def draw(self, x, y, colour, continue_transaction=False):
"""
Draw to a pixel.
x: The horizontal coordinate to draw to.
y: The vertical coordinate to draw to.
colour: The colour to draw.
continue_transaction: (optional, False) Include this as part of
the previous transaction.
"""
assert 0 <= x < self._width
assert 0 <= y < self._height
validate_colour(colour)
red, green, blue, alpha = colour
transaction = self._get_id(continue_transaction, action='draw')
self._cursor.execute(
'INSERT INTO draws ('
' transaction_id, x, y, red, green, blue, alpha'
') VALUES ('
' :transaction_id, :x, :y, :red, :green, :blue, :alpha'
');',
{
'transaction_id': transaction,
'x': x, 'y': y,
'red': red, 'green': green, 'blue': blue, 'alpha': alpha,
}
)
def validate_colour():
"""
Validate a colour
"""
from painterm.colour import validate_colour, Colour
colours = (Colour(-1, 0, 1, 0), (15, 15, 256, 0), (12, 12, 12), (0, 0, 0, 2))
for colour in colours:
with assert_raises(AssertionError):
validate_colour(colour)
validate_colour(Colour(0, 1, 2, 1.0))
validate_colour((0, 1, 2, 0.5))
def new_image(cls, width, height, path=None, background=BACKGROUND,
creation_date=None):
"""
Create a new image.
width: The width of the image (in pixels).
height: The height of the image (in pixels).
path: (optional, None) A pathlib Path representing the location
to save the image. If None, the image will be stored in an
in-memory database.
background: (optional, 0-alpha white) The starting colour for
the pixels.
creation_date: (optional, None) The creation date. If not given,
utcnow will be used.
"""
assert isinstance(width, int) and width > 0
assert isinstance(height, int) and height > 0
validate_colour(background)
red, green, blue, alpha = background
if path:
if path.exists():
raise IOError("File already exists")
location = path.expanduser().absolute().as_uri()
is_uri = True
else:
location = IN_MEMORY
is_uri = False
if creation_date is None:
creation_date = datetime.utcnow()
connection = sqlite3.connect(location, uri=is_uri)
cursor = connection.cursor()
cursor.executescript(SCHEMA)
cursor.execute(
'INSERT INTO meta ('
' major, minor, micro, width, height, creation_date'
') VALUES ('
' ?, ?, ?, ?, ?, ?'
');',
(
*SCHEMA_VERISON,
width, height,
creation_date.strftime(DATE_FORMAT)
)
)
cursor.execute(
'INSERT INTO transactions (id, time, action) '
'VALUES (:id, :time, :action);',
{'id': 0, 'time': 0, 'action': 'fill'}
)
cursor.executemany(
'INSERT INTO draws ('
' transaction_id, x, y, red, green, blue, alpha'
') VALUES ('
' :transaction_id, :x, :y, :red, :green, :blue, :alpha'
');',
(
{
'transaction_id': 0,
'x': x, 'y': y,
'red': red, 'green': green, 'blue': blue, 'alpha': alpha,
}
for x in range(width) for y in range(height)
)
)
cursor.connection.commit()
return Image(connection)
def fill(self, x, y, colour, continue_transaction=False):
"""
flood fill starting at a pixel. Returns a list of (x, y) pairs
representing updated pixels
x: The horizontal coordinate to start at.
y: The vertical coordinate to start at.
colour: The colour to draw.
continue_transaction: (optional, False) Include this as part of
the previous transaction.
"""
assert 0 <= x < self._width
assert 0 <= y < self._height
validate_colour(colour)
red, green, blue, alpha = colour
transaction = self._get_id(continue_transaction, action='fill')
old_colour = self.colour_at(x, y)
dont_fill = set()
fill = {(x, y)}
unchecked = set()
if x > 0:
unchecked.add((x - 1, y))
if x + 1 < self._width:
unchecked.add((x + 1, y))
if y > 0:
unchecked.add((x, y - 1))
if y + 1 < self._height:
unchecked.add((x, y + 1))
# continue to fill
while unchecked:
curr_x, curr_y = xy = unchecked.pop()
if xy in dont_fill or xy in fill:
continue # we already handled this pixel
if self.colour_at(curr_x, curr_y) == old_colour:
fill.add((curr_x, curr_y))
if curr_x > 0:
unchecked.add((curr_x - 1, curr_y))
if curr_x + 1 < self._width:
unchecked.add((curr_x + 1, curr_y))
if curr_y > 0:
unchecked.add((curr_x, curr_y - 1))
if curr_y + 1 < self._height:
unchecked.add((curr_x, curr_y + 1))
else:
dont_fill.add(xy)
self._cursor.executemany(
'INSERT INTO draws ('
' transaction_id, x, y, red, green, blue, alpha'
') VALUES ('
' :transaction_id, :x, :y, :red, :green, :blue, :alpha'
');',
(
{
'transaction_id': transaction,
'x': x, 'y': y,
'red': red, 'green': green, 'blue': blue, 'alpha': alpha,
}
for x, y in fill
)
)
return fill
