Add README / Set current objectives

README.md

@@ -0,0 +1,67 @@
+# Large Instanced Ontology Visualizer
+
+An experimental visualizer designed to render and explore massive instanced ontologies (millions of nodes) with interactive performance.
+
+## 🚀 The Core Challenge
+Ontologies with millions of instances present a significant rendering challenge for traditional graph visualization tools. This project solves this by:
+1.  **Selective Rendering:** Only rendering up to a set limit of nodes (e.g., 2 million) at any given time.
+2.  **Adaptive Sampling:** When zoomed out, it provides a representative spatial sample of the nodes. When zoomed in, the number of nodes within the viewport naturally falls below the rendering limit, allowing for 100% detail with zero performance degradation.
+3.  **Spatial Indexing:** Using a custom Quadtree to manage millions of points in memory and efficiently determine visibility.
+
+## 🛠 Technical Architecture
+
+### 1. Data Pipeline & AnzoGraph Integration
+The project features an automated pipeline to extract and prepare data from an **AnzoGraph** DB:
+-   **SPARQL Extraction:** `scripts/fetch_from_db.ts` connects to AnzoGraph via its SPARQL endpoint. It fetches a seed set of subjects and their related triples, identifying "primary" nodes (objects of `rdf:type`).
+-   **Graph Classification:** Instances are categorized to distinguish between classes and relationships.
+-   **Force-Directed Layout:** `scripts/compute_layout.ts` calculates 2D positions for the nodes using a **Barnes-Hut** optimized force-directed simulation, ensuring scalability for large graphs.
+
+### 2. Quadtree Spatial Index
+To handle millions of nodes without per-frame object allocation:
+-   **In-place Sorting:** The Quadtree (`src/quadtree.ts`) spatially sorts the raw `Float32Array` of positions at build-time.
+-   **Index-Based Access:** Leaves store only the index ranges into the sorted array, pointing directly to the data sent to the GPU.
+-   **Fast Lookups:** Used for both frustum culling and efficient "find node under cursor" calculations.
+
+### 3. WebGL 2 High-Performance Renderer
+The renderer (`src/renderer.ts`) is built for maximum throughput:
+-   **`WEBGL_multi_draw` Extension:** Batches multiple leaf nodes into single draw calls, minimizing CPU overhead.
+-   **Zero-Allocation Render Loop:** The frame loop uses pre-allocated typed arrays to prevent GC pauses.
+-   **Dynamic Level of Detail (LOD):** 
+    -   **Points:** Always visible, with adaptive density based on zoom.
+    -   **Lines:** Automatically rendered when zoomed in deep enough to see individual relationships (< 20k visible nodes).
+    -   **Selection:** Interactive selection of nodes highlights immediate neighbors (incoming/outgoing edges).
+
+## 🚦 Getting Started
+
+### Prerequisites
+-   Docker and Docker Compose
+-   Node.js (for local development)
+
+### Deployment
+The project includes a `docker-compose.yml` that spins up both the **AnzoGraph** database and the visualizer app.
+
+```bash
+# Start the services
+docker-compose up -d
+
+# Inside the app container, the following will run automatically:
+# 1. Fetch data from AnzoGraph (fetch_from_db.ts)
+# 2. Compute the 2D layout (compute_layout.ts)
+# 3. Start the Vite development server
+```
+
+The app will be available at `http://localhost:5173`.
+
+## 🖱 Interactions
+-   **Drag:** Pan the view.
+-   **Scroll:** Zoom in/out at the cursor position.
+-   **Click:** Select a node to see its URI/Label and highlight its neighbors.
+-   **HUD:** Real-time stats on FPS, nodes drawn, and current sampling ratio.
+
+## TODO
+-   **Positioning:** Use better algorithm to position nodes, trying to avoid as much as possible any edges crossing, but at the same time trying to keep the graph compact. 
+-   **Positioning:** Decide how to handle classes which are both instances and classes. 
+-   **Functionality:** Find every equipment with a specific property or that participate in a specific process.
+-   **Functionality:** Find every equipment which is connecte to a well.
+-   **Functionality:** Show every connection witin a specified depth.
+-   **Functionality:** Show every element of a specific class.