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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<h1>Cairo::ImageSurface Class Reference</h1><!-- doxytag: class="Cairo::ImageSurface" --><!-- doxytag: inherits="Cairo::Surface" -->Image surfaces provide the ability to render to memory buffers either allocated by cairo or by the calling code.
<a href="#_details">More...</a>
<p>
Inherits <a class="el" href="classCairo_1_1Surface.html">Cairo::Surface</a>.
<p>
<p>
<a href="classCairo_1_1ImageSurface-members.html">List of all members.</a><table border="0" cellpadding="0" cellspacing="0">
<tr><td></td></tr>
<tr><td colspan="2"><br><h2>Public Member Functions</h2></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"> </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#19a7d3c6f4320c4d812629b3c18925ac">ImageSurface</a> (cairo_surface_t*<a class="el" href="classCairo_1_1Surface.html#d176eb7343b5902df3c19f9f56e59fb4">cobject</a>, bool has_reference=false)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Create a C++ wrapper for the C instance. <a href="#19a7d3c6f4320c4d812629b3c18925ac"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">virtual </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#489f33357db18c23bdf8ebd5d07d8264">~ImageSurface</a> ()</td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#f75b30cde988ad6959bb75862f5b6e2a">get_width</a> () const </td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Gets the width of the <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> in pixels. <a href="#f75b30cde988ad6959bb75862f5b6e2a"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#a0e17bed71b125fd4725386ee1f14d07">get_height</a> () const </td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Gets the height of the <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> in pixels. <a href="#a0e17bed71b125fd4725386ee1f14d07"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">unsigned char* </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#94ba52fe4a201579c8a5541717822bdb">get_data</a> ()</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Get a pointer to the data of the image surface, for direct inspection or modification. <a href="#94ba52fe4a201579c8a5541717822bdb"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">const unsigned char* </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#8858eb704ebe2118baf83f2a104b9140">get_data</a> () const </td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Format</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#edccf9d08b3e5852c0bbb195cf1379a8">get_format</a> () const </td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">gets the format of the surface <a href="#edccf9d08b3e5852c0bbb195cf1379a8"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#4b33c7f1c03197eb66dac3e909c5a39a">get_stride</a> () const </td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Return value: the stride of the image surface in bytes (or 0 if is not an image surface). <a href="#4b33c7f1c03197eb66dac3e909c5a39a"></a><br></td></tr>
<tr><td colspan="2"><br><h2>Static Public Member Functions</h2></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">static int </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#c74f130a3bb36bd9fd70003cd8562ce5">format_stride_for_width</a> (<a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Cairo::Format</a> format, int width)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">This function provides a stride value that will respect all alignment requirements of the accelerated image-rendering code within cairo. <a href="#c74f130a3bb36bd9fd70003cd8562ce5"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a>< <a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a> > </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#82887e1a0480ab16aa891e135f2b28d6">create</a> (<a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Format</a> format, int width, int height)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Creates an image surface of the specified format and dimensions. <a href="#82887e1a0480ab16aa891e135f2b28d6"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a>< <a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a> > </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#feb1b8203f9fa23ff4bca7b70723f370">create</a> (unsigned char* data, <a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Format</a> format, int width, int height, int <a class="elRef" doxygen="libstdc++.tag:http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01005.html#g4d464eb22d9ad823ecb9b7eab22c6300">stride</a>)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Creates an image surface for the provided pixel data. <a href="#feb1b8203f9fa23ff4bca7b70723f370"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a>< <a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a> > </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#ac35bcd255347574036746810f8a2978">create_from_png</a> (<a class="elRef" doxygen="libstdc++.tag:http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a00218.html">std::string</a> filename)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Creates a new image surface and initializes the contents to the given PNG file. <a href="#ac35bcd255347574036746810f8a2978"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a>< <a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a> > </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#7ac275170e7235457c9806aec7cf6f6a">create_from_png_stream</a> (const <a class="el" href="classCairo_1_1Surface.html#f66be8453e3fc558ea1282a911bf60e2">SlotReadFunc</a>& read_func)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Creates a new image surface from PNG data read incrementally via the read_func function. <a href="#7ac275170e7235457c9806aec7cf6f6a"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a>< <a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a> > </td><td class="memItemRight" valign="bottom"><a class="el" href="classCairo_1_1ImageSurface.html#43a9cf2aaaa8b2ef91da00bb244c7098">create_from_png</a> (cairo_read_func_t read_func, void* closure)</td></tr>
</table>
<hr><a name="_details"></a><h2>Detailed Description</h2>
Image surfaces provide the ability to render to memory buffers either allocated by cairo or by the calling code.
