%!PS-Adobe-3.0 EPSF-3.0
%%BoundingBox: 0 0 842 595
% % BoundingBox: 0 0 1138 800 %without scaling

% 595 0 translate 90 rotate %for a landscape printing

% Scattering of light in the air, written by Jenik Hollan 
% This code and the bitmaps made from it are subject to the GPL

% The numbers and indicatrix coefficients hold for the ``CIE sky No.5''

% By a unix command 
%  sed "s/^%CZ/CZ/ ; s/^IT/%IT/" scatt_en.eps >scatt_cz.eps
% a Czech version can be produced. It's easy to write another
% language versions this way -- just add another string lines
% beginning with %xx instead of %CZ,

% Czech strings are iso-8859-2 coded
% Italian strings are iso-8859-1 
% -- sorry for using two encodings within one file...


0.74 dup scale

/CZ {} def
/EN {} def
/IT {} def

%CZ /basefont {/Arial-Medium 18 selectfont} def
%EN /basefont {/Helvetica 16 selectfont} def
IT /basefont {/Arial 16 selectfont} def
basefont

%CZ /basebold {/Arial-Bold 18 selectfont} def
%EN /basebold {/Helvetica-Bold 16 selectfont} def
IT /basebold {/Arial-Bold 16 selectfont} def

%CZ /largefont {/Arial-Medium 23 selectfont} def
%EN /largefont {/Helvetica 20 selectfont} def
IT /largefont {/Arial 20 selectfont} def

%CZ /headingfont {/Arial-Medium 36 selectfont} def
%EN /headingfont {/Helvetica 32 selectfont} def
IT /headingfont {/Arial 32 selectfont} def

%CZ /footerfont {/Arial-Medium 29 selectfont} def
%EN /footerfont {/Helvetica 26 selectfont} def
IT /footerfont {/Arial 26 selectfont} def

%CZ /indfont {/Arial-Medium 14 selectfont} def
%EN /indfont {/Helvetica 12 selectfont} def
IT /indfont {/Arial 12 selectfont} def


/itemmw {20 0 rmoveto} def
/itemm 
%CZ {gsave /Symbol 18 selectfont /bullet glyphshow grestore itemmw  basefont} 
%EN {gsave basefont (@) show grestore itemmw  basefont} 
IT {gsave basefont (@) show grestore itemmw  basefont} 
 def


0 setlinecap

% for sky4:
/c 10 def
/d -3 def
/e 0.45 def

% for sky5:
/c 16 def
/d -3 def
/e 0.30 def

/scatcolor {0.5 0.55 0.65 setrgbcolor} def
/dircolor {0.8 0.7 0.6 setrgbcolor} def

/pi 3.141593 def

/natl 2.71828 def

/airt 40 def  % thickness of the atmosphere
/blw  20 def  % initial light arrow width
/trn  0.7 def % transmitted through 1 AM
/rz 12000 def
/an 20 def % angle between the rays 
/txt -270 def
/indx 520 def
/indy 10 def
/indt 45 def
/indtx 65 def
/incy 40 def

/f 
 {t cos dup mul e mul  
   natl d t mul pi mul 180 div exp 
   natl d pi mul 2 div exp 
   sub 
   c mul 
  add 
  1 add} def


/atm { %the a bit curved atmosphere
 gsave 
  0.9 setgray
  airt 1.4 mul setlinewidth
  0 airt 2 div airt 0.1 mul sub translate 
  0 rz neg
  %500 0 rlineto 
%  5 0 500 -100 5000 arcto 
  rz 87.8 90.12 arc 
   stroke
  0.6 setgray %2 setlinewidth 
  airt 0.4 mul setlinewidth 
  0 rz neg
%  rz airt 1.4 mul 2 div sub 87.8 90.08 arc
  rz airt 2 div sub 87.8 90.12 arc
   stroke
 grestore } def

