/usr/share/doc/liblqr-1-0-dev/html/lqr.html is in liblqr-1-0-dev 0.4.1-1.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 | <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Liquid rescaling</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"><link rel="home" href="index.html" title="The Liquid Rescale library Manual"><link rel="up" href="api-manual.html" title="Chapter 2. LqR library API user manual"><link rel="prev" href="generate-multi-size.html" title="Generating the multi-size image"><link rel="next" href="read-out.html" title="Reading the multi-size image"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Liquid rescaling</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="generate-multi-size.html">Prev</a> </td><th width="60%" align="center">Chapter 2. LqR library API user manual</th><td width="20%" align="right"> <a accesskey="n" href="read-out.html">Next</a></td></tr></table><hr></div><div class="sect1" title="Liquid rescaling"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="lqr"></a>Liquid rescaling</h2></div></div></div><div class="toc"><dl><dt><span class="sect2"><a href="lqr.html#lqr-resize">The resizing method</a></span></dt><dt><span class="sect2"><a href="lqr.html#flatten">Flattening</a></span></dt><dt><span class="sect2"><a href="lqr.html#lqr-cancel">Cancelling an action</a></span></dt></dl></div><div class="sect2" title="The resizing method"><div class="titlepage"><div><div><h3 class="title"><a name="lqr-resize"></a>The resizing method</h3></div></div></div><p>
Once initialised, or if a visibility map has been loaded, the image can be resized through this
function:
</p><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">LqrRetVal <b class="fsfunc">lqr_carver_resize</b>(</code></td><td> LqrCarver * <var class="pdparam">carver</var>, </td></tr><tr><td> </td><td> gint <var class="pdparam">new_width</var>, </td></tr><tr><td> </td><td> gint <var class="pdparam">new_height</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div><p>
</p><p>
This function decides automatically whether it can use the already computed visibility map, it has
to update it or waste it completely and start afresh. This last event occurs when the map was
computed for horizontal resizing and a vertical resize has been requested, or vice versa, and also
when the required enlargment is bigger than the enlargement step value (see
<a class="link" href="tuning.html#lqr-enl-step" title="Setting the enlargement step">Setting the enlargement step</a>). Note that only initialised
carvers can update or change the visibility map; if this is not the case, an error is returned.
</p><p>
The function also takes advantage of the fact that the enlargment process mirrors the shrink
process. For example, if the original size of the image is <code class="literal">(<span class="symbol">w0</span>,
<span class="symbol">h0</span>)</code> and <code class="function">lqr_carver_resize</code> is invoked with
<code class="literal">(<span class="symbol">w0</span> - 100, <span class="symbol">h0</span>)</code> as an argument, then subsequent
calls to the function will allow on-the-fly resizing in the whole range from
<code class="literal">(<span class="symbol">w0</span> - 100, <span class="symbol">h0</span>)</code> to <code class="literal">(<span class="symbol">w0</span>
+ 100, <span class="symbol">h0</span>)</code>. (But note that this may be overcome if
<code class="literal"><span class="symbol">w0</span> + 100</code> is bigger than the enlargement step.)
</p></div><div class="sect2" title="Flattening"><div class="titlepage"><div><div><h3 class="title"><a name="flatten"></a>Flattening</h3></div></div></div><p>
In order to resize in more than one step, the image can be flattened in its current state, thrugh
this function:
</p><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">gboolean <b class="fsfunc">lqr_carver_flatten</b>(</code></td><td> LqrCarver * <var class="pdparam">carver</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div><p>
</p><p>
The return value is <code class="literal"><span class="returnvalue">FALSE</span></code> in case of insufficient memory, <code class="literal"><span class="returnvalue">TRUE</span></code> otherwise.
</p><p>
This function destroys the current visibility map and reinitialises the multi-size image from its
current state.
</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
Every time that the image is flattened (including when changing the resize direction) the
original image and all information about it is lost.
</p></div></div><div class="sect2" title="Cancelling an action"><div class="titlepage"><div><div><h3 class="title"><a name="lqr-cancel"></a>Cancelling an action</h3></div></div></div><p>
The resizing and flattening operations can be aborted using this function:
</p><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">LqrRetVal <b class="fsfunc">lqr_carver_cancel</b>(</code></td><td> LqrCarver * <var class="pdparam">carver</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div><p>
</p><p>
This function can be invoked asynchronously, from a different thread with respect to the one in
which the resizing or flattening methods were called. If successful, this function will return
<code class="literal"><span class="errorcode">LQR_OK</span></code>, and any ongoing resizing or flattening functions will immidiately abort and return the
special value <code class="literal"><span class="errorcode">LQR_USRCANCEL</span></code>; however, this function will have no effect if no operation was in
progress when calling it.
</p><p>
This function can be called multiple times.
</p><div class="important" title="Important" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Important</h3><p>
Whenever a function returns <code class="literal"><span class="errorcode">LQR_USRCANCEL</span></code>, it means that the <code class="classname">LqrCarver</code> object is in an
inconsistent state, and there is currently no way to recover from this situation. Therefore, any
further operation on it must be avoided, and it must be destroyed.
</p></div><div class="important" title="Important" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Important</h3><p>
The functions <code class="function">lqr_carver_resize</code> and <code class="function">lqr_carver_flatten</code>
are not the only ones which can return <code class="literal"><span class="errorcode">LQR_USRCANCEL</span></code>; instead, any function in the library whose
return type is <code class="classname">LqrRetVal</code> and which operates on <code class="classname">LqrCarver</code> objects can
return such value: for example, any function will do so if called over a <code class="classname">LqrCarver</code> object for
which an operation was actually cancelled (but this is not the only possibility).
</p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="generate-multi-size.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="api-manual.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="read-out.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Generating the multi-size image </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Reading the multi-size image</td></tr></table></div></body></html>
|