Commit Graph
4 Commits
Author SHA1 Message Date
arcattackandClaude Fable 5 48c9c8444f Fire VISUALS wave: the authored firesmoke sheet, vertex-alpha effect cards, the case-4 wreck dressing
The "fireballs like the demo vids" arc, decomp/content-grounded end to end,
plus the live-play UX batch verified over the same sessions:

FIRESMOKE SHEET (the PFX fireball fix): every firesmokeN_scr_tex in BTFX.VMF
maps the SAME 64x64 tileable noise image bintA (variants differ only in SCROLL
rate) and firesmoke1_mtl colours it through the "fiery" ramp (0.3,0.1,0.1)->
(0.9,0.7,0.3).  The particle layer now bakes ramp(lum(bintA)) as its sprite
colour (noise detail in alpha) and SCROLLS it at firesmoke1's authored rate
via a texture-transform; the port's radial soft-edge mask moved to a second
CLAMPed stage so the WRAPPED scroll rolls flame through the sprite without
scrolling the edge away.  Old grit x radial bake kept as the no-BINTA fallback.
Impact hits, damage-band smoke and death booms all ride this layer.

AUTHORED TEXTURE SCROLL in the model path: the BMF TEXTURE records carry
SPECIAL " SCROLL u0 v0 du dv" (tag 0x2037); the draw path always supported
per-op scrolling (SetTextureScrolling) but the BGF loader never parsed it, so
every scrolling material rendered frozen.  Wired TexRef -> MatInfo -> batch ->
L4TEXOP.doScroll: the flame cards (flamebig/fire5) now roll fire noise.

VERTEX-ALPHA EFFECT CARDS (the "twisted drill bit of fire" fix): FLAMEBIG's
verts carry authored float RGBA -- white-hot base (1.0,0.99,0.97) -> dark-red
tip fading to alpha -0.2 (the DPL clamp convention).  The loader kept a flat
batch colour and drew it OPAQUE = a solid orange spike.  Corpus sweep: exactly
14 shipped BGFs carry vertex alpha, ALL effect cards (flames, MUZFLASH,
EXDISK_A/B/C, TMST_A/B/C, beam models, DECLOUDS).  Such batches now keep the
authored per-vertex gradient and route to the alpha-blend pass, unlit,
colour = texture x gradient, alpha = the vertex fade; sky objects excluded
(drawAsSky + alphaTest passes NEITHER pass filter -- DECLOUDS stays in the
sky pass).  MUZFLASH/EXDISK render correctly for free when the muzzle-model
work lands.

WRECK DRESSING (the 1996 ExplosionScripts case-4 transcription): pieces spawn
HIDDEN and reveal 0.25s after the boom (the InstanceSwitch delay, behind the
dnboom flash); flamebig hangs over the pile, Y-BILLBOARDED at the camera
(SetOffsetYaw + a camera-pos getter -- the dpl_SetDCSReorientAxes analog);
the MakeDCSFall settle arms at the reveal with the two authored rates (hulk/
debris -0.025 t^2, fires -0.01 t^2 -- the flames ride above the sinking pile
and die with it at burial).  EMPTY-PLACEHOLDER hulk guard: THRDBR.BGF is a
153-byte zero-geometry stub that "loads fine" -- vertex-count check now routes
it to the gendbr fallback (a Thor wreck was invisible).  Hulk content census
recorded: AVADBR==MADDBR==VULDBR geometry (palette-only prefix diffs),
RAPDBR==SNDDBR==STIDBR byte-identical -- wreck variety is materials + the
dressing, not unique piles.

LIVE-PLAY BATCH: muzzle resolve uses the named segmentIndex (raw +0xdc read
was layout garbage); forward launch frame (authored MuzzleVelocity +Z vs the
mech's -Z facing); dock-bottom single window (gauge strip appended below the
world viewport, 1100x600 default, BT_DEV_GAUGES_WINDOW=1 restores the separate
window); portrait sec surface unrotated CW; ammo counters live via typed
bridges (BTAmmoBinCountPtr/BTAmmoBinFeeding/BTWeaponAmmoBin -- raw bin+0x180
and a hand-rolled link walk were garbage); fourth fire key ('4' = Pinky);
panel/arc probes de-aliased (%61 prime).

KB: rendering.md (vertex-alpha card family + scroll), combat-damage.md (hulk
census + THRDBR stub), gauges-hud.md (ammo bridges).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-12 20:04:29 -05:00
arcattackandClaude Fable 5 96b8892e7c Cockpit: the authentic punch STENCIL-CUT -- all 8 cockpits real (task #55)
The user caught the inversion (blocked viewports, see-through frames); the
answer came from the rasterizer board itself: an i860 disassembly of the
VREND.MNG firmware decoded the damageize handler (@0xf040f6f8) -- cmd 0x20
(vr_damage_action) writes the dpl_Punchize token triple onto the punch
geogroup's first three geometry chunks IN FILE ORDER:

  chunk1 = the detailed window-aperture shapes -> an invisible per-pixel MASK
  chunk2 = the coarse hull -> the ONLY colour-drawn geometry (where not masked)
  chunk3 = byte-identical hull twin -> the damage-reset record, never visible

Visible canopy = hull-minus-apertures.  Both earlier readings were wrong ways
around the same three chunks: dropping all punch left floating fragments (no
hull); hiding the duplicate pair hid the HULL and drew the MASK -- the exact
inversion observed.

