imageScaleReference.FCMacro

# Copyright 2016, Jon Nordby <jononor@gmail.com>. Licensed LGPLv2+ & MIT
#
# scaleReference:
# Given a selection of an ImagePlane and a MeasureDistance,
# rescales the ImagePlane to make the distance between two points of the MeasureDistance
# match a given real-life distance.
# The MeasureDistance is then deleted.

import FreeCADGui
script = "scaleReference"

def show(title=None, text=None):
    title = script if title is None else title
    text = title if text is None else text
    from PySide import QtGui
    QtGui.QMessageBox.information(None, title, text)

def getInput(title=None, text=None, default=0.0):
    title = script if title is None else title
    text = title if text is None else text
    from PySide import QtGui
    val = QtGui.QInputDialog.getDouble(None, title, text, default)
    return val

def isImagePlane(obj):
    return obj.TypeId == 'Image::ImagePlane'
def isMeasurement(obj):
    return obj.TypeId == 'App::MeasureDistance'

def scaleReference(image, measurement, current, actual):

    # Calculate image scaling and apply
    scale = actual/current
    image.XSize = image.XSize*scale
    image.YSize = image.YSize*scale

    # TODO: Update measurement to match instead of deleting
    measurement.Document.removeObject(measurement.Name)
    #measurement.P1 = (measurement.P1-image.Placement.Base).scale(scale, scale, 1)
    #measurement.P2 = (measurement.P2-image.Placement.Base).scale(scale, scale, 1)
    #measurement.Label = "Distance: %.3d" % (measurement.Distance,)

def scaleReferenceFromSelection():
    # Extract objects from in selection
    selection = FreeCADGui.Selection.getSelection()
    if len(selection) != 2:
        show(text= script + ": %d objects were selected. Need to select 2: one ImagePlane and one Distance." % (len(selection),))
        return
    
    image, measurement = None, None
    if isImagePlane(selection[0]):
        image, measurement = selection
    else:
        measurement, image = selection

    if not isMeasurement(measurement) or not isImagePlane(image):
        err = script+": Selected objects have wrong type. Got [%s, %s] - expected [Image::ImagePlane, App::MeasureDistance]" \
            % (measurement.TypeId, image.TypeId)
        show(text=err)

    current = measurement.P1.distanceToPoint(measurement.P2)
    actual, ok = getInput(title="Actual length", default=current)
    if not ok:
        # User aborted
        return

    return scaleReference(image, measurement, current, actual)

scaleReferenceFromSelection()