XmGetPixmapByDepth(library call)

NAME
XmGetPixmapByDepth — A pixmap caching function that generates a pixmap, stores it in a pixmap cache, and returns the pixmap

SYNOPSIS

#include <Xm/Xm.h>
Pixmap XmGetPixmapByDepth(
Screen *screen,
char *image_name,
Pixel foreground,
Pixel background,
int depth);

DESCRIPTION

XmGetPixmapByDepth uses the parameter data to perform a lookup in the pixmap cache to see if a pixmap has already been generated that matches the data. If one is found, a reference count is incremented and the pixmap is returned. Applications should use XmDestroyPixmap when the pixmap is no longer needed.

screen
    Specifies the display screen on which the pixmap is to be drawn

image_name
    Specifies the name of the image to be used to generate the pixmap

foreground
    Combines the image with the foreground color to create the pixmap if the image referenced is a bit-per-pixel image

background
    Combines the image with the background color to create the pixmap if the image referenced is a bit-per-pixel image

depth
    Specifies the depth of the pixmap

If a matching pixmap is not found, image_name is used to perform a lookup in the image cache. If an image is found, it is used to generate the pixmap, which is then cached and returned.

If an image is not found, image_name is used as a filename, and a search is made for an X10 or X11 bitmap file. If it is found, the file is read, converted into an image, and cached in the image cache. The image is then used to generate a pixmap, which is cached and returned.

If image_name has a leading / (slash), it specifies a full pathname, and XmGetPixmapByDepth opens the file as specified. Otherwise, image_name specifies a filename. In this case, XmGetPixmapByDepth looks for the file along a search path specified by the XBMLANGPATH environment variable or by a default search path, which varies depending on whether or not the XAPPLRESDIR environment variable is set. The default search path contains a lot of directories. Therefore, XmGetPixmapByDepth will need a relatively long time to search through all these directories for pixmaps and bitmaps. Applications that use a lot of pixmaps and bitmaps will probably run more quickly if XBMLANGPATH is set to a short list of directories. In addition to X bitmap files (XBM), Motif also supports XPM (X Pixmap) file formats, and, from version 2.3, JPEG and PNG image formats. (Note that support of JPEG and PNG image format is an optional feature of Motif, in order to check if current version supports PNG ang JPEG image formats the PNG_SUPPORT and JPEG_SUPPORT macros should be checked correspondingly.) The XBMLANGPATH specifies the path for both XBM, XPM, PNG and JPEG files. XPM files are described in more detail later in this reference page.

The XBMLANGPATH environment variable specifies a search path for X bitmap files. It can contain the substitution field %B, where the image_name argument to XmGetPixmapByDepth is substituted for %B. It can also contain the substitution fields accepted by XtResolvePathname. The substitution field %T is always mapped to bitmaps, and %S is always mapped to NULL.

If XBMLANGPATH is not set, but the environment variable XAPPLRESDIR is set, the following pathnames are searched:

•   %B

•   $XAPPLRESDIR/%L/bitmaps/%N/%B

•   $XAPPLRESDIR/%l_%t/bitmaps/%N/%B

•   $XAPPLRESDIR/%l/bitmaps/%N/%B

•   $XAPPLRESDIR/bitmaps/%N/%B

•   $XAPPLRESDIR/%L/bitmaps/%B

•   $XAPPLRESDIR/%l_%t/bitmaps/%B

•   $XAPPLRESDIR/%l/bitmaps/%B

•   $XAPPLRESDIR/bitmaps/%B

•   $HOME/bitmaps/%B

•   $HOME/%B

•   /usr/lib/X11/%L/bitmaps/%N/%B

•   /usr/lib/X11/%l_%t/bitmaps/%N/%B

•   /usr/lib/X11/%l/bitmaps/%N/%B

•   /usr/lib/X11/bitmaps/%N/%B

•   /usr/lib/X11/%L/bitmaps/%B

•   /usr/lib/X11/%l_%t/bitmaps/%B

•   /usr/lib/X11/%l/bitmaps/%B

•   /usr/lib/X11/bitmaps/%B

•   /usr/include/X11/bitmaps/%B

If neither XBMLANGPATH nor XAPPLRESDIR is set, the following pathnames are searched:

