imjasonh/nescript
1
0
Fork 0
mirror of https://github.com/imjasonh/nescript synced 2026-07-09 09:18:01 +00:00
Code Activity
nescript/examples/war/PLAN.md
Claude 548787ac8a
W0110 inline fallback warning + docs refresh 
W0110: when a function marked `inline` has a body shape the IR
lowerer can't splice (conditional early return, loops, nested
control flow, empty void body), the analyzer now emits a
warning at the declaration site so the declined hint is
visible instead of silently falling back to a regular JSR.

Implementation:
  - New `W0110` error code in `src/errors/diagnostic.rs` (warning level).
  - New `pub fn can_inline_fun(return_type, body) -> bool` in
    `src/ir/lowering.rs`, extracted from the existing capture
    logic so the analyzer and the IR lowerer share the same
    eligibility rules and can never drift.
  - New `check_inline_declinability` analyzer pass called from
    the tail of `analyze_program`, mirroring the existing
    `check_sprite_scanline_budget` / `check_unreachable_states`
    passes. Emits W0110 with help + note text pointing at the
    two accepted body shapes.
  - `capture_inline_bodies` now defers to `can_inline_fun`
    instead of duplicating the match pattern, so the two sides
    stay in lockstep by construction.

Four regression tests in `src/analyzer/tests.rs` cover the
conditional-return and while-loop declines plus the two
accepted shapes (single-return expression, void sequence).

Example source cleanups: `wrap52` in `examples/war/deck.ne`
and `abs_diff` in both `examples/arrays_and_functions.ne` and
`examples/loop_break_continue.ne` drop the `inline` keyword.
All three were dead hints — the `inline` was being silently
declined before this change, so removing it is source-only;
the three ROMs are byte-identical, all 32 emulator goldens
still match.

Docs refresh
  - `docs/language-guide.md`: rewrote the Inline Functions section
    (real behaviour + W0110), added W0105/W0106/W0107/W0108/W0109/
    W0110 to the warnings table, added the `debug.sprite_overflow*`
    builtins + sprite-per-scanline mitigations section to the
    Debug Mode docs, added a `cycle_sprites` statement entry and
    cross-referenced it from `draw`.
  - `docs/nes-reference.md`: fleshed out the "NEScript Memory
    Usage" block with the full ZP + high-RAM layout, including
    the new `$07EF` / `$07FC` / `$07FD` slots for sprite cycling
    and the debug sprite-overflow telemetry.
  - `docs/future-work.md`: documented all four debug query
    builtins in the "What ships today" block; updated the open
    "OAM allocation strategy" question to reference the shipped
    `cycle_sprites` path and ask about an automatic-flicker
    game attribute as a follow-up.
  - `docs/architecture.md`: updated the `ir/` and `optimizer/`
    module summaries to describe real inline splicing (now
    in lowering, not the optimizer).
  - `README.md`: reframed the `inline` bullet from "hint" to
    "real splicing for single-return / void-body shapes";
    expanded the debug-support bullet to mention the four
    query builtins and their stripping in release builds; added
    a new bullet for the three-layer sprite-per-scanline
    mitigations; bumped the test count from 497 → 694; updated
    the war.ne entry to mention the seven compiler bugs are all
    fixed and point readers at `git log` (instead of the
    deleted COMPILER_BUGS.md).
  - `examples/README.md`: same `git log`-pointing rewrite for
    the war.ne entry.

Deletions
  - `examples/war/COMPILER_BUGS.md` is removed. All seven
    catalogued bugs are fixed; the file's historical value
    lives in `git log` now. Every source-code comment and doc
    reference to the file has been updated to either point at
    `git log` or just describe the bug in place.

Test count: 616 unit + 75 integration + 3 doctests = 694 total.
Clippy / fmt clean. 32/32 emulator goldens match.

https://claude.ai/code/session_0143dTgh3UeRrtfHgQwzcv5z
2026-04-15 23:19:07 +00:00

