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# This example shows how to use the InteractorStyleImage and add your own
# event handling. The InteractorStyleImage is a special interactor designed
# to be used with vtkImageActor in a rendering window context. It forces the
# camera to stay perpendicular to the x-y plane.
package require vtk
package require vtkinteraction
# Create the image
#
vtkPNGReader reader
reader SetDataSpacing 0.8 0.8 1.5
reader SetFileName "$VTK_DATA_ROOT/Data/fullhead15.png"
vtkImageShiftScale shiftScale
shiftScale SetInputConnection [reader GetOutputPort]
shiftScale SetShift 0
shiftScale SetScale 0.07
shiftScale SetOutputScalarTypeToUnsignedChar
vtkImageActor ia
[ia GetMapper] SetInputConnection [shiftScale GetOutputPort]
# Create the RenderWindow, Renderer and both Actors
vtkRenderer ren1
vtkRenderWindow renWin
renWin AddRenderer ren1
vtkRenderWindowInteractor iren
iren SetRenderWindow renWin
# Create an image interactor style and associate it with the
# interactive renderer. Then assign some callbacks with the
# appropriate events. THe callbacks are implemented as Tcl procs.
vtkInteractorStyleImage interactor
iren SetInteractorStyle interactor
interactor AddObserver LeftButtonPressEvent {StartZoom}
interactor AddObserver MouseMoveEvent {MouseMove}
interactor AddObserver LeftButtonReleaseEvent {EndZoom}
# Add the actors to the renderer, set the background and size
ren1 AddActor ia
ren1 SetBackground 0.1 0.2 0.4
renWin SetSize 400 400
# render the image
iren AddObserver UserEvent {wm deiconify .vtkInteract}
renWin Render
set cam1 [ren1 GetActiveCamera]
ren1 ResetCameraClippingRange
renWin Render
# prevent the tk window from showing up then start the event loop
wm withdraw .
### Supporting data for callbacks
vtkPoints pts
pts SetNumberOfPoints 4
vtkCellArray lines
lines InsertNextCell 5
lines InsertCellPoint 0
lines InsertCellPoint 1
lines InsertCellPoint 2
lines InsertCellPoint 3
lines InsertCellPoint 0
vtkPolyData pd
pd SetPoints pts
pd SetLines lines
vtkPolyDataMapper2D bboxMapper
bboxMapper SetInputData pd
vtkActor2D bboxActor
bboxActor SetMapper bboxMapper
[bboxActor GetProperty] SetColor 1 0 0
ren1 AddViewProp bboxActor
### Procedures for callbacks---------------------
set X 0
set Y 0
set bboxEnabled 0
proc StartZoom {} {
global X Y bboxEnabled
set xy [iren GetEventPosition]
set X [lindex $xy 0]
set Y [lindex $xy 1]
pts SetPoint 0 $X $Y 0
pts SetPoint 1 $X $Y 0
pts SetPoint 2 $X $Y 0
pts SetPoint 3 $X $Y 0
set bboxEnabled 1
bboxActor VisibilityOn
}
proc MouseMove {} {
global X Y bboxEnabled
if { $bboxEnabled } {
set xy [iren GetEventPosition]
set x [lindex $xy 0]
set y [lindex $xy 1]
pts SetPoint 1 $x $Y 0
pts SetPoint 2 $x $y 0
pts SetPoint 3 $X $y 0
renWin Render
}
}
#Do the hard stuff: pan and dolly
proc EndZoom {} {
global bboxEnabled
set p1 [pts GetPoint 0]
set p2 [pts GetPoint 2]
set x1 [lindex $p1 0]
set y1 [lindex $p1 1]
set x2 [lindex $p2 0]
set y2 [lindex $p2 1]
ren1 SetDisplayPoint $x1 $y1 0
ren1 DisplayToWorld
set p1 [ren1 GetWorldPoint]
ren1 SetDisplayPoint $x2 $y2 0
ren1 DisplayToWorld
set p2 [ren1 GetWorldPoint]
set p1X [lindex $p1 0]
set p1Y [lindex $p1 1]
set p1Z [lindex $p1 2]
set p2X [lindex $p2 0]
set p2Y [lindex $p2 1]
set p2Z [lindex $p2 2]
set camera [ren1 GetActiveCamera]
set focalPt [$camera GetFocalPoint]
set focalX [lindex $focalPt 0]
set focalY [lindex $focalPt 1]
set focalZ [lindex $focalPt 2]
set position [$camera GetPosition]
set positionX [lindex $position 0]
set positionY [lindex $position 1]
set positionZ [lindex $position 2]
set deltaX [expr $focalX - ($p1X + $p2X)/2.0]
set deltaY [expr $focalY - ($p1Y + $p2Y)/2.0]
#Set camera focal point to the center of the box
$camera SetFocalPoint [expr ($p1X + $p2X)/2.0] \
[expr ($p1Y + $p2Y)/2.0] $focalZ
$camera SetPosition [expr $positionX - $deltaX] \
[expr $positionY - $deltaY] $positionZ
#Now dolly the camera to fill the box
#This is a half-assed hack for demonstration purposes
if { $p1X > $p2X } {
set deltaX [expr $p1X - $p2X]
} else {
set deltaX [expr $p2X - $p1X]
}
if { $p1Y > $p2Y } {
set deltaY [expr $p1Y - $p2Y]
} else {
set deltaY [expr $p2Y - $p1Y]
}
set winSize [renWin GetSize]
set winX [lindex $winSize 0]
set winY [lindex $winSize 1]
set sx [expr $deltaX / $winX]
set sy [expr $deltaY / $winY]
if { $sx > $sy } {
set dolly [expr 1.0 + 1.0/(2.0*$sx)]
} else {
set dolly [expr 1.0 + 1.0/(2.0*$sy)]
}
$camera Dolly $dolly
ren1 ResetCameraClippingRange
set bboxEnabled 0
bboxActor VisibilityOff
renWin Render
}
iren Start
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