XGetVisualInfo(3X11)

     NAME
          XGetVisualInfo, XMatchVisualInfo, XVisualIDFromVisual,
          XVisualInfo - obtain visual information and visual structure

     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 structures.

          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 information
          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, XMatchVisualInfo 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