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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Scaling: GDK-PixBuf Reference Manual</title> <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot"> <link rel="home" href="index.html" title="GDK-PixBuf Reference Manual"> <link rel="up" href="rn01.html" title="API Reference"> <link rel="prev" href="gdk-pixbuf-Inline-data.html" title="Inline data"> <link rel="next" href="gdk-pixbuf-gdk-pixbuf-rendering.html" title="Rendering"> <meta name="generator" content="GTK-Doc V1.27 (XML mode)"> <link rel="stylesheet" href="style.css" type="text/css"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle"> <td width="100%" align="left" class="shortcuts"> <a href="#" class="shortcut">Top</a><span id="nav_description"> <span class="dim">|</span> <a href="#gdk-pixbuf-Scaling.description" class="shortcut">Description</a></span> </td> <td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td> <td><a accesskey="u" href="rn01.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td> <td><a accesskey="p" href="gdk-pixbuf-Inline-data.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td> <td><a accesskey="n" href="gdk-pixbuf-gdk-pixbuf-rendering.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td> </tr></table> <div class="refentry"> <a name="gdk-pixbuf-Scaling"></a><div class="titlepage"></div> <div class="refnamediv"><table width="100%"><tr> <td valign="top"> <h2><span class="refentrytitle"><a name="gdk-pixbuf-Scaling.top_of_page"></a>Scaling</span></h2> <p>Scaling — Scaling pixbufs and scaling and alpha blending pixbufs</p> </td> <td class="gallery_image" valign="top" align="right"></td> </tr></table></div> <div class="refsect1"> <a name="gdk-pixbuf-Scaling.functions"></a><h2>Functions</h2> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="functions_return"> <col class="functions_name"> </colgroup> <tbody> <tr> <td class="function_type"> <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * </td> <td class="function_name"> <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()">gdk_pixbuf_scale_simple</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <span class="returnvalue">void</span> </td> <td class="function_name"> <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()">gdk_pixbuf_scale</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * </td> <td class="function_name"> <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite-color-simple" title="gdk_pixbuf_composite_color_simple ()">gdk_pixbuf_composite_color_simple</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <span class="returnvalue">void</span> </td> <td class="function_name"> <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite" title="gdk_pixbuf_composite ()">gdk_pixbuf_composite</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <span class="returnvalue">void</span> </td> <td class="function_name"> <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite-color" title="gdk_pixbuf_composite_color ()">gdk_pixbuf_composite_color</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * </td> <td class="function_name"> <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-rotate-simple" title="gdk_pixbuf_rotate_simple ()">gdk_pixbuf_rotate_simple</a> <span class="c_punctuation">()</span> </td> </tr> <tr> <td class="function_type"> <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * </td> <td class="function_name"> <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-flip" title="gdk_pixbuf_flip ()">gdk_pixbuf_flip</a> <span class="c_punctuation">()</span> </td> </tr> </tbody> </table></div> </div> <div class="refsect1"> <a name="gdk-pixbuf-Scaling.other"></a><h2>Types and Values</h2> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="name"> <col class="description"> </colgroup> <tbody> <tr> <td class="datatype_keyword">enum</td> <td class="function_name"><a class="link" href="gdk-pixbuf-Scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a></td> </tr> <tr> <td class="datatype_keyword">enum</td> <td class="function_name"><a class="link" href="gdk-pixbuf-Scaling.html#GdkPixbufRotation" title="enum GdkPixbufRotation">GdkPixbufRotation</a></td> </tr> </tbody> </table></div> </div> <div class="refsect1"> <a name="gdk-pixbuf-Scaling.includes"></a><h2>Includes</h2> <pre class="synopsis">#include <gdk-pixbuf/gdk-pixdata.h> </pre> </div> <div class="refsect1"> <a name="gdk-pixbuf-Scaling.description"></a><h2>Description</h2> <p>The GdkPixBuf contains functions to scale pixbufs, to scale pixbufs and alpha blend against an existing image, and to scale pixbufs and alpha blend against a solid color or checkerboard. Alpha blending a checkerboard is a common way to show an image with an alpha channel in image-viewing and editing software.</p> <p>Note that in these functions, the terms ‘alpha blending’ and ‘compositing’ are used synonymously.</p> <p>Since the full-featured functions (<a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()"><code class="function">gdk_pixbuf_scale()</code></a>, <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite" title="gdk_pixbuf_composite ()"><code class="function">gdk_pixbuf_composite()</code></a>, and <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite-color" title="gdk_pixbuf_composite_color ()"><code class="function">gdk_pixbuf_composite_color()</code></a>) are rather complex to use and have many arguments, two simple convenience functions are provided, <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()"><code class="function">gdk_pixbuf_scale_simple()</code></a> and <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite-color-simple" title="gdk_pixbuf_composite_color_simple ()"><code class="function">gdk_pixbuf_composite_color_simple()</code></a> which create a new pixbuf of a given size, scale an original image to fit, and then return the new pixbuf.