131 lines
3.9 KiB
Markdown
131 lines
3.9 KiB
Markdown
# Part 4: Field of View and Exploration
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## Overview
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Part 4 introduces the Field of View (FOV) system, transforming our fully-visible dungeon into an atmospheric exploration experience. We leverage McRogueFace's built-in FOV capabilities and perspective system for efficient rendering.
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## What's New in Part 4
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### Field of View System
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- **FOV Calculation**: Using `Grid.compute_fov()` with configurable radius
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- **Perspective System**: Grid tracks which entity is the viewer
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- **Visibility States**: Unexplored (black), explored (dark), visible (lit)
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- **Automatic Updates**: FOV recalculates on player movement
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### Implementation Details
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#### FOV with McRogueFace's Grid
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Unlike TCOD which uses numpy arrays for visibility tracking, McRogueFace's Grid has built-in FOV support:
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```python
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# In GameMap.update_fov()
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self.compute_fov(viewer_x, viewer_y, radius, light_walls=True, algorithm=mcrfpy.FOV_BASIC)
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```
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The Grid automatically:
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- Tracks which tiles have been explored
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- Applies appropriate color overlays (shroud, dark, light)
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- Updates entity visibility based on FOV
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#### Perspective System
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McRogueFace uses a perspective-based rendering approach:
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```python
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# Set the viewer
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self.game_map.perspective = self.player
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# Grid automatically renders from this entity's viewpoint
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```
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This is more efficient than manually updating tile colors every turn.
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#### Color Overlays
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We define overlay colors but let the Grid handle application:
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```python
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# In tiles.py
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SHROUD = mcrfpy.Color(0, 0, 0, 255) # Unexplored
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DARK = mcrfpy.Color(100, 100, 150, 128) # Explored but not visible
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LIGHT = mcrfpy.Color(255, 255, 255, 0) # Currently visible
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```
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### Key Differences from TCOD
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| TCOD Approach | McRogueFace Approach |
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|---------------|----------------------|
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| `visible` and `explored` numpy arrays | Grid's built-in FOV state |
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| Manual tile color switching | Automatic overlay system |
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| `tcod.map.compute_fov()` | `Grid.compute_fov()` |
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| Render conditionals for each tile | Perspective-based rendering |
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### Movement and FOV Updates
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The action system now updates FOV after player movement:
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```python
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# In MovementAction.perform()
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if self.entity == engine.player:
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engine.update_fov()
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```
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## Architecture Notes
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### Why Grid Perspective?
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The perspective system provides several benefits:
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1. **Efficiency**: No per-tile color updates needed
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2. **Flexibility**: Easy to switch viewpoints (for debugging or features)
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3. **Automatic**: Grid handles all rendering details
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4. **Clean**: Separates game logic from rendering concerns
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### Entity Visibility
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Entities automatically update their visibility state:
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```python
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# After FOV calculation
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self.player.update_visibility()
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```
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This ensures entities are only rendered when visible to the current perspective.
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## Files Modified
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- `game/tiles.py`: Added FOV color overlay constants
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- `game/game_map.py`: Added `update_fov()` method
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- `game/engine.py`: Added FOV initialization and update method
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- `game/actions.py`: Update FOV after player movement
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- `main.py`: Updated part description
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## What's Next
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Part 5 will add enemies to our dungeon, introducing:
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- Enemy entities with AI
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- Combat system
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- Turn-based gameplay
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- Health and damage
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The FOV system will make enemies appear and disappear as you explore, adding tension and strategy to the gameplay.
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## Learning Points
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1. **Leverage Framework Features**: Use McRogueFace's built-in systems rather than reimplementing
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2. **Perspective-Based Design**: Think in terms of viewpoints, not global state
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3. **Automatic Systems**: Let the framework handle rendering details
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4. **Clean Integration**: FOV updates fit naturally into the action system
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## Running Part 4
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```bash
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cd simple_tcod_tutorial/build
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./mcrogueface scripts/main.py
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```
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You'll now see:
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- Black unexplored areas
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- Dark blue tint on previously seen areas
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- Full brightness only in your field of view
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- Smooth exploration as you move through the dungeon |