252 lines
9.8 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# War — Implementation Plan
A production-quality card game example for NEScript. This document is
the living plan: each step is checked off as it's completed, and any
mid-flight design changes are recorded in the "Design revisions" section
at the bottom.
---
## 1. Scope & quality bar
A production-grade NES version of War:
- **Title screen** with a big logo, a 3-option menu (`0 PLAYERS` /
`1 PLAYER` / `2 PLAYERS`), blinking "PRESS START", and music.
- **Gameplay** with an animated deal, two live decks with running card
counts, cards that slide between the decks and the center, a readable
face-up card on each side.
- **War / tie-breaker** flow with a distinct "WAR!" banner, an exciting
SFX, and buried cards that actually come out of each player's deck.
- **Victory screen** with the winning player highlighted and a fanfare.
- **Sound**: title music, card-flip click, distinct round-win cues for
A vs B, exciting WAR tie-break sfx, victory fanfare.
---
## 2. File layout
```
examples/war.ne # top-level: game decl, palette, background, sprite sheet, includes, start
examples/war/PLAN.md # this file
examples/war/constants.ne # gameplay + layout constants
examples/war/audio.ne # sfx + music declarations
examples/war/state.ne # global variables (decks, phase, rng, anim timers, ...)
examples/war/rng.ne # 8-bit LFSR PRNG helpers
examples/war/deck.ne # queue ops on decks + pot
examples/war/compare.ne # card rank/suit extraction, round resolver
examples/war/render.ne # draw_card_front / draw_card_back helpers
examples/war/title_state.ne # state Title
examples/war/deal_state.ne # state Deal
examples/war/play_state.ne # state Playing (phase machine)
examples/war/victory_state.ne # state Victory
```
The top-level `examples/war.ne` is the file the pre-commit hook and
emulator harness see. It compiles to `examples/war.nes` without any
tooling changes. The split source files all live under `examples/war/`
and are pulled in via `include "war/<name>.ne"` directives.
---
## 3. Hardware budget
### Sprite budget per frame
All sprites use sprite sub-palette 0 (the NEScript codegen hard-wires
the OAM attribute byte to 0). That gives 4 shared colours:
**transparent, red, white, black** — enough for both red and black suits
on a white card face with a black outline.
Cards are **16×24 px (2 cols × 3 rows = 6 sprites)**. Max on-screen
simultaneously in the steady state:
| Entity | Qty | Sprites | Notes |
|---------------|-----|---------|-------|
| Deck A top | 1 | 6 | card back |
| Deck B top | 1 | 6 | card back |
| Face-up A | 1 | 6 | varies by round |
| Face-up B | 1 | 6 | varies by round |
| Flying card | 1 | 6 | only during anim |
| Cursor / UI | ≤2 | ≤2 | title selector + misc |
| | | **32** | ≤ 64 OAM slots ✓ |
**8-per-scanline check.** Decks are at `y = 80`, face-up cards at
`y = 128`. Those two bands never overlap vertically, so the worst case
is 2 cards side by side within the same band = 4 sprites per scanline.
### Tile budget (max 256)
| Group | Tiles | Purpose |
|-------|-------|---------|
| Card frame | 6 | outline corners + top/bottom blank cells |
| Card back | 4 | diamond-lattice pattern, symmetric |
| Rank glyphs | 13 | A, 2-9, 10, J, Q, K (8×8 each) |
| Small suit (corner) | 4 | ♠ ♥ ♦ ♣ |
| Big suit left half | 4 | left half of large centre pip |
| Big suit right half | 4 | right half |
| Font A-Z | 26 | title/menu/HUD |
| Font 0-9 | 10 | deck counts + HUD |
| Punctuation + space | ~4 | `:`, `!`, space, `?` |
| Big "WAR" banner | 12 | 2×2 block per letter |
| Felt-table tile | 2 | background fill + subtle pattern |
| Border / divider | 4 | thin framing |
| Cursor / arrow | 2 | menu selection |
| **Total** | **~95** | leaves ~150 tiles free |
### RAM budget
| Structure | Bytes | Notes |
|-----------|-------|-------|
| `deck_a: u8[52]` | 52 | circular buffer, packed `rank<<4 \| suit` |
| `deck_b: u8[52]` | 52 | |
| `pot: u8[52]` | 52 | cards currently in play |
| queue cursors, counts, phase, anim timers | ~20 | |
| RNG state | 1 | |
| **Total** | **~180** | well under the ~1700 bytes of general RAM |
---
## 4. Card representation & RNG
### Card encoding
One byte per card, packed as `(rank << 4) | suit`:
- `rank` = 1..13 (`A=1`, `2=2`, …, `10=10`, `J=11`, `Q=12`, `K=13`)
- `suit` = 0..3 (`♠=0`, `♥=1`, `♦=2`, `♣=3`)
### PRNG
8-bit Galois LFSR seeded from the frame counter on title-screen exit.
### Shuffle
Bounded random-swap shuffle: 200 swaps between two 6-bit random
indices, retrying when either index ≥ 52. Uses only `&` and compare,
no multiply or divide.
### Deck as a queue
Each deck is a circular buffer with `front` / `count` cursors. `draw`
bumps `front`, `push_back` writes at `(front + count) % 52`. Modulo is
implemented with `if x >= 52 { x -= 52 }` to avoid the expensive `%`
