Graph 2 (for the Arduboy)

A graphing calculator for your Arduboy!

Features

Here's what's currently here:

• Simple keypad for entering numbers
• An RPN calculator
• Graph output
• Shunting-yard algorithm for converting user-readable functions.
• Formula keyboard
• Direct mode (enter formulas, get response)
• Table view

Here's what I hope to accomplish in the near future:

• Better error reporting
• Coherent UI
• Table "entry mode" and "jump to" setting.
• Settings (disable axis lines, dots instead of lines, DEG or RAD, etc.)

Known Issues

Some issues are copied from the Arduboy forum thread:

• Division operations are reversed (Function-related issue)
• Cursor soft-resets Arduboy when it goes offscreen on main menu RPN debug screen (GraphFont-related issue)
  • This is "solved" but the root issue is not solved.
• Implicit Multiplication doesn't work (Function-related issue) - 2x
• Error reporting doesn't exist - functions fail silently (Function-related issue) - x+
  • Error reporting should happen in two stages -- one where the char string is being parsed, one where the function is being graphed. This would allow for syntax errors to be reported in a place nicer than the graph's draw function.
• Graph object wastes a lot of memory by storing all Y values (Graph-related issue)
• Prepare for functions by converting existing char input system over to a token-based system (Big issue)
  • This means using a more TI-84-like system where there's a dedicated unary minus token and it's completely different from the subtraction token.
• Unary Negative doesn't work (Function-related issue) - -5*x
• Optimize more menus (draw only when you need to)
• There are a few todos hidden in the code.
• Why does cursor.cpp exist?

Screenshots

I'm still working on parts of the UI!

• The window settings are next to recieve an overhaul. I'll add simple "nudge" and "zoom" controls and make the stuff there look better.
• The trace menu is very bare. Need to improve it too.
• Direct could look much much better. A scrolling display not unlike the TI-84 would be welcome.

Here's the menus that are already "done":

If you want to see where I started, check out this Twitter thread!

Credits

• Me - UI, RPN calculator, font
• SmileBASIC Discord - A lot of help with C++
• snail_ - Some help with the Shunting-Yard Algorithm
• yinkou - TinyFont code, used as base for GraphFont