From a19a4d3378586218bb0c9ae2241029a272bfe067 Mon Sep 17 00:00:00 2001
From: LagoLunatic <LagoLunatic@users.noreply.github.com>
Date: Fri, 5 Jan 2024 02:32:41 -0500
Subject: [PATCH] d_bg_s_acch almost

---
 include/SSystem/SComponent/c_m3d_g_pla.h | 20 ++++++++++++--------
 src/SSystem/SComponent/c_bg_w.cpp        |  2 +-
 src/d/d_bg_s_acch.cpp                    | 12 ++++++------
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/include/SSystem/SComponent/c_m3d_g_pla.h b/include/SSystem/SComponent/c_m3d_g_pla.h
index 8b8c562f2..995d90053 100644
--- a/include/SSystem/SComponent/c_m3d_g_pla.h
+++ b/include/SSystem/SComponent/c_m3d_g_pla.h
@@ -24,13 +24,20 @@ public:
     cXyz* GetNP() { return &mNormal; }
     const cXyz* GetNP() const { return &mNormal; }
     f32 GetD() const { return mD; }
-    float getCrossY(const cXyz& i_axis) const { // fake inline
+    void getCrossY(const cXyz& i_axis, f32* i_value) const {
+        if (!cM3d_IsZero(mNormal.y)) {
+            *i_value = (-mNormal.x * i_axis.x - mNormal.z * i_axis.z - mD) / mNormal.y;
+        }
+    }
+    f32 getCrossY_NonIsZero(const cXyz& i_axis) const {
         return (-mNormal.x * i_axis.x - mNormal.z * i_axis.z - mD) / mNormal.y;
     }
-    void getCrossY(const cXyz& i_axis, float* i_value) const {
-        if (!cM3d_IsZero(mNormal.y)) {
-            *i_value = getCrossY(i_axis);
+    bool getCrossYLessD(const Vec& i_axis, f32* i_value) const {
+        if (cM3d_IsZero(mNormal.y)) {
+            return false;
         }
+        *i_value = (-mNormal.x * i_axis.x - mNormal.z * i_axis.z) / mNormal.y;
+        return true;
     }
     f32 getSignedLenPos(const cXyz* param_1) const {
         return cM3d_SignedLenPlaAndPos(this, param_1);
@@ -41,11 +48,8 @@ public:
     // TODO
     void Set(const cM3dGPla*) {}
     void SetupFrom3Vtx(const Vec*, const Vec*, const Vec*) {}
-    cM3dGPla(const cXyz*, float) {}
+    cM3dGPla(const cXyz*, f32) {}
     void cross(const cM3dGLin&, Vec&) const {}
-    void getCrossYLessD(const Vec&, float*) const {}
-    void getCrossY_NonIsZero(const cXyz&) const {}
-    void operator=(const cM3dGPla&) {}
 };  // Size: 0x14
 
 #endif
diff --git a/src/SSystem/SComponent/c_bg_w.cpp b/src/SSystem/SComponent/c_bg_w.cpp
index 250aea6fe..5bfe65b65 100644
--- a/src/SSystem/SComponent/c_bg_w.cpp
+++ b/src/SSystem/SComponent/c_bg_w.cpp
@@ -177,7 +177,7 @@ bool cBgW::RwgGroundCheckGnd(u16 idx, cBgS_GndChk* chk) {
     while (true) {
         cBgW_RwgElm * rwg = &pm_rwg[idx];
         cBgW_TriElm * tri = &pm_tri[idx];
-        f32 y = tri->m_plane.getCrossY(*chk->GetPointP());
+        f32 y = tri->m_plane.getCrossY_NonIsZero(*chk->GetPointP());
         if (RwgGroundCheckCommon(y, (u16)idx, chk))
             ret = true;
         idx = rwg->next;
diff --git a/src/d/d_bg_s_acch.cpp b/src/d/d_bg_s_acch.cpp
index ecab204b6..3887cbec5 100644
--- a/src/d/d_bg_s_acch.cpp
+++ b/src/d/d_bg_s_acch.cpp
@@ -116,7 +116,6 @@ void dBgS_Acch::GroundCheckInit(dBgS&) {
 
 /* 800A2EE8-800A305C       .text GroundCheck__9dBgS_AcchFR4dBgS */
 void dBgS_Acch::GroundCheck(dBgS& i_bgs) {
-    /* Nonmatching */
     if (m_flags & GRND_NONE)
         return;
 
@@ -446,11 +445,12 @@ bool dBgS_Acch::GetOnePolyInfo(cBgS_PolyInfo* dst) {
 
 /* 800A42B4-800A4348       .text GetWallAddY__9dBgS_AcchFR3Veci */
 f32 dBgS_Acch::GetWallAddY(Vec& vec, int) {
-    /* Nonmatching */
-    if (ChkGroundFind() && m_pla.GetNP()->y < 0.5f) {
-        f32 cross_y;
-        m_pla.getCrossY(vec, &cross_y);
-        if (cross_y < 0.0f)
+    if (!ChkGroundFind() || m_pla.mNormal.y < 0.5f) {
+        return 0.0f;
+    }
+    f32 cross_y;
+    if (m_pla.getCrossYLessD(vec, &cross_y)) {
+        if (cross_y > 0.0f)
             cross_y = 0.0f;
         return -cross_y;
     } else {