</p> <p>If the destination pixbuf was created from a readonly source, these operations will force a copy into a mutable buffer.</p> <p>Scaling and alpha blending functions take advantage of MMX hardware acceleration on systems where MMX is supported. If gdk-pixbuf is built with the Sun mediaLib library, these functions are instead accelerated using mediaLib, which provides hardware acceleration on Intel, AMD, and Sparc chipsets. If desired, mediaLib support can be turned off by setting the <code class="literal">GDK_DISABLE_MEDIALIB</code> environment variable. </p> <p>The alpha blending function used is:</p> <div class="informalexample"> <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td class="listing_lines" align="right"><pre>1</pre></td> <td class="listing_code"><pre class="programlisting"><span class="normal">Cd </span><span class="symbol">=</span><span class="normal"> Cs·As </span><span class="symbol">+</span><span class="normal"> </span><span class="function">Cd</span><span class="symbol">(</span><span class="number">1</span><span class="symbol">-</span><span class="normal">As</span><span class="symbol">)</span></pre></td> </tr> </tbody> </table> </div> <p> where <code class="literal">Cd</code> is the destination pixel color, <code class="literal">Cs</code> is the source pixel color, and <code class="literal">As</code> is the source pixel alpha.</p> <p>The following example demonstrates handling an expose event by rendering the appropriate area of a source image (which is scaled to fit the widget) onto the widget's window. The source image is rendered against a checkerboard, which provides a visual representation of the alpha channel if the image has one. If the image doesn't have an alpha channel, calling <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite-color" title="gdk_pixbuf_composite_color ()"><code class="function">gdk_pixbuf_composite_color()</code></a> function has exactly the same effect as calling <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()"><code class="function">gdk_pixbuf_scale()</code></a>.</p> <div class="refsect3"> <a name="id-1.2.10.6.11"></a><h4>Handling an expose event</h4> <div class="informalexample"> <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> <tbody> <tr> <td class="listing_lines" align="right"><pre>1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24</pre></td> <td class="listing_code"><pre class="programlisting"><span class="normal">gboolean</span> <span class="function">expose_cb</span><span class="normal"> </span><span class="symbol">(</span><span class="usertype">GtkWidget</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">widget</span><span class="symbol">,</span><span class="normal"> </span><span class="usertype">GdkEventExpose</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">event</span><span class="symbol">,</span><span class="normal"> </span><span class="usertype">gpointer</span><span class="normal"> data</span><span class="symbol">)</span> <span class="cbracket">{</span> <span class="normal"> </span><span class="usertype">GdkPixbuf</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">dest</span><span class="symbol">;</span> <span class="normal"> dest </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="gdk-pixbuf-Image-Data-in-Memory.html#gdk-pixbuf-new">gdk_pixbuf_new</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal"><a href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GDK-COLORSPACE-RGB:CAPS">GDK_COLORSPACE_RGB</a></span><span class="symbol">,</span><span class="normal"> FALSE</span><span class="symbol">,</span><span class="normal"> </span><span class="number">8</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">width</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">height</span><span class="symbol">);</span> <span class="normal"> </span><span class="function"><a href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite-color">gdk_pixbuf_composite_color</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pixbuf</span><span class="symbol">,</span><span class="normal"> dest</span><span class="symbol">,</span> <span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">width</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">height</span><span class="symbol">,</span> <span class="normal"> </span><span class="symbol">-</span><span class="normal">event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">x</span><span class="symbol">,</span><span class="normal"> </span><span class="symbol">-</span><span class="normal">event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">y</span><span class="symbol">,</span> <span class="normal"> </span><span class="symbol">(</span><span class="type">double</span><span class="symbol">)</span><span class="normal"> widget</span><span class="symbol">-></span><span class="normal">allocation</span><span class="symbol">.