joeylib2/examples/spacetaxi/spacetaxi.h

337 lines
15 KiB
C

// Space Taxi (JoeyLib port) -- shared types and decls.
//
// Architecture (all four JoeyLib targets):
//
// tilemap 40x25 cells, each cell = (tileIndex, paletteSlot).
// jlTilePaste blits the tile bank into the stage one cell
// at a time at level boot, then it's static until the
// scene changes. No per-frame redraw of the tilemap.
//
// taxi Single jlSpriteT with multiple cels (thrust frames,
// facing variants). Save-under + restore-under each frame
// so we don't repaint the tilemap behind it.
//
// passenger Up to 2 simultaneous sprites: one waiting on a pad,
// one already in the cab (or none). Same save/restore
// discipline as the taxi.
//
// audio One ~3-voice event stream rendered per platform:
// SB+PSG-synth (DOS), PT 4-voice (Amiga), YM2149 (ST),
// Ensoniq DOC channels (IIgs). The dispatch lives in
// stAudio.c with one entry point per voice command.
//
// input Joystick port 2 conventionally on the C64: direction =
// the four cardinals (thrust), FIRE = the LANDING GEAR
// toggle while airborne ($63DD: press edge EORs $7197
// bit 0 with an SFX; $6462 requires gear down to land;
// $6190 strips left/right thrust while gear is down).
// Keyboard fallback: arrows + space for hosts without
// joysticks.
//
// Level data lives in a small custom .dat per level (see
// assets/levels/format.md). Tile bitmaps and sprite cels are PNG
// authored externally and baked to native .tbk / .spr blobs at
// build time via tools/assetbake/assetbake.py.
#ifndef SPACETAXI_H
#define SPACETAXI_H
#include <joey/joey.h>
#define ST_TILEMAP_W 40u
#define ST_TILEMAP_H 25u
#define ST_TILE_PIXELS 8u
// The tilemap stores raw C64 screen-RAM character codes. The empty
// (non-colliding) playfield cell is the space character, $20. Every
// other code is non-blank background -- on the C64 it latches a sprite-
// background collision ($D01F). romToLevel.py uses BG=0x20 as the empty
// marker when extracting screen RAM.
#define ST_TILE_EMPTY 0x20u
// Display field is 320x200 (JoeyLib's SURFACE_WIDTH x SURFACE_HEIGHT).
// 40 tiles x 8 px = 320, 25 tiles x 8 px = 200. The bottom 3 rows are
// the HUD band (score / lives / level / current-fare strip). The top
// 22 rows are the playfield where the taxi moves.
// Full C64 screen height. The original title uses all 25 rows
// (frame at 0, 12, 24 + content). For gameplay the bottom 3 rows
// are HUD territory -- HUD draws over the tilemap there.
#define ST_PLAYFIELD_ROWS 25u
#define ST_HUD_ROW 22u
#define ST_HUD_ROW_COUNT 3u
// Maximum stuff. Tuned for fitting the smallest target (IIgs):
// 10 pads is the highest count in any canonical Space Taxi level
// (D and M each have 10 pads; everything else <= 9)
// Exactly ONE fare exists at a time. Verified: the C64 spawns a new
// fare only while its state machine (gDeathStage) is idle, so
// waiting-vs-carrying is the single passenger's `onboard` flag -- NOT
// two passengers. (A prior "waiting + carrying = 2 sprites" note was
// a misconception / false second source of truth.)
#define ST_MAX_PADS 10u
#define ST_MAX_PASSENGERS 1u
// Passenger destination sentinel: "UP PLEASE!" -- the fare wants to be
// flown UP through the top-wall transporter opening rather than to a
// landing pad. This is the C64's $0B destination ($6CB8), used on
// single-pad screens (and when all pads are consumed). Any real pad
// index is 0..ST_MAX_PADS-1, so 0xFE can't collide.
#define ST_DEST_TRANSPORTER 0xFEu
// The transporter opening is a fixed 4-column gap ($67 tiles) in the top
// wall, at columns 18..21 in every canonical Space Taxi screen (verified
// across the extracted tilemaps). Flying the taxi up through it exits the
// screen.
