bone_sse: replace IsParticleBufferEmpty with pure Zig — 1 game call remains (atexit)

src/transform44/bone_sse.zig

@@ -466,6 +466,20 @@ inline fn crossVec3(ax: f32, ay: f32, az: f32, bx: f32, by: f32, bz: f32) [3]f32
 // Output: indices[0] = lower index, [1] = upper index, [2] = interpolation t (float bits)
 // =============================================================================
 
+/// IsParticleBufferEmpty (0x7B5F60) — recursive tree check.
+/// Returns true if any node in the tree has active particles (this->0x64 != 0).
+fn isParticleBufferNotEmpty(ptr: u32) bool {
+    if (ru32(ptr + 0x64) != 0) return true;
+    const count = ru32(ptr + 0x7C);
+    if (count == 0) return false;
+    const children = ptr + 0x80;
+    var i: u32 = 0;
+    while (i < count) : (i += 1) {
+        if (isParticleBufferNotEmpty(ru32(children + i * 4))) return true;
+    }
+    return false;
+}
+
 /// findInterpIdx: temporal-coherence keyframe search.
 /// Reimplementation of game function at 0x713D50 (334 bytes).
 /// Assembly-verified against t44_helpers_asm.txt.
@@ -2252,11 +2266,7 @@ fn additionalParticleLoops(this: u32, model_hdr: u32) void {
             if (emitter_active != 0) {
                 buf_active = 1;
             } else {
-                // Call IsParticleBufferEmpty (0x7B5F60)
-                // Assembly: MOV ECX,[EBP-0x10]; CALL 0x7B5F60
-                // __thiscall(ECX=ptr), plain RET, returns 0 or 1 in EAX
-                const isEmptyFn: *const fn (u32) callconv(.{ .x86_fastcall = .{} }) u32 = @ptrFromInt(0x7B5F60);
-                if (isEmptyFn(local_14) != 0) {
+                if (isParticleBufferNotEmpty(local_14)) {
                     buf_active = 1;
                 }
             }

src/transform44/decompiled/t44_helpers_asm.txt

@@ -775,3 +775,34 @@ OpenJDK 64-Bit Server VM (build 21.0.10+7, mixed mode)
   0x00454A0C  FSTP ST0
   0x00454A0E  RET << RET
 
+
+=== IsParticleBufferEmpty (0x007B5F60, 59 bytes) ===
+  0x007B5F60  8B 41 64                 MOV EAX,dword ptr [ECX + 0x64]
+  0x007B5F63  85 C0                    TEST EAX,EAX
+  0x007B5F65  53                       PUSH EBX
+  0x007B5F66  56                       PUSH ESI
+  0x007B5F67  57                       PUSH EDI
+  0x007B5F68  74 09                    JZ 0x007b5f73
+  0x007B5F6A  5F                       POP EDI
+  0x007B5F6B  5E                       POP ESI
+  0x007B5F6C  B8 01 00 00 00           MOV EAX,0x1
+  0x007B5F71  5B                       POP EBX
+  0x007B5F72  C3                       RET  << RET
+  0x007B5F73  8B 79 7C                 MOV EDI,dword ptr [ECX + 0x7c]
+  0x007B5F76  33 F6                    XOR ESI,ESI
+  0x007B5F78  85 FF                    TEST EDI,EDI
+  0x007B5F7A  76 19                    JBE 0x007b5f95
+  0x007B5F7C  8D 99 80 00 00 00        LEA EBX,[ECX + 0x80]
+  0x007B5F82  8B 0B                    MOV ECX,dword ptr [EBX]
+  0x007B5F84  E8 D7 FF FF FF           CALL 0x007b5f60 << CALL
+  0x007B5F89  85 C0                    TEST EAX,EAX
+  0x007B5F8B  75 DD                    JNZ 0x007b5f6a
+  0x007B5F8D  46                       INC ESI
+  0x007B5F8E  83 C3 04                 ADD EBX,0x4
+  0x007B5F91  3B F7                    CMP ESI,EDI
+  0x007B5F93  72 ED                    JC 0x007b5f82
+  0x007B5F95  5F                       POP EDI
+  0x007B5F96  5E                       POP ESI
+  0x007B5F97  33 C0                    XOR EAX,EAX
+  0x007B5F99  5B                       POP EBX
+  0x007B5F9A  C3                       RET  << RET