Html程序  |  821行  |  18.78 KB

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Magick++ API: Geometry</title>
<link rel="stylesheet" href="magick.css" type="text/css" />
</head>
<body>
<div class="doc-section">
<h1 align="center">Magick::Geometry</h1>
<p>Geometry provides a convenient means to specify a geometry
argument. The object may be initialized from a C string or C++ string
containing a geometry specification. It may also be initialized by
more efficient parameterized constructors. 
</p>
<h3><a name="GeometrySpecifications"></a>Geometry
Specifications</h3>
<p>Geometry specifications are in the form
<kbd>&quot;&lt;width&gt;x&lt;height&gt;{+-}&lt;xoffset&gt;{+-}&lt;yoffset&gt;&quot;</kbd>
(where <i>width</i>, <i>height</i>, <i>xoffset</i>, and <i>yoffset</i>
are numbers) for specifying the size and placement location for an
object. 
</p>
<p style="margin-bottom: 0in">The <i>width</i> and <i>height</i>
parts of the geometry specification are measured in pixels. The
<i>xoffset</i> and <i>yoffset</i> parts are also measured in pixels
and are used to specify the distance of the placement coordinate from
the left and top and edges of the image, respectively. Both types of
offsets are measured from the indicated edge of the object to the
corresponding edge of the image. The X offset may be specified in the
following ways: 
</p>
	<table width="90%" border="1" cellpadding="2" cellspacing="3">
		<col width="21*" />
		<col width="235*" />
		<tr>
			<td width="8%">
				<p>+<i>xoffset</i></p>
			</td>
			<td width="92%">
				<p>The left edge of the object is to be placed <i>xoffset</i>
				pixels in from the <em>left edge </em>of the image.</p>
			</td>
		</tr>
		<tr>
			<td width="8%">
				<p>-<i>xoffset</i></p>
			</td>
			<td width="92%">
				<p>The left edge of the object is to be placed outside the image,
				<i>xoffset</i> pixels out from the <em>left edge </em>of the image.</p>
			</td>
		</tr>
	</table>
<p style="margin-bottom: 0in">The Y offset has similar meanings: 
</p>
	<table width="90%" border="1" cellpadding="2" cellspacing="3">
		<col width="27*" />
		<col width="229*" />
		<tr>
			<td width="11%">
				<p>+<i>yoffset</i></p>
			</td>
			<td width="89%">
				<p>The top edge of the object is to be <i>yoffset</i> pixels
				<em>below</em> the <em>top edge </em>of the image.</p>
			</td>
		</tr>
		<tr>
			<td width="11%">
				<p>-<i>yoffset</i></p>
			</td>
			<td width="89%">
				<p>The top edge of the object is to be <i>yoffset</i> pixels
				<em>above</em> the <em>top edge</em> of the image.</p>
			</td>
		</tr>
	</table>
<p>Offsets must be given as pairs; in other words, in order to
specify either <i>xoffset</i> or <i>yoffset</i> both must be present.
</p>
<h3><a name="ExtendedGeometrySpecifications"></a>ImageMagick
Extensions To Geometry Specifications</h3>
<p style="margin-bottom: 0in">ImageMagick has added a number of
qualifiers to the standard geometry string for use when resizing
images. The form of an extended geometry string is
&quot;<kbd>&lt;width&gt;x&lt;height&gt;{+-}&lt;xoffset&gt;{+-}&lt;yoffset&gt;{%}{!}{&lt;}{&gt;}&quot;</kbd>.
