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><head><title>glPixelZoom</title><link rel="stylesheet" href="style.css" type="text/css"/><meta name="generator" content="DocBook XSL Stylesheets V1.59.1"/><link rel="home" href="index.xml" title="PyOpenGL 2.0.1.07 Man Pages"/><link rel="up" href="reference-GL.xml" title="GL"/><link rel="previous" href="glPixelTransfer.3G.xml" title="glPixelTransfer"/><link rel="next" href="glPointSize.3G.xml" title="glPointSize"/></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">glPixelZoom</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="glPixelTransfer.3G.xml">Prev</a> </td><th width="60%" align="center">GL</th><td width="20%" align="right"> <a accesskey="n" href="glPointSize.3G.xml">Next</a></td></tr></table><hr/></div><div class="refentry" lang="en"><a name="glPixelZoom.3G"/><div class="titlepage"/><div class="refnamediv"><a name="glPixelZoom.3G-name"/><h2>Name</h2><p>glPixelZoom &#8212; specify the pixel zoom factors</p></div><div class="refsynopsisdiv"><a name="glPixelZoom.3G-c_spec"/><h2>C Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code>void <tt>glPixelZoom</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code>GLfloat <i><tt>xfactor</tt></i>, GLfloat <i><tt>yfactor</tt></i>);</code></td></tr></table></div><div class="refsynopsisdiv"><a name="glPixelZoom.3G-python_spec"/><h2>Python Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code><tt>glPixelZoom</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code><i><tt>xfactor</tt></i>, <i><tt>yfactor</tt></i>) &#8594; <tt>None</tt></code></td></tr></table></div><div class="refsect1" lang="en"><a name="glPixelZoom.3G-parameters"/><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><i><tt>xfactor</tt></i>, <i><tt>yfactor</tt></i></span></dt><dd>
						Specify the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
								<mml:mi>x</mml:mi>
							</mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
								<mml:mi>y</mml:mi>
							</mml:math> zoom factors for pixel write operations.
					</dd></dl></div></div><div class="refsect1" lang="en"><a name="glPixelZoom.3G-description"/><h2>Description</h2><p>
			<tt>glPixelZoom</tt> specifies values for the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mi>x</mml:mi>
				</mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mi>y</mml:mi>
				</mml:math> zoom factors. During the execution of <a href="glDrawPixels.3G.xml"><tt>glDrawPixels</tt></a> or
			<a href="glCopyPixels.3G.xml"><tt>glCopyPixels</tt></a>, if (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mi>xr</mml:mi>
				</mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mi>yr</mml:mi>
				</mml:math>) is the current raster position, and a given element is in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mi>m</mml:mi>
				</mml:math>th row and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mi>n</mml:mi>
				</mml:math>th column of the pixel rectangle, then pixels whose centers are in the rectangle with corners at
			(<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mrow>
						<mml:mi>xr</mml:mi>
						<mml:mo>+</mml:mo>
						<mml:mi>n</mml:mi>
						<mml:mo>·</mml:mo>
						<mml:mi>xfactor</mml:mi>
					</mml:mrow>
				</mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mrow>
						<mml:mi>yr</mml:mi>
						<mml:mo>+</mml:mo>
						<mml:mi>m</mml:mi>
						<mml:mo>·</mml:mo>
						<mml:mi>yfactor</mml:mi>
					</mml:mrow>
				</mml:math>) (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mrow>
						<mml:mi>xr</mml:mi>
						<mml:mo>+</mml:mo>
						<mml:mo>(</mml:mo>
						<mml:mi>n+1</mml:mi>
						<mml:mo>)</mml:mo>
						<mml:mo>·</mml:mo>
						<mml:mi>xfactor</mml:mi>
					</mml:mrow>
				</mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
					<mml:mrow>
						<mml:mi>yr</mml:mi>
						<mml:mo>+</mml:mo>
						<mml:mo>(</mml:mo>
						<mml:mi>m+1</mml:mi>
						<mml:mo>)</mml:mo>
						<mml:mo>·</mml:mo>
						<mml:mi>yfactor</mml:mi>
					</mml:mrow>
				</mml:math>) are candidates for replacement. Any pixel whose center lies on the bottom or left edge of this
			rectangular region is also modified.
		</p><p>
			Pixel zoom factors are not limited to positive values. Negative zoom factors reflect the resulting image about the
			current raster position.
		</p></div><div class="refsect1" lang="en"><a name="glPixelZoom.3G-errors"/><h2>Errors</h2><p>
			<tt>GL_INVALID_OPERATION</tt> is generated if <tt>glPixelZoom</tt> is executed between the
			execution of <a href="glBegin.3G.xml"><tt>glBegin</tt></a> and the corresponding execution of <a href="glBegin.3G.xml"><tt>glEnd</tt></a>.
		</p></div><div class="refsect1" lang="en"><a name="glPixelZoom.3G-associated_gets"/><h2>Associated Gets</h2><p>
			<tt>glGet</tt> with argument <tt>GL_ZOOM_X</tt>
		</p><p>
			<tt>glGet</tt> with argument <tt>GL_ZOOM_Y</tt>
		</p></div><div class="refsect1" lang="en"><a name="glPixelZoom.3G-see_also"/><h2>See Also</h2><p>
			<span class="simplelist"><a href="glCopyPixels.3G.xml">glCopyPixels</a>, <a href="glDrawPixels.3G.xml">glDrawPixels</a></span>
		</p></div></div><div class="navfooter"><hr/><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="glPixelTransfer.3G.xml">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="reference-GL.xml">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="glPointSize.3G.xml">Next</a></td></tr><tr><td width="40%" align="left" valign="top">glPixelTransfer </td><td width="20%" align="center"><a accesskey="h" href="index.xml">Home</a></td><td width="40%" align="right" valign="top"> glPointSize</td></tr></table></div></body></html>