61 lines
1.6 KiB
Plaintext
61 lines
1.6 KiB
Plaintext
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'\" e
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'\"! eqn | mmdoc
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'\"macro stdmacro
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.ds Vn Version 1.2
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.ds Dt 24 September 1999
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.ds Re Release 1.2.1
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.ds Dp Jan 14 18:30
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.ds Dm 01 pixelzoom
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.ds Xs 46374 4 pixelzoom.gl
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.TH GLPIXELZOOM 3G
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.SH NAME
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.B "glPixelZoom
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\- specify the pixel zoom factors
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.SH C SPECIFICATION
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void \f3glPixelZoom\fP(
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GLfloat \fIxfactor\fP,
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.nf
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.ta \w'\f3void \fPglPixelZoom( 'u
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GLfloat \fIyfactor\fP )
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.fi
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.EQ
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delim $$
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.EN
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.SH PARAMETERS
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.TP \w'\f2xfactor\fP\ \f2yfactor\fP\ \ 'u
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\f2xfactor\fP, \f2yfactor\fP
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Specify the $x$ and $y$ zoom factors for pixel write operations.
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.SH DESCRIPTION
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\%\f3glPixelZoom\fP specifies values for the $x$ and $y$ zoom factors.
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During the execution of \%\f3glDrawPixels\fP or \%\f3glCopyPixels\fP,
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if ($xr $, $yr $) is the current raster position,
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and a given element is in the $m$th row and $n$th column of the pixel rectangle,
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then pixels whose centers are in the rectangle with corners at
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.sp
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.ce
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($xr ~+~ n cdot "xfactor"$, $yr ~+~ m cdot "yfactor"$)
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.sp
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.ce
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($xr ~+~ (n+1) cdot "xfactor"$, $yr ~+~ (m+1) cdot "yfactor"$)
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.sp
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are candidates for replacement.
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Any pixel whose center lies on the bottom or left edge of this rectangular
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region is also modified.
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.P
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Pixel zoom factors are not limited to positive values.
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Negative zoom factors reflect the resulting image about the current
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raster position.
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.SH ERRORS
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\%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glPixelZoom\fP
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is executed between the execution of \%\f3glBegin\fP
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and the corresponding execution of \%\f3glEnd\fP.
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.SH ASSOCIATED GETS
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\%\f3glGet\fP with argument \%\f3GL_ZOOM_X\fP
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.br
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\%\f3glGet\fP with argument \%\f3GL_ZOOM_Y\fP
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.SH SEE ALSO
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\%\f3glCopyPixels(3G)\fP,
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\%\f3glDrawPixels(3G)\fP
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