/arrclip {
  currentpoint
  currentlinewidth 2 div 
  dup dup dup dup dup dup dup dup 
        0 rmoveto 
  neg exch neg rlineto 
  arrl 0 rlineto 
          rlineto 
  neg exch rlineto
  arrl neg 0 rlineto 
      neg rlineto clip
  %neg 0 
  newpath
  moveto
 } def

% the direct light:
/dirl {
 gsave 
 dircolor
% 0.7 setgray 
 blw setlinewidth 
% 0 blw 2 div r moveto 
 
% gsave 
%  arrclip
%  %1 setlinecap 
%  %airt 4 div 0 rlineto stroke 
% grestore 
 am 
  {
  currentpoint
  gsave 
   /arrl airt def 
   arrclip
   airt 0 rlineto stroke
  grestore
  moveto airt 0 rmoveto
  currentlinewidth dup trn mul setlinewidth
 %  aligning the right (bottom) side of the narrowing line:  
%  pop 1 trn sub mul 2 div 0 exch neg rmoveto 
  gsave 1 setlinecap
   currentlinewidth /clw exch def
   1 trn sub mul 2 div setlinewidth
   /clw currentlinewidth clw add def
   scatcolor
   gsave
    0 clw 2 div rmoveto airt 3 div dup 3 div rlineto stroke     
   grestore
   gsave
    0 clw 2 div neg rmoveto airt 3 div dup 3 div neg rlineto stroke     
   grestore
  grestore  
 } 
 repeat
% 0.2 setgray
 % the final part of light escaping to the Universe:
% airt 0 rlineto currentpoint currentpoint stroke

 /arrl airt 2.3333 mul currentlinewidth 2 div sub def
 [airt 0.6667 mul 2 div airt 0.3333 mul 2 div] 0 setdash 
 arrclip 
 airt 3 mul 0 rlineto stroke

% the arrow:
% 2 setlinecap 
% 0.8 setgray
% moveto -10 10 rlineto stroke 
% moveto -10 -10 rlineto stroke 


 grestore
 } def



% the indicatrix:
/ang 1.5 def

/inarr {
% 0 lineto stroke
 gsave
  /fsmul f s mul def
  /fsmulY fsmul 57.2 ang div div def
  0 0 moveto ang rotate fsmul 0 lineto 
  45 ang add rotate fsmulY 1.414 mul dup 0 rlineto 
  90 rotate 0 rlineto 45 ang add rotate fsmul 0 rlineto fill
 grestore 
 } def
/in { gsave 
 scatcolor 
 currentlinewidth 2 div 0.75 dup scale
 /t 10 def 

 gsave
 t rotate
 180 an div cvi {inarr /t t an add def an rotate} repeat
 grestore

 /t 10 def

 gsave
 t neg rotate
 180 an div cvi {inarr %4 0 moveto f s mul 0 lineto stroke 
  /t t an add def an neg rotate} repeat
 grestore
 grestore
 } def

% f(t)=1+c@(exp(d@t@pi/180)-exp(d@pi/2)) + e@cos(t)@@2

/city {gsave 1 setgray basefont
  0 -2 moveto 
%CZ  (město) 
%EN  (city)
IT  (citta')
  dup stringwidth pop 2 div neg airt 0.2 mul neg rmoveto show
 grestore } def

