From 83462d3f271324d8d1f7e9cb3ce1988bb801e912 Mon Sep 17 00:00:00 2001
From: "Jasper St. Pierre" <jstpierre@mecheye.net>
Date: Thu, 11 Jul 2024 00:26:17 -0700
Subject: [PATCH] d_spline_path

---
 configure.py              |  2 +-
 include/d/d_spline_path.h | 21 ++++++++++--
 src/d/d_spline_path.cpp   | 67 +++++++++++++++++++++++++++++++++------
 3 files changed, 77 insertions(+), 13 deletions(-)

diff --git a/configure.py b/configure.py
index 6cd3cc637..5453f5fe9 100644
--- a/configure.py
+++ b/configure.py
@@ -455,7 +455,7 @@ def JSystemLib(lib_name, objects):
             Object(NonMatching, "d/d_flower.cpp"),
             Object(Matching,    "d/d_item_data.cpp"),
             Object(Matching,    "d/d_seafightgame.cpp"),
-            Object(NonMatching, "d/d_spline_path.cpp"),
+            Object(Matching,    "d/d_spline_path.cpp"),
             Object(Matching,    "d/d_s_actor_data_mng.cpp"),
             Object(Matching,    "d/d_item.cpp"),
             Object(NonMatching, "d/d_2dnumber.cpp"),
diff --git a/include/d/d_spline_path.h b/include/d/d_spline_path.h
index 61c9ac79f..51253d3a0 100644
--- a/include/d/d_spline_path.h
+++ b/include/d/d_spline_path.h
@@ -10,9 +10,24 @@ class d2DBSplinePath {
     void Last() {}
 
     void Init(s32, s32);
-    void Step();
-    void Calc(cXyz*);
-    void Calc(f32*);
+    bool Step();
+    cXyz Calc(cXyz*);
+    f32 Calc(f32*);
+
+public:
+    /* 0x00 */ s32 mFrame;
+    /* 0x04 */ s32 mKeyNum;
+    /* 0x08 */ s32 mDuration;
+    /* 0x0C */ s32 mState;
+    /* 0x10 */ s32 mKeyNo;
+    /* 0x14 */ s32 mEnd;
+    /* 0x18 */ s32 field_0x18;
+    /* 0x1C */ f32 mStep;
+    /* 0x20 */ s32 field_0x20;
+    /* 0x24 */ f32 mCurveWeight[3];
+    /* 0x30 */ s32 mCurveKey[3];
+    /* 0x3C */ void* mUser;
+    /* 0x40 */ void* vtbl; // XXX
 };
 
 #endif /* D_SPLINE_PATH_H */
diff --git a/src/d/d_spline_path.cpp b/src/d/d_spline_path.cpp
index 2dbaf8702..939e4282a 100644
--- a/src/d/d_spline_path.cpp
+++ b/src/d/d_spline_path.cpp
@@ -4,24 +4,73 @@
 //
 
 #include "d/d_spline_path.h"
-#include "dolphin/types.h"
+#include "SSystem/SComponent/c_xyz.h"
 
 /* 800C239C-800C2430       .text Init__14d2DBSplinePathFll */
-void d2DBSplinePath::Init(s32, s32) {
-    /* Nonmatching */
+void d2DBSplinePath::Init(s32 keyNum, s32 duration) {
+    mFrame = 0;
+    mKeyNum = keyNum;
+    mState = 1;
+    mKeyNo = 0;
+    mEnd = duration;
+    mDuration = duration;
+    mStep = f32(mKeyNum < 2 ? 1 : mKeyNum - 2) / f32(mEnd != 0 ? mEnd - 1 : 1);
+    mUser = NULL;
 }
 
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
 /* 800C2430-800C25D8       .text Step__14d2DBSplinePathFv */
-void d2DBSplinePath::Step() {
-    /* Nonmatching */
+bool d2DBSplinePath::Step() {
+    if (mFrame >= mDuration)
+        mState = 0;
+
+    if (mState == 1)
+        mState = 2;
+
+    if (mState == 2) {
+        if (mFrame <= mEnd - 1) {
+            f32 inv;
+            f32 t = mStep * mFrame;
+            mKeyNo = (s32)t;
+            t = t - mKeyNo;
+
+            if (mFrame == mDuration - 1) {
+                mState = 3;
+            }
+            if (mFrame == mEnd - 1) {
+                mState = 3;
+                t = 1.0f;
+            }
+
+            mCurveKey[0] = MIN(mKeyNo + 0, mKeyNum - 1);
+            mCurveKey[1] = MIN(mKeyNo + 1, mKeyNum - 1);
+            mCurveKey[2] = MIN(mKeyNo + 2, mKeyNum - 1);
+
+            inv = 1.0f - t;
+            mCurveWeight[0] = inv * inv * 0.5f;
+            mCurveWeight[1] = t * inv + 0.5f;
+            mCurveWeight[2] = t * t * 0.5f;
+
+            mFrame++;
+        } else {
+            mState = 0;
+        }
+    }
+
+    return mState == 2 || mState == 3;
 }
 
 /* 800C25D8-800C268C       .text Calc__14d2DBSplinePathFP4cXyz */
-void d2DBSplinePath::Calc(cXyz*) {
-    /* Nonmatching */
+cXyz d2DBSplinePath::Calc(cXyz* v) {
+    cXyz ret;
+    ret.x = mCurveWeight[0] * v[mCurveKey[0]].x + mCurveWeight[1] * v[mCurveKey[1]].x + mCurveWeight[2] * v[mCurveKey[2]].x;
+    ret.y = mCurveWeight[0] * v[mCurveKey[0]].y + mCurveWeight[1] * v[mCurveKey[1]].y + mCurveWeight[2] * v[mCurveKey[2]].y;
+    ret.z = mCurveWeight[0] * v[mCurveKey[0]].z + mCurveWeight[1] * v[mCurveKey[1]].z + mCurveWeight[2] * v[mCurveKey[2]].z;
+    return ret;
 }
 
 /* 800C268C-800C26D4       .text Calc__14d2DBSplinePathFPf */
-void d2DBSplinePath::Calc(f32*) {
-    /* Nonmatching */
+f32 d2DBSplinePath::Calc(f32* v) {
+    return mCurveWeight[0] * v[mCurveKey[0]] + mCurveWeight[1] * v[mCurveKey[1]] + mCurveWeight[2] * v[mCurveKey[2]];
 }