Port: bgfload tags per punch patch {non-paired pmesh = mask (role 1),
first twin = hull (role 2), second twin = skip}; L4D3D DrawMesh runs
mask->stencil-1 (no colour/z-write, z-tested), hull->stencil-NOTEQUAL,
mask->stencil-0; device D24X8 -> D24S8 + stencil clear.  The cut never
touches z, so later-drawn entities show through the apertures.
BT_COP_PLATES=1 disables (diag).

In-game, all 8 mechs on pure defaults: connected dark frames with clear
viewports -- thor (the footage mech) shows the central viewport + surrounding
frame exactly as filmed.  Combat regression clean (kill + no NaN).

Arena textured punch uses the same firmware kit; the black-texel alpha path
there is a working approximation, flagged in the KB.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-11 08:53:22 -05:00
arcattackandClaude Fable 5 b6fe686b22 Shadow: authentic terrain tilt + decal draw order (feet layer correctly)
User report: the ground shadow painted OVER the mech's feet.  Root cause: the
flat quad + big depth-bias (-0.004 ~= 2-4 world units) workaround for slope
burial -- a bias big enough to beat the TERRAIN also beat the FEET in the
depth test, and the shadow drew in the late alpha-blend pass (after the mech),
so z-arbitration was the only layering control.

Fix, four co-dependent parts (user-verified live: feet on top, opaque,
survives inclines/declines):

- TILT (mech.cpp UpdateShadowJoint): apply the SKL's own contract for
  jointshadow ("apply terrain angle to pitch and roll") -- quad up aligned to
  the surface normal via an orthonormal basis fed to the ENGINE's own
  LinearMatrix->EulerAngles conversion.  Hand-derived Euler signs are exactly
  how the prior tilt attempts "dug into the hillside"; the engine conversion
  is convention-proof.  ~35 deg cliff-guard cap.
- SAMPLER (mech4.cpp): surface gradient from the collision probes PLUS
  BTVisualGroundLift per probe -- the quad hugs the VISIBLE terrain, whose
  lift varies across a slope; world->local rotation by the TRUE yaw from
  localToWorld, not the drift-prone gDriveHeading mirror (the task-#48 bug
  class).  BT_SHADOW_LOG traces the normals.
- DRAW ORDER (new PASS_SHADOW, l4d3d.h/L4VIDRND/L4VIDEO): shadows draw
  between the STATIC terrain and the DYNAMIC opaque bodies -- the classic
  decal order.  The mech, drawn after, z-passes over the shadow: the bias
  can never paint the shadow over the feet, structurally.
- BIAS pairing (L4D3D.cpp): tilt on (default) -> decal epsilon -0.0008;
  BT_SHADOW_TILT=0 flat fallback -> the old -0.004.  BT_SHADOW_BIAS overrides.

KB (locomotion.md): the four-part arrangement recorded as co-dependent, with
the gait-desync-symptom diagnostic hint retained.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-09 16:59:48 -05:00
arcattackandClaude Opus 4.8 7b7d465e5e Initial commit: bt411 -- standalone Windows BattleTech (Tesla 4.10 port)
Clean, self-contained extraction of the BattleTech-specific work from the
reverse-engineering workspace -- engine + game + content + build, with nothing
from Red Planet or the raw archive dumps. Builds green (Win32) and runs the
single-player drive->animate->target->fire->damage->destroy loop out of the box.

Layout:
  engine/   MUNGA + MUNGA_L4 shared 2007 engine, carrying our BT render/loader
            work (bgfload/L4D3D/L4VIDEO: BSL bit-slice decode, LOD/ground/shadow
            models) + image codec; the minimal rp/ headers the audio HAL needs
  game/     reconstructed BT logic + surviving-original BT source + fwd shims
            + WinMain launcher
  content/  full runtime tree (BTL4.RES, VIDEO/, GAUGE/, AUDIO/, eggs, BTDPL.INI)
  docs/     format specs + reconstruction ledgers
  reference/ raw Ghidra pseudocode (recon source-of-truth) + decomp exporter
  tools/    MP console emulator + map/resource scanners

One top-level CMake builds munga_engine lib + bt410_l4 game lib + btl4.exe.
All paths relativized (186 fwd shims + ~437 CMake abs paths -> repo-relative);
DXSDK is the one external, overridable via -DDXSDK. Verified: builds to a
byte-identical 2.27MB exe and runs combat (TARGET DESTROYED, 0 crashes) against
the bundled content.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-05 21:03:40 -05:00