anim_code_golf.py

versions = [version.strip() for version in (
"""
def t(b):
 L=len;w,n=L(b[0])+3,-1;b=list("@"*w+"@@".join(b)+"@"*w);w+=n;I=b.index
 for i in range(L(b)):
  c=b[i];d={"^":-w,"<":n,">":1,"v":w}.get(c)
  if d:
   while c!='@':
    i+=d;c=b[i]
    if c=='*':b[i]='.'
    elif c in "123456789":i+=I(c)-i or I(c,i+1)-i
    elif c in '/\\':d={-w:n,w:1,1:w,n:-w}[d]*(-1 if c=='/' else 1)
 return "*" not in b
""",
"""
def t(b):
 L=len;w=L(b[0])+3;b=list("@"*w+"@@".join(b)+"@"*w);w-=1;I=b.index
 for i in range(L(b)):
  c=b[i];d={"^":-w,"<":-1,">":1,"v":w}.get(c)
  if d:
   while c!='@':
    i+=d;c=b[i]
    if c=='*':b[i]='.'
    elif c in "123456789":i+=I(c)-i or I(c,i+1)-i
    elif c in '/\\':d={-w:-1,w:1,1:w,-1:-w}[d]*(-1 if c=='/' else 1)
 return "*" not in b
""",
"""
def t(b):
 L=len;w=L(b[0])+3;b=list("@"*w+"@@".join(b)+"@"*w);w-=1;I=b.index
 for i in range(L(b)):
  c=b[i];d={"^":-w,"<":-1,">":1,"v":w}.get(c)
  if d:
   while c!='@':
    i+=d;c=b[i]
    if c=='*':b[i]='.'
    elif c in '/\\':d={-w:-1,w:1,1:w,-1:-w}[d]*(-1 if c=='/' else 1)
    elif c>'0':i+=I(c)-i or I(c,i+1)-i
 return "*" not in b
""",
"""
def t(b):
 w=len(b[0])+2;B=list('@'*w+'@@'.join(b)+'@'*w);l=len(B);C="<>v^";D=[-1,1,w,-w];i=0
 while i<l:
    d=C.find(B[i])
    if-1<d:
     j=i;n=l*4
     while('@'!=B[j])*n:
        c=B[j]
        if'+'>c:B[j]=''
        if'/'==c:d=(d+2)%4
        if'\\'==c:d=3-d
        if c.isdigit():j=(B*2).index(c,j+1)%l
        j+=D[d];n-=1
    i+=1
 return'*'not in B
""",
"""
def t(b):
 w=len(b[0])+2;B=list('@'*w+'@@'.join(b)+'@'*w);l=len(B);i=0
 while i<l:
    d="<>v^".find(B[i])
    if-1<d:
     j=i;n=l*4
     while(B[j]!='@')*n:
        c=B[j]
        if'+'>c:B[j]=''
        if'/'==c:d=(d+2)%4
        if'\\'==c:d=3-d
        if c.isdigit():j=(B*2).index(c,j+1)%l
        j+=[-1,1,w,-w][d];n-=1
    i+=1
 return'*'not in B
""",
"""
def t(b):
 w=len(b[0])+2;B=list('@'*w+'@@'.join(b)+'@'*w);l=len(B);i=0
 while i<l:
    d="<>v^".find(B[i])
    if-1<d:
     j=i;c='.'
     while c not in"@<>v^":
        if'+'>c:B[j]=''
        if'/'==c:d^=2
        if'\\'==c:d^=3
        elif'0'<c:j=(B*2).index(c,j+1)%l
        j+=[-1,1,w,-w][d];c=B[j]
    i+=1
 return'*'not in B
""",
"""
def t(b):
 w=len(b[0])+2;B=list('@'*w+'@@'.join(b)+'@'*w);l=len(B);i=0
 while i<l:
    d="<>v^".find(B[i]);j=i;c='.'
    while c not in"@<>v^":
     if'+'>c:B[j]=''
     if'/'==c:d^=2
     if'\\'==c:d^=3
     elif'0'<c:j=(B*2).index(c,j+1)%l
     j+=[-1,1,w,-w,-i][d];c=B[j]
    i+=1
 return'*'not in B
""",
"""
def t(b):
 w=len(b[0])+1;B=list('@'*w+'@'.join(b)+'@'*w);l=len(B);i=0
 while i<l:
    d="<>v^".find(B[i]);j=i;c='.'
    while c not in"@<>v^":
     if'+'>c:B[j]=''
     if'/'==c:d^=2
     if'\\'==c:d^=3
     elif'0'<c:j=(B*2).index(c,j+1)%l
     j+=[-1,1,w,-w,-j][d];c=B[j]
    i+=1
 return'*'not in B
""",
"""
def t(b):
 w=len(b[0])+1;B=list('@'*w+'@'.join(b));i=l=len(B);C="<>^v@"
 while i:
    j=l-i;i-=1;d=C.find(B[j]);c='.'
    while c not in C:
     if'+'>c:B[j]='.'
     if'0'<c<C:j=(B*2).index(c,j+1)%l
     elif'.'<c:d^=2+(c<C)
     j-=[1,-1,w,-w,j][d];c=B[j%l]
 return'*'not in B
""",
"""
def t(b):
 w=len(b[0])+1;B=list('@'*w+'@'.join(b));i=l=len(B);C="<>^v@"
 while i:
  i-=1;d,j,c=C.find(B[i]),i,'.'
  while(c in C)-1:
   if'+'>c:B[j]='.'
   if'0'<c<C:j=(B*2).index(c,j+1)%l
   elif'.'<c:d^=2+(c<C)
   j-=[1,-1,w,-w,j][d];c=B[j%l]
 return('*'in B)-1
""")]