#define ST_TRANSPORTER_COL_LO 18u
#define ST_TRANSPORTER_COL_HI 22u // exclusive
#define ST_TILE_TRANSPORTER 0x67u
// Fixed-point taxi physics: position and velocity are int16_t in
// units of 1/16 px, so the taxi can drift fractionally and the
// thrust/gravity terms are integers without losing precision over
// the whole field. (22 rows x 8 px x 16 = 2816 < 32767 so int16
// is fine.)
// Match the C64 fixed-point scale: 8-bit sub-pixel (256 sub-units per
// pixel) so the C64's accel=14 and gravity=1 are usable directly
// (14/256 px/frame initial accel; constant 1/256 px/frame gravity).
// Position needs int32_t since a 320-wide playfield * 256 sub-units
// overflows int16_t.
#define ST_SUBPIXEL_SHIFT 8
#define ST_SUBPIXEL (1 << ST_SUBPIXEL_SHIFT)
// Taxi cels are the real C64 art (extractSprites.py): the $C0/$C1
// right-facing and $DC/$DD left-facing pairs with the $6A95 per-frame
// low-bit flicker; the engine flame is the separate direction-indexed
// sprite-2 cel set. Selection lives in stRender.c.
typedef enum {
ST_STATE_TITLE = 0,
ST_STATE_HIGHSCORES, // UP on title -> "THE IMMORTAL CABBIES" ($4C1F)
ST_STATE_INSTRUCTIONS, // DOWN on title -> author/about screen ($556A)
ST_STATE_OPTIONS, // "GAME VARIATIONS" menu ($5295): pick cabbie count
ST_STATE_DEMO, // rolling attract demo (recorded input playback)
ST_STATE_PLAYING,
ST_STATE_LEVEL_DONE,
ST_STATE_GAME_OVER
} StGameStateE;
typedef enum {
ST_DIR_RIGHT = 0,
ST_DIR_LEFT = 1
} StFacingE;
typedef struct {
uint8_t tileX; // landing surface left edge (tile coord)
uint8_t tileY; // landing surface row (tile coord)
uint8_t tileW; // pad width in tiles
uint8_t standX; // passenger stand X (screen px; slot byte6-24)
} StPadT;
typedef struct {
char name[24]; // level display name ("UP & DOWN", etc.)
uint8_t tileBankId; // which tile asset (0 = default bank)
uint8_t musicId; // UNUSED in C64 Space Taxi -- the
// game has no per-level background
// music; gameplay is silent except
// for SFX. Title plays song 8, score
// screen plays song 6 or 7 (see
// MECHANICS.md "Sound (SID)"). Kept
// here as scaffolding for a possible
// future "level-entry jingle" event.
uint8_t bgColor; // background palette slot
uint8_t borderColor; // border palette slot (for HUD if used)
uint8_t taxiSpawnTileX;
uint8_t taxiSpawnTileY;
// Per-level physics templates. Mirror the C64 templates at
// $7D8F/$7D91 (Y/X accel) and $7D93/$7D95 (Y/X gravity). Accels
// are unsigned magnitudes; gravities are int8 so a level can pull
// upward (e.g. canonical level K = -7). Hand-authored levels can
// leave them zero; loader substitutes per-level defaults below.
uint8_t xAccel;
uint8_t yAccel;
int8_t xGrav;
int8_t yGrav;
// VIC color block from C64 $7D00-$7D08, mapped to $D020-$D028 by
// $62F0 (scene-load). borderColor/bgColor above are $7D00/$7D01.