software routine.
---
## 5. State machine
```
Title → Deal → Playing → Victory → Title
```
`Playing` contains an inner phase machine driven by a `u8` phase var:
| Phase | Notes |
|-------|-------|
| `P_WaitA` | Human: wait for input; CPU: wait for think timer |
| `P_FlyA` | 16-frame lerp of A's card from deck to play position |
| `P_WaitB` | symmetric |
| `P_FlyB` | symmetric |
| `P_Reveal` | Both cards visible; brief beat |
| `P_Resolve` | Compare, branch to `P_WinA` / `P_WinB` / `P_WarBanner` |
| `P_WinA` / `P_WinB` | Cards slide to winner deck |
| `P_WarBanner` | Flash "WAR!" banner, play `WarFlash` |
| `P_WarBury` | Bury 3 face-down cards from each deck |
| `P_Check` | Win-condition check, possibly `transition Victory` |
Game modes (`0`/`1`/`2` players) are captured by two `bool` flags
`a_is_cpu` / `b_is_cpu` chosen on title exit.
---
## 6. Audio
| Name | Channel | Shape |
|------------|---------|-------|
| `FlipCard` | pulse 1 | short descending click |
| `CheerA` | pulse 1 | 8-frame rising arpeggio, pitch envelope |
| `CheerB` | pulse 1 | 8-frame descending arpeggio, pitch envelope |
| `WarFlash` | pulse 1 | 16-frame pitch sweep, loud → soft → loud |
| `ThudDown` | noise | 4-frame noise burst (bury animation) |
| `TitleTheme` | pulse 2 | brisk 4/4 march, looping |
| Victory | builtin `fanfare` | one-shot on win |
---
## 7. Implementation steps
All steps complete. The order they actually shipped in is below
(the original 12-step plan got compressed once the early steps
turned up enough compiler bugs to demand investigation in
parallel).
- [x] Step 1: Skeleton — top-level file, every included file
filled with a real implementation, compiles cleanly.
- [x] Step 2: Felt background — replaced the builtin-smiley
grid with a custom `TILE_FELT_BG` cross-hatch tile.
- [x] Step 3: Card art — bold rank glyphs (1 tile each), small
corner suits, big centre pip halves, card-back lattice,
card frame helpers (`draw_card_face` / `draw_card_back`).
- [x] Step 4: Deck data structures — circular buffers with
front/count cursors, packed `(rank << 4) | suit` cards,
Galois LFSR PRNG, bounded random-swap shuffle, deal/split.
- [x] Step 5: Title state — BIG WAR banner, "CARD GAME"
subtitle, 3-line menu with cursor, blinking PRESS A,
title-music + autopilot.
- [x] Step 6: Deal state — animated deal with FlipCard sfx and
growing deck-back stacks.
- [x] Step 7: Play state phase machine — `match phase` over the
11 P_* phases, fly animation that doesn't overshoot, win
cues, debounced human input.
- [x] Step 8: War tie-break — BIG WAR banner reused as a
strobing flash, ThudDown noise sfx for each buried card,
pot grows by 6 per side per war.
- [x] Step 9: Victory state — staggered "PLAYER X / WINS"
banner, top-of-deck showcase card, builtin fanfare,
auto-return to Title.
- [x] Step 10: Polish pass — bold sprite font, card-fly
timing/overshoot fix, P_WAR_BURY redraws the previous
face-ups, draw_word_war removed (was orphaned by the BIG
WAR helper), title state shares the BIG WAR helper.
- [x] Step 11: Capture goldens, verify all 31 ROMs match, war
golden lands cleanly on a mid-fly-A frame at frame 180.
- [x] Step 12: Update README.md and examples/README.md.
- [x] Code review pass: read every file end-to-end, fix any
mistakes found.
Seven compiler bugs were discovered along the way and all fixed
on this branch — see `git log` for the full list. Every
workaround that was originally in the war source has been
reverted now that the underlying bugs are fixed.
---
## 8. Design revisions
A few things shifted from the approved plan:
- **`arm_fly` is 4 params, not 6.** The 5th and 6th params
(`fly_card`, `fly_face_up`) are written to globals at every
call site instead, because the v0.1 ABI only passes four
parameters via the zero-page transport slots. The 4-param
limit now produces a clean E0506 diagnostic so future authors
see the error up front instead of chasing silent
miscompiles.
- **The `Playing` state's phase machine uses `match`, not a
flat if-chain.** The if-chain shape allowed two phases to run
in the same frame after a `set_phase` transition, which made
the card-fly animation overshoot its endpoint by `FLY_STEP`.
`match` runs only the first matching arm.
- **Card frame outline tiles (`TILE_FRAME_TL`/`TR`/`BL`/`BR`)
are still allocated in the Tileset but unused.** The card
faces use the rank/suit/pip tiles directly with white card
bodies that visually separate from the dark felt — a card
frame would have made each tile cramped without much
readability gain. Constants are kept for layout stability;
the tiles themselves serve as a 4-tile reserve for future
art tweaks.
- **The deal animation** is a single bouncing card-back, not a
full 52-card cascade. Cleaner and cheaper, and the FlipCard
click rhythm carries the "we're dealing!" feel by itself.
View git blame Copy permalink