path: root/demos/curveBezier.tcl

# these simple samples have been developped by C. Mertz mertz@cena.fr in perl
# tcl version by Jean-Paul Imbert imbert@cena.fr

if {![info exists zincDemo]} {
    error "This script should be run from the zinc-widget demo."
}


set w .curveBezier
catch {destroy $w}
toplevel $w
wm title $w "Zinc Curve Bezier Demonstration"
wm iconname $w Curve

set defaultfont [font create -family Helvetica -size 10 -weight bold]

frame $w.buttons
pack $w.buttons -side bottom -fill x -pady 2m
button $w.buttons.dismiss -text Dismiss -command "destroy $w"
button $w.buttons.code -text "See Code" -command "showCode $w"
pack $w.buttons.dismiss $w.buttons.code -side left -expand 1


text $w.text -relief sunken -borderwidth 2 -setgrid true -height 3
pack $w.text -expand yes -fill both

$w.text insert 0.0 {
6 examples of curves containing control points are displayed 
 with the list of control points written just below.
You can move the handles to modify the bezier curves
}

zinc $w.zinc -width 700 -height 650 -font 9x15 -borderwidth 0 -backcolor white
pack $w.zinc


set group [$w.zinc add group 1]

$w.zinc add text $group -position {50 20} -anchor w \
    -text {Examples of curve items using cubic bezier control points} \
    -color grey20

## Please note: much of the following items below could be computed
$w.zinc add text $group -position {25 270} -anchor w -tags bezier1 \
    -color grey20 -width 270
$w.zinc add curve $group {100 200 100 100} -tags {line1 l1-2} \
    -linecolor \#888888 -filled 0 -linewidth 2
$w.zinc add curve $group {400 100 400 200} -tags {line1 l3-4} \
    -linecolor \#888888 -filled 0 -linewidth 2
$w.zinc add curve $group {{100 200} {100 100 c} {400 100 c} {400 200}} \
    -tags bezier1 -closed 0 -linecolor red -linewidth 5
$w.zinc add arc $group {90 190 110 210} -tags {handle1 p1} -filled 1 \
    -fillcolor \#BBBBBB
$w.zinc add arc $group {90 90 110 110} -tags {handle1 p2} -filled 1 \
    -linewidth 0 -fillcolor grey80 -filled 1
$w.zinc add arc $group {390 90 410 110} -tags {handle1 p3} -filled 1 \
    -linewidth 0 -fillcolor grey80 -filled 1
$w.zinc add arc $group {390 190 410 210} -tags {handle1 p4} -filled 1 \
    -fillcolor \#BBBBBB

$w.zinc add text $group -position {570 270} -anchor w -tags bezier2 \
    -color grey20 -width 270
$w.zinc add curve $group {600 200 675 100} -tags {line2 l1-2} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {975 100 900 200} -tags {line2 l3-4} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {{600 200} {675 100 c} {975 100 c} {900 200}} \
    -tags bezier2 -closed 0 -linecolor red -linewidth 5
$w.zinc add arc $group {590 190 610 210} -tags {handle2 p1} -filled 1 \
    -linecolor grey80 -linewidth 2
$w.zinc add arc $group {665 90 685 110} -tags {handle2 p2} -filled 1 \
    -linewidth 0 -fillcolor grey80
$w.zinc add arc $group {965 90 985 110} -tags {handle2 p3} -filled 1 \
    -linewidth 0 -fillcolor grey80
$w.zinc add arc $group {890 190 910 210} -tags {handle2 p4} -filled 1 \
    -linecolor grey80 -linewidth 2

$w.zinc add text $group -position {25 570} -anchor w -tags bezier3 \
    -color grey20 -width 270
$w.zinc add curve $group {100 500 25 400} -tags {line3 l1-2} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {475 400 400 500} -tags {line3 l3-4} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {{100 500} {25 400 c} {475 400 c} {400 500}} \
    -tags {bezier3} -closed 0 -linecolor red -linewidth 5
$w.zinc add arc $group {90 490 110 510} -tags {handle3 p1} -filled 1 \
    -linecolor grey80 -linewidth 2
$w.zinc add arc $group {15 390 35 410} -tags {handle3 p2} -filled 1 \
    -linewidth 0 -fillcolor grey80 
$w.zinc add arc $group {465 390 485 410} -tags {handle3 p3} -filled 1 \
    -linewidth 0 -fillcolor grey80 
$w.zinc add arc $group {390 490 410 510} -tags {handle3 p4} -filled 1 \
    -linecolor grey80 -linewidth 2

