Reference · Engine

Town and event-area assembly

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A town's scene file (town01 is Mac Anu) holds each piece in its own space: the floor, building and detail pieces of every district overlap at the origin. The game assembles them from tables in gcmn.prg. One C++ class per town (ROOTTOWN01-05) and per event area (EVENTAREA01...) builds its pieces from those tables and draws them itself. The port's piney-gen (placement::statics) reads the tables into the build as data, and crates/piney-data/src/statics holds their types.

Static models

STATIC_MODEL_INFO   0x14 bytes, e.g. RT_MODELTABLE00 (32 rows), EA_MODELTABLE01
  +0x00  int     type        the draw pass: 1 floor, 2 obj, 3 obj2 (0 other)
  +0x04  char *  modelname   an MDL_ object in the scene file
  +0x08  int     postype     0 none, 1 a DummyPos, 2 a DummyPosRot
  +0x0c  char *  posname     the DMY_ object that gives the position
  +0x10  float   clip        drawn only within this distance of the camera

• Construction. STATICMODEL::STATICMODEL (0x005cffd0) looks the model up by name and copies the dummy's position; for postype 2 it also copies the rotation.
• Drawing. STATICMODEL::Draw (0x005d01c0) builds sceVu0UnitMatrix then sceVu0TransMatrix(position) and draws it. The rotation is not applied, so a piece is its model translated to its dummy. It computes the distance to the camera and never uses it: clip culls nothing.
• Mac Anu. In RT_MODELTABLE00, MDL_floor_NN, MDL_obj_NN and MDL_obj2_NN all sit at DMY_floor_NNpos: district 01 at (0, 9600, 0), 03 at (−6000, 0, 0), 04 at (6000, 0, 0), and so on. The LOD copies MDL_obj_02lod and _05lod share their districts' dummies and replace rows 8 and 11 when the camera is far enough south (below).
• Which pieces draw. ROOTTOWN01::DrawFloor (0x00422ba0) walks its 32 STATICMODELs and draws those of type 1, skipping districts by clip[3] (this+0x1b0..+0x1b8), which ROOTTOWN01::Draw sets each frame from the camera eye: clip[0] on the gate plaza, clip[1] on the south plaza, clip[2] beyond y 1600 (0x44c8 << 16). The rules are on the field game page and in crates/piney-world/src/town01.rs, whose MacAnu::select gives what the game's Draw gives for any camera eye (run side by side in eemu, tools/test_world_rs.py).

type is the draw pass: ROOTTOWN01::DrawFloor, DrawObj and DrawObj2 (0x00422ba0, 0x004224c0, 0x00422900) draw the rows whose type is 1, 2 and 3, and DrawObj2 draws the static objects of type 3 too. In Mac Anu, ROOTTOWN01::Draw (0x00423b10) draws the type-0 rows itself: the static objects of type 0 (the ships) first, the model rows of type 0 (the tower MDL_sr1tow01) last. Dun Loireag's ROOTTOWN02 (0x004240c0, Draw 0x004266a0) draws its 20 rows by type without clip rules, its static objects of types 2 and 3 in DrawObj and DrawObj2, and the model rows of type 0 last (it has none): Dun Loireag. The other classes' type-0 rows have not been traced. The port carries type as DrawPass, and postype with posname as Position (none, a DummyPos or a DummyPosRot by name).

Static objects

STATIC_OBJ_INFO     0x18 bytes, e.g. RT_OBJTABLE00 (11 rows)
  +0x00  int     type
  +0x04  char *  clumpname   a CMP_ clump, or NULL
  +0x08  char *  anmname     the ANM_ animation that moves it
  +0x0c  int     postype     as above
  +0x10  char *  posname
  +0x14  float   clip

STATICOBJECT::STATICOBJECT (0x005cf9b0) creates the animation, or the clump when the row names no animation. It sets its root matrix with ccCoord::SetMatrix_PosRotZYX(position, rotation) from the dummy (T Rx Ry Rz, the rotation turned to radians when the chunk is decoded), so one animation can stand at several dummies. STATICOBJECT::Draw draws within clip of the camera eye (in the ground plane) and steps the animation only then. piney_data::statics places both (ModelTable::place, StaticObj::root); piney-world's town builds each root as the game stores it (sceVu0RotMatrix of the dummy's radians, pi * deg / 180 as Decode_DummyPosRot converts them, then the position), matching the game's matrices bit for bit. Mac Anu's six flags are ANM_sr1fla1_a at DMY_sr1fla1_01pos..06pos, and its two ships are ANM_sr1shi1_a at DMY_sr1shi01/02. STATICOBJECT::Draw advances the animation, then draws the animation and the clump.

The files a town loads

Each constructor asks ccStream::GetCCSAdrs for its scene files by name. piney-gen (placement::statics) reads the names out of the code: the $a0 string built just before each call.

EVENTAREAB0 picks its stage by game.field (fields 1-8; field 8 adds se4_8), through the constructor's jump table: the story maps.

The d files are the towns in crisis. ROOTTOWN01 (0x004215a4) takes town01d when saveData+0x6772 - the crisis byte - is set and town01 otherwise, and keeps the stream at this+0x1a4. wat1 is loaded either way; it holds the canal water, one plane (MDL_wat00, x ±7,800, y −8,700 to 8,100, about 100 below the streets) with 15 morph targets for its waves. The constructor makes three ccAnms of ANM_sr1wat1_a (named by the global wateranmname), duplicates OBJ_wat00 in each, and roots all three at the identity (the constants at 0x005d4a90 and 0x005d4aa0 are all zeros with w = 1). town_z holds no models: its seven Eff chunks are the lens flare's EFF_sflenz_1-6 and the clouds' EFF_srzsmo1, each with its texture (Dun Loireag).

The three waters are all drawn in Mac Anu and Dun Loireag: water 0 with the frame-buffer copy behind it (the refraction), waters 1 and 2 with their UVs scrolled, water 1 in U and water 2 in V (Dun Loireag). ROOTTOWN01's constructor also builds the sky CMP_sr1bac1 and, in town01d, CMP_sr1dat1_1-3 itself; DrawBG draws them at the origin: the sky on objLayer, the three over it on WORLD_MAN's layers at +0x49c, +0x4a0 and +0x4a4 (priorities -80, -70, -60), MAT_sr1dat1_2 scrolled in U and MAT_sr1dat1_3 in U and V by 0.002 a frame (crates/piney-world/src/town01.rs, CRISIS_SKY). ROOTTOWN03-05 (Carmina Gade, Fort Ouph, Lia Fail) are on their page; their DrawMap is on the minimap page.

The tables

placement::statics finds every *MODELTABLE* and *OBJTABLE* object in gcmn.prg: 16 model tables (172 rows) and 11 object tables. It matches each to the DATA.BIN members holding every object it names:

EA_MODELTABLE02 and 0202 both fit se1_2: the two blocks of area 15's map, the holy ground and the church, which EVENTAREA02::ChangeBlock builds in turn (area 15's story map).

Unknown

• What the first water copy's different Duplicate flag (8200 against 8192) changes.