</span><span class="normal">width </span><span class="symbol">/</span><span class="normal"> </span><span class="function"><a href="gdk-pixbuf-The-GdkPixbuf-Structure.html#gdk-pixbuf-get-width">gdk_pixbuf_get_width</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pixbuf</span><span class="symbol">),</span> <span class="normal"> </span><span class="symbol">(</span><span class="type">double</span><span class="symbol">)</span><span class="normal"> widget</span><span class="symbol">-></span><span class="normal">allocation</span><span class="symbol">.</span><span class="normal">height </span><span class="symbol">/</span><span class="normal"> </span><span class="function"><a href="gdk-pixbuf-The-GdkPixbuf-Structure.html#gdk-pixbuf-get-height">gdk_pixbuf_get_height</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">pixbuf</span><span class="symbol">),</span> <span class="normal"> <a href="gdk-pixbuf-Scaling.html#GDK-INTERP-BILINEAR:CAPS">GDK_INTERP_BILINEAR</a></span><span class="symbol">,</span><span class="normal"> </span><span class="number">255</span><span class="symbol">,</span> <span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">x</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">y</span><span class="symbol">,</span><span class="normal"> </span><span class="number">16</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0xaaaaaa</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0x555555</span><span class="symbol">);</span> <span class="normal"> </span><span class="function">gdk_draw_pixbuf</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">widget</span><span class="symbol">-></span><span class="normal">window</span><span class="symbol">,</span><span class="normal"> widget</span><span class="symbol">-></span><span class="normal">style</span><span class="symbol">-></span><span class="normal">fg_gc</span><span class="symbol">[</span><span class="normal">GTK_STATE_NORMAL</span><span class="symbol">],</span><span class="normal"> dest</span><span class="symbol">,</span> <span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> </span><span class="number">0</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">x</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">y</span><span class="symbol">,</span> <span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">width</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">height</span><span class="symbol">,</span> <span class="normal"> GDK_RGB_DITHER_NORMAL</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">x</span><span class="symbol">,</span><span class="normal"> event</span><span class="symbol">-></span><span class="normal">area</span><span class="symbol">.</span><span class="normal">y</span><span class="symbol">);</span> <span class="normal"> </span> <span class="normal"> </span><span class="function"><a href="gdk-pixbuf-Reference-Counting-and-Memory-Mangement.html#gdk-pixbuf-unref">gdk_pixbuf_unref</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">dest</span><span class="symbol">);</span> <span class="normal"> </span> <span class="normal"> </span><span class="keyword">return</span><span class="normal"> TRUE</span><span class="symbol">;</span> <span class="cbracket">}</span></pre></td> </tr> </tbody> </table> </div> <p></p> </div> </div> <div class="refsect1"> <a name="gdk-pixbuf-Scaling.functions_details"></a><h2>Functions</h2> <div class="refsect2"> <a name="gdk-pixbuf-scale-simple"></a><h3>gdk_pixbuf_scale_simple ()</h3> <pre class="programlisting"><a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * gdk_pixbuf_scale_simple (<em class="parameter"><code>const <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *src</code></em>, <em class="parameter"><code><span class="type">int</span> dest_width</code></em>, <em class="parameter"><code><span class="type">int</span> dest_height</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-Scaling.html#GdkInterpType" title="enum GdkInterpType"><span class="type">GdkInterpType</span></a> interp_type</code></em>);</pre> <p>Create a new <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> containing a copy of <em class="parameter"><code>src</code></em> scaled to <em class="parameter"><code>dest_width</code></em> x <em class="parameter"><code>dest_height</code></em> . Leaves <em class="parameter"><code>src</code></em> unaffected. <em class="parameter"><code>interp_type</code></em> should be <a class="link" href="gdk-pixbuf-Scaling.html#GDK-INTERP-NEAREST:CAPS"><span class="type">GDK_INTERP_NEAREST</span></a> if you want maximum speed (but when scaling down <a class="link" href="gdk-pixbuf-Scaling.html#GDK-INTERP-NEAREST:CAPS"><span class="type">GDK_INTERP_NEAREST</span></a> is usually unusably ugly). The default <em class="parameter"><code>interp_type</code></em> should be <a class="link" href="gdk-pixbuf-Scaling.html#GDK-INTERP-BILINEAR:CAPS"><span class="type">GDK_INTERP_BILINEAR</span></a> which offers reasonable quality and speed.</p> <p>You can scale a sub-portion of <em class="parameter"><code>src</code></em> by creating a sub-pixbuf pointing into <em class="parameter"><code>src</code></em> ; see <a class="link" href="gdk-pixbuf-Image-Data-in-Memory.html#gdk-pixbuf-new-subpixbuf" title="gdk_pixbuf_new_subpixbuf ()"><code class="function">gdk_pixbuf_new_subpixbuf()</code></a>.</p> <p>If <em class="parameter"><code>dest_width</code></em> and <em class="parameter"><code>dest_height</code></em> are equal to the <em class="parameter"><code>src</code></em> width and height, a copy of <em class="parameter"><code>src</code></em> is returned, avoiding any scaling.