AxionPlot

A full graphing calculator built with C and Raylib, compiled to WebAssembly for the browser.

Plot functions interactively with pan/zoom, multiple graph modes, an on-screen keypad, scientific calculator, value tables, trace mode, and adjustable display quality.

Features

Graphing

• Cartesian plots: y = sin(x), x^2 + a*x + b
• Parametric plots: x(t) = cos(t), y(t) = sin(t)
• Polar plots: r(t) = 1 + cos(t)
• Up to 32 simultaneous graphs with show/hide toggles
• Adaptive grid with axis labels
• Trace mode: vertical cursor shows (x, y) on each visible graph
• Pan (drag) and zoom (scroll wheel) on the plot area

Display quality

• Adjustable window sizes: 1280×720, 1600×900, 1920×1080, 2560×1440
• Supersampling quality: 1× (standard), 2× (high), 3× (ultra)
• MSAA and HiDPI support on desktop
• Display tab in-app (window size on desktop; canvas follows browser on web)

Calculator

• Scientific expression evaluation (sin, cos, tan, sqrt, ln, log, abs, etc.)
• Variables a, b, c assignable via a=2 or a=sin(pi/4)
• On-screen keypad for numbers, operators, and functions
• Value table for any plotted function

Platforms

• Native desktop (Linux, macOS, Windows)
• Web browser via WebAssembly

Requirements

• CMake 3.15+
• make and a C compiler (GCC or Clang)
• OpenGL development libraries (desktop only)
• git (for fetching Raylib and Emscripten)

Build

All builds go through the Makefile (which wraps CMake):

make              # native desktop build (default 1920×1080 @ 2× quality)
make native       # same as above
make wasm         # WebAssembly build
make run          # build and run native app
make run-web      # build WASM and serve at http://localhost:8000
make clean        # remove build/ and build-web/

Override default resolution at build time:

make native WIDTH=1280 HEIGHT=720 SCALE=1
make wasm WIDTH=1920 HEIGHT=1080 SCALE=1   # web defaults to SCALE=1

Emscripten setup

One-time install (clones SDK to tools/emsdk/):

make setup-emsdk
make wasm

The Makefile activates Emscripten automatically for make wasm. To use emcc directly in your shell:

source tools/emsdk/emsdk_env.sh

Manual Emscripten install

If you prefer a system-wide install:

git clone https://github.com/emscripten-core/emsdk.git ~/emsdk
cd ~/emsdk
./emsdk install latest
./emsdk activate latest
source ~/emsdk/emsdk_env.sh
make wasm

Fedora users may also need:

sudo dnf install cmake gcc git python3

Run

Desktop:

make run
# or
./build/AxionPlot

Web:

make run-web
# Open http://localhost:8000/

Use the Display tab to change render quality. On desktop you can also change window size; on web the canvas follows the browser window.

Deploy to Cloudflare Pages

Cloudflare's build image does not include cmake by default. Use the provided build script:

Setting	Value
Build command	bash scripts/cloudflare-build.sh
Build output directory	build-web

The script installs cmake (via apt or a portable download), sets up Emscripten, and builds the WASM bundle. It also copies _headers so .wasm files are served with the correct MIME type.

Alternative (if cmake is already available):

make setup-emsdk && make wasm SCALE=1

Usage

Input / Action	Result
sin(x)	Plot sine wave (Cartesian mode)
cos(t), sin(t)	Plot circle (Parametric mode)
1+cos(t)	Plot cardioid (Polar mode)
a=3	Set variable a to 3
Display tab	Change window size and render quality
F11	Toggle fullscreen (desktop)
Mouse drag (plot area)	Pan
Scroll wheel (plot area)	Zoom toward cursor

Project layout

src/           Application source
lib/           tinyexpr and raygui
web/           Emscripten HTML shell
CMakeLists.txt Build definition (used by Makefile)
Makefile       Build entry point

License

See LICENSE.