<p>
The supported image formats are those defined in <a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Cairo::Format</a><p>
An <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> is the most generic type of <a class="el" href="classCairo_1_1Surface.html" title="A cairo surface represents an image, either as the destination of a drawing operation...">Surface</a> and the only one that is available by default. You can either create an <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> whose data is managed by <a class="el" href="namespaceCairo.html">Cairo</a>, or you can create an <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> with a data buffer that you allocated yourself so that you can have full access to the data.<p>
When you create an <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> with your own data buffer, you are free to examine the results at any point and do whatever you want with it. Note that if you modify anything and later want to continue to draw to the surface with cairo, you must let cairo know via <a class="el" href="classCairo_1_1Surface.html#77b1f860cc55f4ad168e100108e0b7bb" title="Tells cairo to consider the data buffer dirty.">Cairo::Surface::mark_dirty()</a><p>
Note that like all surfaces, an <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> is a reference-counted object that should be used via <a class="el" href="classCairo_1_1RefPtr.html" title="RefPtr<> is a reference-counting shared smartpointer.">Cairo::RefPtr</a>. <hr><h2>Constructor& Destructor Documentation</h2>
<a class="anchor" name="19a7d3c6f4320c4d812629b3c18925ac"></a><!-- doxytag: member="Cairo::ImageSurface::ImageSurface" ref="19a7d3c6f4320c4d812629b3c18925ac" args="(cairo_surface_t *cobject, bool has_reference=false)" -->
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<td class="memname">Cairo::ImageSurface::ImageSurface </td>
<td>(</td>
<td class="paramtype">cairo_surface_t * </td>
<td class="paramname"> <em>cobject</em>, </td>
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<td class="paramkey"></td>
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<td class="paramtype">bool </td>
<td class="paramname"> <em>has_reference</em> = <code>false</code></td><td> </td>
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<td></td><td></td><td><code> [explicit]</code></td>
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<p>
Create a C++ wrapper for the C instance.
<p>
This C++ instance should then be given to a <a class="el" href="classCairo_1_1RefPtr.html" title="RefPtr<> is a reference-counting shared smartpointer.">RefPtr</a>. <dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>cobject</em> </td><td>The C instance. </td></tr>
<tr><td valign="top"></td><td valign="top"><em>has_reference</em> </td><td>Whether we already have a reference. Otherwise, the constructor will take an extra reference. </td></tr>
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<a class="anchor" name="489f33357db18c23bdf8ebd5d07d8264"></a><!-- doxytag: member="Cairo::ImageSurface::~ImageSurface" ref="489f33357db18c23bdf8ebd5d07d8264" args="()" -->
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<td class="memname">virtual Cairo::ImageSurface::~ImageSurface </td>
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<td> ) </td>
<td><code> [virtual]</code></td>
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<hr><h2>Member Function Documentation</h2>
<a class="anchor" name="feb1b8203f9fa23ff4bca7b70723f370"></a><!-- doxytag: member="Cairo::ImageSurface::create" ref="feb1b8203f9fa23ff4bca7b70723f370" args="(unsigned char *data, Format format, int width, int height, int stride)" -->
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<td class="memname">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a><<a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a>> Cairo::ImageSurface::create </td>
<td>(</td>
<td class="paramtype">unsigned char * </td>
<td class="paramname"> <em>data</em>, </td>
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<td class="paramtype"><a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Format</a> </td>
<td class="paramname"> <em>format</em>, </td>
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<td class="paramtype">int </td>
<td class="paramname"> <em>width</em>, </td>
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<td class="paramtype">int </td>
<td class="paramname"> <em>height</em>, </td>
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Creates an image surface for the provided pixel data.