</p> <p>For more complicated scaling/alpha blending see <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()"><code class="function">gdk_pixbuf_scale()</code></a> and <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite" title="gdk_pixbuf_composite ()"><code class="function">gdk_pixbuf_composite()</code></a>.</p> <div class="refsect3"> <a name="gdk-pixbuf-scale-simple.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody> <tr> <td class="parameter_name"><p>src</p></td> <td class="parameter_description"><p>a <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a></p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_width</p></td> <td class="parameter_description"><p>the width of destination image</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_height</p></td> <td class="parameter_description"><p>the height of destination image</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>interp_type</p></td> <td class="parameter_description"><p>the interpolation type for the transformation.</p></td> <td class="parameter_annotations"> </td> </tr> </tbody> </table></div> </div> <div class="refsect3"> <a name="gdk-pixbuf-scale-simple.returns"></a><h4>Returns</h4> <p>the new <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <code class="literal">NULL</code> if not enough memory could be allocated for it. </p> <p><span class="annotation">[<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>][<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p> </div> </div> <hr> <div class="refsect2"> <a name="gdk-pixbuf-scale"></a><h3>gdk_pixbuf_scale ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gdk_pixbuf_scale (<em class="parameter"><code>const <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *src</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *dest</code></em>, <em class="parameter"><code><span class="type">int</span> dest_x</code></em>, <em class="parameter"><code><span class="type">int</span> dest_y</code></em>, <em class="parameter"><code><span class="type">int</span> dest_width</code></em>, <em class="parameter"><code><span class="type">int</span> dest_height</code></em>, <em class="parameter"><code><span class="type">double</span> offset_x</code></em>, <em class="parameter"><code><span class="type">double</span> offset_y</code></em>, <em class="parameter"><code><span class="type">double</span> scale_x</code></em>, <em class="parameter"><code><span class="type">double</span> scale_y</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-Scaling.html#GdkInterpType" title="enum GdkInterpType"><span class="type">GdkInterpType</span></a> interp_type</code></em>);</pre> <p>Creates a transformation of the source image <em class="parameter"><code>src</code></em> by scaling by <em class="parameter"><code>scale_x</code></em> and <em class="parameter"><code>scale_y</code></em> then translating by <em class="parameter"><code>offset_x</code></em> and <em class="parameter"><code>offset_y</code></em> , then renders the rectangle (<em class="parameter"><code>dest_x</code></em> , <em class="parameter"><code>dest_y</code></em> , <em class="parameter"><code>dest_width</code></em> , <em class="parameter"><code>dest_height</code></em> ) of the resulting image onto the destination image replacing the previous contents.</p> <p>Try to use <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()"><code class="function">gdk_pixbuf_scale_simple()</code></a> first, this function is the industrial-strength power tool you can fall back to if <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()"><code class="function">gdk_pixbuf_scale_simple()</code></a> isn't powerful enough.</p> <p>If the source rectangle overlaps the destination rectangle on the same pixbuf, it will be overwritten during the scaling which results in rendering artifacts.</p> <div class="refsect3"> <a name="gdk-pixbuf-scale.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody> <tr> <td class="parameter_name"><p>src</p></td> <td class="parameter_description"><p>a <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a></p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest</p></td> <td class="parameter_description"><p>the <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> into which to render the results</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_x</p></td> <td class="parameter_description"><p>the left coordinate for region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_y</p></td> <td class="parameter_description"><p>the top coordinate for region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_width</p></td> <td class="parameter_description"><p>the width of the region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_height</p></td> <td class="parameter_description"><p>the height of the region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>offset_x</p></td> <td class="parameter_description"><p>the offset in the X direction (currently rounded to an integer)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>offset_y</p></td> <td class="parameter_description"><p>the offset in the Y direction (currently rounded to an integer)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>scale_x</p></td> <td class="parameter_description"><p>the scale factor in the X direction</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>scale_y</p></td> <td class="parameter_description"><p>the scale factor in the Y direction</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>interp_type</p></td> <td class="parameter_description"><p>the interpolation type for the transformation.