zenith-desktop

Imported from ajeet-krish/zenith-desktop (AGENTS.md). Install upstream with npx skills add ajeet-krish/zenith-desktop. Copyright stays with the author.

Project Context, Zenith: High-Fidelity Orbital Propagation Engine

Style Rules

• No em dashes or two hyphens (--) in any file. Use standard punctuation.
• C++ code style: 4-space indentation, K&R braces, no tabs, no trailing whitespace.
• Variable naming: snake_case for local variables, PascalCase for structs/classes, SCREAMING_SNAKE_CASE for constants.
• Header-only pattern: All core logic in .hpp files with #pragma once. Use inline for functions and variables to avoid ODR violations.
• Enum classes: All enums use enum class with PascalCase values.
• Global variables: g_ prefix for inline globals (e.g., g_mu_earth, g_use_j2).
• HTML/CSS: Double quotes for attributes, 2-space indentation, semantic HTML5 elements.
• JavaScript: ES6+ modules where supported, 2-space indentation, single quotes for strings, semicolons required.
• No em dashes in JS/HTML: Use -- or — entity.

Goal

Build and deploy a comprehensive orbital mechanics suite in C++20 as a portfolio piece for Flight Dynamics Analyst roles (MDA, SpaceX, ULA). Covers the full flight dynamics pipeline: parse, propagate, determine, analyze, visualize. Uses Apple Metal GPU compute for parallel propagation of 10,000+ orbits, Dear ImGui + OpenGL for real-time visualization, and Python for orbit determination.

Target Audience

Aerospace hiring managers at MDA, SpaceX, Lockheed Martin, ULA, and similar. The project must communicate: orbit propagation competency (SGP4, numerical integrators, force models), orbit determination skills (batch least-squares, EKF), conjunction assessment, GPU computing (Metal), and engineering communication (interactive visualization, portfolio website).

Hardware

MacBook Pro M5, 16GB unified memory, 10-core GPU. Apple Silicon -- no CUDA support. Use Apple Metal for GPU compute.

Current Status

File Layout

zenith/
├── AGENTS.md                    # This file
├── README.md                    # Project overview
├── PROJECT_PLAN.md              # Comprehensive project plan
├── CMakeLists.txt               # Build system
├── .gitignore
│
├── src/
│   ├── core/                    # Layer 1: Physics engine (header-only)
│   │   ├── orbit_types.hpp      # State vectors, orbital elements, constants
│   │   ├── time_system.hpp      # UTC, UT1, TAI, Julian date conversions
│   │   ├── coordinate_frames.hpp # TEME, GCRF, ECEF conversions
│   │   ├── kepler.hpp           # Keplerian propagation
│   │   ├── sgp4_parser.hpp      # TLE parsing
│   │   ├── sgp4_propagator.hpp  # SGP4/SDP4 analytical propagation
│   │   ├── force_models.hpp     # J2/J4, drag, SRP, third-body
│   │   └── integrators.hpp      # RK4, RK45 (Dormand-Prince)
│   │
│   ├── gpu/                     # Layer 2: Metal compute (Phase 2)
│   │   ├── metal_context.hpp
│   │   ├── orbit_kernel.metal
│   │   ├── gpu_propagator.hpp
│   │   └── buffer_pool.hpp
│   │
│   ├── analysis/                # Layer 3: Analysis (Phase 3)
│   │   ├── conjunction.hpp
│   │   ├── ground_track.hpp
│   │   ├── pass_predictor.hpp
│   │   ├── maneuver.hpp
│   │   ├── monte_carlo.hpp
│   │   └── coverage.hpp
│   │
│   ├── viz/                     # Layer 4: Visualization (Phase 4)
│   │   ├── orbit_viewer.hpp
│   │   ├── earth_renderer.hpp
│   │   ├── orbit_trail.hpp
│   │   └── imgui_interface.hpp
│   │
│   └── main_propagate.cpp       # CLI entry point
│
├── python/
│   ├── pyproject.toml
│   ├── orbit_determination/     # Batch LS + EKF (Phase 3)
│   ├── data/                    # TLE fetcher
│   └── postprocess/             # Matplotlib plots
│
├── tests/
│   ├── test_kepler.cpp
│   ├── test_sgp4.cpp
│   ├── test_force_models.cpp
│   ├── test_integrators.cpp
│   └── test_time_system.cpp
│
├── validation/
│   ├── sgp4_test_vectors.txt
│   └── vallado_examples.txt
│
├── docs/                        # Portfolio website (Phase 5)
│   ├── index.html
│   ├── orbit-viewer.html
│   ├── theory.html
│   ├── results.html
│   ├── implementation.html
│   ├── css/style.css
│   └── assets/
│
└── .github/workflows/ci.yml

Build Commands

Key Architecture Decisions