<p>
The output buffer must be kept around until the surface is destroyed or <a class="el" href="classCairo_1_1Surface.html#8d8afee4ddb4935b85698f27099646a0" title="This function finishes the surface and drops all references to external resources...">finish()</a> is called on the surface. The initial contents of buffer will be used as the initial image contents; you must explicitly clear the buffer, using, for example, <a class="el" href="classCairo_1_1Context.html#85ee124b89c43dc29ff0d964bd005c11" title="Adds a closed-subpath rectangle of the given size to the current path at position...">Context::rectangle()</a> and <a class="el" href="classCairo_1_1Context.html#0a484790884dd138108b07c0ebbbe21d" title="A drawing operator that fills the current path according to the current fill rule...">Context::fill()</a> if you want it cleared.<p>
Note that the stride may be larger than <em>width</em>* <em>bytes_per_pixel</em> to provide proper alignment for each pixel and row. This alignment is required to allow high-performance rendering within cairo. The correct way to obtain a legal stride value is to call <a class="el" href="classCairo_1_1ImageSurface.html#c74f130a3bb36bd9fd70003cd8562ce5" title="This function provides a stride value that will respect all alignment requirements...">format_stride_for_width()</a> with the desired format and maximum image width value, and the use the resulting stride value to allocate the data and to create the image surface. See <a class="el" href="classCairo_1_1ImageSurface.html#c74f130a3bb36bd9fd70003cd8562ce5" title="This function provides a stride value that will respect all alignment requirements...">format_stride_for_width()</a> for example code.<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>data</em> </td><td>a pointer to a buffer supplied by the application in which to write contents. This pointer must be suitably aligned for any kind of variable, (for example, a pointer returned by malloc). </td></tr>
<tr><td valign="top"></td><td valign="top"><em>format</em> </td><td>the format of pixels in the buffer </td></tr>
<tr><td valign="top"></td><td valign="top"><em>width</em> </td><td>the width of the image to be stored in the buffer </td></tr>
<tr><td valign="top"></td><td valign="top"><em>height</em> </td><td>the height of the image to be stored in the buffer </td></tr>
<tr><td valign="top"></td><td valign="top"><em>stride</em> </td><td>the number of bytes between the start of rows in the buffer as allocated. This value should always be computed by cairo_format_stride_for_width() before allocating the data buffer. </td></tr>
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<dl class="return" compact><dt><b>Returns:</b></dt><dd>a <a class="el" href="classCairo_1_1RefPtr.html" title="RefPtr<> is a reference-counting shared smartpointer.">RefPtr</a> to the newly created surface. </dd></dl>
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<a class="anchor" name="82887e1a0480ab16aa891e135f2b28d6"></a><!-- doxytag: member="Cairo::ImageSurface::create" ref="82887e1a0480ab16aa891e135f2b28d6" args="(Format format, int width, int height)" -->
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<td class="memname">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a><<a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a>> Cairo::ImageSurface::create </td>
<td>(</td>
<td class="paramtype"><a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Format</a> </td>
<td class="paramname"> <em>format</em>, </td>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"> <em>width</em>, </td>
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<td class="paramtype">int </td>
<td class="paramname"> <em>height</em></td><td> </td>
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<td>)</td>
<td></td><td></td><td><code> [static]</code></td>
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<p>
Creates an image surface of the specified format and dimensions.
<p>
Initially the surface contents are all 0. (Specifically, within each pixel, each color or alpha channel belonging to format will be 0. The contents of bits within a pixel, but not belonging to the given format are undefined).<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>format</em> </td><td>format of pixels in the surface to create </td></tr>
<tr><td valign="top"></td><td valign="top"><em>width</em> </td><td>width of the surface, in pixels </td></tr>
<tr><td valign="top"></td><td valign="top"><em>height</em> </td><td>height of the surface, in pixels </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>a <a class="el" href="classCairo_1_1RefPtr.html" title="RefPtr<> is a reference-counting shared smartpointer.">RefPtr</a> to the newly created surface. </dd></dl>
<dl compact><dt><b>Examples: </b></dt><dd>
<a class="el" href="image-surface_8cc-example.html#a1">image-surface.cc</a>, <a class="el" href="toy-text_8cc-example.html#a1">toy-text.cc</a>, and <a class="el" href="user-font_8cc-example.html#a4">user-font.cc</a>.</dl>
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<a class="anchor" name="43a9cf2aaaa8b2ef91da00bb244c7098"></a><!-- doxytag: member="Cairo::ImageSurface::create_from_png" ref="43a9cf2aaaa8b2ef91da00bb244c7098" args="(cairo_read_func_t read_func, void *closure)" -->
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<td class="memname">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a><<a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a>> Cairo::ImageSurface::create_from_png </td>
<td>(</td>
<td class="paramtype">cairo_read_func_t </td>
<td class="paramname"> <em>read_func</em>, </td>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">void * </td>
<td class="paramname"> <em>closure</em></td><td> </td>
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<td>)</td>
<td></td><td></td><td><code> [static]</code></td>
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<p>
<dl class="deprecated" compact><dt><b><a class="el" href="deprecated.html#_deprecated000006">Deprecated:</a></b></dt><dd>Use create_from_png_stream instead </dd></dl>
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<a class="anchor" name="ac35bcd255347574036746810f8a2978"></a><!-- doxytag: member="Cairo::ImageSurface::create_from_png" ref="ac35bcd255347574036746810f8a2978" args="(std::string filename)" -->
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<td class="memname">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a><<a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a>> Cairo::ImageSurface::create_from_png </td>
<td>(</td>
<td class="paramtype"><a class="elRef" doxygen="libstdc++.tag:http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a00218.html">std::string</a> </td>
<td class="paramname"> <em>filename</em> </td>
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<td><code> [static]</code></td>
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<p>
Creates a new image surface and initializes the contents to the given PNG file.
