mirror of
https://github.com/imjasonh/nescript
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A complete, playable Pong game split across examples/pong/*.ne files
and pulled in from a top-level examples/pong.ne. Features:
- **Title screen** with a 3-option menu (CPU VS CPU / 1 PLAYER /
2 PLAYERS), a cursor sprite, blinking "PRESS A" prompt, brisk
title march on pulse 2, and autopilot that auto-confirms CPU VS
CPU after 45 frames of no input so the headless jsnes golden
harness reaches gameplay by frame 180.
- **Ball physics** with signed-magnitude velocity (u8 magnitude +
sign bit per axis), wall bounce at top/bottom, paddle AABB
collision with push-out, and score-out detection at left/right
exits.
- **Multi-ball** via parallel ball_* arrays (MAX_BALLS = 3). Each
ball scores a point independently; the round continues until the
last ball exits the playfield.
- **CPU AI** that tracks the nearest active ball heading toward its
side with a per-frame step, 4 px dead zone, and CPU_SPEED = 1 so
rallies can end naturally.
- **Three powerup types** that spawn every ~4 seconds, bounce off
all four walls, and are caught by paddle AABB overlap:
1. LONG — extends the catching paddle from 24 → 40 px for 5 hits
2. FAST — doubles ball x-velocity on the catcher's next hit
3. MULTI — spawns two extra balls on the catcher's next hit
- **Victory** at first-to-7 with a "PLAYER N WINS" banner and the
builtin fanfare, auto-returning to Title.
- **Audio**: 5 user-declared sfx (WallBounce, PaddleHit, Score,
PowerSpawn, PowerCatch) plus a title march and the builtin
fanfare for victory.
Source layout mirrors examples/war:
examples/pong.ne top-level game shell
examples/pong/PLAN.md living design doc
examples/pong/constants.ne layout + gameplay constants
examples/pong/assets.ne 45-tile Tileset (paddles, ball, alphabet,
digits, cursor, center-line, powerup icons)
examples/pong/audio.ne sfx + music declarations
examples/pong/state.ne all mutable globals
examples/pong/rng.ne 8-bit Galois LFSR
examples/pong/render.ne draw helpers
examples/pong/input.ne paddle step (human + CPU AI)
examples/pong/ball.ne multi-ball physics + paddle collision
examples/pong/powerup.ne powerup entity (spawn, bounce, catch, apply)
examples/pong/title_state.ne state Title + menu
examples/pong/play_state.ne state Playing (P_SERVE/P_PLAY/P_POINT)
examples/pong/victory_state.ne state Victory
Verification:
- 616 compiler unit tests pass (cargo test --all-targets)
- cargo fmt / cargo clippy --all-targets -- -D warnings clean
- 33/33 emulator harness goldens match
- examples/pong.nes builds byte-identically from source
https://claude.ai/code/session_0134F5uwDEVTes2Ee9S7JeXy
121 lines
4.1 KiB
Text
121 lines
4.1 KiB
Text
// pong/title_state.ne — the Title state.
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//
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// Draws "PONG" at the top of the screen, a 3-option menu (CPU VS
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// CPU / 1 PLAYER / 2 PLAYERS) with a cursor, and a blinking
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// "PRESS A" prompt below. If nothing happens for TITLE_AUTO_FRAMES
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// the menu auto-commits to CPU VS CPU so the headless jsnes
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// golden capture always reaches gameplay by frame 180.
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state Title {
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on enter {
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title_cursor = 0 // default: CPU VS CPU (autopilot pick)
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title_timer = 0
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title_blink = 0
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title_debounce = 0
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start_music TitleTheme
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}
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on frame {
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global_tick += 1
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title_timer += 1
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title_blink += 1
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if title_blink >= 60 {
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title_blink = 0
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}
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if title_debounce > 0 {
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title_debounce -= 1
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}
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// ── "PONG" banner ─────────────────────────────────
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//
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// Until the BIG PONG banner lands in the polish
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// milestone, we draw the name in the 8×8 font at
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// roughly 2× scale by spacing letters 16 px apart. That
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// reads as a title without eating a dozen extra tiles.
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draw_letter(88, 40, 15) // P
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draw_letter(104, 40, 14) // O
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draw_letter(120, 40, 13) // N
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draw_letter(136, 40, 6) // G
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// ── Menu options ──────────────────────────────────
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//
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// Three vertically-stacked rows. Row 0 = CPU VS CPU,
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// row 1 = 1 PLAYER, row 2 = 2 PLAYER (no S — plural is
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// implied, and dropping the S keeps each row short
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// enough that the cursor sprite + row fits under the
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// sprites-per-scanline budget).
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//
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// Row 0: "CPU VS CPU"
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draw_word_cpu(80, 96)
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draw_word_vs (112, 96)
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draw_word_cpu(136, 96)
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// Row 1: "1 PLAYER"
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draw_digit(88, 120, 1)
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draw_word_player(104, 120)
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// Row 2: "2 PLAYER"
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draw_digit(88, 144, 2)
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draw_word_player(104, 144)
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// Cursor sits to the left of the selected option, at
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// y = 96 / 120 / 144 depending on title_cursor.
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var cursor_y: u8 = 96 + (title_cursor << 3) + (title_cursor << 4) // +24 per row
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draw Tileset at: (64, cursor_y) frame: TILE_CURSOR
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// ── Blinking "PRESS A" prompt ─────────────────────
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if title_blink < 30 {
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draw_word_press(96, 184)
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draw_letter(144, 184, 0) // A
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}
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// ── Input handling ────────────────────────────────
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if title_debounce == 0 {
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if button.up {
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if title_cursor > 0 {
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title_cursor -= 1
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}
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title_debounce = 10
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title_timer = 0
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play PaddleHit
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}
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if button.down {
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if title_cursor < 2 {
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title_cursor += 1
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}
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title_debounce = 10
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title_timer = 0
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play PaddleHit
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}
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if button.a or button.start {
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mode = title_cursor
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rng_seed((global_tick & 0xFF) as u8)
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transition Playing
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}
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}
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// ── Autopilot for the headless harness ────────────
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if title_timer >= TITLE_AUTO_FRAMES {
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mode = MODE_CPU_VS_CPU
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title_cursor = 0
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rng_seed((global_tick & 0xFF) as u8)
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transition Playing
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}
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}
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on exit {
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stop_music
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// Translate the menu selection into per-side is_cpu flags
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// the playing state reads each frame.
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if mode == MODE_CPU_VS_CPU {
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is_cpu[0] = 1
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is_cpu[1] = 1
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}
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if mode == MODE_HUMAN_VS_CPU {
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is_cpu[0] = 0
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is_cpu[1] = 1
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}
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if mode == MODE_HUMAN_VS_HUMAN {
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is_cpu[0] = 0
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is_cpu[1] = 0
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}
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}
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}
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