Extended geometry strings should <em>only</em> be used <em>when resizing
an image</em>. Using an extended geometry string for other
applications may cause the API call to fail. The available
qualifiers are shown in the following table: 
</p>
<p align="center" STYLE="margin-bottom: 0in"><b>ImageMagick Geometry
Qualifiers</b></p>
	<table width="90%" border="1" cellpadding="2" cellspacing="3">
		<col width="36*" />
		<col width="220*" />
		<tr>
			<td width="14%">
				<p align="center"><b>Qualifier</b></p>
			</td>
			<td width="86%">
				<p align="center"><b>Description</b></p>
			</td>
		</tr>
		<tr>
			<td width="14%">
				<p align="center"><b>%</b></p>
			</td>
			<td width="86%">
				<p>Interpret width and height as a <b>percentage</b> of the
				current size.</p>
			</td>
		</tr>
		<tr>
			<td width="14%">
				<p align="center"><b>!</b></p>
			</td>
			<td width="86%">
				<p>Resize to width and height <b>exactly</b>, loosing original
				aspect ratio.</p>
			</td>
		</tr>
		<tr>
			<td width="14%">
				<p align="center"><b>&lt;</b></p>
			</td>
			<td width="86%">
				<p>Resize only if the image is <b>smaller</b> than the geometry
				specification.</p>
			</td>
		</tr>
		<tr>
			<td width="14%">
				<p align="center"><b>&gt;</b></p>
			</td>
			<td width="86%">
				<p>Resize only if the image is <b>greater</b> than the geometry
				specification.</p>
			</td>
		</tr>
	</table>
<h3><a name="PostscriptPageSize"></a>Postscript Page Size Extension
To Geometry Specifications</h3>
<p>Any geometry string specification supplied to the Geometry
constructor is considered to be a Postscript page size nickname if
the first character is not numeric. The Geometry constructor converts
these page size specifications into the equivalent numeric geometry
string specification (preserving any offset component) prior to
conversion to the internal object format. Postscript page size
specifications are short-hand for the pixel geometry required to fill
a page of that size. Since the 11x17 inch page size used in the US
starts with a digit, it is not supported as a Postscript page size
nickname. Instead, substitute the geometry specification &quot;<kbd>792x1224&gt;&quot;</kbd>
when 11x17 output is desired. 
</p>
<p style="margin-bottom: 0in">An example of a Postscript page size
specification is <kbd>&quot;letter+43+43&gt;&quot;</kbd>. 
</p>
<p align="center" style="margin-bottom: 0in"><b>Postscript Page Size
Nicknames</b></p>
	<table width="70%" border="1" cellpadding="2" cellspacing="3">
		<col width="105*" />
		<col width="151*" />
		<tr>
			<td width="41%">
				<p align="center"><b>Postscript Page Size Nickname</b></p>
			</td>
			<td width="59%">
				<p align="center"><b>Equivalent Extended Geometry Specification</b></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">Ledger</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1224x792&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">Legal</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">612x1008&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">Letter</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">612x792&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">LetterSmall</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">612x792&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">ArchE</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">2592x3456&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">ArchD</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1728x2592&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">ArchC</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1296x1728&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">ArchB</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">864x1296&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">ArchA</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">648x864&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A0</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">2380x3368&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A1</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1684x2380&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A2</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1190x1684&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A3</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">842x1190&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A4</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">595x842&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A4Small</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">595x842&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A5</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">421x595&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A6</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">297x421&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A7</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">210x297&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A8</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">148x210&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A9</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">105x148&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">A10</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">74x105&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">B0</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">2836x4008&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">B1</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">2004x2836&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">B2</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1418x2004&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">B3</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1002x1418&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">B4</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">709x1002&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">B5</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">501x709&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">C0</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">2600x3677&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">C1</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1837x2600&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">C2</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">1298x1837&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">C3</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">918x1298&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">C4</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">649x918&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">C5</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">459x649&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">C6</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">323x459&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">Flsa</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">612x936&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">Flse</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">612x936&gt;</font></p>
			</td>
		</tr>
		<tr>
			<td width="41%">
				<p align="center"><font size="2">HalfLetter</font></p>
			</td>
			<td width="59%">
				<p align="center"><font size="2">396x612&gt;</font></p>
			</td>
		</tr>
	</table>
<H3 align="center">Geometry Methods</H3>
<p style="margin-bottom: 0in">Geometry provides methods to initialize
its value from strings, from a set of parameters, or via attributes.
