#!/bin/sh
#$Id: kaleidowrl2pov,v 1.4 2002/04/06 16:38:42 rl Exp $
# Convert a VRML file generated by Kaleido to  POV-Ray scene description.
# The polyhedra are resized to have a unit circumsphere.
#
# Usage: kaleidowrl2pov <file.wrl >file.pov
#
# Note: The default 6 digit precision in Kaleido results in non-planarity
# of faces to be detected by POV-Ray, so a 16 digits precision is used here
# (and kaleido has to be run with a -d16 option).
#
# Author: Nadav Har'El <nyh@math.technion.ac.il>
# Adapted to VRML97 by Zvi Har'El <rl@math.technion.ac.il>

cat <<END_OF_PREAMBLE
#include "colors.inc"
camera {
   location  <0, 0.5,-7>
   direction <0, 0,  1>
   up        <0, 0.3,  0>
   right     <0.3, 0,  0>
   look_at   <0, 0, 0>
}
light_source {<10, 20, -30> color 1.5*White}
sky_sphere { pigment { White } }
#declare F_Face =
finish {
        reflection 0.01
        diffuse 0.4
        ambient 0.3
        phong 0.3 phong_size 5
}
END_OF_PREAMBLE

gawk '
	BEGIN { state=0
		maxrad=0 
	}
	/Color{/ {state=1; next}
	state==1 && /color\[/ {
		n=split($0,a,"[[,]")
		
		ncolors=n-2	# extra color[ and ] removed
		for(i=0;i<ncolors;i++){
			colors[i]="<" a[i+2] ">"
			gsub(" ",",",colors[i])
		}
		next
	}
	/Coordinate{/ {state=2; next}
	state==2 && /point\[/ {state=3; npoints=0; next}
	state==3 && /\]/ {state=5; next}
	state==3 && !/^[ 	]*#/ {
		x[npoints]=$1
		y[npoints]=$2
		z[npoints]=$3
		gsub(",","",z[npoints])
		rad=sqrt(x[npoints]*x[npoints]+y[npoints]*y[npoints]+z[npoints]*z[npoints])
		if(rad>maxrad)maxrad=rad
		npoints++
	}
	state==5 && /coordIndex/ {state=6; nfaces=0; next}
	state==6 && /\]/ {state=7; next}
	state==6 {
		n=split($0,a,",")
		gsub("^[ \t]*","",a[1]) # remove leading spaces
		nedges[nfaces]=0
		for(i=1;i<n;i++){	# the last is always null
			if(a[i]==(-1)){
				nfaces++
				nedges[nfaces]=0
			} else {
				polyg[nfaces,nedges[nfaces]++]=a[i]
			}
		}
			
	}

	state==7 && /colorIndex/ {
		n=split($0,a,"[[,]")
		
		nm=n-2	# extra colorIndex[ and ] removed
		for(i=0;i<nm;i++){
			colorIndex[i]=a[i+2]
		}
		next
	}
	state==7 && /}/ {state=8; next}
	
	END {
		for(i=0;i<ncolors;i++){
			print "#declare T_Face_" i " ="
			print "texture {"
                        print "pigment {rgb " colors[i] "}"
			print "finish {F_Face}"
			print "}"
		}
		for(i=0;i<nfaces;i++){
			print "polygon {"
			print nedges[i]+1 ","
			for(j=0;j<nedges[i];j++){
				printf("<%.16g,%.16g,%.16g>,\n",x[polyg[i,j]]/maxrad,y[polyg[i,j]]/maxrad,z[polyg[i,j]]/maxrad)
			}
			printf("<%.16g,%.16g,%.16g>\n",x[polyg[i,0]]/maxrad,y[polyg[i,0]]/maxrad,z[polyg[i,0]]/maxrad)
			print "texture { T_Face_" colorIndex[i]+0 "}"
			print "}"
		}
	}
'