#VRML V2.0 utf8

#######################################################
# SnailTrail.wrl   V1.0  (24-Sep-1998)
# =====================
# Idea spark : Patrick Jermann, TECFA, University of Geneva
# Conception : David Ott, TECFA
# TecSupport : Sylvere Martin-Michiellot, TECFA
# Copyright  : David.Ott@tecfa.unige.ch
#
# Free for all non-commercial uses if you keep this notice
# intact and share with other.
#
# Description :
# SnailTrail.wrl was designed to leave a trace of the
# users exploration of the Virtual World. It
# belongs to the awareness tools family, and is
# supposed to give information enabling the user
# see which places he visited. The code is quite
# simple and has the following properties :
#  -leaves a red trace behind the user,
#  -outputs the number of points of the 
#   IndexedLineSet in the VRMLconsole
#
# Next steps :
# Find a way to reduce point number for faster
# rendering, either by taking the position each X sec.
# with a TimeSensor {interval X}, or by limiting the
# point array size (but this would clamp off earlier
# trail information), or by comparing segment (t;t-1)
# with segment (t-1;t-2) and deciding if the orientation
# of the 2 segments are almost similar (let's say less
# than X degrees difference) and if so replacing t-1
# with t.
########################################################

# ProximiySensor tracks user movements
DEF PS ProximitySensor {size 1e25 1e25 1e25}

# IndexedLineSet updated whenever user changes location
Shape {
   geometry DEF ILS IndexedLineSet {
      colorPerVertex FALSE
      color Color { color 1 0 0} # color of the trace
      coord DEF Coord Coordinate{}
   }
}

# This Shape{} is just for demo purpose. The code works without it :)
Shape { 
   appearance Appearance {
      material Material {
	 diffuseColor .5 .5 .5
      }
   }
   geometry Box {}
}

# This script adds the actualPosition to the point array
# and adds the actual point array length to the coordIndex
# array.
DEF SCR Script {
  eventIn SFVec3f newPos
  field MFVec3f theArray []
  field SFNode pointArray USE Coord
  eventOut MFInt32 coordIndex
  eventOut MFVec3f point
  url [
 	"vrmlscript:
         function newPos(actualPosition) {
         var theArray = pointArray.point;
         var theArrayLength = theArray.length;
         var i = theArrayLength;
         theArray[i] = new SFVec3f(actualPosition.x,actualPosition.y,actualPosition.z);
         point = theArray;
         coordIndex[i] = theArrayLength;
         print(i);
         }"
       ]
}

# Route ProximitySensor to Script
ROUTE PS.position_changed TO SCR.newPos

# Route Script to IndexedLineSet
ROUTE SCR.point TO Coord.point
ROUTE SCR.coordIndex TO ILS.coordIndex