TikZ Studio

A visual editor for creating TikZ diagrams, built with Qt6 and C++. Draw shapes interactively and export clean LaTeX TikZ code.

Features

• Drawing Tools: Points, lines, polygons, curves (smooth splines), ellipses/circles
• Shape Tools: Rectangle, circle, ellipse, triangle, regular polygon (N-gon)
• Background Tracing: Load an image to trace over with adjustable opacity
• Per-Vertex Corner Radius: Round individual corners of polygons
• Real-Time TikZ Output: See generated code update as you draw
• Compile & Preview: One-click compilation with pdflatex to verify output
• Context Menus: Right-click shapes to edit properties, round corners, delete
• Grid Snapping: Coordinates snap to 0.25 TikZ unit grid
• UofSC Color Palette: Built-in University of South Carolina brand colors

Requirements

• Qt6 (or Qt5 with minor adjustments)
• CMake 3.16+
• C++17 compiler
• pdflatex (for compile & preview feature)

macOS

brew install qt@6 cmake

Ubuntu/Debian

sudo apt install qt6-base-dev cmake build-essential texlive-latex-base

Building

cd tikz-studio
mkdir build && cd build
cmake ..
make -j$(nproc)

Running

# macOS
open tikz_editor.app

# Linux
./tikz_editor

Project Structure

tikz-studio/
├── CMakeLists.txt          # Build configuration
├── src/
│   ├── main.cpp            # Application entry point
│   ├── common.h            # Global constants, coordinate transforms, colors
│   ├── data/               # Data model classes (document state)
│   │   ├── document.h/cpp  # Central document holding all shapes
│   │   ├── point.h/cpp     # Named point with coordinates
│   │   ├── line.h/cpp      # Line between two points
│   │   ├── polygon.h/cpp   # Closed polygon with per-vertex corner radius
│   │   ├── curve.h/cpp     # Smooth curve through control points
│   │   └── ellipse.h/cpp   # Ellipse/circle with center, radii, rotation
│   └── gui/                # Qt graphics and UI classes
│       ├── mainwindow.h/cpp      # Main application window
│       ├── canvas.h/cpp          # QGraphicsScene handling drawing logic
│       ├── canvasview.h/cpp      # QGraphicsView with zoom/pan
│       ├── toolpalette.h/cpp     # Tool selection buttons
│       ├── colorpalette.h/cpp    # Color selection buttons
│       ├── propertiespanel.h/cpp # Properties editor for selected shapes
│       ├── pointitem.h/cpp       # Visual representation of Point
│       ├── lineitem.h/cpp        # Visual representation of Line
│       ├── polygonitem.h/cpp     # Visual representation of Polygon
│       ├── curveitem.h/cpp       # Visual representation of Curve
│       └── ellipseitem.h/cpp     # Visual representation of Ellipse
└── resources/              # (Reserved for icons, etc.)

Architecture

Model-View Separation

The application follows a strict model-view pattern:

• Data classes (src/data/): Pure data objects representing geometric primitives. These emit changed() signals when modified and know how to serialize themselves to TikZ code.

• Graphics items (src/gui/*item.cpp): Qt QGraphicsItem subclasses that visualize the data. They observe their corresponding data object and update when it changes.

• Document: Central container holding all shapes. Manages creation/deletion and generates the complete TikZ output.

Coordinate System

• TikZ coordinates: Standard mathematical (Y-up) coordinate system
• Screen coordinates: Qt's Y-down coordinate system
• Conversion: toScreen() and fromScreen() functions in common.h
• Scale: 40 pixels = 1 TikZ unit (configurable via GLOBAL_SCALE)
• Grid: Minor grid at 0.25 units, major grid at 1.0 unit

Tool System

Tools are enumerated in common.h:

Tool	Description
Select	Click to select, drag to move shapes
Point	Click to place named coordinate points
Line	Click two points or positions to draw a line
Polygon	Click to add vertices, double-click to close
Curve	Click to add control points, double-click to finish
Rectangle	Drag to draw axis-aligned rectangle
Circle	Drag to draw circle (radius from center to cursor)
Ellipse	Drag to draw ellipse (separate X/Y radii)
Triangle	Drag to draw equilateral triangle
RegularPolygon	Drag to draw N-sided regular polygon

TikZ Code Generation

Each shape class implements a tikz() method returning its TikZ representation:

• Points: \coordinate (name) at (x, y);
• Lines: \draw (start) -- (end);
• Polygons: \draw[fill=color] (p1) -- (p2) -- ... -- cycle;
• Curves: \draw plot[smooth] coordinates {(p1) (p2) ...};
• Ellipses: \draw (center) ellipse (rx and ry);

Rounded corners use TikZ's rounded corners=Xpt option or per-vertex bezier control points.

