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></DIV
><H1
><A
NAME="GDK-VISUALS"
>Visuals</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN5628"
></A
><H2
>Name</H2
>Visuals -- manipulation of visuals.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN5631"
></A
><H2
>Synopsis</H2
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="SYNOPSIS"
> #include <gdk/gdk.h>
struct <A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>;
enum <A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
>;
enum <A
HREF="gdk-visuals.html#GDKBYTEORDER"
>GdkByteOrder</A
>;
void <A
HREF="gdk-visuals.html#GDK-QUERY-DEPTHS"
>gdk_query_depths</A
> (<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> **depths,
<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> *count);
void <A
HREF="gdk-visuals.html#GDK-QUERY-VISUAL-TYPES"
>gdk_query_visual_types</A
> (<A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> **visual_types,
<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> *count);
<A
HREF=../glib/glib-doubly-linked-lists.html#GLIST
>GList</A>* <A
HREF="gdk-visuals.html#GDK-LIST-VISUALS"
>gdk_list_visuals</A
> (void);
<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-BEST-DEPTH"
>gdk_visual_get_best_depth</A
> (void);
<A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-BEST-TYPE"
>gdk_visual_get_best_type</A
> (void);
<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-SYSTEM"
>gdk_visual_get_system</A
> (void);
<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-BEST"
>gdk_visual_get_best</A
> (void);
<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-BEST-WITH-DEPTH"
>gdk_visual_get_best_with_depth</A
> (<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> depth);
<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-BEST-WITH-TYPE"
>gdk_visual_get_best_with_type</A
> (<A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> visual_type);
<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-BEST-WITH-BOTH"
>gdk_visual_get_best_with_both</A
> (<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> depth,
<A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> visual_type);
<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* <A
HREF="gdk-visuals.html#GDK-VISUAL-REF"
>gdk_visual_ref</A
> (<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
> *visual);
void <A
HREF="gdk-visuals.html#GDK-VISUAL-UNREF"
>gdk_visual_unref</A
> (<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
> *visual);</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN5668"
></A
><H2
>Description</H2
><P
>The way that the data stored on the screen is stored
in memory can vary considerably between different X
servers; some X servers even support multiple formats
used simultaneously. An X <I
CLASS="FIRSTTERM"
>visual</I
>
represents a particular format for screen data.
It includes information about the number of bits
used for each color, the way the bits are translated
into an RGB value for display, and the way the bits
are stored in memory.</P
><P
>There are several standard visuals. The visual returned
by <A
HREF="gdk-visuals.html#GDK-VISUAL-GET-SYSTEM"
>gdk_visual_get_system</A
>() is the system's default
visual. <A
HREF="gdk-gdkrgb.html#GDK-RGB-GET-VISUAL"
>gdk_rgb_get_visual</A
>() return the visual most
suited to displaying full-color image data. If you
use the calls in GdkRGB, you should create your windows
using this visual (and the colormap returned by
gdk_rgb_get_colormap()).</P
><P
>A number of functions are provided for determining
the "best" available visual. For the purposes of
making this determination, higher bit depths are
considered better, and for visuals of the same
bit depth, <TT
CLASS="LITERAL"
>GDK_VISUAL_PSEUDO_COLOR</TT
> is preferred at
8bpp, otherwise, the visual types are ranked in the
order of (highest to lowest) <TT
CLASS="LITERAL"
>GDK_VISUAL_DIRECT_COLOR</TT
>,
<TT
CLASS="LITERAL"
>GDK_VISUAL_TRUE_COLOR</TT
>, <TT
CLASS="LITERAL"
>GDK_VISUAL_PSEUDO_COLOR</TT
>,
<TT
CLASS="LITERAL"
>GDK_VISUAL_STATIC_COLOR</TT
>, <TT
CLASS="LITERAL"
>GDK_VISUAL_GRAYSCALE</TT
>,
then <TT
CLASS="LITERAL"
>GDK_VISUAL_STATIC_GRAY</TT
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN5684"
></A
><H2
>Details</H2
><DIV
CLASS="REFSECT2"
><A
NAME="AEN5686"
></A
><H3
><A
NAME="GDKVISUAL"
></A
>struct GdkVisual</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>struct GdkVisual
{
GdkVisualType type;
gint depth;
GdkByteOrder byte_order;
gint colormap_size;
gint bits_per_rgb;
guint32 red_mask;
gint red_shift;
gint red_prec;
guint32 green_mask;
gint green_shift;
gint green_prec;
guint32 blue_mask;
gint blue_shift;
gint blue_prec;
};</PRE
></TD
></TR
></TABLE
><P
>The GdkVisual structure contains information about
a particular visual. It contains the following
public fields.
<DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5691"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFF0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>type</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The type of this visual.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>depth</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The number of bits per pixel.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>byte_order</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The byte-order for this visual.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>colormap_size</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The number of entries in the colormap, for
visuals of type GDK_VISUAL_PSEUDO_COLOR or
GDK_VISUAL_GRAY_SCALE. For other visual types, it
is the number of possible levels per color component.
If the visual has different numbers of levels for
different components, the value of this field is
undefined.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>bits_per_rgb</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The number of significant bits per red, green, or blue
when specifying colors for this visual. (For instance,
for <A
HREF="gdk-colormaps-and-colors.html#GDK-COLORMAP-ALLOC-COLOR"
>gdk_colormap_alloc_color</A
>())</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>red_mask</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>A mask giving the bits in a pixel value that
correspond to the red field. Significant only for
<TT
CLASS="LITERAL"
>GDK_VISUAL_PSEUDOCOLOR</TT
> and <TT
CLASS="LITERAL"
>GDK_VISUAL_DIRECTCOLOR</TT
>.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>red_shift, red_prec</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The <TT
CLASS="STRUCTFIELD"
><I
>red_shift</I
></TT
> and
<TT
CLASS="STRUCTFIELD"
><I
>red_prec</I
></TT
> give an alternate presentation
of the information in <TT
CLASS="STRUCTFIELD"
><I
>red_mask</I
></TT
>.
<TT
CLASS="STRUCTFIELD"
><I
>red_mask</I
></TT
> is a contiguous sequence
of <TT
CLASS="STRUCTFIELD"
><I
>red_prec</I
></TT
> starting at bit
number <TT
CLASS="STRUCTFIELD"
><I
>red_shift</I
></TT
>. For example,
<A
HREF="gdk-visuals.html#RGBMASK"
>Figure 1</A
> shows constructing a pixel value
out of three 16 bit color values. </TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>green_mask</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>A mask giving the bits in a pixel value that
correspond to the green field.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>green_shift, green_prec</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The <TT
CLASS="STRUCTFIELD"
><I
>green_shift</I
></TT
> and
<TT
CLASS="STRUCTFIELD"
><I
>green_prec</I
></TT
> give an alternate presentation
of the information in <TT
CLASS="STRUCTFIELD"
><I
>green_mask</I
></TT
>.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>blue_mask</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>A mask giving the bits in a pixel value that
correspond to the blue field.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>blue_shift, blue_prec</I
></TT
></TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The <TT
CLASS="STRUCTFIELD"
><I
>blue_shift</I
></TT
> and
<TT
CLASS="STRUCTFIELD"
><I
>blue_prec</I
></TT
> give an alternate presentation
of the information in <TT
CLASS="STRUCTFIELD"
><I
>blue_mask</I
></TT
>.</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></P
><DIV
CLASS="FIGURE"
><A
NAME="RGBMASK"
></A
><P
><B
>Figure 1. Constructing a pixel value from components</B
></P
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>guint
pixel_from_rgb (GdkVisual *visual,
guchar r, guchar b, guchar g)
{
return ((r >> (16 - visual->red_prec)) << visual->red_shift) |
((g >> (16 - visual->green_prec)) << visual->green_shift) |
((r >> (16 - visual->blue_prec)) << visual->blue_shift);
}</PRE
></TD
></TR
></TABLE
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5759"
></A
><H3
><A
NAME="GDKVISUALTYPE"
></A
>enum GdkVisualType</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>typedef enum
{
GDK_VISUAL_STATIC_GRAY,
GDK_VISUAL_GRAYSCALE,
GDK_VISUAL_STATIC_COLOR,
GDK_VISUAL_PSEUDO_COLOR,
GDK_VISUAL_TRUE_COLOR,
GDK_VISUAL_DIRECT_COLOR
} GdkVisualType;</PRE
></TD
></TR
></TABLE
><P
>A set of values that describe the manner in which the
pixel values for a visual are converted into RGB
values for display.
<DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5764"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#F0F0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_VISUAL_STATIC_GRAY</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>Each pixel value indexes a grayscale value directly.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_VISUAL_GRAYSCALE</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>Each pixel is an index into a color map that maps
pixel values into grayscale values. The color map can
be changed by an application.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_VISUAL_STATIC_COLOR</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>Each pixel value is an index into a predefined,
unmodifiable color map that maps pixel values into
rgb values.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_VISUAL_PSEUDO_COLOR</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>Each pixel is an index into a color map that maps
pixel values into rgb values. The color map can
be changed by an application.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_TRUE_COLOR</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>Each pixel value directly contains red, green,
and blue components. The <TT
CLASS="STRUCTFIELD"
><I
>red_mask</I
></TT
>,
<TT
CLASS="STRUCTFIELD"
><I
>green_mask</I
></TT
>, and
<TT
CLASS="STRUCTFIELD"
><I
>blue_mask</I
></TT
> fields of the <A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>
structure describe how the components are assembled into
a pixel value.
.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_DIRECT_COLOR</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>Each pixel value contains red, green, and blue
components as for <TT
CLASS="LITERAL"
>GDK_TRUE_COLOR</TT
>, but the components
are mapped via a color table into the final output
table instead of being converted directly..</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></P
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5792"
></A
><H3
><A
NAME="GDKBYTEORDER"
></A
>enum GdkByteOrder</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>typedef enum
{
GDK_LSB_FIRST,
GDK_MSB_FIRST
} GdkByteOrder;</PRE
></TD
></TR
></TABLE
><P
>A set of values describing the possible byte-orders
for storing pixel values in memory.
<DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5797"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#F0F0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_LSB_FIRST</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The values are stored with the least-significant byte
first. For instance, the 32-bit value 0xffeecc would be stored
in memory as 0xcc, 0xee, 0xff, 0x00.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="LEFT"
VALIGN="TOP"
>GDK_MSB_FIRST</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>The values are stored with the least-significant byte
first. For instance, the 32-bit value 0xffeecc would be stored
in memory as 0xff, 0xee, 0xcc, 0x00.</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></P
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5808"
></A
><H3
><A
NAME="GDK-QUERY-DEPTHS"
></A
>gdk_query_depths ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gdk_query_depths (<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> **depths,
<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> *count);</PRE
></TD
></TR
></TABLE
><P
>Lists the available color depths. The returned values
are pointers to static storage and should not be
modified or freed.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5815"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>depths</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>a location to store a pointer to an array
holding the available color depths.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>count</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>a location to store the number of values in <TT
CLASS="PARAMETER"
><I
>depths</I
></TT
>.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5829"
></A
><H3
><A
NAME="GDK-QUERY-VISUAL-TYPES"
></A
>gdk_query_visual_types ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gdk_query_visual_types (<A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> **visual_types,
<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> *count);</PRE
></TD
></TR
></TABLE
><P
>Lists the available visual types. The returned values
are pointers to static storage and should not be
modified or freed.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5836"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>visual_types</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>a location to store a pointer to an
array holding the available visual types.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>count</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>a location to store the number of values in <TT
CLASS="PARAMETER"
><I
>visual</I
></TT
> types.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5850"
></A
><H3
><A
NAME="GDK-LIST-VISUALS"
></A
>gdk_list_visuals ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF=../glib/glib-doubly-linked-lists.html#GLIST
>GList</A>* gdk_list_visuals (void);</PRE
></TD
></TR
></TABLE
><P
>Lists the available visuals.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5856"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>A <A
HREF=../glib/glib-doubly-linked-lists.html#GLIST
>GList</A> of the available visuals. The list
should be freed this list with <A
HREF=../glib/glib-doubly-linked-lists.html#G-LIST-FREE
>g_list_free</A>().