0 25 translate

%50 100 translate

gsave
 318 130 translate

% @ 5 degrees angular height:
/s 32 def       
% (s is the scattered part / 3, i.e. 96 / 3 for 5 deg ang. height)
 gsave 
  indx indy translate
  5 rotate in 
 grestore
 gsave  
  atm
  0 airt 0.05 mul moveto 
  5 rotate /am 10 def dirl 
 grestore
 basefont
 city
 gsave
  0 incy translate
  0 -10 translate
  txt 40 moveto 
  itemm 
%CZ  (  5 stupňů nahoru:) 
%EN  (  5 degrees upwards:) 
IT  (  5 gradi verso l'alto:) 
   show
  txt 20 moveto 
  itemmw 
%CZ (97 \% se rozptýlí,) 
%EN  (97 \% scatters,) 
IT  (il 97 \% č diffusa,) 
   show
  txt  0 moveto 
  itemmw 
%CZ (z toho 45 \% dolů,) 
%EN  (from 45 \% downwards,)        
IT  (di cui il 45 \% verso il basso,)        
   show
  txt -20 moveto 
  itemmw 
%CZ (celkem se tedy vrátí dolů) 
%EN  (altogether it returns down) 
IT  (perciň torna verso il basso) 
   show
  txt -40 moveto 
  itemmw basebold (45 \% ) show basefont 
%CZ (takového světla.) 
%EN  (of such light.) 
IT  (del totale verso l'alto.) 
   show
 grestore


% @ 15 degrees angular height:
 0 190 translate
 gsave
  indx indy translate 15 rotate
  /s 25 def
  in
 grestore
 gsave atm 
  0 airt 0.05 mul moveto 
  15 rotate /am 4 def dirl 
 grestore
 city
 gsave
  0 incy translate
  0 -10 translate
  txt 40 moveto 
  itemm  
%CZ (15 stupňů nahoru:) 
%EN (15 degrees upwards:)  
IT (15 gradi verso l'alto:)  
   show
  txt 20 moveto 
  itemmw 
%CZ (76 \% se rozptýlí,)
%EN (76 \% scatters,) 
IT (76 \% č diffusa,) 
   show
  txt  0 moveto 
  itemmw 
%CZ (z toho 40 \% dolů,)
%EN (from 40 \% downwards,) 
IT (di cui il 40 \% verso il basso,) 
   show
  txt -20 moveto 
  itemmw 
%CZ (celkem se tedy vrátí dolů)
%EN (altogether it returns down) 
IT (perciň torna verso il basso) 
   show
  txt -40 moveto 
  itemmw basebold (31 \% ) show basefont 
%CZ (takového světla,)
%EN (of such light,)
IT (del totale verso l'alto,)
   show 
 grestore
 gsave 
  455 75 moveto basefont
%CZ (jen 0,7 = 0,24 světla unikne nerozptýleno) 
%EN (just 0.7 = 0.24 of the light escapes unscattered)  
IT (appena 0.7 = 0.24 della luce sfugge nello spazio senza essere diffusa)  
  stringwidth pop neg 0 rmoveto    
%CZ (jen 0,7)
%EN (just 0.7)
IT (appena 0.7)
   show 
  0 10 rmoveto indfont (4) show 0 -10 rmoveto
  basefont
%CZ (= 0,24 světla unikne nerozptýleno) 
%EN (= 0.24 of the light escapes unscattered)   
IT (= 0.24 della luce sfugge senza essere diffusa)   
  show
 grestore


% @ 90 degrees angular height:
 0 190 translate
 gsave
  indx indy translate 90 rotate
  /s 10 def
  in
 grestore
 gsave 
  atm 
  0 airt 0.1 mul moveto 
  90 rotate /am 1 def dirl 
 grestore
 city

 gsave 
  0 incy translate
  largefont
  txt 115 moveto 
%CZ (Když jde světlo z lamp) 
%EN (When the light from lamps)
IT (Quando la luce emessa dagli apparecchi)
   show
  txt  90 moveto 
%CZ (či osvětlených ploch)
%EN (or illuminated surfaces)
IT (o dalle superfici illuminate)
   show
  txt  65 moveto 
%CZ (směrem:)
%EN (goes:)
IT (č inviata:)
   show
  0 -10 translate
  txt 40 moveto 
  itemm 
%CZ (90 stupňů vzhůru:) 
%EN (90 degrees upwards:)   
IT (90 gradi verso l'alto:)   
   show
  txt 20 moveto 
  itemmw 
%CZ (30 \% se rozptýlí,)
%EN (30 \% scatters,) 
IT (30 \% č diffusa,) 
   show
  txt  0 moveto 
  itemmw 
%CZ (z toho 28 \% dolů,) 
%EN (from 28 \% downwards,) 
IT (di cui il 28 \% verso il basso,) 
   show
  txt -20 moveto 
  itemmw 
%CZ (celkem se tedy vrátí dolů jen) 
%EN (altogether it returns down just) 
IT (perciň torna verso il basso solo l') 
   show
  txt -40 moveto 
  itemmw basebold (  8 \% ) show basefont 
%CZ  (takového světla,) 
%EN  (of such light,) 
IT  (del totale verso l'alto,) 
  show
 grestore