The methods available for use in Geometry are shown in the following
table: 
</p>
<p align="center" style="margin-bottom: 0in"><b>Geometry Methods</b></p>
<table width="100%" border="1" cellpadding="2" cellspacing="3">
	<col width="25*" />
	<col width="26*" />
	<col width="111*" />
	<col width="94*" />
	<tr>
		<td width="10%">
			<p align="center"><b>Method</b></p>
		</td>
		<td width="10%">
			<p align="center"><b>Return Type</b></p>
		</td>
		<td width="44%">
			<p align="center"><b>Signature(s)</b></p>
		</td>
		<td width="37%">
			<p align="center"><b>Description</b></p>
		</td>
	</tr>
	<tr>
		<td rowspan="3" width="10%"> 
			<p>Geometry</p>
		</td>
		<td rowspan="3" width="10%" bgcolor="#666666">
			<p>&#160;</p>
		</td>
		<td width="44%">
			<p>size_t width_, size_t height_, ssize_t xOff_ =
			0, ssize_t yOff_ = 0, bool xNegative_ = false, bool
			yNegative_ = false</p>
		</td>
		<td width="37%">
			<p>Construct geometry via explicit parameters.</p>
		</td>
	</tr>
	<tr>
		<td width="44%">
			<p>const string geometry_</p>
		</td>
		<td width="37%">
			<p>Construct geometry from C++ string</p>
		</td>
	</tr>
	<tr>
		<td width="44%">
			<p>const char * geometry_</p>
		</td>
		<td width="37%">
			<p>Construct geometry from C string</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>width</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>size_t width_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Width</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>size_t</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>height</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>size_t height_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Height</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>size_t</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>xOff</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>ssize_t xOff_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>X offset from origin</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>ssize_t</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>yOff</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>ssize_t yOff_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Y offset from origin</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>size_t</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>xNegative</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>bool xNegative_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Sign of X offset negative? (X origin at right)</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>bool</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>yNegative</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>bool yNegative_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Sign of Y offset negative? (Y origin at bottom)</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>bool</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>percent</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>bool percent_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Width and height are expressed as percentages</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>bool</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>aspect</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>bool aspect_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Resize without preserving aspect ratio (!)</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>bool</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>greater</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>bool greater_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Resize if image is greater than size (&gt;)</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>bool</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>less</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>bool less_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Resize if image is less than size (&lt;)</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>bool</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td rowspan="2" width="10%">
			<p>isValid</p>
		</td>
		<td width="10%">
			<p>void</p>
		</td>
		<td width="44%">
			<p>bool isValid_</p>
		</td>
		<td rowspan="2" width="37%">
			<p>Does object contain a valid geometry? May be set to <i>false</i>
			in order to invalidate an existing geometry object.</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>bool</p>
		</td>
		<td width="44%">
			<p>void</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>operator =</p>
		</td>
		<td width="10%">
			<p>const Geometry&amp;</p>
		</td>
		<td width="44%">
			<p>const string geometry_</p>
		</td>
		<td width="37%">
			<p>Set geometry via C++ string</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>operator =</p>
		</td>
		<td width="10%">
			<p>const Geometry&amp;</p>
		</td>
		<td width="44%">
			<p>const char * geometry_</p>
		</td>
		<td width="37%">
			<p>Set geometry via C string</p>
		</td>
	</tr>
	<tr>
		<td width="10%">
			<p>operator string</p>
		</td>
		<td width="10%">
			<p>string</p>
		</td>
		<td width="44%">
			<p>Geometry&amp;</p>
		</td>
		<td width="37%">
			<p>Obtain C++ string representation of geometry</p>
		</td>
	</tr>
</table>
<p>In addition, we support these yet to be documented geometry flags: the fill area flag ('^') and the pixel area count limit flag ('@').</p>
<p><br /><br />
</p>
</div>
</body>
</html>