</p></td> <td class="parameter_annotations"> </td> </tr> </tbody> </table></div> </div> </div> <hr> <div class="refsect2"> <a name="gdk-pixbuf-composite-color-simple"></a><h3>gdk_pixbuf_composite_color_simple ()</h3> <pre class="programlisting"><a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * gdk_pixbuf_composite_color_simple (<em class="parameter"><code>const <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *src</code></em>, <em class="parameter"><code><span class="type">int</span> dest_width</code></em>, <em class="parameter"><code><span class="type">int</span> dest_height</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-Scaling.html#GdkInterpType" title="enum GdkInterpType"><span class="type">GdkInterpType</span></a> interp_type</code></em>, <em class="parameter"><code><span class="type">int</span> overall_alpha</code></em>, <em class="parameter"><code><span class="type">int</span> check_size</code></em>, <em class="parameter"><code><span class="type">guint32</span> color1</code></em>, <em class="parameter"><code><span class="type">guint32</span> color2</code></em>);</pre> <p>Creates a new <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> by scaling <em class="parameter"><code>src</code></em> to <em class="parameter"><code>dest_width</code></em> x <em class="parameter"><code>dest_height</code></em> and alpha blending the result with a checkboard of colors <em class="parameter"><code>color1</code></em> and <em class="parameter"><code>color2</code></em> .</p> <div class="refsect3"> <a name="gdk-pixbuf-composite-color-simple.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody> <tr> <td class="parameter_name"><p>src</p></td> <td class="parameter_description"><p>a <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a></p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_width</p></td> <td class="parameter_description"><p>the width of destination image</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_height</p></td> <td class="parameter_description"><p>the height of destination image</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>interp_type</p></td> <td class="parameter_description"><p>the interpolation type for the transformation.</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>overall_alpha</p></td> <td class="parameter_description"><p>overall alpha for source image (0..255)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>check_size</p></td> <td class="parameter_description"><p>the size of checks in the checkboard (must be a power of two)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>color1</p></td> <td class="parameter_description"><p>the color of check at upper left</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>color2</p></td> <td class="parameter_description"><p>the color of the other check</p></td> <td class="parameter_annotations"> </td> </tr> </tbody> </table></div> </div> <div class="refsect3"> <a name="gdk-pixbuf-composite-color-simple.returns"></a><h4>Returns</h4> <p>the new <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <code class="literal">NULL</code> if not enough memory could be allocated for it. </p> <p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p> </div> </div> <hr> <div class="refsect2"> <a name="gdk-pixbuf-composite"></a><h3>gdk_pixbuf_composite ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gdk_pixbuf_composite (<em class="parameter"><code>const <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *src</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *dest</code></em>, <em class="parameter"><code><span class="type">int</span> dest_x</code></em>, <em class="parameter"><code><span class="type">int</span> dest_y</code></em>, <em class="parameter"><code><span class="type">int</span> dest_width</code></em>, <em class="parameter"><code><span class="type">int</span> dest_height</code></em>, <em class="parameter"><code><span class="type">double</span> offset_x</code></em>, <em class="parameter"><code><span class="type">double</span> offset_y</code></em>, <em class="parameter"><code><span class="type">double</span> scale_x</code></em>, <em class="parameter"><code><span class="type">double</span> scale_y</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-Scaling.html#GdkInterpType" title="enum GdkInterpType"><span class="type">GdkInterpType</span></a> interp_type</code></em>, <em class="parameter"><code><span class="type">int</span> overall_alpha</code></em>);</pre> <p>Creates a transformation of the source image <em class="parameter"><code>src</code></em> by scaling by <em class="parameter"><code>scale_x</code></em> and <em class="parameter"><code>scale_y</code></em> then translating by <em class="parameter"><code>offset_x</code></em> and <em class="parameter"><code>offset_y</code></em> . This gives an image in the coordinates of the destination pixbuf. The rectangle (<em class="parameter"><code>dest_x</code></em> , <em class="parameter"><code>dest_y</code></em> , <em class="parameter"><code>dest_width</code></em> , <em class="parameter"><code>dest_height</code></em> ) is then alpha blended onto the corresponding rectangle of the original destination image.