.TH PAINT 9.1
.CT 1 games
.SH NAME
paint \- draw pictures in a layer
.SH SYNOPSIS
.B paint
.SH DESCRIPTION
.PP
.I Paint
is a program for artistic interactive drawing.
Buttons 1 and 2 draw in different ways,
e.g. depositing and erasing paint.
Button 3 gets a menu.
Certain menu items contain arrows, which if touched call submenus.
Moving off the right of a submenu causes it to disappear.
Some items toggle a state on and off; a
.L *
appears in the abnormal state.
Pressing button 1 while holding button 3 gets a short help
message for the menu item.
The top-level menu contains:
.PP
.de fq
\f5\\$1\fR	\\$2	\\$3 \\$4 \\$5 \\$6
..
.nf
.ta \w'\f5Line style\fP 'u +\w'\(-> 'u
.fq Style \(-> "Different kinds of brush strokes"
.fq Operation \(-> "Ways of putting paint on canvas"
.fq Texture \(-> "Things to do to the texture pattern"
.fq Brush \(-> "Things to do to the paintbrush"
.fq Canvas \(-> "Things to do to the whole picture"
.fq State \(-> "Change things saved in \fI.paintstate\fP"
.fq Fill "" "Fill an area of the picture"
.fq Green "" "Erase the entire picture"
.fq Mask "" "Display mask instead of image"
.fq Exit
.fi
.PP
The
.B Style
submenu:
.PP
.nf
.fq Paint "" "Multiple brush spots while holding button 1 or 2
.fq Circles "" "Circles; press at center and release at circumference
.fq Lines "" "Rubber-band brush lines
.fq Curves "" "Continuous strokes while holding button 1 or 2
.fq "Line Style" \(-> "Solid, dotted, dashed, etc. lines
.fi
.PP
Entries in the
.B Line Style
sub-submenu are strings of 
.LR A s, 
.LR B s
and dot that
describe dotted and dashed lines.
.L A
stands for the brush on the button pushed,
.L B
stands for the brush on the other button; 
.L .
for
no brush at all.
The string is cycled through at successive points when drawing
Lines, Curves, or Circles.
Thus 
.L A
means a solid line,
.L A...
means a 1 in 4 dotted
line, and
.L AAAA....
means 4-pixel dashes.
.PP
The
.B Operation
submenu assigns a pair of operations for buttons 1 and 2.
A hidden `mask' plane describes the shape that has been painted;
black pixels in the mask are inside, green outside.
Likewise, the brush
consists of a pair of rectangular image and mask planes.
There are 11 effective operations to combine the part of the brush
inside its mask
with the part of the picture it sits on (see
the Porter/Duff paper for details); selected pairs can be assigned to the
buttons:
.PP
.nf
.ta \w'\f5Line style\fP \(-> 'u
.fq Above/Erase "Button 1 paints on top, Button 2 erases
.fq Below/Erase "Button 1 paints behind, Button 2 erases
.fq Above/Below "Button 1 paints on top, Button 2 behind
.fq Inside/Erase "Button 1 paints inside, Button 2 erases
.fq Brush/Clear "Special effects
.fq AoutB/AinB "Special effects
.fq BinA/BatopA "Special effects
.fq Xor/Above "Special effects
.fi
.PP
.B Above
paints on top of the picture, as in
`normal' paint programs.
.PP
.B Below
paints underneath\(emonly in places that were not
previously covered.
.PP
.B Inside
paints on top, but only inside the already-painted part.
.PP
The other 7 operations are best described as `special effects'.
Try them out
to see what they do, or look at the Porter/Duff paper.
.PP
Texture
facilities paint with a repeating 16\(mu16 pattern instead of copies of
a brush.
The
.B Texture
submenu contains:
.PP
.nf
.ta \w'\f5Line style\fP 'u +\w'\(-> 'u
.fq Texture "" "Turn texturing on or off
.fq Make "" "Pick a texture from the picture
.fq Negate "" "Reverse the texture's green and black
.fq Save "" "Name a texture and copy it into a file
.fq Library \(-> "List and and retrieve textures in library
.fq Get "" "Type a name and get a texture from a file
.fi
.PP
.B Make
gives a 16\(mu16 square cursor with which to pick
a texture.
.PP
The
.B Brush
submenu has the same items
for brushes.
.B Make
allows you to sweep out a region to use as a brush.
.PP
The
.B Canvas
submenu contains
.BR Negate ,
.BR Save ,
.BR Library ,
and
.BR Get ,
in this case pertaining to entire pictures.
A library picture
is saved in a file containing the image plane then the
mask plane in
.IR bitfile (9.5)
format.
.PP
The file
.B .paintstate
in the current directory remembers
the names of the current brush, texture,
and libraries between sessions.
The
.B State
submenu displays the library names at the bottom
of the layer, where they can be edited:
.PP
.nf
.ta \w'\f5Line style\fP \(-> 'u
.fq Brushes  "" "Name the brush directory
.fq Pictures  "" "Name the picture directory
.fq Textures  "" "Name the texture directory
.fi
.PP
The
.B Fill
menu item gives an arrowhead cursor.
If you touch down with button 3 at a point not painted,
the rookwise-connected
region containing it will fill with black.
On completion, the
black will be replaced by the current texture.
While the region is filling, any button click aborts the operation.
.PP
The current selections from the
.BR "Brush Library" ,
.BR Style ,
.BR Operation ,
.BR Texture ,
and
.B "Line Style"
menus are marked with a 
.LR * ,
and are displayed in the information box
at the bottom of the layer.
.SH FILES
.TF /usr/jerq/lib/paint/brush
.TP
.F /usr/jerq/lib/paint/brush
the default brush library
.TP
.F /usr/jerq/lib/paint/tex
the default texture library
.TP
.F \&.paintstate
state of terminated program
.SH SEE ALSO
.IR mbits (6),
.IR bitfile (9.5), 
.IR brush (9.1),
.IR cip (9.1),
.IR ped (9.1)
.br
Thomas Porter and Tom Duff,
`Compositing Digital Images,'
Siggraph '84 Proceedings