How do you make a line without the line command?

[Bp103]

I've been trying to figure out how to recreate the line command in Qbasic for a while now but I've been failing at it. I've also googled for this too but it turns up useless results that all use a line command of some sort.

how do you make a line from point(x,y) to point(x2,y2) with out the line command?

E.g. to draw a circle its

Code: Select all

x=50
y=50
r=10
for i=0 to 360 step .1
    x2=x+(r*sin(i*3.141/180))
    y2=y+(r*cos(i*3.141/180))
    pset(x2,y2), _rgb(255,255,255)
next

This'll really help me out when I need to make a line in things that can't use the line command like text mode or a unsupported vesa mode. Thanks.

[burger2227]

You cannot use graphics like PSET to draw a line in text mode.

You can only draw text lines using ASCII characters.

Your example needed an underscore before _RGB for QB64.

[Bp103]

You cannot use graphics like PSET to draw a line in text mode.

You can only draw text lines using ASCII characters.

Yes.

Code: Select all

x=5
y=5
r=4
for i=0 to 360
    x2=x+(r*sin(i*3.141/180))
    y2=y+(r*cos(i*3.141/180))
    locate y2,x2
    print"x"
next

Also It was a snip from my FreeBasic project and I let the rgb command slip by on accident. Help would be much appreciated.

edit: after messing with the circle snip I found this to be a solution. Its far from perfect but it is good enough.

Code: Select all

dim x,y,tilt as double
dim i as integer
randomize timer
screen 13
const Xres=320 'Setup the resolution for 13h
const Yres=200

x=Xres/2 'Set up the line so
y=Yres/2 ' it is in the center

tilt=rnd*6.2899 'random tilt (6.2899 is the max tilt it seems)

for i=0 to 100 'plot outward 100 steps
    
    x=x+cos(tilt) 'The math for X
    y=y+sin(tilt) 'The math for Y
    
    pset(x,y),15  'dot
    
next
sleep -1

edit2: The algorithm I was looking for is known as Bresenham's line algorithm.
http://en.wikipedia.org/wiki/Bresenham's_line_algorithm

[burger2227]

It approaches the multiplier, but can never quite reach it.

RND can only return values from 0 to .9999999