<p>
<dl class="note" compact><dt><b>Note:</b></dt><dd>For this function to be available, cairo must have been compiled with PNG support.</dd></dl>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>filename</em> </td><td>name of PNG file to load </td></tr>
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<dl class="return" compact><dt><b>Returns:</b></dt><dd>a <a class="el" href="classCairo_1_1RefPtr.html" title="RefPtr<> is a reference-counting shared smartpointer.">RefPtr</a> to the new cairo_surface_t initialized with the contents of the PNG image file. </dd></dl>
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<a class="anchor" name="7ac275170e7235457c9806aec7cf6f6a"></a><!-- doxytag: member="Cairo::ImageSurface::create_from_png_stream" ref="7ac275170e7235457c9806aec7cf6f6a" args="(const SlotReadFunc &read_func)" -->
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<td class="memname">static <a class="el" href="classCairo_1_1RefPtr.html">RefPtr</a><<a class="el" href="classCairo_1_1ImageSurface.html">ImageSurface</a>> Cairo::ImageSurface::create_from_png_stream </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="classCairo_1_1Surface.html#f66be8453e3fc558ea1282a911bf60e2">SlotReadFunc</a>& </td>
<td class="paramname"> <em>read_func</em> </td>
<td> ) </td>
<td><code> [static]</code></td>
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<p>
Creates a new image surface from PNG data read incrementally via the read_func function.
<p>
<dl class="note" compact><dt><b>Note:</b></dt><dd>For this function to be available, cairo must have been compiled with PNG support.</dd></dl>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>read_func</em> </td><td>function called to read the data of the file </td></tr>
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<dl class="return" compact><dt><b>Returns:</b></dt><dd>a <a class="el" href="classCairo_1_1RefPtr.html" title="RefPtr<> is a reference-counting shared smartpointer.">RefPtr</a> to the new cairo_surface_t initialized with the contents of the PNG image file. </dd></dl>
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<a class="anchor" name="c74f130a3bb36bd9fd70003cd8562ce5"></a><!-- doxytag: member="Cairo::ImageSurface::format_stride_for_width" ref="c74f130a3bb36bd9fd70003cd8562ce5" args="(Cairo::Format format, int width)" -->
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<td class="memname">static int Cairo::ImageSurface::format_stride_for_width </td>
<td>(</td>
<td class="paramtype"><a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Cairo::Format</a> </td>
<td class="paramname"> <em>format</em>, </td>
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<td></td>
<td class="paramtype">int </td>
<td class="paramname"> <em>width</em></td><td> </td>
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<td>)</td>
<td></td><td></td><td><code> [static]</code></td>
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<p>
This function provides a stride value that will respect all alignment requirements of the accelerated image-rendering code within cairo.
