OpenZoom

OpenZoom is a Windows-only camera magnification playground that experiments with real-time capture, GPU/CPU image processing, and live presentation. The current milestone runs entirely on the CPU for stability while keeping the CUDA + Direct3D12 pathway wired up for future kernels.

Highlights

• Media Foundation capture thread that speaks BGRA32, RGB32, NV12, and YUY2 and normalises everything into BGRA for rendering.
• Qt 6 widget shell hosting a Direct3D 12 swap chain, including resize-aware layout and clean shutdown handling.
• Debug-friendly grid compositor (defaults to 2×2 but now flexes to fit active views) that shows raw input, grayscale, zoom, and combined output so filter stages are easy to inspect.
• CUDA external-memory interop path now active with optional spatial sharpening (FSR 1.0-style or NVIDIA NIS) plus the legacy Gaussian blur toggle for clearer zoomed text.
• Temporal smoothing kernel adds an exponential running average to tame shimmer without losing responsiveness.
• Batch script that bootstraps a Visual Studio 2022 build, scrubs stale CMake caches, and launches the app when compilation succeeds.

Project Status

CPU presentation path is production-ready for debugging. CUDA kernels and zero-copy plumbing are staged but inactive. Next major push is to restore GPU processing inside the Qt/D3D12 architecture.

See docs/progress.md for a live task board and chatgpt_future_readme.txt for long-term design notes.

Prerequisites

• Windows 10/11 with a CUDA-capable NVIDIA GPU (SM 7.5, 8.6, or 8.9 tested).
• Visual Studio 2022 with Desktop C++ workload and the Windows 10/11 SDK.
• CUDA Toolkit 13.x (ensure nvcc and headers are on PATH/INCLUDE).
• Qt 6.9.3 (MSVC 2022 64-bit build) or adjust QT_PREFIX/Qt6_DIR to match your install.
• CMake ≥ 3.23; Ninja is optional but recommended for non-MSBuild workflows.

Quick Start (Visual Studio generator)

1. Open a "x64 Native Tools Command Prompt for VS 2022" or a PowerShell session with VS, Qt, and CUDA on PATH.
2. Run the helper script:

   scripts\build_and_run.bat

3. If Windows reports missing Qt6*.dll files, append the Qt bin directory (for example C:\Qt\6.9.3\msvc2022_64\bin) to PATH or copy those DLLs next to open_zoom.exe.

Alternative: Ninja build

cmake -S . -B build-ninja -G "Ninja" -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH="C:/Qt/6.9.3/msvc2022_64" -DCMAKE_CUDA_ARCHITECTURES="75;86;89"
cmake --build build-ninja

Run the produced open_zoom.exe from build-ninja (ensure Qt DLLs are discoverable).

Bundled Release build

scripts\build_release_bundle.bat

Creates dist\OpenZoom\ with open_zoom.exe, the required Qt DLLs, and CUDA runtime components (when CUDA is enabled) so the app can be copied to another machine.

Runtime Controls

• Camera picker combo box selects the active Media Foundation device.
• Black & White checkbox toggles grayscale processing.
• Zoom checkbox enables the magnifier.
• Temporal Smooth checkbox blends frames using an exponential running average (slider controls the new-frame weight).
• Rotation button cycles the scene clockwise in 90° steps and updates the full processing pipeline, keeping focus tools aligned with the rotated view.
• The debug grid displays: top-left raw feed, top-right grayscale, bottom-left zoom, bottom-right combined result, expanding beyond 2×2 when additional stages are enabled.
• Session preferences persist automatically. OpenZoom saves the most recent camera choice and tuning values to %APPDATA%\OpenZoom\OpenZoom\settings.json; delete that file to reset back to the defaults.

Repository Layout

• src/app/ – Qt application shell, entry point, and high-level wiring.
• src/cuda/ – CUDA interop surface, kernels, and future GPU helpers.
• src/d3d12/, src/capture/, src/ui/, src/common/ – stubs reserved for the ongoing modularisation work (see module README files).
• include/openzoom/ – Public headers mirroring the src/ tree.
• docs/ – Supplemental design notes, license notices, agent guides.
• scripts/ – Local tooling (build, bundling, automation helpers).
• cmake/ – CMake option definitions and shared configuration fragments.
• ref/ – External references and scratch assets (ignored by git).
• build/ – Default out-of-source build directory (generated).

Development Notes

• The CPU path keeps frame processing deterministic for debugging; CUDA kernels will re-use the same pipeline once interop validation is complete.
• Stale build trees (e.g., when switching between \wsl$ and local paths) can confuse CMake; the batch script auto-cleans mismatched caches.
• When experimenting with CUDA interop, ensure CudaInteropSurface::IsValid gates presentation to avoid presenting invalid resources.

Roadmap

• Restore CUDA external-memory interop and port temporal filters (averaging, stabilization scaffolding).
• Add still-frame capture and encoding once GPU path returns.
• Improve presentation overlays (FPS, format diagnostics, histogram views).
• Expand automated checks for kernel outputs and add regression tests via OPENZOOM_ENABLE_TESTS.

For deeper architectural context and historical notes, start with docs/README.md.

License

This project is dual-licensed:

• GPL-3.0 — open-source usage under the GNU General Public License (license text included in LICENSE).
• Commercial License — proprietary terms available by contacting sales@example.com.

By submitting a pull request you agree that your contribution may be distributed under both licenses. Third-party notices are collected in docs/THIRD_PARTY_LICENSES.md.