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✏️ Editing: tcolor

#!/bin/sh
# the next line restarts using wish \
exec wish8.6 "$0" ${1+"$@"}

# tcolor --
# This script implements a simple color editor, where you can
# create colors using either the RGB, HSB, or CYM color spaces
# and apply the color to existing applications.

package require Tk 8.4
wm title . "Color Editor"

# Global variables that control the program:
#
# colorSpace -			Color space currently being used for
#				editing.  Must be "rgb", "cmy", or "hsb".
# label1, label2, label3 -	Labels for the scales.
# red, green, blue -		Current color intensities in decimal
#				on a scale of 0-65535.
# color -			A string giving the current color value
#				in the proper form for x:
#				#RRRRGGGGBBBB
# updating -			Non-zero means that we're in the middle of
#				updating the scales to load a new color,so
#				information shouldn't be propagating back
#				from the scales to other elements of the
#				program:  this would make an infinite loop.
# command -			Holds the command that has been typed
#				into the "Command" entry.
# autoUpdate -			1 means execute the update command
#				automatically whenever the color changes.
# name -			Name for new color, typed into entry.

set colorSpace hsb
set red 65535
set green 0
set blue 0
set color #ffff00000000
set updating 0
set autoUpdate 1
set name ""

# Create the menu bar at the top of the window.

. configure -menu [menu .menu]
menu .menu.file
.menu add cascade  -menu .menu.file  -label File  -underline 0
.menu.file add radio -label "RGB color space" -variable colorSpace \
	-value rgb -underline 0 -command {changeColorSpace rgb}
.menu.file add radio -label "CMY color space" -variable colorSpace \
	-value cmy -underline 0 -command {changeColorSpace cmy}
.menu.file add radio -label "HSB color space" -variable colorSpace \
	-value hsb -underline 0 -command {changeColorSpace hsb}
.menu.file add separator
.menu.file add radio -label "Automatic updates" -variable autoUpdate \
	-value 1 -underline 0
.menu.file add radio -label "Manual updates" -variable autoUpdate \
	-value 0 -underline 0
.menu.file add separator
.menu.file add command -label "Exit program" -underline 0 -command {exit}

# Create the command entry window at the bottom of the window, along
# with the update button.

labelframe .command -text "Command:" -padx {1m 0}
entry .command.e -textvariable command
button .command.update -text Update -command doUpdate
pack .command.update -side right -pady .1c -padx {.25c 0}
pack .command.e -expand yes -fill x -ipadx 0.25c

# Create the listbox that holds all of the color names in rgb.txt,
# if an rgb.txt file can be found.

grid .command -sticky nsew -row 2 -columnspan 3 -padx 1m -pady {0 1m}

grid columnconfigure . {1 2} -weight 1
grid rowconfigure . 0 -weight 1
foreach i {
    /usr/local/lib/X11/rgb.txt /usr/lib/X11/rgb.txt
    /X11/R5/lib/X11/rgb.txt /X11/R4/lib/rgb/rgb.txt
    /usr/openwin/lib/X11/rgb.txt
} {
    if {![file readable $i]} {
	continue;
    }
    set f [open $i]
    labelframe .names -text "Select:" -padx .1c -pady .1c
    grid .names -row 0 -column 0 -sticky nsew -padx .15c -pady .15c -rowspan 2
    grid columnconfigure . 0 -weight 1
    listbox .names.lb -width 20 -height 12 -yscrollcommand ".names.s set" \
	-exportselection false
    bind .names.lb <Double-1> {
	    tc_loadNamedColor [.names.lb get [.names.lb curselection]]
    }
    scrollbar .names.s -orient vertical -command ".names.lb yview"
    pack .names.lb .names.s -side left -fill y -expand 1
    while {[gets $f line] >= 0} {
	if {[regexp {^\s*\d+\s+\d+\s+\d+\s+(\S+)$} $line -> col]} {
	    .names.lb insert end $col
	}
    }
    close $f
    break
}