•   %B

•   $HOME/%L/bitmaps/%N/%B

•   $HOME/%l_%t/bitmaps/%N/%B

•   $HOME/%l/bitmaps/%N/%B

•   $HOME/bitmaps/%N/%B

•   $HOME/%L/bitmaps/%B

•   $HOME/%l_%t/bitmaps/%B

•   $HOME/%l/bitmaps/%B

•   $HOME/bitmaps/%B

•   $HOME/%B

•   /usr/lib/X11/%L/bitmaps/%N/%B

•   /usr/lib/X11/%l_%t/bitmaps/%N/%B

•   /usr/lib/X11/%l/bitmaps/%N/%B

•   /usr/lib/X11/bitmaps/%N/%B

•   /usr/lib/X11/%L/bitmaps/%B

•   /usr/lib/X11/%l_%t/bitmaps/%B

•   /usr/lib/X11/%l/bitmaps/%B

•   /usr/lib/X11/bitmaps/%B

•   /usr/include/X11/bitmaps/%B

These paths are defaults that vendors may change. For example, a vendor may use different directories for /usr/lib/X11 and /usr/include/X11.

The following substitutions are used in these paths:

%B  The image name, from the image_name argument

%N  The class name of the application

%L  The display's language string. This string is influenced by XtSetLanguageProc. The default string is determined by calling setlocale(LC_ALL, NULL).

%l_%t
    The language and territory component of the display's language string

%l  The language component of the display's language string

The contents of the file must conform to the rules for X11 bitmap files. In other words, Motif can read any X11 conformant bitmap file.

The XPM file format is used for storing or getting back colored X pixmaps from files. The XPM library is provided as unsupported with Motif. To build applications without XPM, use the NO_XPM macro. The following shows both XBM and XPM files, respectively, for a plaid pattern.

/* XBM file */
#define plaid_width 22
#define plaid_height 22
#define plaid_x_hot -1
#define plaid_y_hot -1
static char plaid_bits[] = {
   0x75, 0xfd, 0x3f, 0xaa, 0xfa, 0x3e, 0x75, 0xfd, 0x3f, 0xaa, 0xfa, 0x3e,
   0x75, 0xfd, 0x3f, 0xff, 0x57, 0x15, 0x75, 0xfd, 0x3f, 0xaa, 0xfa, 0x3e,
   0x75, 0xfd, 0x3f, 0xaa, 0xfa, 0x3e, 0x75, 0xfd, 0x3f, 0x20, 0xa8, 0x2b,
   0x20, 0x50, 0x15, 0x20, 0xa8, 0x2b, 0x20, 0x50, 0x15, 0x20, 0xa8, 0x2b,
   0xff, 0xff, 0x3f, 0x20, 0xa8, 0x2b, 0x20, 0x50, 0x15, 0x20, 0xa8, 0x2b,
   0x20, 0x50, 0x15, 0x20, 0xa8, 0x2b};

/* XPM file */
static char * plaid[] = {
/* plaid pixmap
 * width height ncolors chars_per_pixel */
"22 22 4 2 ",
/* colors */
"   c red       m white  s light_color ",
"Y  c green     m black  s lines_in_mix ",
"+  c yellow    m white  s lines_in_dark ",
"x              m black  s dark_color ",
/* pixels */
"x   x   x x x   x   x x x x x x + x x x x x ",
"  x   x   x   x   x   x x x x x x x x x x x ",
"x   x   x x x   x   x x x x x x + x x x x x ",
"  x   x   x   x   x   x x x x x x x x x x x ",
"x   x   x x x   x   x x x x x x + x x x x x ",
"Y Y Y Y Y x Y Y Y Y Y + x + x + x + x + x + ",
"x   x   x x x   x   x x x x x x + x x x x x ",
"  x   x   x   x   x   x x x x x x x x x x x ",
"x   x   x x x   x   x x x x x x + x x x x x ",
"  x   x   x   x   x   x x x x x x x x x x x ",
"x   x   x x x   x   x x x x x x + x x x x x ",
"          x           x   x   x Y x   x   x ",
"          x             x   x   Y   x   x   ",
"          x           x   x   x Y x   x   x ",
"x x x x x x x x x x x x x x x x x x x x x x ",
"          x           x   x   x Y x   x   x ",
"          x             x   x   Y   x   x   ",
"          x           x   x   x Y x   x   x ",
"          x             x   x   Y   x   x   ",
"          x           x   x   x Y x   x   x "
};

RETURN

Returns a pixmap when successful; returns XmUNSPECIFIED_PIXMAP if the image corresponding to image_name cannot be found.

RELATED

XmDestroyPixmap(3), XmInstallImage(3), and XmUninstallImage(3).