[Feature]: Add support for plotting multiple expressions

[nsh07]

So, what is it about?

Implement a way for the user to plot multiple expressions, similar to how Desmos allows you to. Also allow the user to choose a color for each expression's graph.

Code of Conduct

• I agree to follow this project's Code of Conduct

[saumya1317]

assign this to me @nsh07

[nsh07]

sure, but first can you give me a brief overview of how you'll implement this feature?

[nsh07]

@saumya1317 I've assigned this to you. Just one thing: can you give me a brief overview of how you'll implement this before you start working, as asked above?

[saumya1317]

i will be creating a list/vector to store multiple expressions
Each entry contains: expression string, color, enabled flag
Default to having one expression (current behavior) , Add "Add Expression" button in left pane
For each expression: text input + color picker + delete button
Keep existing zoom slider at the top , then i will oop through all enabled expressions
For each expression:
Parse with exprtk (same logic as current)
Generate points using the expression
Draw polyline with chosen color
and will Handle both regular functions and parametric curves so if in very brief i will be doing ->Add the data structure at the top of our main loop
->Create the UI controls in the left pane (below the zoom slider)
->Modify the plotting section to iterate over all expressions
->Test with multiple functions like sin(x), cos(x), x^2

[nsh07]

Sounds great! Go ahead with the PR.

[nsh07]

@guptanshuman124 are you interested in implementing this? Make sure to keep it really simple, only add a plus button below the current expression to add more expressions, nothing else.

[guptanshuman124]

@nsh07 I have implemented multi-expression support and have little bugs in panning and zoom if you say I would make a pr for that.