[Question]
  [
Write a program that takes in a rectangular block of text made up of `X`'s and `.`'s, such as this rough `A`:
```
......
..XX..
.X..X.
.XXXX.
.X..X.
.X..X.
```
Output a representation of this grid rotated 45 degrees counterclockwise by drawing a slash — forward or backward depending on context — everywhere an `X` borders a `.` or the side of the grid (with spaces filling in the rest):
```
 /\/\
/ /\ \
\/ /  \
/\/ /\ \
\  /  \/
 \ \
  \ \
   \/
```
The number of trailing and leading spaces (and newlines) doesn't matter as long as the shape of the `X`'s in the input is maintained by the slashes. It's ok to trim extra rows or columns of `.`'s.
For I/O you may use any combination of stdin/stdout/files/command line parameters. For example your script might take in a file name of the `X.` pattern and rewrite the file with the slash pattern. Or your script might take in the `X.` pattern from stdin line by line (pressing `d` when done) and output the result to stdout.
The input may be arbitrarily large, but you may assume it is always well formatted.
No characters besides `/ \` and newlines should be in any output.
# Scoring
The shortest code in bytes wins. Use <https://mothereff.in/byte-counter> as a byte counter if you use non-ASCII characters.
**Bonus:** Minus 50 bytes if you can change (replace, not remove) one character in your program so it outputs the slash grid rotated 45 degrees *clockwise*, e.g.:
```
   /\/\
  / /\ \
 /  \ \/
/ /\ \/\
\/  \  /
    / /
   / /
   \/
```
# Input Samples
```
XXXXXXXXX
X.......X
X.XXXXX.X
X.X...X.X
X.X.X.X.X
X.X...X.X
X.XXXXX.X
X.......X
XXXXXXXXX
XXX...XXX....XXX...XXX
X..X..X..X..X.....X...
XXX...XXX...X.....X.XX
X.....X.....X.....X..X
X.....X......XXX...XXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX...X
X...X...............X...............X...........X...................X...X
X...X...XXXXXXXXX...X...XXXXX...XXXXXXXXX...XXXXX...XXXXX...XXXXX...X...X
X...............X.......X...X...........X...........X...X...X.......X...X
XXXXXXXXX...X...XXXXXXXXX...XXXXXXXXX...XXXXX...X...X...X...XXXXXXXXX...X
X.......X...X...............X...........X...X...X...X...X...........X...X
X...X...XXXXXXXXXXXXX...X...X...XXXXXXXXX...XXXXX...X...XXXXXXXXX...X...X
X...X...............X...X...X.......X...........X...........X.......X...X
X...XXXXXXXXXXXXX...XXXXX...XXXXX...X...XXXXX...XXXXXXXXX...X...XXXXX...X
X...........X.......X...X.......X...X.......X...........X...X...........X
X...XXXXX...XXXXX...X...XXXXX...X...XXXXXXXXX...X...X...X...XXXXXXXXXXXXX
X.......X.......X...X...X.......X.......X.......X...X...X.......X.......X
XXXXXXXXXXXXX...X...X...X...XXXXXXXXX...X...XXXXX...X...XXXXX...XXXXX...X
X...........X...X...........X.......X...X.......X...X.......X...........X
X...XXXXX...X...XXXXXXXXX...XXXXX...X...XXXXX...XXXXX...XXXXXXXXXXXXX...X
X...X.......X...........X...........X.......X...X...X...............X...X
X...X...XXXXXXXXX...X...XXXXX...XXXXXXXXX...X...X...XXXXXXXXXXXXX...X...X
X...X...........X...X...X...X...X...........X...............X...X.......X
X...XXXXXXXXX...X...X...X...XXXXX...XXXXXXXXX...XXXXXXXXX...X...XXXXXXXXX
X...X.......X...X...X...........X...........X...X.......X...............X
X...X...XXXXX...XXXXX...XXXXX...XXXXXXXXX...XXXXX...X...XXXXXXXXX...X...X
X...X...................X...........X...............X...............X...X
X...XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
```
([maze source](http://ascii.co.uk/art/maze))
*Related Questions:*  
[Draw the Hilbert curve using slashes](https://codegolf.stackexchange.com/questions/34852/draw-the-hilbert-curve-using-slashes)  
[Align a horizontally-aligned, right-angled ASCII shape along a diagonal](https://codegolf.stackexchange.com/questions/21730/align-a-horizontally-aligned-right-angled-ascii-shape-along-a-diagonal)
  
[Answer]
# Python 2 - ~~236, 228, 226, 221, 250, 248~~ 246 - 50 = 196
```
s=input().split()
s=zip(*s[::-1])
X=len(s[0])+2
d=('.',)
B=[d*X]
s=B+[d+tuple(l)+d for l in s]+B
Y=len(s)
for x in range(X,-Y,-1):print' '*abs(x)+''.join(' \\'[s[y-1][x+y-1]!=s[y-1][x+y]]+' /'[s[y-1][x+y]!=s[y][x+y]]for y in range(1,Y)if 0<x+y<X)
```
I added the optional bonus feature that switches the direction from clockwise to counterclockwise. Basically, the second line simply rotates the input by 90 degrees. To switch between both options, replace `s=zip(...)` by something like `S=zip(...)` (i.e. assign to a variable that won't be used again).
