Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 72x 72x 72x 1x 1x 1x 1x 1x 1x 1x 1x | /*
mask patterns
Mask 000 Mask 001 Mask 010 Mask 011
______ ______ ______ ______
▕▀▄▀▄▀▄⎸ ▕▀▀▀▀▀▀⎸ ▕█ █ ⎸ ▕▀ ▄▀ ▄⎸
▕▀▄▀▄▀▄⎸ ▕▀▀▀▀▀▀⎸ ▕█ █ ⎸ ▕▄▀ ▄▀ ⎸
▕▀▄▀▄▀▄⎸ ▕▀▀▀▀▀▀⎸ ▕█ █ ⎸ ▕ ▄▀ ▄▀⎸
⎺⎺⎺⎺⎺⎺ ⎺⎺⎺⎺⎺⎺ ⎺⎺⎺⎺⎺⎺ ⎺⎺⎺⎺⎺⎺
Mask 100 Mask 101 Mask 110 Mask 111
______ ______ ______ ______
▕███ ⎸ ▕█▀▀▀▀▀⎸ ▕███▀▀▀⎸ ▕▀ ▀▄█▄⎸
▕ ███⎸ ▕█ ▄▀▄ ⎸ ▕█▀▄▀█ ⎸ ▕▀▄ ▄▀█⎸
▕███ ⎸ ▕█ ▀ ⎸ ▕█ ▀▀▄█⎸ ▕ ██▄ ⎸
⎺⎺⎺⎺⎺⎺ ⎺⎺⎺⎺⎺⎺ ⎺⎺⎺⎺⎺⎺ ⎺⎺⎺⎺⎺⎺
*/
/** @type {MaskPatternFunction[]} */
const maskPatternFunctions = [
(i, j) => (i + j) % 2 === 0, // PATTERN000
(i, _) => i % 2 === 0, // PATTERN001
(_, j) => j % 3 === 0, // PATTERN010
(i, j) => (i + j) % 3 === 0, // PATTERN011
(i, j) => (Math.floor(i / 2) + Math.floor(j / 3)) % 2 === 0, // PATTERN100
(i, j) => (i * j) % 2 + (i * j) % 3 === 0, // PATTERN101
(i, j) => ((i * j) % 2 + (i * j) % 3) % 2 === 0, // PATTERN110
(i, j) => ((i * j) % 3 + (i + j) % 2) % 2 === 0, // PATTERN110
]
/**
* @param {number} maskPattern - mask pattern, an integer number between 0 and 7
* @returns {MaskPatternFunction} mask pattern function
*/
export function getMaskPatternFunction (maskPattern) {
const result = maskPatternFunctions[maskPattern]
if (!result) {
throw Error(`bad maskPattern: ${maskPattern}`)
}
return result
};
/**
* @callback MaskPatternFunction
* @param {number} x - horizontal position
* @param {number} y - vertical position
* @returns {boolean} true to paint a black pixel, false to paint a white pixel
*/
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