<p>
Typical usage will be of the form:<p>
<div class="fragment"><pre class="fragment"> <span class="keywordtype">int</span> <a class="codeRef" doxygen="libstdc++.tag:http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01005.html#g4d464eb22d9ad823ecb9b7eab22c6300">stride</a>;
<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *data;
<a class="code" href="classCairo_1_1RefPtr.html" title="RefPtr&lt;&gt; is a reference-counting shared smartpointer.">Cairo::RefPtr<Cairo::ImageSurface></a> surface;
stride = <a class="code" href="classCairo_1_1ImageSurface.html#c74f130a3bb36bd9fd70003cd8562ce5" title="This function provides a stride value that will respect all alignment requirements...">Cairo::ImageSurface::format_stride_for_width</a> (format, width);
data = malloc (stride * height);
surface = <a class="code" href="classCairo_1_1ImageSurface.html#82887e1a0480ab16aa891e135f2b28d6" title="Creates an image surface of the specified format and dimensions.">Cairo::ImageSurface::create</a> (data, format, width, height);
</pre></div><p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>format</em> </td><td>A <a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Cairo::Format</a> value </td></tr>
<tr><td valign="top"></td><td valign="top"><em>width</em> </td><td>The desired width of an image surface to be created. </td></tr>
</table>
</dl>
<dl class="return" compact><dt><b>Returns:</b></dt><dd>the appropriate stride to use given the desired format and width, or -1 if either the format is invalid or the width too large.</dd></dl>
<dl class="since" compact><dt><b>Since:</b></dt><dd>1.6 </dd></dl>
</div>
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<a class="anchor" name="8858eb704ebe2118baf83f2a104b9140"></a><!-- doxytag: member="Cairo::ImageSurface::get_data" ref="8858eb704ebe2118baf83f2a104b9140" args="() const " -->
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<td class="memname">const unsigned char* Cairo::ImageSurface::get_data </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const</td>
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<p>
</div>
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<a class="anchor" name="94ba52fe4a201579c8a5541717822bdb"></a><!-- doxytag: member="Cairo::ImageSurface::get_data" ref="94ba52fe4a201579c8a5541717822bdb" args="()" -->
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<td class="memname">unsigned char* Cairo::ImageSurface::get_data </td>
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<p>
Get a pointer to the data of the image surface, for direct inspection or modification.
<p>
Return value: a pointer to the image data of this surface or NULL if is not an image surface.
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<a class="anchor" name="edccf9d08b3e5852c0bbb195cf1379a8"></a><!-- doxytag: member="Cairo::ImageSurface::get_format" ref="edccf9d08b3e5852c0bbb195cf1379a8" args="() const " -->
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<td class="memname"><a class="el" href="namespaceCairo.html#d3f86970e1bd354b263303c9b8759166">Format</a> Cairo::ImageSurface::get_format </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const</td>
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<p>
gets the format of the surface
<p>
</div>
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<a class="anchor" name="a0e17bed71b125fd4725386ee1f14d07"></a><!-- doxytag: member="Cairo::ImageSurface::get_height" ref="a0e17bed71b125fd4725386ee1f14d07" args="() const " -->
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<td class="memname">int Cairo::ImageSurface::get_height </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const</td>
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<p>
Gets the height of the <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> in pixels.
<p>
</div>
</div><p>
<a class="anchor" name="4b33c7f1c03197eb66dac3e909c5a39a"></a><!-- doxytag: member="Cairo::ImageSurface::get_stride" ref="4b33c7f1c03197eb66dac3e909c5a39a" args="() const " -->
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<td class="memname">int Cairo::ImageSurface::get_stride </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const</td>
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<p>
Return value: the stride of the image surface in bytes (or 0 if is not an image surface).
<p>
The stride is the distance in bytes from the beginning of one row of the image data to the beginning of the next row.
</div>
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<a class="anchor" name="f75b30cde988ad6959bb75862f5b6e2a"></a><!-- doxytag: member="Cairo::ImageSurface::get_width" ref="f75b30cde988ad6959bb75862f5b6e2a" args="() const " -->
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<td class="memname">int Cairo::ImageSurface::get_width </td>
<td>(</td>
<td class="paramname"> </td>
<td> ) </td>
<td> const</td>
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<p>
Gets the width of the <a class="el" href="classCairo_1_1ImageSurface.html" title="Image surfaces provide the ability to render to memory buffers either allocated by...">ImageSurface</a> in pixels.
<p>
</div>
</div><p>
<hr>The documentation for this class was generated from the following file:<ul>
<li>cairomm/surface.h</ul>
</div>
<hr size="1"><address style="text-align: right;"><small>Generated on Thu Aug 13 11:40:14 2009 for cairomm by 
<a href="http://www.doxygen.org/index.html">
<img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.9 </small></address>
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