Implement a Read-Eval-Print Loop (REPL) effect that provides a
HUD-style overlay for interactive pipeline control.
## New Files
- engine/effects/plugins/repl.py - REPL effect plugin with command processor
- engine/display/backends/terminal.py - Added raw mode and input handling
- examples/repl_simple.py - Simple demonstration script
- tests/test_repl_effect.py - 18 comprehensive tests
## Features
### REPL Interface
- HUD-style overlay showing FPS, command history, output buffer size
- Command history navigation (Up/Down arrows)
- Command execution (Enter)
- Character input and backspace support
- Output buffer with scrolling
### Commands
- help - Show available commands
- status - Show pipeline status and metrics
- effects - List all effects in pipeline
- effect <name> <on|off> - Toggle effect
- param <effect> <param> <value> - Set parameter
- pipeline - Show current pipeline order
- clear - Clear output buffer
- quit - Show exit message
### Terminal Input Support
- Added set_raw_mode() to TerminalDisplay for capturing keystrokes
- Added get_input_keys() to read keyboard input
- Proper terminal state restoration on cleanup
## Usage
Add 'repl' to effects in your configuration:
## Testing
All 18 REPL tests pass, covering:
- Effect registration
- Command processing
- Navigation (history, editing)
- Configuration
- Rendering
## Integration
The REPL effect integrates with the existing pipeline system:
- Uses EffectPlugin interface
- Supports partial updates
- Reads metrics from EffectContext
- Can be controlled via keyboard when terminal display is in raw mode
Next steps:
- Integrate REPL input handling into pipeline_runner.py
- Add keyboard event processing loop
- Create full demo with interactive features
- Implements pipeline hot-rebuild with state preservation (issue #43)
- Adds auto-injection of MVP stages for missing capabilities
- Adds radial camera mode for polar coordinate scanning
- Adds afterimage and motionblur effects using framebuffer history
- Adds comprehensive acceptance tests for camera modes and pipeline rebuild
- Updates presets.toml with new effect configurations
Related to: #35 (Pipeline Mutation API epic)
Closes: #43, #44, #45
- Fixes issue #45: Add state property to EffectContext for motionblur/afterimage effects
- Fixes issue #44: Reset camera bounce direction state in reset() method
- Fixes issue #43: Implement pipeline hot-rebuild with state preservation
- Adds radial camera mode for polar coordinate scanning
- Adds afterimage and motionblur effects
- Adds acceptance tests for camera and pipeline rebuild
Closes#43, #44, #45
- Add entropy field to EffectConfig (0.0 = calm, 1.0 = chaotic)
- Provide compute_entropy() method in EffectContext for dynamic scoring
- Update Fade, Firehose, Glitch, Noise plugin defaults with entropy values
- Enables finer control: intensity (strength) vs entropy (randomness)
This separates deterministic effect strength from probabilistic chaos, allowing more expressive control in UI panel and presets.
Fixes#32
- Move effects_plugins/ to engine/effects/plugins/
- Update imports in engine/app.py
- Update imports in all test files
- Follows capability-based deps architecture
Closes#27
Two critical fixes:
1. ListDataSource Cache Bug
- Previously, ListDataSource.__init__ cached raw tuples directly
- get_items() would return cached raw tuples without converting to SourceItem
- This caused SourceItemsToBufferStage to receive tuples and stringify them
- Results: ugly tuple representations in terminal/pygame instead of formatted text
- Fix: Store raw items in _raw_items, let fetch() convert to SourceItem
- Cache now contains proper SourceItem objects
2. Camera Dependency Resolution
- CameraStage declared dependency on 'source.items' exactly
- DataSourceStage provides 'source.headlines' (or 'source.poetry', etc.)
- Capability matching didn't trigger prefix match for exact dependency
- Fix: Change CameraStage dependency to 'source' for prefix matching
3. Added app.py Camera Stage Support
- Pipeline now adds camera stage from preset.camera config
- Supports vertical, horizontal, omni, floating, bounce modes
- Tests now passing with proper data flow through all stages
Tests: All 502 tests passing, 16 skipped
- Add PartialUpdate dataclass and supports_partial_updates to EffectPlugin
- Add dirty region tracking to Canvas (mark_dirty, get_dirty_rows, etc.)
- Canvas auto-marks dirty on put_region, put_text, fill
- CanvasStage exposes dirty rows via pipeline context
- EffectChain creates PartialUpdate and calls process_partial() for optimized effects
- HudEffect implements process_partial() to skip processing when rows 0-2 not dirty
- This enables effects to skip work when canvas regions haven't changed
- Add Camera class with modes: vertical, horizontal, omni, floating
- Refactor scroll.py and demo to use Camera abstraction
- Add vis_offset for horizontal scrolling support
- Add camera_x to EffectContext for effects
- Add pygame window resize handling
- Add HUD effect plugin for demo mode
- Add --demo flag to run demo mode
- Add tests for Camera and vis_offset
