Infinite Canvas

This project is being built collaboratively with Claude (Anthropic's AI assistant). The architecture, features, and code are developed through an iterative conversation — Claude writes and refines the implementation while the human steers the design.

Crystal + Raylib desktop app: an infinite, pannable/zoomable canvas for sketching diagrams and taking notes. Supports rectangles with editable labels and plain text nodes.

Prerequisites

• Crystal >= 1.10
• Raylib 5.0 native library
• OpenSSL development libraries (required by Crystal's UUID stdlib)

On macOS: brew install crystal raylib openssl On Arch: pacman -S crystal shards raylib openssl

Building Raylib 5.0 locally (Debian/Ubuntu)

If a distro package for Raylib 5.0 is not available, build it from source and install it under the repo directory so no root access is required:

# Install build tools, Raylib's system dependencies, and OpenSSL dev headers
sudo apt-get install -y cmake libasound2-dev libx11-dev libxrandr-dev \
    libxi-dev libgl1-mesa-dev libglu1-mesa-dev libxcursor-dev libxinerama-dev \
    libssl-dev

# Clone and build Raylib 5.0
git clone --depth 1 --branch 5.0 https://github.com/raysan5/raylib
cmake raylib -DBUILD_SHARED_LIBS=ON -DCMAKE_BUILD_TYPE=Release -B raylib/build
cmake --build raylib/build

# Install into a local prefix (no sudo needed)
cmake --install raylib/build --prefix local

This places libraylib.so under local/lib/.

Build & run

Source env.sh to set the library paths, then use the standard shards commands:

source env.sh
shards install
shards build --release
./bin/infinite_canvas

When Raylib is installed system-wide (e.g. via a package manager) the source env.sh step can be skipped.

Both variables in env.sh point to the locally built Raylib:

You can make the run-time path permanent by adding the following line to /etc/ld.so.conf.d/raylib.conf (requires root) and then running sudo ldconfig:

/absolute/path/to/local/lib

Controls

Tools

Switch tools with the keyboard. The active tool is shown in the top-left HUD.

After placing an element with Rect or Text, the tool automatically returns to Select and the new element is selected.

Editing

Canvas navigation

The canvas is saved to canvas.json in the working directory on exit and restored automatically on next launch.

Layout

• src/infinite_canvas.cr — entry point, window setup, main loop, HUD
• src/canvas.cr — camera, grid, input handling, element management
• src/element.cr — Element base class, RectElement, TextElement
• src/persistence.cr — JSON serialization for save/load