XGetVisualInfo(XS)       X Version 11 (Release 5)         XGetVisualInfo(XS)
                                6 January 1993


 Name

    XGetVisualInfo - 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.

    nitemsreturn  Returns the number of matching visual structures.

    screen         Specifies the screen.

    visual         Specifies the visual type.

    vinfomask     Specifies the visual mask value.

    vinforeturn   Returns the matched visual information.

    vinfotemplate 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 vinfotemplate.  If no
    visual structures match the template using the specified vinfomask,
    XGetVisualInfo returns a NULL.  To free the data returned by this func-
    tion, use XFree.

    The XMatchVisualInfo function returns the visual information for a visual
    that matches the specified depth and class for a screen.  Because multi-
    ple 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 vinforeturn.  Oth-
    erwise, 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;
          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(XS)
    Xlib - C Language X Interface