# Create the three scales for editing the color, and the entry for
# typing in a color value.

frame .adjust
foreach i {1 2 3} {
    label .adjust.l$i -textvariable label$i -pady 0
    labelframe .adjust.$i -labelwidget .adjust.l$i -padx 1m -pady 1m
    scale .scale$i -from 0 -to 1000 -length 6c -orient horizontal \
	    -command tc_scaleChanged
    pack .scale$i -in .adjust.$i
    pack .adjust.$i
}
grid .adjust -row 0 -column 1 -sticky nsew -padx .15c -pady .15c

labelframe .name -text "Name:" -padx 1m -pady 1m
entry .name.e -textvariable name -width 10
pack .name.e -side right -expand 1 -fill x
bind .name.e <Return> {tc_loadNamedColor $name}
grid .name   -column 1 -row 1 -sticky nsew -padx .15c -pady .15c

# Create the color display swatch on the right side of the window.

labelframe .sample -text "Color:" -padx 1m -pady 1m
frame .sample.swatch -width 2c -height 5c -background $color
label .sample.value -textvariable color -width 13 -font {Courier 12}
pack .sample.swatch -side top -expand yes -fill both
pack .sample.value -side bottom -pady .25c
grid .sample -row 0 -column 2 -sticky nsew -padx .15c -pady .15c -rowspan 2

# The procedure below is invoked when one of the scales is adjusted.
# It propagates color information from the current scale readings
# to everywhere else that it is used.

proc tc_scaleChanged args {
    global red green blue colorSpace color updating autoUpdate
    if {$updating} {
	return
    }
    switch $colorSpace {
	rgb {
	    set red   [format %.0f [expr {[.scale1 get]*65.535}]]
	    set green [format %.0f [expr {[.scale2 get]*65.535}]]
	    set blue  [format %.0f [expr {[.scale3 get]*65.535}]]
	}
	cmy {
	    set red   [format %.0f [expr {65535 - [.scale1 get]*65.535}]]
	    set green [format %.0f [expr {65535 - [.scale2 get]*65.535}]]
	    set blue  [format %.0f [expr {65535 - [.scale3 get]*65.535}]]
	}
	hsb {
	    set list [hsbToRgb [expr {[.scale1 get]/1000.0}] \
		    [expr {[.scale2 get]/1000.0}] \
		    [expr {[.scale3 get]/1000.0}]]
	    set red [lindex $list 0]
	    set green [lindex $list 1]
	    set blue [lindex $list 2]
	}
    }
    set color [format "#%04x%04x%04x" $red $green $blue]
    .sample.swatch config -bg $color
    if {$autoUpdate} doUpdate
    update idletasks
}

# The procedure below is invoked to update the scales from the
# current red, green, and blue intensities.  It's invoked after
# a change in the color space and after a named color value has
# been loaded.

proc tc_setScales {} {
    global red green blue colorSpace updating
    set updating 1
    switch $colorSpace {
	rgb {
	    .scale1 set [format %.0f [expr {$red/65.535}]]
	    .scale2 set [format %.0f [expr {$green/65.535}]]
	    .scale3 set [format %.0f [expr {$blue/65.535}]]
	}
	cmy {
	    .scale1 set [format %.0f [expr {(65535-$red)/65.535}]]
	    .scale2 set [format %.0f [expr {(65535-$green)/65.535}]]
	    .scale3 set [format %.0f [expr {(65535-$blue)/65.535}]]
	}
	hsb {
	    set list [rgbToHsv $red $green $blue]
	    .scale1 set [format %.0f [expr {[lindex $list 0] * 1000.0}]]
	    .scale2 set [format %.0f [expr {[lindex $list 1] * 1000.0}]]
	    .scale3 set [format %.0f [expr {[lindex $list 2] * 1000.0}]]
	}
    }
    set updating 0
}

# The procedure below is invoked when a named color has been
# selected from the listbox or typed into the entry.  It loads
# the color into the editor.

proc tc_loadNamedColor name {
    global red green blue color autoUpdate

if {[string index $name 0] != "#"} {
	set list [winfo rgb .sample.swatch $name]
	set red [lindex $list 0]
	set green [lindex $list 1]
	set blue [lindex $list 2]
    } else {
	switch [string length $name] {
	    4  {set format "#%1x%1x%1x"; set shift 12}
	    7  {set format "#%2x%2x%2x"; set shift 8}
	    10 {set format "#%3x%3x%3x"; set shift 4}
	    13 {set format "#%4x%4x%4x"; set shift 0}
	    default {error "syntax error in color name \"$name\""}
	}
	if {[scan $name $format red green blue] != 3} {
	    error "syntax error in color name \"$name\""
	}
	set red   [expr {$red<<$shift}]
	set green [expr {$green<<$shift}]
	set blue  [expr {$blue<<$shift}]
    }
    tc_setScales
    set color [format "#%04x%04x%04x" $red $green $blue]
    .sample.swatch config -bg $color
    if {$autoUpdate} doUpdate
}

