BITMAP(1) RISC/os Reference Manual BITMAP(1)
NAME
bitmap, bmtoa, atobm - bitmap editor and converter utilities
for X
SYNOPSIS
bitmap [-options ...] filename WIDTHxHEIGHT
bmtoa [-chars ...] [filename]
atobm [-chars cc] [-name variable] [-xhot number] [-yhot
number] [filename]
DESCRIPTION
The bitmap program is a rudimentary tool for creating or
editing rectangular images made up of 1's and 0's. Bitmaps
are used in X for defining clipping regions, cursor shapes,
icon shapes, and tile and stipple patterns.
The bmtoa and atobm filters convert bitmap files (FILE FOR-
MAT) to and from ASCII strings. They are most commonly used
to quickly print out bitmaps and to generate versions for
including in text.
USAGE
Bitmap displays grid in which each square represents a sin-
gle bit in the picture being edited. Squares can be set,
cleared, or inverted directly with the buttons on the
pointer and a menu of higher level operations such as draw
line and fill circle is provided to the side of the grid.
Actual size versions of the bitmap as it would appear nor-
mally and inverted appear below the menu.
If the bitmap is to be used for defining a cursor, one of
the squares in the images may be designated as the hotspot.
This determines where the cursor is actually pointing. For
cursors with sharp tips (such as arrows or fingers), this is
usually at the end of the tip; for symmetric cursors (such
as crosses or bullseyes), this is usually at the center.
Bitmaps are stored as small C code fragments suitable for
including in applications. They provide an array of bits as
well as symbolic constants giving the width, height, and
hotspot (if specified) that may be used in creating cursors,
icons, and tiles.
The WIDTHxHEIGHT argument gives the size to use when creat-
ing a new bitmap (the default is 16x16). Existing bitmaps
are always edited at their current size.
If the bitmap window is resized by the window manager, the
size of the squares in the grid will shrink or enlarge to
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fit.
OPTIONS
Bitmap accepts the following options:
-help
This option will cause a brief description of the allow-
able options and parameters to be printed.
-display display
This option specifies the name of the X server to used.
-geometry geometry
This option specifies the placement and size of the bit-
map window on the screen. See X for details.
-nodashed
This option indicates that the grid lines in the work
area should not be drawn using dashed lines. Although
dashed lines are prettier than solid lines, on some
servers they are significantly slower.
-name variablename
This option specifies the variable name to be used when
writing out the bitmap file. The default is to use the
basename of the filename command line argument.
-bw number
This option specifies the border width in pixels of the
main window.
-fn font
This option specifies the font to be used in the but-
tons.
-fg color
This option specifies the color to be used for the fore-
ground.
-bg color
This option specifies the color to be used for the back-
ground.
-hl color
This option specifies the color to be used for
highlighting.
-bd color
This option specifies the color to be used for the win-
dow border.
-ms color
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This option specifies the color to be used for the
pointer (mouse).
Bmtoa accepts the following option:
-chars cc
This option specifies the pair of characters to use in
the string version of the bitmap. The first character
is used for 0 bits and the second character is used for
1 bits. The default is to use dashes (-) for 0's and
sharp signs (#) for 1's.
Atobm accepts the following options:
-chars cc
This option specifies the pair of characters to use when
converting string bitmaps into arrays of numbers. The
first character represents a 0 bit and the second char-
acter represents a 1 bit. The default is to use dashes
(-) for 0's and sharp signs (#) for 1's.
-name variable
This option specifies the variable name to be used when
writing out the bitmap file. The default is to use the
basename of the filename command line argument or leave
it blank if the standard input is read.
-xhot number
This option specifies the X coordinate of the hotspot.
Only positive values are allowed. By default, no
hotspot information is included.
-yhot number
This option specifies the Y coordinate of the hotspot.
Only positive values are allowed. By default, no
hotspot information is included.
CHANGING GRID SQUARES
Grid squares may be set, cleared, or inverted by pointing to
them and clicking one of the buttons indicated below. Mul-
tiple squares can be changed at once by holding the button
down and dragging the cursor across them. Set squares are
filled and represent 1's in the bitmap; clear squares are
empty and represent 0's.
Button 1
This button (usually leftmost on the pointer) is
used to set one or more squares. The corresponding
bit or bits in the bitmap are turned on (set to 1)
and the square or squares are filled.
Button 2
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This button (usually in the middle) is used to
invert one or more squares. The corresponding bit
or bits in the bitmap are flipped (1's become 0's
and 0's become 1's).
Button 3
This button (usually on the right) is used to clear
one or more squares. The corresponding bit or bits
in the bitmap are turned off (set to 0) and the
square or squares are emptied.
MENU COMMANDS
To make defining shapes easier, bitmap provides 13 commands
for drawing whole sections of the grid at once, 2 commands
for manipulating the hotspot, and 2 commands for updating
the bitmap file and exiting. A command buttons for each of
these operations is located to the right of the grid.