</p> <p>When the destination rectangle contains parts not in the source image, the data at the edges of the source image is replicated to infinity. </p> <p><span class="inlinemediaobject"><img src="composite.png"></span></p> <div class="refsect3"> <a name="gdk-pixbuf-composite.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody> <tr> <td class="parameter_name"><p>src</p></td> <td class="parameter_description"><p>a <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a></p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest</p></td> <td class="parameter_description"><p>the <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> into which to render the results</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_x</p></td> <td class="parameter_description"><p>the left coordinate for region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_y</p></td> <td class="parameter_description"><p>the top coordinate for region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_width</p></td> <td class="parameter_description"><p>the width of the region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_height</p></td> <td class="parameter_description"><p>the height of the region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>offset_x</p></td> <td class="parameter_description"><p>the offset in the X direction (currently rounded to an integer)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>offset_y</p></td> <td class="parameter_description"><p>the offset in the Y direction (currently rounded to an integer)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>scale_x</p></td> <td class="parameter_description"><p>the scale factor in the X direction</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>scale_y</p></td> <td class="parameter_description"><p>the scale factor in the Y direction</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>interp_type</p></td> <td class="parameter_description"><p>the interpolation type for the transformation.</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>overall_alpha</p></td> <td class="parameter_description"><p>overall alpha for source image (0..255)</p></td> <td class="parameter_annotations"> </td> </tr> </tbody> </table></div> </div> </div> <hr> <div class="refsect2"> <a name="gdk-pixbuf-composite-color"></a><h3>gdk_pixbuf_composite_color ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gdk_pixbuf_composite_color (<em class="parameter"><code>const <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *src</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *dest</code></em>, <em class="parameter"><code><span class="type">int</span> dest_x</code></em>, <em class="parameter"><code><span class="type">int</span> dest_y</code></em>, <em class="parameter"><code><span class="type">int</span> dest_width</code></em>, <em class="parameter"><code><span class="type">int</span> dest_height</code></em>, <em class="parameter"><code><span class="type">double</span> offset_x</code></em>, <em class="parameter"><code><span class="type">double</span> offset_y</code></em>, <em class="parameter"><code><span class="type">double</span> scale_x</code></em>, <em class="parameter"><code><span class="type">double</span> scale_y</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-Scaling.html#GdkInterpType" title="enum GdkInterpType"><span class="type">GdkInterpType</span></a> interp_type</code></em>, <em class="parameter"><code><span class="type">int</span> overall_alpha</code></em>, <em class="parameter"><code><span class="type">int</span> check_x</code></em>, <em class="parameter"><code><span class="type">int</span> check_y</code></em>, <em class="parameter"><code><span class="type">int</span> check_size</code></em>, <em class="parameter"><code><span class="type">guint32</span> color1</code></em>, <em class="parameter"><code><span class="type">guint32</span> color2</code></em>);</pre> <p>Creates a transformation of the source image <em class="parameter"><code>src</code></em> by scaling by <em class="parameter"><code>scale_x</code></em> and <em class="parameter"><code>scale_y</code></em> then translating by <em class="parameter"><code>offset_x</code></em> and <em class="parameter"><code>offset_y</code></em> , then alpha blends the rectangle (<em class="parameter"><code>dest_x</code></em> ,<em class="parameter"><code>dest_y</code></em> , <em class="parameter"><code>dest_width</code></em> , <em class="parameter"><code>dest_height</code></em> ) of the resulting image with a checkboard of the colors <em class="parameter"><code>color1</code></em> and <em class="parameter"><code>color2</code></em> and renders it onto the destination image.</p> <p>If the source image has no alpha channel, and <em class="parameter"><code>overall_alpha</code></em> is 255, a fast path is used which omits the alpha blending and just performs the scaling.</p> <p>See <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-composite-color-simple" title="gdk_pixbuf_composite_color_simple ()"><code class="function">gdk_pixbuf_composite_color_simple()</code></a> for a simpler variant of this function suitable for many tasks.</p> <div class="refsect3"> <a name="gdk-pixbuf-composite-color.