Usage

Basic Workflow

1. Select a tool from the left toolbar
2. Choose stroke/fill colors from the color palette
3. Draw on the canvas (click, drag, or click-click depending on tool)
4. View generated TikZ in the right panel
5. Click "Compile & Preview" to verify the LaTeX output
6. Export via File → Export TikZ

Keyboard Shortcuts

Key	Action
Ctrl+N	New document
Ctrl+O	Open document
Ctrl+S	Save document
Ctrl+Shift+S	Save as
Ctrl+E	Export TikZ
Ctrl+Z	Undo
Ctrl+Shift+Z	Redo
Delete	Delete selected
Ctrl++	Zoom in
Ctrl+-	Zoom out
Ctrl+0	Reset zoom

Right-Click Context Menu

Right-click on any shape to access:

• Polygons: Round All Corners, Sharp All Corners, Convert to Circle
• Ellipses: Make Circle (equalize radii)
• All shapes: Edit Properties, Delete

Background Images

1. Open the "Background" dock panel
2. Click "Load Image..." to select an image
3. Adjust opacity slider to see grid through image
4. Draw over the image to trace

Future Improvements

High Priority

• Undo/Redo integration: Currently stubbed with QUndoStack but commands not implemented
• Arrow heads: Add arrow tip styles for lines and curves
• Text labels: Add text/label tool for annotating diagrams
• Snap to points: When drawing, snap to existing named points
• Bezier curve tool: Direct bezier control point manipulation
• Copy/Paste: Duplicate shapes with Ctrl+C/Ctrl+V

Medium Priority

• Layer system: Organize shapes into layers with visibility toggles
• Style presets: Save and reuse line width/color/fill combinations
• TikZ import: Parse existing TikZ code to edit visually
• Multiple documents: Tab-based interface for multiple files
• Dimension tool: Draw measurement annotations
• Align/distribute: Align selected shapes horizontally/vertically

Low Priority / Nice-to-Have

• Node shapes: TikZ node shapes (rectangle, circle, diamond, etc.)
• Decorations: Zigzag, coil, snake line decorations
• Patterns: Fill patterns (hatching, dots, etc.)
• Export formats: SVG, PNG export in addition to TikZ
• Theming: Dark mode support
• Plugin system: Extensible tool/shape system

Intelligent Drawing Tools

• Image-to-TikZ vectorization: Import a raster image and automatically trace it into editable TikZ shapes using edge detection and contour extraction
• Path simplification: Use Ramer-Douglas-Peucker with a user-controlled epsilon to trade accuracy for readability — fewer bezier control points, shorter decimals
• Coordinate snapping on import: Round all imported coordinates to a configurable grid (e.g. 0.25 units) to eliminate ugly long decimals and produce human-readable output
• Primitive recognition: Detect circles, ellipses, and polylines in traced contours and emit native TikZ primitives (\draw ... circle, ellipse, --) instead of bezier approximations
• Color region detection: Segment color regions from the source image and assign fill colors to closed shapes automatically
• Control system diagram import: Recognize handdrawn block diagram elements (blocks, summing junctions, signal lines, arrowheads) and emit semantic TikZ using the positioning and arrows libraries with relative node placement rather than raw coordinates
• Transfer function parsing: Parse user-provided transfer function labels (e.g. K/(s+a), s^2 + 2*zeta*omega*s + omega^2) into symbolic form using SymPy for downstream analysis
• Block diagram reduction: Compute closed-loop transfer function from extracted topology — series/parallel/single-loop cases first, with Mason's gain formula for multi-loop systems
• System analysis backend: Call python-control as a subprocess to compute step response, impulse response, Bode plot, Nyquist, and root locus from the reduced transfer function
• Analysis type inference: Detect system type from diagram structure (PID, filter, observer, etc.) and offer the most relevant analyses automatically
• Response plot codegen: Generate pgfplots TikZ from simulation output and insert the resulting plot directly into the tikz-studio document as an editable figure

Code Quality

• Unit tests: Add tests for coordinate transforms, TikZ generation
• Fix Qt6 deprecation warnings: Update addAction() calls to new API
• Error handling: Better error messages for compile failures
• Settings persistence: Remember window layout, recent files
• Localization: i18n support for multiple languages

Design

The UI uses a clean black and white theme for clarity:

• All UI elements (menus, toolbars, buttons, panels) are white with black borders
• Selected tools and pressed buttons invert to black with white text
• The color palette retains the full UofSC color set for selecting shape fill/stroke colors

Shape Color Palette

Built-in UofSC brand colors for shapes (defined in common.h):

Color	Hex
Garnet	#73000A
Black	#000000
White	#FFFFFF
Rose	#CC2E40
Atlantic	#466A9F
Congaree	#1F414D
Horseshoe	#65780B
Grass	#CED318
Honeycomb	#A49137
Dark Garnet	#570008
Azalea	#844247

License

MIT License - See LICENSE file for details.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Submit a pull request

Please follow the existing code style and add tests for new functionality.