drawable

class cbc.drawable.Drawable(width, height, fill=0)

Represents a two-dimensional drawing surface composed of RGBA pixels. A drawable contains pixels which holds a list of rows, each of which is a list of Color instances (each of which represents a single pixel). For example, a 3x3 drawable looks like this:

>>> d = cbc.Drawable(3, 3)
>>> d.width
3
>>> d.height
3
>>> d.pixels
[[Color('#000000'), Color('#000000'), Color('#000000')],
[Color('#000000'), Color('#000000'), Color('#000000')],
[Color('#000000'), Color('#000000'), Color('#000000')]]

Internally, the drawable actually represents things more efficiently (a fixed array of 32-bit integers holding the RGBA data), but the Python interface emulates a list of lists of Color instances. Methods are provided to get and set pixels individually:

>>> d.get(1, 0)
Color('#000000')
>>> d.set(1, 0, cbc.Color('red'))
>>> d.get(1, 0)
Color('#660000')
>>> d.pixels
[[Color('#000000'), Color('#660000'), Color('#000000')],
[Color('#000000'), Color('#000000'), Color('#000000')],
[Color('#000000'), Color('#000000'), Color('#000000')]]

Alternatively, you can address pixels directly, but be aware when doing so that the first coordinate selects the row (the “y” coordinate):

>>> d[1, 0]
Color('#000000')
>>> d[0, 1]
Color('#660000')
>>> d[0, 1] = cbc.Color('green')
>>> d[0, 1]
Color('#002200')

You can also select and assign to slices of pixels to manipulate whole ranges at once:

>>> d.pixels[:, 0] = [cbc.Color('red')] * 3
>>> d.pixels[:, 1] = [cbc.Color('white')] * 3
>>> d.pixels[:, 2] = [cbc.Color('blue')] * 3
>>> d.pixels
[[Color('#660000'), Color('#ffffff'), Color('#000066')],
[Color('#660000'), Color('#ffffff'), Color('#000066')],
[Color('#660000'), Color('#ffffff'), Color('#000066')]]
>>> d.pixels[:2, :] = [[cbc.Color('cyan')] * 3] * 2
>>> d.pixels
[[Color('#002266'), Color('#002266'), Color('#002266')],
[Color('#002266'), Color('#002266'), Color('#002266')],
[Color('#660000'), Color('#ffffff'), Color('#000066')]]

Finally, the clear() method can be used to quickly reset things to black:

>>> d.clear()
>>> d.pixels
[[Color('#000000'), Color('#000000'), Color('#000000')],
[Color('#000000'), Color('#000000'), Color('#000000')],
[Color('#000000'), Color('#000000'), Color('#000000')]]

clear(c=Color('#000000'))

Reset all pixels to black.

draw(x, y, source, blend_mode=None)

Draw the source Drawable onto the current Drawable at coordinates (x, y). The blend_mode controls how the alpha-channel of the source is treated.

classmethod from_string(width, height, data, colors={' ': 'black', '.': 'darkgray', 'B': 'lightblue', 'C': 'lightcyan', 'G': 'lightgreen', 'M': 'lightmagenta', 'R': 'lightred', 'W': 'white', 'b': 'blue', 'c': 'cyan', 'g': 'green', 'm': 'magenta', 'n': 'brown', 'o': 'orange', 'r': 'red', 'w': 'gray', 'y': 'yellow'})

Constructs a Drawable from the given data which is a string containing width x height characters. Each character represents a Color with colors mapping each character to a color.

The default color map is as follows:

char	color	char	color
space	black	.	dark gray
r	red	R	light red
g	green	G	light green
o	brown	y	yellow
b	blue	B	light blue
m	magenta	M	light magenta
c	cyan	C	light cyan
w	gray	W	white

Hence, to construct a rainy-cloud for the display, you could use the following:

cloud = cbc.Drawable.from_string(
    5, 5,
    " . . "
    "....."
    " b b "
    "     "
    " b b ")
cbc.display.draw(0, 0, cloud)

get(x, y)

Return the pixel at (x, y).

property height

Returns the height of the drawable.

property pixels

Represents the pixels of the drawable as a list of list of Color instances. The outer list represents rows (in the same way numpy represents two-dimensional arrays), while the inner represents columns. Hence, addressing pixels is done with the y-coordinate followed by the x-coordinate:

>>> d = cbc.Drawable(3, 2)
>>> d.width
3
>>> d.height
2
>>> d.pixels
[[Color('#000000'), Color('#000000'), Color('#000000')],
[Color('#000000'), Color('#000000'), Color('#000000')]]
>>> len(d)
2
>>> len(d[0])
3

Slices can be obtained and assigned to in order to rapidly manipulate multiple pixels. Fast methods are used internally to copy between drawables:

>>> source = cbc.Drawable(5, 5)
>>> target = cbc.Drawable(5, 5)
>>> source.pixels = [[cbc.Color('white')] * 5] * 5
>>> target.pixels[:3, :3] = source.pixels[:3, :3]

set(x, y, c)

Set the pixel at (x, y) to the color.Color c.

property width

Returns the width of the drawable.