From 1acd6f1a9778c1fc7153bf81a51f0006e1871f72 Mon Sep 17 00:00:00 2001
From: "Jasper St. Pierre" <jstpierre@mecheye.net>
Date: Sat, 20 Jan 2024 10:44:36 -0800
Subject: [PATCH] c_m3d work

---
 include/SSystem/SComponent/c_m3d.h |  1 -
 src/SSystem/SComponent/c_m3d.cpp   | 26 +++++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/include/SSystem/SComponent/c_m3d.h b/include/SSystem/SComponent/c_m3d.h
index 959768a57..584354b9b 100644
--- a/include/SSystem/SComponent/c_m3d.h
+++ b/include/SSystem/SComponent/c_m3d.h
@@ -23,7 +23,6 @@ extern f32 G_CM3D_F_ABS_MIN;
 
 void cM3d_InDivPos1(const Vec*, const Vec*, f32, Vec*);
 void cM3d_InDivPos2(const Vec*, const Vec*, f32, Vec*);
-f32 cM3d_Len2dSq(f32, f32, f32, f32);
 bool cM3d_Len2dSqPntAndSegLine(f32, f32, f32, f32, f32, f32, f32*, f32*, f32*);
 bool cM3d_Len3dSqPntAndSegLine(const cM3dGLin*, const Vec*, Vec*, f32*);
 f32 cM3d_SignedLenPlaAndPos(const cM3dGPla*, const Vec*);
diff --git a/src/SSystem/SComponent/c_m3d.cpp b/src/SSystem/SComponent/c_m3d.cpp
index 908aeacc8..468646766 100644
--- a/src/SSystem/SComponent/c_m3d.cpp
+++ b/src/SSystem/SComponent/c_m3d.cpp
@@ -58,9 +58,33 @@ void cM3d_InDivPos2(const Vec* v0, const Vec* v1, f32 scale, Vec* pDst) {
     cM3d_InDivPos1(v0, &tmp, scale, pDst);
 }
 
+inline f32 cM3d_Len2dSq(f32 x0, f32 y0, f32 x1, f32 y1) {
+    f32 x = x0 - x1;
+    f32 y = y0 - y1;
+    return x*x + y*y;
+}
+
 /* 8024A4B4-8024A56C       .text cM3d_Len2dSqPntAndSegLine__FffffffPfPfPf */
-bool cM3d_Len2dSqPntAndSegLine(f32, f32, f32, f32, f32, f32, f32*, f32*, f32*) {
+bool cM3d_Len2dSqPntAndSegLine(f32 xp, f32 yp, f32 x0, f32 y0, f32 x1, f32 y1, f32* outx, f32* outy, f32* seg) {
     /* Nonmatching */
+    bool ret = false;
+    f32 xd = x1 - x0;
+    f32 yd = y1 - y0;
+    f32 dot = (xd*xd + yd*yd);
+    if (cM3d_IsZero(dot)) {
+        *seg = 0.0f;
+        return ret;
+    }
+
+    f32 t = (x1 * (xp - x0) + y1 * (yp - y0)) / dot;
+    if (t >= 0.0f && t <= 1.0f) {
+        ret = true;
+    }
+
+    *outx = x0 + xd * t;
+    *outy = y0 + yd * t;
+    *seg = cM3d_Len2dSq(*outx, *outy, xp, yp);
+    return ret;
 }
 
 /* 8024A56C-8024A670       .text cM3d_Len3dSqPntAndSegLine__FPC8cM3dGLinPC3VecP3VecPf */