Several of the commands operate on rectangular portions of
the grid. These areas are selected after the command button
is pressed by moving the cursor to the upper left square of
the desired area, pressing a pointer button, dragging the
cursor to the lower right hand corner (with the button still
pressed) , and then releasing the button. The command may
be aborted by pressing any other button while dragging or by
releasing outside the grid.
To invoke a command, move the pointer over that command and
click any button.
Clear All
This command is used to clear all of the bits in
the bitmap as if Button 3 had been dragged through
every square in the grid. It cannot be undone.
Set All
This command is used to set all of the bits in the
bitmap as if Button 1 had been dragged through
every square in the grid. It cannot be undone.
Invert All
This command is used to invert all of the bits in
the bitmap as if Button 2 had been dragged through
every square in the grid.
Clear Area
This command is used to clear a region of the grid
as if Button 3 had been dragged through each of the
squares in the region. When this command is
invoked, the cursor will change shape to indicate
that the area to be cleared should be selected as
outlined above.
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Set Area
This command is used to set a region of the grid as
if Button 1 had been dragged through each of the
squares in the region. When this command is
invoked, the cursor will change shape to indicate
that the area to be set should be selected as out-
lined above.
Invert Area
This command is used to inverted a region of the
grid as if Button 2 had been dragged through each
of the squares in the region. When this command is
invoked, the cursor will change shape to indicate
that the area to be inverted should be selected as
outlined above.
Copy Area
This command is used to copy a region of the grid
from one location to another. When this command is
invoked, the cursor will change shape to indicate
that the area to be copied should be selected as
outlined above. The cursor should then be clicked
on the square to which the upper left hand corner
of the region should be copied.
Move Area
This command is used to move a region of the grid
from one location to another. When this command is
invoked, the cursor will change shape to indicate
that the area to be moved should be selected as
outlined above. The cursor should then be clicked
on the square to which the upper left hand corner
of the region should be moved. Any squares in the
region's old position that aren't also in the new
position are cleared.
Overlay Area
This command is used to copy all of the set squares
in a region of the grid from one location to
another. When this command is invoked, the cursor
will change shape to indicate that the area to be
copied should be selected as outlined above. The
cursor should then be clicked on the square to
which the upper left hand corner of the region
should be overlaid. Only the squares that are set
in the region will be touched in the new location.
Line
This command will set the squares in a line between
two points. When this command is invoked, the cur-
sor will change shape to indicate that the pointer
should be clicked on the two end points of the
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line.
Circle
This command will set the squares on a circle
specified by a center and a point on the curve.
When this command is invoked, the cursor will
change shape to indicate that the pointer should be
clicked on the center of the circle and then over a
point on the curve. Small circles may not look
very round because of the size of the grid and the
limits of having to work with discrete pixels.
Filled Circle
This command will set all of the squares in a cir-
cle specified by a center and a point on the curve.
When this command is invoked, the cursor will
change shape to indicate that the pointer should be
clicked on the center of the circle and then over a
point on the curve. All squares side and including
the circle are set.
Flood Fill
This command will set all clear squares in an
enclosed shape. When this command is invoked, the
cursor will change shape to indicate that the
pointer should be clicked on any empty square
inside the shape to be filled. All empty squares
that border horizontally or vertically with the
indicated square are set out to the enclosing
shape. If the shape is not closed, the entire grid
will be filled.
Set Hot Spot
This command designates one square in the grid as
the hot spot if this bitmap to be used for defining
a cursor. When the command is invoked, the cursor
will change indicating that the pointer should be
clicked on the square to contain the hot spot.
Clear Hot Spot
This command removes any designated hot spot from
the bitmap.
Write Output
This command writes a small fragment of C code
representing the bitmap to the filename specified
on the command line. If the file already exists,
the original file will be renamed to filename~
before the new file is created. If an error occurs
in either the renaming or the writing of the bitmap
file, a dialog box will appear asking whether or
not bitmap should use /tmp/filename instead.
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Quit
This command causes bitmap to display a dialog box
asking whether or not it should save the bitmap (if
it has changed) and then exit. Answering yes is
the same as invoking Write Output; no causes bitmap
to simply exit; and cancel will abort the Quit com-
mand so that more changes may be made.
FILE FORMAT
The Write Output command stores bitmaps as simple C program
fragments that can be compiled into programs, referred to by
X Toolkit pixmap resources, manipulated by other programs
(see xsetroot), or read in using utility routines in the
various programming libraries. The width and height of the
bitmap as well as the hotspot, if specified, are written as
preprocessor symbols at the start of the file. The bitmap
image is then written out as an array of characters:
#define name_width 11
#define name_height 5
#define name_x_hot 5
#define name_y_hot 2
static char name_bits[] = {
0x91, 0x04, 0xca, 0x06, 0x84,
0x04, 0x8a, 0x04, 0x91, 0x04
};
The name prefix to the preprocessor symbols and to the bits
array is constructed from the filename argument given on the
command line. Any directories are stripped off the front of
the name and any suffix beginning with a period is stripped
off the end. Any remaining non-alphabetic characters are
replaced with underscores. The name_x_hot and name_y_hot
symbols will only be present if a hotspot has been desig-
nated using the Set Hot Spot command.
