How to draw a line on really low resolution

Question

I am currently working on a project on arduino which involves drawing a line on a 8x8 rgb led display, given 2 random coordinates, how do I determine which pixels between them should be painted?

Any help is apprecieated

Answer 1

Here is a simple implementation of the line drawing algorithm mentioned above.

Note that this example will only work if x1 is less than x2.

void drawLine(int x1, int y1, int x2, int y2) {
  int dx = x2 - x1;
  int dy = y2 - y1;

  for (int x = x1; x < x2; x++){ 
    int y = y1 + dy * (x - x1) / dx;
    plot(x, y);
  }
}

void plot(int x, int y) {
  // Draw each pixel
}