# Changelog

*Last updated: Tuesday, April 7, 2026*

## Active Areas

| Area | Changes (30d) | Status |
|------|---|---|
| Main loop & systems | 9 churn | Active — explicit storage parameters |
| Dialog system | 10 churn | Active — projectiles, camera, rendering |
| Render core | 15 churn | Active — text pipeline, font atlas, globals |
| World state | 8 churn | Active — intent storage, component management |
| Player mechanics | 6 churn | Stable — character bundle, player states |
| Shader system | 4 churn | Active — gizmo lines, dissolve, snow light |
| Content pipeline | 1 churn | New — Blender export addon |

## Recent Changes

### System Signature Refactor (Major)
- **Completed**: All 16 systems refactored to take explicit `Storage<T>` parameters instead of `&World`/`&mut World`.
- **Pattern**: Functions receive only storages they need (e.g., `camera_follow_system` takes `&Storage<FollowComponent>`, `&Storage<CameraComponent>`, `&mut Storage<Transform>`).
- **Benefit**: Explicit data dependencies improve borrow checker clarity and code readability.
- **Main loop** (`src/main.rs`): Updated to pass individual storage fields at call sites rather than whole `World` reference.
- **Affected systems**: `camera_input_system`, `camera_intent_system`, `camera_follow_system`, `camera_noclip_system`, `camera_ground_clamp_system`, `dialog_camera_transition_system`, `dialog_camera_system`, `player_input_system`, `physics_sync_system`, `render_system`, `particle_intent_system`, `particle_update_system`, `trigger_system`, `dialog_system`, `dialog_projectile_system`, all state machines.

### Intent-Based Architecture
- **Completed major refactor** (3 weeks ago): Systems communicate through one-frame `Storage<T>` intents instead of direct function calls.
- **Intent types**: `FollowPlayerIntent`, `StopFollowingIntent`, `CameraTransitionIntent`, `SpawnParticleIntent`.
- **Consumer pattern**: Systems read intents from world storage, act on them, then remove them. Producers don't import consumer modules.

### Dialog System Suite
- **Dialog state machine**: Ink-based story progression with display timer, projectile phases, parry mechanics.
- **Projectile system**: Spawns physics-driven projectiles with parry windows; detects hits vs. evasion vs. parries (I/J/L buttons).
- **Dialog camera**: Auto-frames all dialog participants; transitions smoothly between follow-cam and dialog-cam via intent; computes centroid + spread.
- **Bubble rendering**: Billboard-based text with word-wrap, dynamic sizing (tail height → body dimensions), border/fill colors, RGBA text atlas.

### Text & Font Rendering
- **Font atlas pipeline**: Pre-rasterized glyphs (16×8 grid, 124px cells) from Departure Mono font.
- **Text measurement**: Character-width aware layout with line wrapping against max bubble width.
- **Vertex-based text**: Custom `TextVertex` (position, UV) fed into dedicated text pipeline with view-proj uniform.

### Particle System
- **Intent-driven spawning**: `particle_intent_system` reads `spawn_particle_intents` Vec, transfers configs into persistent `ParticleBuffers`.
- **Configurable emitters**: Burst count, lifetime range, speed range, directional spread (cone), gravity, size range, color gradient.
- **Snow particle integration**: Spawned continuously at camera position for screen-fill effect; `spawn_snow_particles` adds particles to `ParticleBuffers`.

### Render Pipeline
- **Global renderer via thread-local**: `render::global` module centralizes `Device`/`Queue` access for loaders and systems.
- **Draw call generation**: `render_system` reads `entities`, `transforms`, `meshes`, `dissolves` storages; generates `DrawCall` per visible entity.
- **Gizmo shader**: Fragment shader outputs world-normal as axis color (X=red, Y=green, Z=blue).
- **Snow light accumulation**: Persistent texture tracking deformation; blue-noise dithering maps snow brightness into tile pattern.
- **Dissolve shader**: Blue-noise masked alpha cutoff; controlled by `enable_dissolve` uniform.

### Tree Occlusion & Instances
- **Tree dissolve system**: Per-instance dissolve amounts lerp toward targets; updated via `tree_occlusion_system` which reads player transforms and cameras.
- **Instance buffer sync**: `tree_instance_buffer_update_system` syncs dissolve state changes to GPU buffer after state updates.

### Trigger & Event Flow
- **Sphere-based triggers**: `trigger_system` runs each fixed step; reads `triggers`, `transforms`, `player_tags` storages; fires `TriggerEvent` with `Entered`/`Exited` kinds.
- **Activation filtering**: `TriggerFilter::Player` specifies which entity types can activate.
- **Event queue**: Events collected in `world.trigger_events` and consumed by `dialog_system` to spawn bubbles.

### Player State Machine
- **State hierarchy**: Idle, Walking, Jumping, Falling, Leaping (dash), Rolling.
- **Physics per-state**: `state_machine_physics_system` applies damping on enter (Idle), horizontal input application (Walking), vertical velocity control (Jumping).
- **Transition logic**: Grounded checks, input presence, airtime duration.

### Editor & Inspector
- **Dear ImGui integration**: Inspector window with player state display, entity transform gizmos.
- **Entity selection**: Right-click picking calls `picking::pick_entity` with ray; gizmo renders for selected entity when editor active.
- **UI mode gating**: Systems check `editor.wants_keyboard()`/`wants_mouse()` to suppress game input during inspector focus.

### Blender Export Addon
- **Plugin**: `blender/addons/snow_trail_export.py` provides one-click glTF + EXR export from Blender 5.0.
- **glTF operator** (`SNOWTRAIL_OT_export_gltf`): Exports selected mesh objects to `assets/meshes/{blend_filename}.gltf` with configurable modifiers, vertex colors, materials.
- **Heightmap bake operator** (`SNOWTRAIL_OT_export_heightmap`): Calls `generate_heightmap.py` to bake terrain Z-position as 32-bit EXR to `assets/textures/terrain_heightmap.exr` (1024px default).
- **UI panel**: "Snow Trail" category in 3D viewport; auto-discovers project root by walking directory tree until `assets/` and `blender/` found.

## Stability

| Area | Last Changed | Status |
|---|---|---|
| Physics manager | 80+ days | Stable |
| Camera follow | 30 days | Stable — now takes explicit storage params |
| Movement component | 30+ days | Stable |
| Mesh loader | 30+ days | Stable |
| Spotlight sync | 30 days | Stable — explicit storage params applied |
| State machine physics | 30 days | Stable |
| Debug colliders | 30+ days | Stable |
| System signatures | New | Stable — refactor complete, no behavioral changes |

## Open Threads

- **Global renderer thread-local**: Marked for gradual migration to explicit `RenderContext` parameters on systems/loaders.
- **Dialog parry mechanics**: Gameplay tuning (PARRY_WINDOW_RADIUS, HIT_RADIUS) ongoing.
- **Tree occlusion performance**: Occlusion system runs every frame; no visibility culling yet. Scalability unknown for >100 trees.
- **Heightmap bake normalization**: Exported EXR uses raw Z-coordinate; game may need per-level scale application.