$w.zinc add text $group -position {570 570} -anchor w -tags bezier4 \
    -color grey20 -width 270
$w.zinc add curve $group {600 500 600 350} -tags {line4 l1-2} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {900 650 900 500} -tags {line4 l3-4} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {{600 500} {600 350 c} {900 650 c} {900 500}} \
    -tags {bezier4} -closed 0 -linecolor red -linewidth 5
$w.zinc add arc $group {590 490 610 510} -tags {handle4 p1} -filled 1 \
    -linecolor grey80 -linewidth 2
$w.zinc add arc $group {590 340 610 360} -tags {handle4 p2} -filled 1 \
    -linewidth 0 -fillcolor grey80
$w.zinc add arc $group {890 640 910 660} -tags {handle4 p3} -filled 1 \
    -linewidth 0 -fillcolor grey80
$w.zinc add arc $group {890 490 910 510} -tags {handle4 p4} -filled 1 \
    -linecolor grey80 -linewidth 2

$w.zinc add text $group -position {25 870} -anchor w -tags bezier5 \
    -color grey20 -width 270
$w.zinc add curve $group {100 800 175 700} -tags {line5 l1-2} \
    -linecolor \#888888 -filled 0 -linewidth 2
$w.zinc add curve $group {325 700 400 800} -tags {line5 l3-4} \
    -linecolor \#888888 -filled 0 -linewidth 2
$w.zinc add curve $group {{100 800} {175 700 c} {325 700 c} {400 800}} \
    -tags {bezier5} -closed 0 -linecolor red -linewidth 5
$w.zinc add arc $group {90 790 110 810} -tags {handle5 p1} -filled 1 \
    -linecolor grey80 -linewidth 2
$w.zinc add arc $group {165 690 185 710} -tags {handle5 p2} -filled 1 \
    -linewidth 0 -fillcolor grey80 -filled 1
$w.zinc add arc $group {315 690 335 710} -tags {handle5 p3} -filled 1 \
    -linewidth 0 -fillcolor grey80 -filled 1
$w.zinc add arc $group {390 790 410 810} -tags {handle5 p4} -filled 1 \
    -linecolor grey80 -linewidth 2

$w.zinc add text $group -position {570 970} -anchor w -tags bezier6 \
    -color grey20 -width 280
$w.zinc add curve $group {600 800 625 700} -tags {line6 l1-2} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {725 700 750 800} -tags {line6 l3-4} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {750 800 775 900} -tags {line6 l4-5} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {875 900 900 800} -tags {line6 l6-7} \
    -linecolor \#888888 -linewidth 2
$w.zinc add curve $group {
    {600 800} {625 700 c} {725 700 c} {750 800}
    {775 900 c} {875 900 c} {900 800}
} -tags {bezier6} -filled 0 -closed 0 -linecolor red -linewidth 5
$w.zinc add arc $group {590 790 610 810} -tags {handle6 p1} -filled 1 \
    -linecolor grey80 -linewidth 2
$w.zinc add arc $group {615 690 635 710} -tags {handle6 p2} -filled 1 \
    -linewidth 0 -fillcolor grey80
$w.zinc add arc $group {715 690 735 710} -tags {handle6 p3} -filled 1 \
    -linewidth 0 -fillcolor grey80
$w.zinc add arc $group {740 790 760 810} -tags {handle6 p4} -filled 1 \
    -linecolor blue -fillcolor blue -linewidth 2
$w.zinc add arc $group {766 891 784 909} -tags {handle6 p5} -filled 1 \
    -linecolor grey80 -linewidth 4
$w.zinc add arc $group {865 890 885 910} -tags {handle6 p6} -filled 1 \
    -linewidth 0 -fillcolor grey80
$w.zinc add arc $group {890 790 910 810} -tags {handle6 p7} -filled 1 \
    -linecolor grey80 -linewidth 2