// bgColor1/2/3 and spriteMc0/1 only matter in VIC multicolor mode
// which the JoeyLib port doesn't reproduce -- they're stored so
// the .dat format stays a faithful capture of $7D00-$7D08 but the
// runtime ignores them. sprite0Color/sprite1Color drive the cab
// and flame placeholder colors when no sprite asset is authored.
uint8_t bgColor1; // $D022 (multicolor only, unused)
uint8_t bgColor2; // $D023 (multicolor only, unused)
uint8_t bgColor3; // $D024 (multicolor only, unused)
uint8_t spriteMc0; // $D025 sprite multicolor 0 (unused)
uint8_t spriteMc1; // $D026 sprite multicolor 1 (unused)
uint8_t sprite0Color; // $D027 sprite 0 (taxi)
uint8_t sprite1Color; // $D028 sprite 1 (flame)
uint8_t padCount;
StPadT pads[ST_MAX_PADS];
// Tilemap: tile-index per cell (row-major).
uint8_t tilemap[ST_TILEMAP_W * ST_PLAYFIELD_ROWS];
// Palette slot per cell -- which surface palette index a cell uses.
uint8_t colormap[ST_TILEMAP_W * ST_PLAYFIELD_ROWS];
} StLevelT;
typedef struct {
// 16-bit-fixed-point position (8 bits sub-pixel + 8 bits pixel),
// but stored in int32_t so a 320-wide playfield fits without
// wrap. `x >> ST_SUBPIXEL_SHIFT` is the pixel column.
int32_t x;
int32_t y;
int16_t vx; // velocity accumulator (sub-pixel/frame)
int16_t vy;
StFacingE facing;
bool thrusting; // any directional input held this frame
int8_t thrustDx; // -1 left, 0 neutral, +1 right
int8_t thrustDy; // -1 up, 0 neutral, +1 down
// Held-direction bit mask, mirroring $716A's encoding (the index
// into the $6DB0 flame cel table): 1=UP 2=DOWN 4=LEFT 8=RIGHT.
// With gear down the left/right bits are stripped before this is
// built, exactly like $6190 AND #$13 feeding $60D6.
uint8_t dirMask;
// Landing gear ($7197 bit 0). Toggled by a FIRE press edge while
// airborne, retracted on takeoff ($65B0), REQUIRED down to land
// ($6462) -- gear-up contact with a pad is a crash.
bool gearDown;
bool fireHeld; // previous-frame fire state (edge detect)
bool landed; // sitting on a pad
uint8_t onPad; // pad index if landed (0xFF if none)
// Death-animation countdown. >0 means crashed -- engine keeps the
// cab integrating under gravity (no explosion visual; the C64
// just lets the cab fall, see VERIFIED.md "Stage 1 $665F death
// branch"). Reaches 0 -> respawn (or game-over). Mirrors the
// C64's $6B24/$6B4C phase-2/3 timing.
uint8_t crashTicks;
// Crash phase split ($6A72 fall vs $6B2A impact walk): false while
// the debris tumbles, true once it hits the floor.
bool crashImpacted;
// Transporter shrink-warp progress (0 = not warping; 1..64 = the
// takeoff/shrink animation $5C91/$5CB9). During the warp the taxi
// recedes up through the opening; the screen advances when it ends.
uint8_t warpFrame;
} StTaxiT;
// Passenger lifecycle phases (see the field comments in StPassengerT
// for the C64 sequences each one mirrors).
typedef enum {
ST_PASS_BEAM_IN = 0, // materialize at standX ($CB..$C7)
ST_PASS_WAIT, // stand + wave ($66D6 cycle)
ST_PASS_WALK_TO_CAB, // walk to the captured taxi X
ST_PASS_BOARD_OUT, // shrink into the cab ($C7..$CB)
ST_PASS_RIDING, // aboard, invisible
ST_PASS_DROP_IN, // delivery: materialize beside the cab
ST_PASS_WALK_TO_PAD, // walk to the destination standX
ST_PASS_DROP_OUT // shrink out -- fare complete
} StPassPhaseE;
typedef struct {
bool active;
bool onboard; // in the cab (true) or waiting at pad (false)
uint8_t currentPad; // where they are if waiting
uint8_t destPad;
int16_t x; // pixel position
int16_t y;
// Passenger lifecycle, per the traced sequences: materialize
// ($CB..$C7 grow-in), wave in place ($66D6 cycle -- he NEVER
// walks while waiting), walk to the landed cab ($6811 captures
// the taxi X once; $C4/$C5 leftward, $C2/$C3 rightward, +/-2 px
// per 3-tick step), shrink into the cab ($C7..$CB), ride, and
// the delivery mirror (materialize at the cab, walk to standX,
// shrink out).
