Matrix Scaling

ID:2011441
 
Jan 3 2016, 12:43 pm
(See the best response by Ter13.)
Code:
Line(mob/a,mob/b)
    var/obj/T = new/obj/Line
    var/angle=a.AngleTo(b)
    var/scale=get_dist_sq(a,b)
    while(1)
        sleep(0.25)
        angle=a.AngleTo(b)
        scale=get_dist_sq(a,b)
        T.transform=turn(matrix()*2*scale,angle)
        CopyLoc(T,a)


Problem description:

Is it possible to scale only the X/Y values as needed in order to keep the width of the line relatively similar? If so, what sort of math should I utilize?

Jan 3 2016, 10:11 pm
Best response
The correct process is to scale on a single axis, and then rotate it. See matrix.Scale():

Line(mob/a,mob/b)
    var/obj/T = new/obj/Line
    var/angle=a.AngleTo(b)
    var/scale=get_dist_sq(a,b)
    var/matrix/m
    while(1)
        sleep(0.25)
        angle=a.AngleTo(b)
        scale=get_dist_sq(a,b)
        m = matrix()
        T.transform=turn(m.Scale(1,scale),angle)
        CopyLoc(T,a)
Jan 4 2016, 7:31 am
In response to Ter13
Ah, okay. Thanks! I wasn't sure if rotations would do anything to the scaling and make everything all wonky or not.