width = max(len(line) for version in versions for line in version.split("\n"))
height = max(len(version.split("\n")) for version in versions)

import difflib
from PIL import Image, ImageFont, ImageDraw, ImageChops, GifImagePlugin
font = ImageFont.truetype("/Library/Fonts/Courier New.ttf", 15)
em, lineheight = 9, 14
anim_frames = 1

def render(text, ofs, diff, diff_ch, frames):
    for frame in range(anim_frames if ofs is not None else 1):
        image = Image.new("RGB", (width * em + int(em * 1.5), height * lineheight + int(lineheight/2)), "white")
        frames.append(image)
        draw = ImageDraw.Draw(image)
        x, y = 0, 0
        for i, ch in enumerate(text): 
            if ch == '\n':
                x = 0
                y += lineheight
            else:
                if i == ofs:
                    draw.rectangle((x, y, x + em, y + lineheight),
                        fill='red' if diff=='+' else 'blue')
                    scale = 1.0 / 3 * frame
                    if diff == '-':
                        scale = 1.0 - scale
                    draw.text((x, y), ch, font=font,
                        fill='yellow')
                    draw.rectangle((x + em, y, x + em + em, y + lineheight),
                        fill='white')
                    x += int(round(float(em) * scale))
                draw.text((x, y), ch, font=font, fill=0)
                x += em
        del draw
                
frames = []
render(versions[0], None, None, None, frames)

prev = versions[0]
for i in range(3, len(versions)):
    curr = versions[i]
    print "==== %d (%d %d) ====" % (i, len(curr), len(prev)-len(curr))
    adjust = 0
    for ofs, diff in enumerate(difflib.ndiff(prev, curr)):
        diff, ch = diff[0], diff[-1]
        if diff in "+-":
            render(prev, ofs-adjust, diff, ch, frames)
            if diff == "+":
                prev = prev[:ofs-adjust] + ch + prev[ofs-adjust:]
            else:
                assert prev[ofs-adjust] == ch, (ofs, prev[:ofs+1], ch)
                prev = prev[:ofs-adjust] + prev[ofs-adjust+1:]
                adjust += 1
    assert prev == curr
render(versions[-1], None, None, None, frames)
        
with open("anim.gif", "wb") as f:
    prev = None
    for frame in frames:
        frame = frame.convert('P', palette=Image.WEB)
        if not prev:
            for s in GifImagePlugin.getheader(frame)[0]:
                f.write(s)
            prev = frame.copy()
            frame = GifImagePlugin.getdata(frame)
        else:
            delta = ImageChops.subtract_modulo(frame, prev)
            prev = frame.copy()
            bbox = delta.getbbox()
            if bbox:
                frame = GifImagePlugin.getdata(frame.crop(bbox), offset = bbox[:2])
            else:
                continue
        for s in frame:
            f.write(s)
    f.write(";")