Get all pixel coordinates between 2 points

Question

I want to get all the x,y coordinates between 2 given points, on a straight line. While this seems like such an easy task, I can\'t seem to get my head around it.

So, fo

Answer 1

Based on the wiki article, here's my JS code which handles both high and low lines:

const drawLine = (x0, y0, x1, y1) => {
  const lineLow = (x0, y0, x1, y1) => {
    const dx = x1 - x0
    let dy = y1 - y0
    let yi = 1

    if (dy < 0) {
      yi = -1
      dy = -dy
    }

    let D = 2 * dy - dx
    let y = y0

    for (let x = x0; x < x1; x++) {
      drawPoint(x, y)

      if (D > 0) {
        y = y + yi
        D = D - 2 * dx
      }

      D = D + 2 * dy
    }
  }

  const lineHigh = (x0, y0, x1, y1) => {
    let dx = x1 - x0
    const dy = y1 - y0
    let xi = 1

    if (dx < 0) {
      xi = -1
      dx = -dx
    }

    let D = 2 * dx - dy
    let x = x0

    for (let y = y0; y < y1; y++) {
      drawPoint(x, y)

      if (D > 0) {
        x = x + xi
        D = D - 2 * dy
      }

      D = D + 2 * dx
    }
  }

  const { abs } = Math

  if (abs(y1 - y0) < abs(x1 - x0)) {
    if (x0 > x1) {
      lineLow(x1, y1, x0, y0)
    } else {
      lineLow(x0, y0, x1, y1)
    }
  } else {
    if (y0 > y1) {
      lineHigh(x1, y1, x0, y0)
    } else {
      lineHigh(x0, y0, x1, y1)
    }
  }
}