```
.XX.X....X...XX.X.X
X...X...X.X.X...X.X
.X..X...XXX..X..XXX
..X.X...X.X...X.X.X
XX..XXX.X.X.XX..X.X
                 /\           /\/\ 
                 \ \          \/\ \ 
               /\ \ \         /\ \/  
               \ \/  \     /\ \/   /\ 
             /\ \  /\ \    \ \/\  / /  
            / /  \ \ \/     \/\/ / /    
            \/    \ \           / /      
            /\/\/\ \/          / /        
            \/\/\/             \ \    /\/\ 
        /\/\    /\              \ \  / /\/  
        \/\ \  / /               \/ /  \/\   
        /\/  \ \/                  / /\  /    
        \  /\ \                    \/ / / /\/\ 
         \ \ \/                      / /  \/\ \ 
   /\     \ \                        \/   /\ \/  
   \ \     \/                          /\ \/   /\ 
 /\ \ \  /\                            \ \/\  / /  
/ /  \ \/ /                             \/\/ / / /\ 
\/    \  /                                  /  \/ /
/\/\/\ \/                                  / /\  /
\/\/\/                                     \/ / /
    /\                                       / /
   / /                                       \/
   \/
```
[Answer]
# MATLAB - 286 - 50 = 236
**Minified:**
```
S=input('');x=rot90(reshape(input('','s'),S),1);S=size(x);D=sum(S);[r,c]=ind2sub(S,find(x==88));A=zeros(D);f=@(o,p)sub2ind([D D],r+c+o-1,c-r+S(1)+p);A(f(1,1))=1;t=f(0,0);A(t)=A(t)+1;A(f(1,0))=3;t=f(0,1);A(t)=A(t)+3;fprintf('%s',char([(1-mod(A,2))*32+(A==1)*47+(A==3)*92,ones(D,1)*13]'))
```
**Expanded:**
```
S = input('');
x = rot90( reshape( input('','s'), S ), 1 );
S = size( x );
D = sum( S );
[r,c] = ind2sub( S, find( x==88 ) );
A = zeros( D );
f = @(o,p) sub2ind( [D D], r+c+o-1, c-r+S(1)+p );
A(f(1,1)) = 1;
t = f(0,0); A(t) = A(t)+1;
A(f(1,0)) = 3;
t = f(0,1); A(t) = A(t)+3;
fprintf( '%s', char( [(1-mod( A, 2 ))*32 + (A==1)*47 + (A==3)*92, ones( D, 1 )*13]' ) )
```
The code can be further reduced by 6 characters (to tie the current lead) by eliminating the cast to type `char`, but this results in a warning from MATLAB, and I wasn't sure if that was allowed.
It can be reduced by an additional 13 characters if the input is required to have a "marked up" format such as `['X..';'.X.';'..X']`, but I didn't figure this was allowed either. Currently the script just accepts two numbers (row and column dimensions) and then reads in a single string of grid characters.
**Bonus**
By changing the `1` in the call `x = rot90( ..., 1 );` to a `0`, the transformation changes from a CCW 45° rotation to a CW 45° rotation. In fact, all possible 45° + n·90° rotations are possible by stepping this parameter from `0` to `3`.
**Sample Outputs:**
```
XXX...XXX....XXX...XXX
X..X..X..X..X.....X...
XXX...XXX...X.....X.XX
X.....X.....X.....X..X
X.....X......XXX...XXX
                     /\    
                    / /    
                   / / /\  
                   \/ /  \ 
                   /\ \/\ \
                   \ \  / /
               /\   \ \/ / 
              / /    \/\/  
             / /           
             \/            
             /\    /\      
             \ \  / /      
              \ \/ /       
        /\/\   \/\/        
       / /\/               
      / / /\               
      \ \/ /               
       \  /                
        \ \                
  /\/\   \ \               
 / /\/    \/               
/ / /\                     
\ \/ /                     
 \  /                      
  \ \                      
   \ \                     
    \/                     
    /\                     
   /  \                    
  / /\ \                   
 /  \ \/                   
/ /\ \/\                   
\/  \/\/                   
          /\               
         /  \              
        / /\ \             
       /  \ \/             
      / /\ \/\             
      \/  \/\/             
               /\/\        
              / /\ \       
             / /  \ \      
             \/    \/      
             /\            
             \ \           
              \ \    /\/\  
               \/   / /\ \ 
                   / /  \ \
                   \/ /\ \/
                   /\ \ \  
                   \ \/ /  
                    \  /   
                     \/    
```
[Answer]
# Perl - 409
```
while(<>){$a[$.]=[/./g]}$l=$#a<($g=@{$a[1]})?$#a:$g;$r=$#a+$g-1;for$d(1..$r){for$e(1..$l){if(($b=$a[$c=($d>$g?$d-$g:0)+$e][$n=-($d-$c+1)])&&$n<0){$h[$d][$e]=$b;}}$h[$d]=[(0)x(($l-{@$h[$d]})/2),@{$h[$d]}];}sub z{"\0"x((reverse(1..$g),(2..$r-$g+1))[int($q++/2)-1]).join'',map{$_ eq'X'?($q%2?'/\\':'\/'):"\0\0"}@_}@i="\0"x2x$l;for$f(@h){$i[$#i]=(z@$f)^$i[$#i];$i[$#i+1]=z@$f}for$j(@i){print$j=~s/[\0s]/ /gr."\n"}
```
Reads from stdin and prints to stdout.
Example outputs:
```
XXX
X..
XXX
..X
XXX
     /\
    / / 
   / / /\
   \ \/  \
    \  /\ \
     \/ / /
       / /
       \/
XXXXXXXXX
X........
X.XXXXXXX
X.X.....X
X.X..X..X
X.XXXX..X
X...X...X
XXXXXXXXX
           /\
          / / 
         / / /\
        / / /  \
       / / / /\ \
      / / / /  \ \
     / / / /    \ \
    / / / / /\   \ \
   / / / /  \ \  / /
   \ \ \ \  / / / /
    \ \ \ \/  \/ /
     \ \ \  /\  /
      \ \ \/ / /
       \ \  / /
        \ \/ /
         \  /
          \/
```
]