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5867"
></A
><H3
><A
NAME="GDK-VISUAL-GET-BEST-DEPTH"
></A
>gdk_visual_get_best_depth ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> gdk_visual_get_best_depth (void);</PRE
></TD
></TR
></TABLE
><P
>Returns the best available color depth.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5873"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the best available color depth.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5882"
></A
><H3
><A
NAME="GDK-VISUAL-GET-BEST-TYPE"
></A
>gdk_visual_get_best_type ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> gdk_visual_get_best_type (void);</PRE
></TD
></TR
></TABLE
><P
>Returns the best available visual type.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5888"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the best available visual type.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5897"
></A
><H3
><A
NAME="GDK-VISUAL-GET-SYSTEM"
></A
>gdk_visual_get_system ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* gdk_visual_get_system (void);</PRE
></TD
></TR
></TABLE
><P
>Returns the system's default visual.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5903"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the system's default visual.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5912"
></A
><H3
><A
NAME="GDK-VISUAL-GET-BEST"
></A
>gdk_visual_get_best ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* gdk_visual_get_best (void);</PRE
></TD
></TR
></TABLE
><P
>Returns the best available visual.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5918"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the best available visual.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5927"
></A
><H3
><A
NAME="GDK-VISUAL-GET-BEST-WITH-DEPTH"
></A
>gdk_visual_get_best_with_depth ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* gdk_visual_get_best_with_depth (<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> depth);</PRE
></TD
></TR
></TABLE
><P
>Returns the best available visual with a certain depth.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5934"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>depth</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the desired color depth</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the best available visual with <TT
CLASS="PARAMETER"
><I
>depth</I
></TT
> bits per pixel
or <TT
CLASS="LITERAL"
>NULL</TT
> if no visuals with that type are available.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5949"
></A
><H3
><A
NAME="GDK-VISUAL-GET-BEST-WITH-TYPE"
></A
>gdk_visual_get_best_with_type ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* gdk_visual_get_best_with_type (<A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> visual_type);</PRE
></TD
></TR
></TABLE
><P
>Returns the best available visual of a certain visual type.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5956"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>visual_type</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the desired visual type.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the visual of the given type with the highest depth
or <TT
CLASS="LITERAL"
>NULL</TT
> if no visuals of that type are available.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5970"
></A
><H3
><A
NAME="GDK-VISUAL-GET-BEST-WITH-BOTH"
></A
>gdk_visual_get_best_with_both ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* gdk_visual_get_best_with_both (<A
HREF=../glib/glib-basic-types.html#GINT
>gint</A> depth,
<A
HREF="gdk-visuals.html#GDKVISUALTYPE"
>GdkVisualType</A
> visual_type);</PRE
></TD
></TR
></TABLE
><P
>Returns the best available visual </P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN5978"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>depth</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the desired visual type.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>visual_type</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the desired depth.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>the best available visual with the given depth
and visual type, or <TT
CLASS="LITERAL"
>NULL</TT
> if no matching visuals are
available.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN5996"
></A
><H3
><A
NAME="GDK-VISUAL-REF"
></A
>gdk_visual_ref ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
><A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>* gdk_visual_ref (<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
> *visual);</PRE
></TD
></TR
></TABLE
><P
>In theory, increases the reference count of a visual. However,
the set of visuals is determined statically when GTK+ is
initialized, so this operation does nothing.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN6003"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>visual</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>a <A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>.</TD
></TR
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><I
CLASS="EMPHASIS"
>Returns</I
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>visual</I
></TT
>.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><HR><DIV
CLASS="REFSECT2"
><A
NAME="AEN6018"
></A
><H3
><A
NAME="GDK-VISUAL-UNREF"
></A
>gdk_visual_unref ()</H3
><TABLE
BORDER="0"
BGCOLOR="#D6E8FF"
WIDTH="100%"
CELLPADDING="6"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gdk_visual_unref (<A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
> *visual);</PRE
></TD
></TR
></TABLE
><P
>In theory, decreases the reference count of a visual. Like
<A
HREF="gdk-visuals.html#GDK-VISUAL-REF"
>gdk_visual_ref</A
>(), this operation does nothing.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN6025"
></A
><P
></P
><TABLE
BORDER="0"
WIDTH="100%"
BGCOLOR="#FFD0D0"
CELLSPACING="0"
CELLPADDING="4"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
WIDTH="20%"
ALIGN="RIGHT"
VALIGN="TOP"
><TT
CLASS="PARAMETER"
><I
>visual</I
></TT
> :</TD
><TD
WIDTH="80%"
ALIGN="LEFT"
VALIGN="TOP"
>a <A
HREF="gdk-visuals.html#GDKVISUAL"
>GdkVisual</A
>.
</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><BR
CLEAR="all"><BR><TABLE
WIDTH="100%"
BORDER="0"
BGCOLOR="#000000"
CELLPADDING="1"
CELLSPACING="0"
><TR
><TD
WIDTH="25%"
BGCOLOR="#C00000"
ALIGN="left"
><A
HREF="gdk-color-contexts.html"
><FONT
COLOR="#FFFFFF"
SIZE="3"
><B
><<< Previous Page</B
></FONT
></A
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SIZE="3"
><B
><A
HREF="index.html"
><FONT
COLOR="#FFFFFF"
SIZE="3"
><B
>Home</B
></FONT
></A
></B
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WIDTH="25%"
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><FONT
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HREF="gdk.html"
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