$w.zinc scale $group 0.6 0.6

## Set the text of the text item with a tag "tag"
## to a human-readable form of the coords of the
## corresponding curve with the same tag "tag"
proc setText {tag} {
    global w
    set textItem  [$w.zinc find withtype text $tag]
    set curveItem [$w.zinc find withtype curve $tag]
    set coords [$w.zinc coords $curveItem]
    set count 0
    $w.zinc itemconfigure $textItem -text $coords
}

foreach bezierCount {1 2 3 4 5 6} {
    setText "bezier$bezierCount"
    set curveItem [$w.zinc find withtype curve "bezier$bezierCount"]
    set coords [$w.zinc coords $curveItem]
    #puts "$bezierCount : $curveItem : $coords"
    $w.zinc bind "handle$bezierCount" <1> {itemStartDrag %x %y}
    $w.zinc bind "handle$bezierCount" <B1-Motion> {itemDrag %x %y}
    #$w.zinc bind "handle$bezierCount" "<ButtonPress-1>" {\&press \&motion}
    #$w.zinc bind "handle$bezierCount" "<ButtonRelease-1>" {\&release}
}




##### bindings for moving the handles
set item ""
set bezierNum "" 
set ptNum ""

set x_orig ""
set y_orig ""

proc itemStartDrag {x y} {
    global w
    global x_orig y_orig
    global bezierNum ptNum
    global item
    set x_orig $x
    set y_orig $y
    set item [$w.zinc find withtag current]
    
    foreach val [$w.zinc gettags $item] {
	regexp {([a-z]+)(\d)} $val "" name num
	if {$name=="handle"} {set bezierNum $num}
	if {$name=="p"} {set ptNum $num}
    }
    #puts "bezierNum=$bezierNum ptNum=$ptNum"
}

# Callback for moving an item
proc itemDrag {x y} {
    global x_orig y_orig
    global w
    global item
    $w.zinc transform $item "[expr $x-$x_orig] [expr $y-$y_orig]"
    moveHandle [expr $x-$x_orig] [expr $y-$y_orig]
    set x_orig $x;
    set y_orig $y;
}


proc moveHandle {dx dy} {
    global w
    global bezierNum
    global ptNum
    global item
    set pt1 [lindex [$w.zinc coords $item] 0]
    set pt2 [lindex [$w.zinc coords $item] 1]
    
    ## modifying the handle coords
    $w.zinc coords $item "[expr [lindex $pt1 0]+$dx] [expr [lindex $pt1 1]+$dy] [expr [lindex $pt2 0]+$dx] [expr [lindex $pt2 1]+$dy]"
    set prevPtNum [expr $ptNum-1]
    
    # there should only be one such item!
    set lineA [$w.zinc find withtag "line$bezierNum && l$prevPtNum-$ptNum"]
    if {$lineA!=""} {
	set x [lindex [$w.zinc coords $lineA 0 1] 0]
	set y [lindex [$w.zinc coords $lineA 0 1] 1]
	$w.zinc coords $lineA 0 1 "[expr $x+$dx] [expr $y+$dy]"
    }
    
    set nextPtNum [expr $ptNum+1]
    # there should only be one such item:
    set lineB [$w.zinc find withtag "line$bezierNum && l$ptNum-$nextPtNum"]
    if {$lineB!=""} {
	set x [lindex [$w.zinc coords $lineB 0 0] 0]
	set y [lindex [$w.zinc coords $lineB 0 0] 1]
	$w.zinc coords $lineB 0 0 "[expr $x+$dx] [expr $y+$dy]"
    }
    set tab [$w.zinc coords "bezier$bezierNum" 0 [expr $ptNum-1]]
    set x [lindex $tab 0]
    set y [lindex $tab 1]
    set control [lindex $tab 2]
    $w.zinc coords "bezier$bezierNum" 0 [expr $ptNum-1] "[expr $x+$dx] [expr $y+$dy] $control"
    setText "bezier$bezierNum"  
}