A 2D integer raycasting algorithm in Swift

Raycast.swift

    var dx = abs(endPoint.x - startPoint.x)
    var dy = abs(endPoint.y - startPoint.y)
    var x = startPoint.x
    var y = startPoint.y
    var steps = 1 + dx + dy
    let incrementX = (endPoint.x > startPoint.x) ? 1 : -1
    let incrementY = (endPoint.y > startPoint.y) ? 1 : -1
    var error = dx - dy
    dx *= 2
    dy *= 2

    while steps > 0 {
        if resultHandler(Vec2(x, y)) {
            return true
        }

        if error > 0 {
            x += incrementX
            error -= dy
        } else {
            y += incrementY
            error += dx
        }
        steps -= 1
    }
    
    return false