Draw a line without knowing the end point or from how many points it's composed of.

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1

I want to Draw a line without knowing the end point or from how many points it’s composed of. In this case i can’t use delta x or maxnbpoints and a counter. I want the program to draw a line from my first touch location until touchstate ends. Moreover, i want the user to be able to lift up his finger and countinue without losing the previous drawn lines.

Can anyone be of anyhelp??

2

if you have one point but not the second it works

here (x1,y1) is not in the screen


-- Test Infinite Line

function setup()
end

function draw()
    background(40, 40, 50)
    strokeWidth(5) ; fill(49, 255, 0, 255)
    x1=math.random(1000)*-1
    y1=math.random(1000)*-1
    x2=math.random(1000)
    y2=math.random(1000)
    line(x1,y1,x2,y2)
end
3

Now I understand!

There have been quite a few posts about this, when people try to make a drawing program, where you can draw lines with your finger.

For example

https://codea.io/talk/discussion/comment/531

https://codea.io/talk/discussion/2774/drawing-on-codea

https://codea.io/talk/discussion/5798/fun-line-drawing

If you search on “drawing program” in the search box at the top right of screen, you may find more examples.

4

Thank you both @Ignatz and @hpsoft… I will try them and let you know

5

@Ignatz i used the first link you sent me : “http://codea.io/talk/discussion/comment/531”
I altered one thing so it can be used on my code. Instead of defining red green blue and alpha i defined a variable colorfill because the colour changes when you hit a certain button… The code is running with no error.

But it seems it lost its capacity to keep the line drawn on the figure.
can you help?