XGetVisualInfo(3X11)

NAME
       XGetVisualInfo, XMatchVisualInfo, XVisualIDFromVisual,
       XVisualInfo - obtain visual information and visual struc-
       ture

SYNTAX
       XVisualInfo *XGetVisualInfo(display, vinfo_mask,
       vinfo_template, nitems_return)
             Display *display;
             long vinfo_mask;
             XVisualInfo *vinfo_template;
             int *nitems_return;

       Status XMatchVisualInfo(display, screen, depth, class,
       vinfo_return)
             Display *display;
             int screen;
             int depth;
             int class;
             XVisualInfo *vinfo_return;

       VisualID XVisualIDFromVisual(visual)
              Visual *visual;

ARGUMENTS
       class     Specifies the class of the screen.

       depth     Specifies the depth of the screen.

       display   Specifies the connection to the X server.

       nitems_return
                 Returns the number of matching visual struc-
                 tures.

       screen    Specifies the screen.

       visual    Specifies the visual type.

       vinfo_mask
                 Specifies the visual mask value.

       vinfo_return
                 Returns the matched visual information.

       vinfo_template
                 Specifies the visual attributes that are to be
                 used in matching the visual structures.

DESCRIPTION
       The XGetVisualInfo function returns a list of visual
       structures that have attributes equal to the attributes
       specified by vinfo_template.  If no visual structures
       match the template using the specified vinfo_mask,

       XGetVisualInfo returns a NULL.  To free the data returned
       by this function, use XFree.

       The XMatchVisualInfo function returns the visual informa-
       tion for a visual that matches the specified depth and
       class for a screen.  Because multiple visuals that match
       the specified depth and class can exist, the exact visual
       chosen is undefined.  If a visual is found, XMatchVisual-
       Info returns nonzero and the information on the visual to
       vinfo_return.  Otherwise, when a visual is not found,
       XMatchVisualInfo returns zero.

       The XVisualIDFromVisual function returns the visual ID for
       the specified visual type.

STRUCTURES
       The XVisualInfo structure contains:

       /* Visual information mask bits */
       #define   VisualNoMask                0x0
       #define   VisualIDMask                0x1
       #define   VisualScreenMask            0x2
       #define   VisualDepthMask             0x4
       #define   VisualClassMask             0x8
       #define   VisualRedMaskMask           0x10
       #define   VisualGreenMaskMask         0x20
       #define   VisualBlueMaskMask          0x40
       #define   VisualColormapSizeMask      0x80
       #define   VisualBitsPerRGBMask        0x100
       #define   VisualAllMask               0x1FF
       /* Values */

       typedef struct {
            Visual *visual;
            VisualID visualid;
            int screen;
            unsigned int depth;
            int class;
            unsigned long red_mask;
            unsigned long green_mask;
            unsigned long blue_mask;
            int colormap_size;
            int bits_per_rgb;
       } XVisualInfo;

SEE ALSO
       XFree(3X11) 
       Xlib - C Language X Interface