# The procedure below is invoked when a new color space is selected.
# It changes the labels on the scales and re-loads the scales with
# the appropriate values for the current color in the new color space

proc changeColorSpace space {
    global label1 label2 label3
    switch $space {
	rgb {
	    set label1 "Adjust Red:"
	    set label2 "Adjust Green:"
	    set label3 "Adjust Blue:"
	    tc_setScales
	    return
	}
	cmy {
	    set label1 "Adjust Cyan:"
	    set label2 "Adjust Magenta:"
	    set label3 "Adjust Yellow:"
	    tc_setScales
	    return
	}
	hsb {
	    set label1 "Adjust Hue:"
	    set label2 "Adjust Saturation:"
	    set label3 "Adjust Brightness:"
	    tc_setScales
	    return
	}
    }
}

# The procedure below converts an RGB value to HSB.  It takes red, green,
# and blue components (0-65535) as arguments, and returns a list containing
# HSB components (floating-point, 0-1) as result.  The code here is a copy
# of the code on page 615 of "Fundamentals of Interactive Computer Graphics"
# by Foley and Van Dam.

proc rgbToHsv {red green blue} {
    if {$red > $green} {
	set max [expr {double($red)}]
	set min [expr {double($green)}]
    } else {
	set max [expr {double($green)}]
	set min [expr {double($red)}]
    }
    if {$blue > $max} {
	set max [expr {double($blue)}]
    } elseif {$blue < $min} {
	set min [expr {double($blue)}]
    }
    set range [expr {$max-$min}]
    if {$max == 0} {
	set sat 0
    } else {
	set sat [expr {($max-$min)/$max}]
    }
    if {$sat == 0} {
	set hue 0
    } else {
	set rc [expr {($max - $red)/$range}]
	set gc [expr {($max - $green)/$range}]
	set bc [expr {($max - $blue)/$range}]
	if {$red == $max} {
	    set hue [expr {($bc - $gc)/6.0}]
	} elseif {$green == $max} {
	    set hue [expr {(2 + $rc - $bc)/6.0}]
	} else {
	    set hue [expr {(4 + $gc - $rc)/6.0}]
	}
	if {$hue < 0.0} {
	    set hue [expr {$hue + 1.0}]
	}
    }
    return [list $hue $sat [expr {$max/65535}]]
}

# The procedure below converts an HSB value to RGB.  It takes hue, saturation,
# and value components (floating-point, 0-1.0) as arguments, and returns a
# list containing RGB components (integers, 0-65535) as result.  The code
# here is a copy of the code on page 616 of "Fundamentals of Interactive
# Computer Graphics" by Foley and Van Dam.

proc hsbToRgb {hue sat value} {
    set v [format %.0f [expr {65535.0*$value}]]
    if {$sat == 0} {
	return "$v $v $v"
    } else {
	set hue [expr {$hue*6.0}]
	if {$hue >= 6.0} {
	    set hue 0.0
	}
	scan $hue. %d i
	set f [expr {$hue-$i}]
	set p [format %.0f [expr {65535.0*$value*(1 - $sat)}]]
	set q [format %.0f [expr {65535.0*$value*(1 - ($sat*$f))}]]
	set t [format %.0f [expr {65535.0*$value*(1 - ($sat*(1 - $f)))}]]
	switch $i {
	    0 {return "$v $t $p"}
	    1 {return "$q $v $p"}
	    2 {return "$p $v $t"}
	    3 {return "$p $q $v"}
	    4 {return "$t $p $v"}
	    5 {return "$v $p $q"}
	    default {error "i value $i is out of range"}
	}
    }
}

# The procedure below is invoked when the "Update" button is pressed,
# and whenever the color changes if update mode is enabled.  It
# propagates color information as determined by the command in the
# Command entry.

proc doUpdate {} {
    global color command
    set newCmd $command
    regsub -all %% $command $color newCmd
    eval $newCmd
}

changeColorSpace hsb

# Local Variables:
# mode: tcl
# End:

MR SKB