Each character in the the array contains 8 bits from one row
of the image (rows are padded out at the end to a multiple
of 8 to make this is possible). Rows are written out from
left to right and top to bottom. The first character of the
array holds the leftmost 8 bits of top line, and the last
characters holds the right most 8 bits (including padding)
of the bottom line. Within each character, the leftmost bit
in the bitmap is the least significant bit in the character.
This process can be demonstrated visually by splitting a row
into words containing 8 bits each, reversing the bits each
word (since Arabic numbers have the significant digit on the
right and images have the least significant bit on the
left), and translating each word from binary to hexadecimal.
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In the following example, the array of 1's and 0's on the
left represents a bitmap containing 5 rows and 11 columns
that spells X11. To its right is is the same array split
into 8 bit words with each row padded with 0's so that it is
a multiple of 8 in length (16):
10001001001 10001001 00100000
01010011011 01010011 01100000
00100001001 00100001 00100000
01010001001 01010001 00100000
10001001001 10001001 00100000
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Reversing the bits in each word of the padded, split version
of the bitmap yields the left hand figure below. Interpret-
ing each word as hexadecimal number yields the array of
numbers on the right:
10010001 00000100 0x91 0x04
11001010 00000110 0xca 0x06
10000100 00000100 0x84 0x04
10001010 00000100 0x8a 0x04
10010001 00000100 0x91 0x04
The character array can then be generated by reading each
row from left to right, top to bottom:
static char name_bits[] = {
0x91, 0x04, 0xca, 0x06, 0x84,
0x04, 0x8a, 0x04, 0x91, 0x04
};
The bmtoa program may be used to convert bitmap files into
arrays of characters for printing or including in text
files. The atobm program can be used to convert strings
back to bitmap format.
USING BITMAPS IN PROGRAMS
The format of bitmap files is designed to make bitmaps and
cursors easy to use within X programs. The following code
could be used to create a cursor from bitmaps defined in
this.cursor and this_mask.cursor:
#include "this.cursor"
#include "this_mask.cursor"
XColor foreground, background;
/* fill in foreground and background color structures */
Pixmap source = XCreateBitmapFromData (display, drawable,
this_bits, this_width, this_height);
Pixmap mask = XCreateBitmapFromData (display, drawable,
this_mask_bits, this_mask_width, this_mask_height);
Cursor cursor = XCreatePixmapCursor (display, source, mask,
foreground, background, this_x_hot, this_y_hot);
Additional routines are available for reading in bitmap
files and returning the data in the file, in Bitmap
(single-plane Pixmap for use with routines that require
stipples), or full depth Pixmaps (often used for window
backgrounds and borders). Applications writers should be
careful to understand the difference between Bitmaps and
Pixmaps so that their programs function correctly on color
and monochrome displays.
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BITMAP(1) RISC/os Reference Manual BITMAP(1)
For backward compatibility, bitmap will also accept X10 for-
mat bitmap files. However, when the file is written out
again it will be in X11 format
X DEFAULTS
Bitmap uses the following resources:
Background
The window's background color. Bits which are 0 in the
bitmap are displayed in this color. This option is use-
ful only on color displays. The default value is white.
BorderColor
The border color. This option is useful only on color
displays. The default value is black.
BorderWidth
The border width. The default value is 2.
BodyFont
The text font. The default value is variable.
Dashed
If ``off'', then bitmap will draw the grid lines with
solid lines. The default is ``on''.
Foreground
The foreground color. Bits which are 1 in the bitmap
are displayed in this color. This option is useful only
on color displays. The default value is black.
Highlight
The highlight color. bitmap uses this color to show the
hot spot and to indicate rectangular areas that will be
affected by the Move Area, Copy Area, Set Area, and
Invert Area commands. If a highlight color is not
given, then bitmap will highlight by inverting. This
option is useful only on color displays.
Mouse
The pointer (mouse) cursor's color. This option is use-
ful only on color displays. The default value is black.
Geometry
The size and location of the bitmap window.
Dimensions
The WIDTHxHEIGHT to use when creating a new bitmap.
SEE ALSO
X(1), Xlib - C Language X Interface (particularly the sec-
tion on Manipulating Bitmaps), XmuReadBitmapDataFromFile
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BUGS
The old command line arguments aren't consistent with other
X programs.
If you move the pointer too fast while holding a pointer
button down, some squares may be missed. This is caused by
limitations in how frequently the X server can sample the
pointer location.
There is no way to write to a file other than the one speci-
fied on the command line.
There is no way to change the size of the bitmap once the
program has started.
There is no undo command.
COPYRIGHT
Copyright 1988, Massachusetts Institute of Technology.
See X(1) for a full statement of rights and permissions.
AUTHOR
bitmap by Ron Newman, MIT Project Athena; documentation,
bmtoa, and atobm by Jim Fulton, MIT X Consortium.
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