- Add _cmd_available() method to list all registered effect types
- Discover plugins and query registry to get complete list
- Add 'available' to help text and command processing
- Update help description for 'effects' command to clarify it shows current pipeline
- Add help text for add_stage, remove_stage, swap_stages, move_stage commands
- Implement _cmd_add_stage, _cmd_remove_stage, _cmd_swap_stages, _cmd_move_stage methods
- Update _handle_pipeline_mutation in main.py and pipeline_runner.py
- Fix fragile test by testing output buffer directly instead of rendered output
- Remove \033[1;1H, \033[2;1H, \033[3;1H from HUD rendering
- HUD text now appears at correct positions without cursor interference
- Prompt appears at left margin as expected
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
- 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
