snake: snake.py annotate

snake

annotate snake.py @ 117:0a95e3796113

fixed redraw error

author	Alex Martynov <martiran@kodomo.fbb.msu.ru>
date	Mon, 20 Dec 2010 14:41:51 +0300
parents	7352863453bc 9486211ec334
children	10d32d7755ff

rev	line source
me@44	1 """Guts of snakes."""
me@44	2
me@34	3 import engine
me@34	4
me@34	5 def preprocess(line):
me@44	6 """Remove comments and junk spaces from line of snake definition file."""
me@34	7 if '//' in line:
me@34	8 line = line[:line.index('//')]
me@34	9 line = line.rstrip()
me@34	10 return line
martiran@30	11
me@109	12 class File(object):
me@109	13 """Wrapper around file that saves the current line number."""
me@109	14 def __init__(self, file):
me@109	15 self.file = file
me@109	16 self.name = file.name
me@109	17 self.line_no = 0
me@109	18 def __iter__(self):
me@109	19 for line_no, line in enumerate(self.file, self.line_no):
me@109	20 self.line_no = line_no
me@109	21 yield line
me@109	22
martiran@30	23 class Snake(object):
me@44	24 """Snakes.
me@44	25
me@44	26 Attributes:
me@44	27
me@44	28 - `cells` -- list of cells belonging to the snake The first of these cells
me@44	29 becomes head, the last one becomes tail, the rest ar body. If snake has
me@44	30 only one cell, it is tail.
me@44	31 - `color` -- color of snake
me@44	32 - `rules` -- a list of Rule objects
me@44	33 """
me@44	34
martiran@32	35 def __init__ (self, cells, color):
martiran@32	36 self.cells = cells
martiran@32	37 self.color = color
martiran@32	38 self.rules = []
me@34	39
me@34	40 def load (self, file):
me@44	41 """Load snake description from file.
me@44	42
me@44	43 See program design docs for file syntax.
me@44	44 """
me@109	45 file = File(file)
me@109	46 try:
me@109	47 self._load(file)
me@109	48 except Exception, e:
me@109	49 raise Exception("%s:%s: %s" % (file.name, file.line_no, e))
me@109	50
me@109	51 def _load (self, file):
me@109	52 """Actually do the loading."""
me@65	53 for line in file:
me@88	54 magic, self.name = preprocess(line).split(' ', 1)
me@65	55 break
me@34	56 assert magic == "snake", "This is not snake file"
me@65	57 for line in file:
me@65	58 line = preprocess(line)
me@34	59 if line == 'end':
me@34	60 break
me@34	61 assert line == '', "Rules must be separated by empty lines"
me@51	62 self.rules.append(Rule(self).load(file))
me@34	63
martiran@30	64 def fill (self):
me@44	65 """Mark every cell in `self.cells` as belonging to self."""
martiran@32	66 for cell in self.cells:
martiran@32	67 cell.snake = self
martiran@111	68 for cell in self.cells:
martiran@111	69 cell.type = 'body'
Alex@75	70 self.cells[0].type = 'head'
Alex@75	71 self.cells[-1].type = 'tail'
martiran@31	72 return
me@34	73
martiran@30	74 class Rule(object):
me@44	75 """Rule defining possible behaviour of snake."""
me@34	76
me@34	77 codes = {
me@34	78 'h': 'head',
me@34	79 'b': 'body',
me@34	80 't': 'tail',
me@34	81 '#': 'wall',
me@34	82 ' ': 'any',
me@34	83 '-': 'empty',
me@34	84 }
me@34	85
martiran@32	86 def __init__ (self, snake):
martiran@32	87 self.snake = snake
me@80	88 self.direction = (0, -1)
me@34	89 self.pattern = {}
me@34	90
me@34	91 def load (self, file):
me@70	92 """Load rule definition from file.
me@70	93
me@70	94 Ignore any leading empty lines.
me@70	95 Return self.
me@70	96 """
me@34	97 y = 0
me@34	98 for line in file:
me@34	99 line = preprocess(line)
me@34	100 if y == 0 and line == '':
me@34	101 continue
me@41	102 assert len(line) == 8, "Rule lines must be exactly 7 chars long"
me@34	103 assert line[-1] == ';', "Rule lines must end with semicolon"
me@63	104 for x, char in enumerate(line[:7]):
me@34	105 self.parse_cell(x, y, char)
me@34	106 y += 1
me@68	107 if y == 7:
me@68	108 break
me@70	109 return self
me@34	110
me@34	111 def parse_cell(self, x, y, char):
me@44	112 """Parse definition of cell in rule file.
me@44	113
me@44	114 Cell is defined by one character.
me@44	115 """
me@73	116 is_my = char.islower()
me@73	117 char = char.lower()
me@73	118 assert char in self.codes, "Illegal symbol in rule: %s" % char
me@51	119 cell = engine.Cell(x, y, self.snake)
me@34	120 if char in 'htb':
me@73	121 if is_my:
me@51	122 cell.snake_type = 'my'
me@34	123 else:
me@51	124 cell.snake_type = 'enemy'
me@37	125 if char == 'h':
me@37	126 assert (x, y) == (3, 3), "Own head must in the center of rule"
me@37	127 if (x, y) == (3, 3):
me@37	128 assert char == 'h', "In the center of rule must be own head"
me@73	129 cell.type = self.codes[char]
me@34	130 self.pattern[x, y] = cell
me@34	131
martiran@32	132 def applies (self, field, x, y):
me@44	133 """True if the rule applies in the field at position (x,y)."""
me@38	134 for px, fx in zip(range(7), range(x - 3, x + 4)):
me@38	135 for py, fy in zip(range(7), range(y - 3, y + 4)):
me@49	136 if (fx, fy) in field:
me@43	137 if field[fx, fy] != self.pattern[px, py]:
me@43	138 return False
me@43	139 else:
me@43	140 if self.pattern[px, py].type != 'any':
me@43	141 return False
me@38	142 return True
me@34	143
me@104	144 def rotate (self, direction):
me@104	145 """Rotate rule pattern to head in `direction`."""
me@104	146 for i in range(4):
me@104	147 if self.direction == direction:
me@104	148 return
me@39	149 self.rotate_ccw()
me@104	150 raise AssertionError("Illegal direction: %s" % direction)
me@39	151
me@39	152 def rotate_ccw(self):
me@44	153 """Rotate rule pattern one time counterclockwise."""
me@39	154 pattern = {}
me@39	155 for x in range(7):
me@39	156 for y in range(7):
me@39	157 pattern[y, 6 - x] = self.pattern[x, y]
me@39	158 self.pattern = pattern
me@39	159 x, y = self.direction
me@39	160 self.direction = y, -x
me@34	161
me@34	162 # vim: set ts=4 sts=4 sw=4 et: