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Canvas

Must be included via require.

canvas.new​

Creates a new canvas instance.

Parameters​

  1. Width.
  2. Height.

canvas.bmp​

Creates a new canvas instance based on a BMP image.

Parameters​

  1. The BMP image as a string.

canvas.qrcode​

Creates a new canvas instance containing a QR code.

Parameters​

  1. The string to be encoded.
  2. An optional table of options.

Options​

  • "ecl" specifies the error correction level between "low", "medium", "quartile", "high". defaults to "low".
  • "border" specifies the number of pixels around the QR code. defaults to 0.
  • "bg" specifies the background color. defaults to 0x000000 for black.
  • "fg" specifies the background color. defaults to 0xffffff for white.
pluto
local canvas = require "canvas"
local c = canvas.qrcode("Hello from Pluto!", { fg = 0xffffff, bg = 0x000000 })
print(c:tobwstring(0xffffff))
--> █▀▀▀▀▀█ ▄ █▄▄ █▀▀▀▀▀█
--> █ ███ █ ▄█▄▄█ █ ███ █
--> █ ▀▀▀ █ ▄▀ █▄ █ ▀▀▀ █
--> ▀▀▀▀▀▀▀ ▀▄▀▄█ ▀▀▀▀▀▀▀
--> ▀▀███ ▀███ █▀▀ ▀▄█▄▀▄
--> █▄▀▄▀█▀█▀▀ ▀█▄▀▄▄██▀ 
--> ▀▀▀▀▀ ▀ █▀█▀ ▄█▄▄▄  ▀
--> █▀▀▀▀▀█ ▀  ▀██▀▄ ▄██ 
--> █ ███ █ █▄ ▄█▄██▄▄ ▄ 
--> █ ▀▀▀ █ █▄ ▀█▀ ▀▄▄█  
--> ▀▀▀▀▀▀▀ ▀   ▀ ▀ ▀  ▀

canvas.get​

Gets the color of the pixel at the given coordinates.

Parameters​

  1. The canvas instance.
  2. The X coordinate.
  3. The Y coordinate.

Returns​

The color as an integer.

canvas.set​

Sets the color of the pixel at the given coordinates.

Parameters​

  1. The canvas instance.
  2. The X coordinate.
  3. The Y coordinate.
  4. The color as an integer.

canvas.fill​

Sets every pixel to the given color.

Parameters​

  1. The canvas instance.
  2. The color as an integer.

canvas.size​

Get the size of a canvas.

Parameters​

  1. The canvas instance.

Returns​

  1. Width.
  2. Height.

canvas.mulsize​

Multiplies the size of a canvas.

Parameters​

  1. The canvas instance.
  2. The multiplier. Must be 2 or higher.

canvas.tobmp​

Convert a canvas to a BMP image.

Parameters​

  1. The canvas instance.

Returns​

A string.

canvas.topng​

Convert a canvas to a PNG image.

Parameters​

  1. The canvas instance.

Returns​

A string.

pluto
local { base64, canvas } = require "*"
local c = new canvas(5, 5)
c:fill(0xff0000)
print("data:image/png;base64,"..base64.encode(c:topng()))
--> data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAIAAAACDbGyAAAAW0lEQVQIHQFQAK//AP8AAP8AAP8AAP8AAP8AAAD/AAD/AAD/AAD/AAD/AAAA/wAA/wAA/wAA/wAA/wAAAP8AAP8AAP8AAP8AAP8AAAD/AAD/AAD/AAD/AAD/AAD9fBjo3iScjwAAAABJRU5ErkJggg==

canvas.tobwstring​

Convert a canvas to a black and white unicode string. This requires the height of the canvas to be an even number; if it is not, a black line will be added to the bottom of the canvas.

Parameters​

  1. The canvas instance.
  2. The color to be "white." Any other color will be "black."

Returns​

A string.