 gsave 
  455 %airt 9 div neg 
      -3 moveto 
  %1.1 neg rotate
  1.7 neg rotate
  basefont
  gsave 0 23 rmoveto  
%CZ (zakřivená zemská  a t m o s f é r a :) 
%EN (the curved Earth  a t m o s p h e r e :) 
IT (l'A T M O S F E R A della Terra curva:) 
   dup stringwidth pop neg 0 rmoveto show 
  grestore
  gsave 0  3 rmoveto 
%CZ (každá její tloušťka rozptýlí asi 30 \% světla) 
%EN  (each its thickness scatters some 30 \% of the light) 
IT  (ogni spessore diffonde circa il 30 \% della luce) 
   dup stringwidth pop neg 0 rmoveto show 
  grestore
 grestore

 gsave 
  largefont
  0 -10 translate
  gsave 
   scatcolor 
   indx indt add 115 moveto 
%CZ (Souhrn světla) 
%EN (Sum of the light) 
IT (Il totale della luce) 
   show 
   indx indt add  90 moveto 
%CZ (rozptýleného ovzduším) 
%EN (scattered by the air)
IT (diffusa dall'aria)
   show
  grestore 
  indx indt add  65 moveto 
%CZ (a jeho skutečné směry) 
%EN (and its true directions)
IT (e le sue direzioni)
  show
  indx indt add  40 moveto (-) show -3 0 rmoveto 
%CZ (- většinou podobné) 
%EN (- mostly similar)
IT (- simili)
  show
  indx indt add  15 moveto 
%CZ (směru původnímu) 
%EN (to the original direction)
IT (alla direzione originale)
  show
  gsave 
   blw 5 add 115 moveto dircolor 
%CZ  (Vzhůru vyslané světlo zeslabené rozptylem) 
%EN  (The light sent upward attenuated by scattering) 
IT  (La luce inviata verso l'alto attenuata dalla diffusione) 
   show 
   blw 5 add 90 moveto 
%CZ   (na plynu a aerosolech, než unikne do vesmíru,) 
%EN   (on gas and aerosols, before it escapes to space,)
IT   (per i gas e aerosol, prima di sfuggire nello spazio,)
   show 
   blw 5 add 65 moveto scatcolor 
%CZ   (a jeho rozptýlené části \(schematicky\)) 
%EN   (and its scattered parts \(schematically\))
IT   (e le sue parti diffuse \(schematicamente\))
   show
  grestore

 grestore

grestore

%0 200 translate

1138 2 div 720 moveto
headingfont
%CZ  (Proč je noční nebe nad městem i daleko od něj stále světlé?) 
%EN  (Why the sky over your town and even far from it glows so much?)
IT  (Perché il cielo della tua cittŕ e anche lontano da essa č cosě luminoso?)
dup
stringwidth pop 2 div neg 0 rmoveto show

1138 2 div 22 moveto
footerfont
%CZ  (Který z uvedených případů k tomu podle vás přispívá nejvíce?) 
%EN  (Which of the cases given above contributes most to the skyglow, in your opinion?)
IT  (Quali dei casi mostrati contribuisce maggiormente all'inquinamento luminoso, secondo te?)
dup
stringwidth pop 2 div neg 0 rmoveto show

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