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

Edit: The solution below only applies from a geometrical point of view. Drawing on a screen is different than theoretical geometry, you should listen to the people suggesting Bresenham's algorithm.

---

Given, two points, and knowing that the line's equation is y = m*x + b, where m is the slope and b the intercept, you can calculate m and b and then apply the equation to all the values of the X axis between your A and B points:

var A = [10, 5];
var B = [15, 90];

function slope(a, b) {
    if (a[0] == b[0]) {
        return null;
    }

    return (b[1] - a[1]) / (b[0] - a[0]);
}

function intercept(point, slope) {
    if (slope === null) {
        // vertical line
        return point[0];
    }

    return point[1] - slope * point[0];
}

var m = slope(A, B);
var b = intercept(A, m);

var coordinates = [];
for (var x = A[0]; x <= B[0]; x++) {
    var y = m * x + b;
    coordinates.push([x, y]);
}

console.log(coordinates); // [[10, 5], [11, 22], [12, 39], [13, 56], [14, 73], [15, 90]]