Subversion Repositories planix.SVN

.TH TWEAK 1

.CT 1 graphics

.SH NAME

tweak \- edit image files, subfont files, face files, etc.

.SH SYNOPSIS

.B tweak

[

.I file ...

]

.SH DESCRIPTION

.I Tweak

edits existing files holding various forms of images.

To create original images, start from an existing image, subfont, etc.

.PP

.I Tweak

reads its argument

.I files

and displays the resulting images in a vertical column.

If the image is too wide to fit across the display, it

is folded much like a long line of text in an

.IR rio

window.

Under each image is displayed one or two lines of text

presenting its parameters.

The first line shows the image's

.BR depth ,

the number

of bits per pixel;

.BR r ,

the rectangle covered by the image;

and the name of the

.B file

from which it was read.

If the file is a subfont, a second line presents a hexadecimal 16-bit

.B offset

to be applied to character values from the subfont

(typically as stored in a font file; see

.IR font (6));

and the subfont's

.BR n ,

.BR height ,

and

.B ascent

as defined in

.IR cachechars (2).

.PP

By means described below, magnified views of portions of the images

may be displayed.

The text associated with such a view includes

.BR mag ,

the magnification.

If the view is of a single character from a subfont, the second

line of text shows the character's value (including the subfont's offset)

in hexadecimal and as a character in

.I tweak's

default font; the character's

.BR x ,

.BR top ,

.BR bottom ,

.BR left ,

and

.BR width

as defined in

.IR cachechars (2);

and

.BR iwidth ,

the physical width of the image in the subfont's image.

.PP

There are two methods to obtain a magnified view of a character from a

subfont.

The first is to click mouse button 1 over the image of the character in

the subfont.  The second is to select the

.B char

entry on the button 3 menu,

point the resulting gunsight cursor at the desired subfont and click button 3,

and then type at the text prompt at the bottom of the screen the

character value, either as a multi-digit hexadecimal number or as a single

rune representing the character.

.PP

To magnify a portion of other types of image files,

click button 1 over the unmagnified file.

The cursor will switch to a cross.

Still with button 1, sweep a rectangle, as in

.BR rio ,

that encloses the portion of the image to be magnified.

(If the file is 16×16 or smaller,

.I tweak

will just magnify the entire file; no sweeping is necessary.)

.PP

Pressing buttons 1 and 2 within magnified images changes pixel values.

By default, button 1 sets the pixel to all zeros and button 2 sets the pixel

to all ones.

.PP

Across the top of the screen is a textual display of global parameters.

These values, as well as many of the textual values associated with

the images, may be edited by clicking button 1 on the displayed

value and typing a new value.

The values along the top of the screen are:

.TP

.B mag

Default magnification.

.TP

.B val(hex)

The value used to modify pixels within magnified images.

The value must be in hexadecimal, optionally preceded by a

tilde for bitwise negation.

.TP

.B but1

.TP

.B but2

The pixel value written when the corresponding button is pressed over a pixel.

.TP

.B invert-on-copy

Whether the pixel values are inverted when a

.B copy

operation is performed.

.PP

Under button 3 is a menu holding a variety of functions.

Many of these functions prompt for the image upon which to act

by switching to a gunsight cursor; click button 3 over the

selection, or click a different button to cancel the action.

.TP

.B open

Read and display a file.  The name of the file is typed to the prompt

on the bottom line.

.TP

.B read

Reread a file.

.TP

.B write

Write a file.

.TP

.B copy

Use the copy function, default

.BR S ,

to transfer a rectangle of pixels from one image to another.

The program prompts with a cross cursor; sweep out a rectangle in

one image or just click button 3 to select the whole image.

The program will leave that rectangle in place and

attach another one to the cursor.  Move that rectangle to the desired

place in any image and click button 3, or another button to cancel the action.

.TP

.B char

As described above, open a magnified view of a character image in a subfont.

.TP

.B pixels

Report the coordinate and value of individual pixels indicated by pressing button 3.

This is a mode of operation canceled by pressing button 1 or 2.

.TP

.B close

Close the specified image.

If the image is the unmagnified file, also close any magnified views of that file.

.TP

.B exit

Quit

.IR tweak .

The program will complain once about modified but unwritten files.

.SH SOURCE

.B /sys/src/cmd/tweak.c

.SH "SEE ALSO"

.IR cachechars (2),

.IR image (6),

.IR font (6)

.SH BUGS

For a program written to adjust width tables in fonts,

.I tweak

has been pushed unreasonably far.