Proximity warning

References

1. ^ abIn the US build (SLUS-00707), Game_NpcUpdate picks the enemies the pocket radio reacts to by distance alone, with no line-of-sight test. An enemy (a character id up to Chara_MonsterCybil, the code's last common enemy) counts while its health is above 0, its CharaFlag_NoRadioStatic flag is clear (Split Head's init sets it; other setters weren't read), and its squared distance from Harry on the ground plane, x and z with height ignored, is under 32² world units (a unit is Q12 1.0). In maps flagged MapFlag_Interior with one or two active chunks, which the code calls low-visibility interiors, the enemy must also share Harry's 40-unit chunk cell on both axes. The code keeps the three nearest, and the radio's two static channels (g_RadioNoise[2]) each follow one of the nearest two, only while ItemToggleFlag_RadioOn is set. Each channel is panned toward its enemy, and its volume falls with distance: the attenuation is the distance converted by Q12_TO_Q4 (sixteenths of a unit, by the decompilers' reading, which their comment "TODO: Is it Q4 here?" doubts), halved outside low-visibility interiors, capped at 255, and Sd_SfxAttributesUpdate takes that share out of 255 from the volume. Computed under that reading, the static falls silent at about 16 units in a low-visibility interior and about 32 units elsewhere.Codeshdecompilations/silent-hill-decomprevised
   How we know

   218    posXShift6 = Q12_TO_Q6(g_SysWork.playerWork.player.position.vx);
   219    posZShift6 = Q12_TO_Q6(g_SysWork.playerWork.player.position.vz);
   ⋮
   227        closestNpcInfos[j].distanceToNpc = SQUARE(32);
   

   243        // Only process enemy NPC for radio interference.
   244        if (curNpc->model.charaId <= CHARA_LAST_ENEMY_ID)
   ⋮
   246            // Compute square integer distance from player to NPC.
   247            curDistToNpc = Q12_SQUARE_PRECISE(Q12_TO_Q6(curNpc->position.vx) - posXShift6) +
   248                           Q12_SQUARE_PRECISE(Q12_TO_Q6(curNpc->position.vz) - posZShift6);
   ⋮
   250            // Check if map is low-visibility interior.
   251            isLowVisInterior = false;
   252            if (g_MapOverlayHdr.mapInfo->flags & MapFlag_Interior)
   ⋮
   254                isLowVisInterior = (g_MapOverlayHdr.mapInfo->flags & (MapFlag_OneActiveChunk |
   255                                                                      MapFlag_TwoActiveChunks)) > 0;
   ⋮
   262                if (curNpc->health <= Q12(0.0f)             ||
   263                    curNpc->flags & CharaFlag_NoRadioStatic ||
   ⋮
   

   7#define CHUNK_SIZE                        40.0f
   

   #define CHARA_LAST_ENEMY_ID Chara_MonsterCybil

   62    splitHead->flags    |= CharaFlag_NoRadioStatic | CharaFlag_Hit;
   

   155    s_CloseNpcInfo  closestNpcInfos[3];
   

   181    s32 func_800382B0(s32 bitIdx)
   ⋮
   185        for (i = 0; i < (ARRAY_SIZE(closestNpcInfos) - 1); i++)
   ⋮
   197    static s32 func_800382EC()
   ⋮
   201        for (i = 0; i < (ARRAY_SIZE(closestNpcInfos) - 1); i++)
   

   68s_RadioNoise g_RadioNoise[2];
   

   362    if (!(g_SavegamePtr->itemToggleFlags & ItemToggleFlag_RadioOn))
   ⋮
   364        return;
   

   423            isExterior = false;
   424            if (!(g_MapOverlayHdr.mapInfo->flags & MapFlag_Interior) ||
   425                !(g_MapOverlayHdr.mapInfo->flags & (MapFlag_OneActiveChunk | MapFlag_TwoActiveChunks)))
   ⋮
   427                isExterior = true;
   ⋮
   433                balance      = Vc_StereoBalanceGet(&closeNpcInfo->position);
   ⋮
   435                // Compute volume from distance.
   436                distToNpc = Q12_TO_Q4(SquareRoot12(Q12(closeNpcInfo->distanceToNpc)));
   437                if (isExterior)
   ⋮
   439                    distToNpc = DIV_FAST(distToNpc, 2);
   ⋮
   442                // Compute clamped volume from Q4 distance. TODO: Is it Q4 here?
   443                vol = CLAMP(distToNpc, Q8(0.0f), Q8_CLAMPED(1.0f));
   ⋮
   445                Sd_SfxAttributesUpdate(Sfx_RadioInterferenceLoop + l, balance, vol, 0);
   

   560    convertedVol                = vol;
   561    convertedVol                = g_Sd_VabPlayingInfo.volumeLeft - ((g_Sd_VabPlayingInfo.volumeLeft * (convertedVol)) / 255);
   

   Checked against the evidence by its author, an AI model, 2026-10-22.

   Revised after a check by a second AI model, 2026-10-22.

   In the claim ledger