><h3>IM_REGION_LSKIP()</h3> |
| <pre class="programlisting">#define IM_REGION_LSKIP(R)</pre> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>R</code></em> :</span></p></td> |
| <td>a <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The number of bytes to add to move down a scanline. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_REGION_N_ELEMENTS()"> |
| <a name="IM-REGION-N-ELEMENTS:CAPS"></a><h3>IM_REGION_N_ELEMENTS()</h3> |
| <pre class="programlisting">#define IM_REGION_N_ELEMENTS(R)</pre> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>R</code></em> :</span></p></td> |
| <td>a <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The number of band elements across a region. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_REGION_SIZEOF_LINE()"> |
| <a name="IM-REGION-SIZEOF-LINE:CAPS"></a><h3>IM_REGION_SIZEOF_LINE()</h3> |
| <pre class="programlisting">#define IM_REGION_SIZEOF_LINE(R)</pre> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>R</code></em> :</span></p></td> |
| <td>a <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The number of bytes across a region. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_REGION_ADDR()"> |
| <a name="IM-REGION-ADDR:CAPS"></a><h3>IM_REGION_ADDR()</h3> |
| <pre class="programlisting">#define IM_REGION_ADDR(B,X,Y)</pre> |
| <p> |
| This macro returns a pointer to a pixel in a region. The (x, y) coordinates |
| need to be within the <a class="link" href="libvips-rect.html#Rect" title="Rect"><span class="type">Rect</span></a> (<em class="parameter"><code>R->valid</code></em>). |
| </p> |
| <p> |
| If DEBUG is defined, you get a version that checks bounds for you. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>R</code></em> :</span></p></td> |
| <td>a <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>X</code></em> :</span></p></td> |
| <td>x coordinate |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>Y</code></em> :</span></p></td> |
| <td>y coordinate |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The address of pixel (x,y) in the region. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_REGION_ADDR_TOPLEFT()"> |
| <a name="IM-REGION-ADDR-TOPLEFT:CAPS"></a><h3>IM_REGION_ADDR_TOPLEFT()</h3> |
| <pre class="programlisting">#define IM_REGION_ADDR_TOPLEFT(B) ( (B)->data ) |
| </pre> |
| <p> |
| This macro returns a pointer to the top-left pixel in the <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a>, that is, |
| the pixel at (<em class="parameter"><code>R->valid.left</code></em>, <em class="parameter"><code>R->valid.top</code></em>). |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>R</code></em> :</span></p></td> |
| <td>a <a class="link" href="libvips-region.html#REGION:CAPS" title="REGION"><span class="type">REGION</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The address of the top-left pixel in the region. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <div class="refsect1" title="See Also"> |
| <a name="libvips-region.see-also"></a><h2>See Also</h2> |
| <a class="link" href="libvips-image.html" title="image">image</a>, |
| <a class="link" href="libvips-generate.html" title="generate">generate</a> |
| </div> |
| </div> |
| <div class="footer"> |
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