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody> <tr> <td class="parameter_name"><p>src</p></td> <td class="parameter_description"><p>a <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a></p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest</p></td> <td class="parameter_description"><p>the <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> into which to render the results</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_x</p></td> <td class="parameter_description"><p>the left coordinate for region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_y</p></td> <td class="parameter_description"><p>the top coordinate for region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_width</p></td> <td class="parameter_description"><p>the width of the region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>dest_height</p></td> <td class="parameter_description"><p>the height of the region to render</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>offset_x</p></td> <td class="parameter_description"><p>the offset in the X direction (currently rounded to an integer)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>offset_y</p></td> <td class="parameter_description"><p>the offset in the Y direction (currently rounded to an integer)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>scale_x</p></td> <td class="parameter_description"><p>the scale factor in the X direction</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>scale_y</p></td> <td class="parameter_description"><p>the scale factor in the Y direction</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>interp_type</p></td> <td class="parameter_description"><p>the interpolation type for the transformation.</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>overall_alpha</p></td> <td class="parameter_description"><p>overall alpha for source image (0..255)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>check_x</p></td> <td class="parameter_description"><p>the X offset for the checkboard (origin of checkboard is at -<em class="parameter"><code>check_x</code></em> , -<em class="parameter"><code>check_y</code></em> )</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>check_y</p></td> <td class="parameter_description"><p>the Y offset for the checkboard </p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>check_size</p></td> <td class="parameter_description"><p>the size of checks in the checkboard (must be a power of two)</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>color1</p></td> <td class="parameter_description"><p>the color of check at upper left</p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>color2</p></td> <td class="parameter_description"><p>the color of the other check</p></td> <td class="parameter_annotations"> </td> </tr> </tbody> </table></div> </div> </div> <hr> <div class="refsect2"> <a name="gdk-pixbuf-rotate-simple"></a><h3>gdk_pixbuf_rotate_simple ()</h3> <pre class="programlisting"><a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * gdk_pixbuf_rotate_simple (<em class="parameter"><code>const <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *src</code></em>, <em class="parameter"><code><a class="link" href="gdk-pixbuf-Scaling.html#GdkPixbufRotation" title="enum GdkPixbufRotation"><span class="type">GdkPixbufRotation</span></a> angle</code></em>);</pre> <p>Rotates a pixbuf by a multiple of 90 degrees, and returns the result in a new pixbuf.</p> <p>If <em class="parameter"><code>angle</code></em> is 0, a copy of <em class="parameter"><code>src</code></em> is returned, avoiding any rotation.</p> <div class="refsect3"> <a name="gdk-pixbuf-rotate-simple.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody> <tr> <td class="parameter_name"><p>src</p></td> <td class="parameter_description"><p>a <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a></p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>angle</p></td> <td class="parameter_description"><p>the angle to rotate by</p></td> <td class="parameter_annotations"> </td> </tr> </tbody> </table></div> </div> <div class="refsect3"> <a name="gdk-pixbuf-rotate-simple.returns"></a><h4>Returns</h4> <p>the new <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <code class="literal">NULL</code> if not enough memory could be allocated for it. </p> <p><span class="annotation">[<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>][<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p> </div> <p class="since">Since: <a class="link" href="api-index-2-6.html#api-index-2.6">2.6</a></p> </div> <hr> <div class="refsect2"> <a name="gdk-pixbuf-flip"></a><h3>gdk_pixbuf_flip ()</h3> <pre class="programlisting"><a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="returnvalue">GdkPixbuf</span></a> * gdk_pixbuf_flip (<em class="parameter"><code>const <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> *src</code></em>, <em class="parameter"><code><span class="type">gboolean</span> horizontal</code></em>);</pre> <p>Flips a pixbuf horizontally or vertically and returns the result in a new pixbuf.</p> <div class="refsect3"> <a name="gdk-pixbuf-flip.parameters"></a><h4>Parameters</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="150px" class="parameters_name"> <col class="parameters_description"> <col width="200px" class="parameters_annotations"> </colgroup> <tbody> <tr> <td class="parameter_name"><p>src</p></td> <td class="parameter_description"><p>a <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a></p></td> <td class="parameter_annotations"> </td> </tr> <tr> <td class="parameter_name"><p>horizontal</p></td> <td class="parameter_description"><p><code class="literal">TRUE</code> to flip horizontally, <code class="literal">FALSE</code> to flip vertically</p></td> <td class="parameter_annotations"> </td> </tr> </tbody> </table></div> </div> <div class="refsect3"> <a name="gdk-pixbuf-flip.returns"></a><h4>Returns</h4> <p>the new <a class="link" href="gdk-pixbuf-The-GdkPixbuf-Structure.