Add Debug Timer to Title Bar

Summary

Implemented a debug timer in the emulator title bar that shows the time elapsed since the emulator starts and the time until the first event (frame ready). The timer is initialized at the start of `run()`, detects when the first ready frame occurs, and updates the title bar every 60 frames with the elapsed time and the time until the first event (if it has already occurred).

Hardware Concept

Timing and Events in Emulation:

In an emulator, it is important to be able to measure the time from when the emulation starts until important events occur. The first critical event is when the PPU marks a frame as ready (`frame_ready_ = true`), indicating that the emulator has completed its first rendering cycle.

The time to first event is useful for diagnosing initialization problems, since if the emulator takes too long to generate the first frame, it may indicate problems in component initialization or synchronization between the CPU and PPU.

The total elapsed time allows you to monitor the emulator's performance and verify that it is running at the correct speed (60 FPS).

Implementation

Added three instance variables to the debug timer:

• _start_time: Emulator startup time (when callingrun())
• _first_event_time: Time when the first event occurs (None until it occurs)
• _first_event_detected: Flag to indicate if the first event has already been detected

Components created/modified

• src/viboy.py: Added instance variables in__init__(), timer initialization inrun(), detection of the first event, and updating the title with the timer

Design decisions

Initialization inrun():The timer is initialized at the beginning ofrun()instead of in__init__()because the emulator can be initialized multiple times, but we only want to measure the time since the execution starts.

Detection of the first event:It is detected whenget_frame_ready_and_reset()returnstruefor the first time, indicating that the PPU has completed its first frame.

Title update:The title updates every 60 frames (approximately every second) to avoid overload, and shows both the total elapsed time and the time until the first event (if it has already occurred).

Affected Files

• src/viboy.py- Added instance variables for the timer, initialization of the timer inrun(), detection of the first event, and updating the title with the timer

Tests and Verification

The implementation was verified by:

• Visual verification:The timer appears in the title bar and updates correctly
• Logs:The logs[Viboy-Timer]appear when the emulator starts and when the first event is detected
• Title format:The title shows the correct format:"Viboy Color v0.0.2 - [Game Name] - FPS: XX.X - Time: XX.XXXs | First Event: XX.XXXs"

Test command:

timeout 30 python3 main.py roms/tetris.gb

Expected result:

• The timer appears in the title bar from the beginning
• The time is updated approximately every second
• When the first frame occurs, the time until the first event is also shown
• The logs[Viboy-Timer]appear on the console

Sources consulted

• Implementation based on general knowledge of timing and events in emulation
• Python documentationtime.time()for time measurement

Educational Integrity

Next Steps

• [ ] Continue with the log analysis of Step 0343
• [ ] Step 0345: Detailed analysis of framebuffer-display correspondence based on the logs of Step 0343
• [ ] Step 0346: Implement correction based on findings