Dusk/WeirdUtils
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 1 Wiki Activity

math_sse: fix calling conventions from Ghidra disassembly verification

Browse Source 
Hooks 1,3 (vecMulMat4, quatMulMat4): thiscall->fastcall. Assembly
confirms EDX is read as a parameter (FMUL [EDX+...]) before any write.
Detour types TC2r->FC3r, AB wrappers abTC2r->abFC3r.

Hook 15 (0x699330): removed entirely. Was misidentified as vectorNormalize
but Ghidra shows it's a vec3 componentwise >= comparison returning u32.
Silicon-only function (not UnitXP), stub already in silicon.zig. Our
normalize implementation would have silently corrupted comparison results.

Also fixed comment accuracy: hook 8 RET 0x4 (not plain RET), hook 14
__thiscall (not __fastcall). Bitmask selection replaces MATH_TEST_HOOK
single-select with proper bit flags. 17 hooks total, mask 0x77FFE.
This commit is contained in:
MarcelineVQ
2026-03-14 18:44:22 -07:00
parent 2018ca45fa
commit 8307e525d9
2 changed files with 113 additions and 136 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/transform44/math_sse.zig
+5 -18
View File
@@ -149,7 +149,7 @@ export fn scaleMatrix3x3ByVector(mat: u32, vec: u32) u32 {
}
/// 0x7BDD00: Scale 3x3 rotation portion by uniform scalar
/// __thiscall(ECX=mat4x4, stack: factor_float), plain RET
/// __thiscall(ECX=mat4x4, stack: factor_float), RET 0x4
/// Reference: polyfill.cpp line 162
export fn scaleMatrix3x3ByScalar(mat: u32, factor_bits: u32) void {
const f: f32 = @bitCast(factor_bits);
@@ -253,7 +253,7 @@ export fn createAxisAngleRotMat4x4(result: u32, axis: u32, angle_bits: u32, is_u
}
// =============================================================================
// Vector math primitives (0x672130, 0x602630, 0x4549F0, 0x699330)
// Vector math primitives (0x672130, 0x602630, 0x4549F0)
//
// These are called thousands of times per frame from collision, terrain,
// and rendering code. The originals use x87 FPU.
@@ -282,7 +282,7 @@ export fn dotProduct(a: u32, b: u32) f64 {
}
/// 0x4549F0: Squared magnitude of vec3 (returns double in ST(0))
/// __fastcall(ECX=vec3), plain RET
/// __thiscall(ECX=vec3), plain RET
/// Note: Ghidra labels this "emptyFunction" — it's NOT empty, it returns x*x+y*y+z*z
/// Reference: polyfill.cpp line 289
export fn squaredMagnitude(vec: u32) f64 {
@@ -292,21 +292,8 @@ export fn squaredMagnitude(vec: u32) f64 {
return x * x + y * y + z * z;
}
/// 0x699330: Vector normalize (in-place) — from libSiliconPatch symbols
/// __fastcall(ECX=vec3, EDX=vec3_other?), RET
/// TODO: verify calling convention from assembly before enabling
export fn vectorNormalize(vec: u32, _: u32) void {
const x = rf32(vec);
const y = rf32(vec + 4);
const z = rf32(vec + 8);
const len = @sqrt(x * x + y * y + z * z);
if (len > 1.0e-7) {
const inv = 1.0 / len;
wf32(vec, x * inv);
wf32(vec + 4, y * inv);
wf32(vec + 8, z * inv);
}
}
// 0x699330 removed -- was misidentified as normalize, actually vec3 comparison
// from libSiliconPatch (not UnitXP). Stub lives in src/silicon/silicon.zig.
// =============================================================================
// Polynomial evaluation (0x453620)