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <code class="literal">NULL</code> if not enough memory could be allocated for it. </p> <p><span class="annotation">[<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>][<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p> </div> <p class="since">Since: <a class="link" href="api-index-2-6.html#api-index-2.6">2.6</a></p> </div> </div> <div class="refsect1"> <a name="gdk-pixbuf-Scaling.other_details"></a><h2>Types and Values</h2> <div class="refsect2"> <a name="GdkInterpType"></a><h3>enum GdkInterpType</h3> <p>This enumeration describes the different interpolation modes that can be used with the scaling functions. <em class="parameter"><code>GDK_INTERP_NEAREST</code></em> is the fastest scaling method, but has horrible quality when scaling down. <em class="parameter"><code>GDK_INTERP_BILINEAR</code></em> is the best choice if you aren't sure what to choose, it has a good speed/quality balance.</p> <p> <note> Cubic filtering is missing from the list; hyperbolic interpolation is just as fast and results in higher quality. </note></p> <div class="refsect3"> <a name="GdkInterpType.members"></a><h4>Members</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="300px" class="enum_members_name"> <col class="enum_members_description"> <col width="200px" class="enum_members_annotations"> </colgroup> <tbody> <tr> <td class="enum_member_name"><p><a name="GDK-INTERP-NEAREST:CAPS"></a>GDK_INTERP_NEAREST</p></td> <td class="enum_member_description"> <p>Nearest neighbor sampling; this is the fastest and lowest quality mode. Quality is normally unacceptable when scaling down, but may be OK when scaling up.</p> </td> <td class="enum_member_annotations"> </td> </tr> <tr> <td class="enum_member_name"><p><a name="GDK-INTERP-TILES:CAPS"></a>GDK_INTERP_TILES</p></td> <td class="enum_member_description"> <p>This is an accurate simulation of the PostScript image operator without any interpolation enabled. Each pixel is rendered as a tiny parallelogram of solid color, the edges of which are implemented with antialiasing. It resembles nearest neighbor for enlargement, and bilinear for reduction.</p> </td> <td class="enum_member_annotations"> </td> </tr> <tr> <td class="enum_member_name"><p><a name="GDK-INTERP-BILINEAR:CAPS"></a>GDK_INTERP_BILINEAR</p></td> <td class="enum_member_description"> <p>Best quality/speed balance; use this mode by default. Bilinear interpolation. For enlargement, it is equivalent to point-sampling the ideal bilinear-interpolated image. For reduction, it is equivalent to laying down small tiles and integrating over the coverage area.</p> </td> <td class="enum_member_annotations"> </td> </tr> <tr> <td class="enum_member_name"><p><a name="GDK-INTERP-HYPER:CAPS"></a>GDK_INTERP_HYPER</p></td> <td class="enum_member_description"> <p>This is the slowest and highest quality reconstruction function. It is derived from the hyperbolic filters in Wolberg's "Digital Image Warping", and is formally defined as the hyperbolic-filter sampling the ideal hyperbolic-filter interpolated image (the filter is designed to be idempotent for 1:1 pixel mapping).</p> </td> <td class="enum_member_annotations"> </td> </tr> </tbody> </table></div> </div> </div> <hr> <div class="refsect2"> <a name="GdkPixbufRotation"></a><h3>enum GdkPixbufRotation</h3> <p>The possible rotations which can be passed to <a class="link" href="gdk-pixbuf-Scaling.html#gdk-pixbuf-rotate-simple" title="gdk_pixbuf_rotate_simple ()"><code class="function">gdk_pixbuf_rotate_simple()</code></a>. To make them easier to use, their numerical values are the actual degrees.</p> <div class="refsect3"> <a name="GdkPixbufRotation.members"></a><h4>Members</h4> <div class="informaltable"><table class="informaltable" width="100%" border="0"> <colgroup> <col width="300px" class="enum_members_name"> <col class="enum_members_description"> <col width="200px" class="enum_members_annotations"> </colgroup> <tbody> <tr> <td class="enum_member_name"><p><a name="GDK-PIXBUF-ROTATE-NONE:CAPS"></a>GDK_PIXBUF_ROTATE_NONE</p></td> <td class="enum_member_description"> <p>No rotation.</p> </td> <td class="enum_member_annotations"> </td> </tr> <tr> <td class="enum_member_name"><p><a name="GDK-PIXBUF-ROTATE-COUNTERCLOCKWISE:CAPS"></a>GDK_PIXBUF_ROTATE_COUNTERCLOCKWISE</p></td> <td class="enum_member_description"> <p>Rotate by 90 degrees.</p> </td> <td class="enum_member_annotations"> </td> </tr> <tr> <td class="enum_member_name"><p><a name="GDK-PIXBUF-ROTATE-UPSIDEDOWN:CAPS"></a>GDK_PIXBUF_ROTATE_UPSIDEDOWN</p></td> <td class="enum_member_description"> <p>Rotate by 180 degrees.</p> </td> <td class="enum_member_annotations"> </td> </tr> <tr> <td class="enum_member_name"><p><a name="GDK-PIXBUF-ROTATE-CLOCKWISE:CAPS"></a>GDK_PIXBUF_ROTATE_CLOCKWISE</p></td> <td class="enum_member_description"> <p>Rotate by 270 degrees.</p> </td> <td class="enum_member_annotations"> </td> </tr> </tbody> </table></div> </div> </div> </div> <div class="refsect1"> <a name="gdk-pixbuf-Scaling.see-also"></a><h2>See Also</h2> <p><link linkend="gdk-GdkRGB">GdkRGB</link>.</p> </div> </div> <div class="footer"> <hr>Generated by GTK-Doc V1.27</div> </body> </html>
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