.\"     Title: \fBlqr_rwindow_read\fR
.\"    Author: Carlo Baldassi
.\" Generator: DocBook XSL Stylesheets v1.73.2 <http://docbook.sf.net/>
.\"      Date: 10 Maj 2009
.\"    Manual: LqR library API reference
.\"    Source: LqR library 0.4.1 API (3:1:3)
.\"
.TH "\FBLQR_RWINDOW_READ\FR" "3" "10 Maj 2009" "LqR library 0.4.1 API (3:1:3)" "LqR library API reference"
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.nh
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.ad l
.SH "NAME"
lqr_rwindow_read \- read the content of a LqrReadingWindow object
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <lqr\&.h>
.fi
.ft
.HP 24
.BI "gfloat lqr_rwindow_read(LqrReadingWindow*\ " "rwindow" ", gint\ " "x" ", gint\ " "y" ", gint\ " "channel" ");"
.SH "DESCRIPTION"
.PP
The function
\fBlqr_rwindow_read\fR
returns the content of the reading window
\fIrwindow\fR
at point
\fIx\fR,
\fIy\fR
and at channel
\fIchannel\fR\&.
.PP
The coordinates
\fIx\fR
and
\fIy\fR
are relative to the
\fIrwindow\fR
centre, and they both can range from
\-radius
to
radius
(extremes included), where
radius
can be obtained with the function
\fBlqr_rwindow_get_radius\fR(3)\&.
.PP
The function returns
0
when the coordinates are out of range, either because they are beyond the
\fIrwindow\fR
radius or because they are outside the image boundary\&.
.PP
The
\fIchannel\fR
parameter specifies which channel to read out; depending on the
\fIrwindow\fR
reader type, the range and meaning of this parameter changes: for the cases
LQR_ER_BRIGHTNESS
and
LQR_ER_LUMA
it must be
0, because the readout consists of a single channel, for
LQR_ER_RGBA
it must be between
0
and
3
(and then the readout will contain the RGBA information), while for
LQR_ER_CUSTOM
it must be one of the original image channels\&.
.SH "SEE ALSO"
.PP

\fBlqr_carver_set_energy_function\fR(3), \fBlqr_rwindow_get_read_t\fR(3), \fBlqr_rwindow_get_radius\fR(3), \fBlqr_rwindow_get_channels\fR(3)
.SH "COPYRIGHT"
Copyright \(co 2007-2009 Carlo Baldassi
.br