Created
January 11, 2022 13:16
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/** | |
* Bresenhams line algorithm for integers. | |
* @see https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm#Algorithm_for_integer_arithmetic | |
*/ | |
function plotLine(x0, y0, x1, y1) { | |
/** Step direction on the x-axis */ | |
let sx = x0 < x1 ? 1 : -1 | |
/** Step direction on the y-axis */ | |
let sy = y0 < y1 ? 1 : -1 | |
let dx = Math.abs(x1 - x0) | |
let dy = -Math.abs(y1 - y0) | |
/** error value e_xy, which is balanced between x and y coords */ | |
let err = dx + dy | |
while (true) { | |
// Each coordinate | |
console.log(x0, y0) | |
if (x0 == x1 && y0 == y1) break | |
let e2 = 2 * err | |
if (e2 >= dy) { | |
/* e_xy+e_x > 0 */ | |
err += dy | |
x0 += sx | |
} | |
if (e2 <= dx) { | |
/* e_xy+e_y < 0 */ | |
err += dx | |
y0 += sy | |
} | |
} | |
} |
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