Cross-platform scroll wheel support + argparse display/fps + safer serve timer

[TheCodingSoldier]

What this PR does

Makes Encode-A-Pong work cleanly on any computer with a scroll wheel mouse (Windows, macOS, desktop Linux) while keeping the Raspberry Pi Zero 2 W + Kuman 3.5" experience 100% identical.

Running python3 pong.py with no arguments on the Pi = zero behaviour change.

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Changes (safe, additive only)

1. argparse CLI arguments (all default to current Pi values)

python3 pong.py                     # identical to before — 480×320 @ 30fps
python3 pong.py --width 800 --height 480   # custom display
python3 pong.py --fps 60                   # desktop smooth framerate

2. is_pi_framebuffer() platform detection

• Checks for /dev/fb0 (only exists on Linux framebuffer systems like Pi)
• Pi: mouse cursor stays hidden (same as before)
• Desktop: mouse cursor stays visible so the OS cursor doesn't disappear

3. round() instead of int() for scroll accumulation

• int(scroll_accum * PADDLE_SPEED) silently drops small fractional scroll inputs
• round() preserves them → paddle feels more responsive on high-precision mice
• No impact on Pi encoder (which always emits whole integer ticks)

4. Timestamp-based serve timer (pygame.time.get_ticks())

• Old: serve_timer -= dt — could behave inconsistently if dt spikes on first frame
• New: serve_until = now + SERVE_DELAY_MS / if now < serve_until: — rock solid on all hardware
• Same 800 ms delay, same feel

5. AI_PADDLE_X moved inside run()

• Was a module-level constant using hardcoded WIDTH
• Now calculated after argparse so it correctly uses whatever --width is passed
• On Pi with no args: same value 480 - 10 - 8 = 462

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What was NOT changed

• All collision logic — untouched
• All drawing code — untouched
• All game constants (WIN_SCORE, PADDLE_SPEED, AI_SPEED, BALL_SPEED_*) — untouched
• make_bg_surface(), reset_ball(), bounce_ball(), clamp_paddle() — logic unchanged
• pygame.SCALED + vsync fallback chain — identical
• pygame.display.update() — kept (correct for Pi framebuffer)
• SERVE_DELAY_MS = 800 — same value

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Testing

• python3 pong.py on Pi Zero 2 W + Kuman 3.5" display
• python3 pong.py on desktop Linux
• python3 pong.py --fps 60 on desktop
• python3 pong.py --width 800 --height 480 on desktop

[Copilot]

Copilot review overview

🟡 Changes recommended

The implementation can misidentify desktop Linux, discard fractional scroll input, and accept invalid display dimensions.

Get a fresh assessment by requesting another Copilot review.

Review effort: Lite
Findings: 3 · 1

Open (4)

• Validate display dimensions as positive integers · New
• Avoid misidentifying all framebuffer systems as Raspberry Pi · New
• Preserve un-applied scroll remainder · New
• Update documentation for changed APIs and display flags · New

What changed in this PR

Adds configurable display size/FPS and cross-platform mouse-wheel behavior while preserving the Raspberry Pi defaults.

Changes:

• Adds argparse options for width, height, and FPS.
• Makes paddle positioning and rendering dimension-aware.
• Replaces frame-delta serve timing with timestamps and updates cursor/scroll handling.

File	Description
pong.py	Implements CLI configuration, platform detection, dynamic dimensions, scroll handling, and serve timing.

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