StPassPhaseE phase;
int16_t targetX; // walk destination (captured once)
// Step counter within the current phase; in ST_PASS_WAIT it is
// the 0..3 wave-cycle index, in the walk phases its low bit is
// the stride cel alternation.
uint8_t waitPhase;
} StPassengerT;
typedef struct {
StGameStateE state;
StLevelT level;
StTaxiT taxi;
StPassengerT passengers[ST_MAX_PASSENGERS];
uint32_t score;
uint8_t lives;
uint8_t levelIndex;
// Attract-demo playback state (ST_STATE_DEMO): the recorded RLE
// input stream and its cursor, plus the crash-finished signal the
// engine raises instead of decrementing lives ($6B57).
const uint8_t *demoStream;
uint16_t demoLen;
uint16_t demoOff;
uint8_t demoTimer;
uint8_t demoMask;
bool demoEnded;
// Player-selectable fare quota (1..4). Mirrors C64 $7213 (the
// GAME-VARIATIONS "cabbies" count), set on the title screen via
// LEFT/RIGHT joystick ($5310-$5328). This is the GLOBAL number of
// fares to deliver before the game completes -- NOT per-level.
uint8_t fareTarget;
} StGameT;
// Public entry points (one per source file).
bool stLevelLoad(StLevelT *out, const char *path);
void stRenderInit(jlSurfaceT *stage);
void stRenderShutdown(void);
// Blit the level's static tile art into the stage. Called once per
// scene change; falls back to colored solid tiles per index-range
// when no tile bank asset is loaded.
void stRenderLevel(jlSurfaceT *stage, const StLevelT *level);
void stRenderFrame(jlSurfaceT *stage, const StGameT *game);
// Tell the renderer the current game.level contents changed. Required
// after stLevelLoad even when the StLevelT pointer is unchanged --
// stRenderLevel's dirty-cache compares pointers, not contents.
void stRenderLevelChanged(void);
void stRenderTitleAdvance(void);
bool stRenderTitleIntroDone(void);
void stRenderTitleReset(void);
// Draw an ASCII string into the stage at tile coords (bx, by) using
// the loaded font asset. No-op if the font asset failed to load.
void stRenderDrawText(jlSurfaceT *stage, uint8_t bx, uint8_t by, const char *s);
void stEngineReset(StGameT *game);
void stEngineTick(StGameT *game);
// True when the taxi has flown up into the top-wall transporter opening
// (used to trigger a screen exit).
bool stEngineInTransporter(const StGameT *game);
// Begin the transporter shrink-warp (taxi.warpFrame 0 -> 1).
void stEngineStartWarp(StGameT *game);
// Advance the shrink-warp one frame; returns true when it completes.
bool stEngineWarpTick(StGameT *game);
// Current shrink step 0..7 (0 = full size, 7 = smallest) for rendering.
uint8_t stEngineWarpStep(const StGameT *game);
void stPassengerReset(StGameT *game);
void stPassengerTick(StGameT *game);
// Called when the taxi exits up through the transporter: delivers a
// carried "UP PLEASE" fare (if any) before the screen advances.
void stPassengerTransporterExit(StGameT *game);
void stAudioInit(void);
void stAudioShutdown(void);
void stAudioFrameTick(void); // call once per host frame; counts down SFX
void stAudioPlayMusic(uint8_t musicId);
void stAudioStopMusic(void);
void stAudioSfxThrust(bool on);
void stAudioSfxGear(void);
void stAudioSfxLand(void);
void stAudioSfxPickup(void);
void stAudioSfxDropoff(void);
void stAudioSfxCrash(void);
void stHudDraw(jlSurfaceT *stage, const StGameT *game);
#endif