feat: integrate a* and pathfinding service (#259)

Author: tommy-xr

Cargo.lock

@@ -166,7 +166,7 @@ The visualization successfully displays:
 
 ## Phase 3: A* Pathfinding Integration
 
-**Goal**: Implement pathfinding using the `pathfinding` crate to find routes through the cell graph.
+**Goal**: Implement pathfinding using the `pathfinding` crate to find routes through the cell graph with interactive testing.
 
 ### Dependencies
 
@@ -179,9 +179,12 @@ pathfinding = "4"
 
 | File | Action | Purpose |
 |------|--------|---------|
-| `shock2vr/src/pathfinding/mod.rs` | Create | Pathfinding service and queries |
+| `shock2vr/src/pathfinding/mod.rs` | Create | PathfindingService and AIPATH cell queries |
 | `shock2vr/src/pathfinding/cell_graph.rs` | Create | Graph adapter for pathfinding crate |
+| `shock2vr/src/pathfinding/path_visualization.rs` | Create | Multi-path visualization system |
 | `shock2vr/src/lib.rs` | Modify | Add pathfinding module |
+| `runtimes/desktop_runtime/src/main.rs` | Modify | Add P key for interactive pathfinding test |
+| `runtimes/debug_runtime/src/main.rs` | Modify | Add HTTP pathfinding-test commands |
 
 ### Core API Design
 
@@ -193,7 +196,8 @@ pub struct PathfindingService {
 }
 
 impl PathfindingService {
-    /// Find the cell containing a world position
+    /// Find the AIPATH cell containing a world position
+    /// Uses simple point-in-polygon tests (can be optimized later)
     pub fn cell_from_position(&self, pos: Vector3<f32>) -> Option<u32>;
 
     /// Find path from start position to goal position
@@ -216,6 +220,54 @@ impl PathfindingService {
 }
 ```
 
+### Interactive Pathfinding Test System
+
+**Desktop Runtime (P Key):**
+- **Press 1**: Set start position (player location), show green marker
+- **Press 2**: Set goal position (player location), compute A* path, show green path
+- **Press 3**: Reset/clear all markers and test paths
+
+**Debug Runtime (HTTP Commands):**
+```bash
+# Set start position to player's current location
+curl -X POST http://127.0.0.1:8080/v1/pathfinding-test -d '{"action": "set_start"}'
+
+# Set goal position and compute path
+curl -X POST http://127.0.0.1:8080/v1/pathfinding-test -d '{"action": "set_goal"}'
+
+# Clear test data
+curl -X POST http://127.0.0.1:8080/v1/pathfinding-test -d '{"action": "reset"}'
+```
+
+### Multi-Path Visualization System
+
+```rust
+// shock2vr/src/pathfinding/path_visualization.rs
+
+pub struct PathVisualizationSystem {
+    pub paths: HashMap<String, ComputedPath>,
+}
+
+pub struct ComputedPath {
+    pub waypoints: Vec<Vector3<f32>>,
+    pub color: Vector3<f32>,      // Green for test, different colors for AI
+    pub name: String,             // "test_path", "grunt_1_path", etc.
+    pub markers: Vec<PathMarker>, // Start/goal markers
+}
+
+pub struct PathMarker {
+    pub position: Vector3<f32>,
+    pub marker_type: MarkerType,  // Start, Goal, Waypoint
+    pub color: Vector3<f32>,
+}
+```
+
+This design supports:
+- **Interactive testing** before AI integration
+- **Multiple simultaneous paths** for different AI entities
+- **Easy switching** between spatial query strategies
+- **Flexible visualization** with named paths and custom colors
+
 ### Implementation Steps
 
 1. **Create pathfinding module structure**

projects/ai-pathfinding.md

@@ -23,6 +23,7 @@ num-derive = "0.3.3"
 num-traits = "0.2.15"
 once_cell = "1.17.0"
 ordered-float = "3.4.0"
+pathfinding = "4"
 pcx = "0.2.3"
 rapier3d = { version = "0.19.0", features = ["debug-render"] }
 serde_json = "1.0.91"

shock2vr/Cargo.toml

@@ -12,6 +12,7 @@ mod creature;
 mod gui;
 mod hud;
 mod mission;
+pub mod pathfinding;
 pub mod paths;
 mod physics;
 mod quest_info;

shock2vr/src/lib.rs

@@ -1,8 +1,12 @@
+use crate::creature::HUMAN_HEIGHT;
 /// Pathfinding debug visualization for AI navigation mesh
 use cgmath::Vector3;
 use dark::mission::PathDatabase;
 use engine::scene::{SceneObject, VertexPosition, color_material, lines_mesh};
 
+/// Height offset for pathfinding visualization - center of human height
+const PATH_NODE_HEIGHT: f32 = HUMAN_HEIGHT / 2.0;
+
 /// Renders pathfinding visualization as scene objects
 ///
 /// Creates cyan lines for navigation cells and polygons, and yellow lines for cell links.
@@ -14,9 +18,9 @@ pub fn render_pathfinding_debug(path_database: &PathDatabase) -> Vec<SceneObject
 
     // Render path cells as cyan polygons and center crosses
     for cell in &path_database.cells {
-        let center = cell.center;
+        let center = cell.center + Vector3::new(0.0, PATH_NODE_HEIGHT, 0.0);
 
-        // Create a small cross at the center
+        // Create a small cross at the center (raised to human eye level)
         let size = 0.1;
         cyan_lines.push(VertexPosition {
             position: Vector3::new(center.x - size, center.y, center.z),
@@ -66,14 +70,16 @@ pub fn render_pathfinding_debug(path_database: &PathDatabase) -> Vec<SceneObject
         let to_cell_idx = link.to_cell as usize;
 
         if from_cell_idx < path_database.cells.len() && to_cell_idx < path_database.cells.len() {
-            let from_center = &path_database.cells[from_cell_idx].center;
-            let to_center = &path_database.cells[to_cell_idx].center;
+            let from_center = path_database.cells[from_cell_idx].center
+                + Vector3::new(0.0, PATH_NODE_HEIGHT, 0.0);
+            let to_center =
+                path_database.cells[to_cell_idx].center + Vector3::new(0.0, PATH_NODE_HEIGHT, 0.0);
 
             yellow_lines.push(VertexPosition {
-                position: Vector3::new(from_center.x, from_center.y, from_center.z),
+                position: from_center,
             });
             yellow_lines.push(VertexPosition {
-                position: Vector3::new(to_center.x, to_center.y, to_center.z),
+                position: to_center,
             });
         }
     }