From 0353b402a8c6ae07dc804c639034f4b8120b125b Mon Sep 17 00:00:00 2001
From: Human Gamer <39096122+HumanGamer@users.noreply.github.com>
Date: Sun, 24 Mar 2024 15:49:21 -0500
Subject: [PATCH] Multiple Physics Modes

---
 engine/source/game/marble/marble.cpp        | 47 +++++++++++++++++++++
 engine/source/game/marble/marble.h          | 10 +++++
 engine/source/game/marble/marblephysics.cpp | 11 +++--
 3 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/engine/source/game/marble/marble.cpp b/engine/source/game/marble/marble.cpp
index 454ccbc2..84bcafda 100644
--- a/engine/source/game/marble/marble.cpp
+++ b/engine/source/game/marble/marble.cpp
@@ -147,6 +147,8 @@ Marble::Marble()
     mSinglePrecision.mPosition = mPosition;
     mSinglePrecision.mVelocity = mVelocity;
     mSinglePrecision.mOmega = mOmega;
+
+    mPhysics = XNA;
 }
 
 Marble::~Marble()
@@ -407,6 +409,13 @@ void Marble::setMode(U32 mode)
     setMaskBits(PowerUpMask);
 }
 
+void Marble::setPhysics(U32 physics)
+{
+    mPhysics = physics;
+
+    setMaskBits(GravityMask);
+}
+
 void Marble::setOOB(bool isOOB)
 {
     mOOB = isOOB;
@@ -551,6 +560,11 @@ U32 Marble::packUpdate(NetConnection* conn, U32 mask, BitStream* stream)
     stream->writeFlag(isControl);
     stream->writeFlag(gravityChange);
 
+    if (stream->writeFlag((mask & GravityMask) != 0))
+    {
+        stream->writeInt(mPhysics, 7);
+    }
+
     if (stream->writeFlag((mask & PowerUpMask) != 0))
     {
         stream->writeRangedU32(mPowerUpId, 0, PowerUpData::MaxPowerUps - 1);
@@ -639,6 +653,11 @@ void Marble::unpackUpdate(NetConnection* conn, BitStream* stream)
     bool warp = stream->readFlag();
     bool isGravWarp = stream->readFlag();
 
+    if (stream->readFlag())
+    {
+        setPhysics(stream->readInt(7));
+    }
+
     if (stream->readFlag())
     {
         mPowerUpId = stream->readRangedU32(0, PowerUpData::MaxPowerUps - 1);
@@ -2240,6 +2259,34 @@ ConsoleMethod(Marble, setMode, void, 3, 3, "(mode)")
     object->setMode(newMode | modeFlags[i]);
 }
 
+ConsoleMethod(Marble, setPhysics, void, 3, 3, "(physics)")
+{
+    const char* physics = argv[2];
+    U32 physicsFlags[3];
+    const char* physicsStrings[3];
+
+    physicsStrings[0] = "MBU";
+    physicsFlags[0] = Marble::MBU;
+
+    physicsStrings[1] = "MBG";
+    physicsFlags[1] = Marble::MBG;
+
+    physicsStrings[2] = "XNA";
+    physicsFlags[2] = Marble::XNA;
+
+    S32 i = 0;
+    while (dStricmp(physicsStrings[i], physics))
+    {
+        if (++i >= 3)
+        {
+            Con::errorf("Marble:: Unknown physics mode: %s", physics);
+            return;
+        }
+    }
+
+    object->setPhysics(physicsFlags[i]);
+}
+
 ConsoleMethod(Marble, setPad, void, 3, 3, "(pad)")
 {
     U32 padId = dAtoi(argv[2]);
diff --git a/engine/source/game/marble/marble.h b/engine/source/game/marble/marble.h
index bfe7dfbe..54588f2e 100644
--- a/engine/source/game/marble/marble.h
+++ b/engine/source/game/marble/marble.h
@@ -66,6 +66,13 @@ class Marble : public ShapeBase
         FinishMode = 0x40
     };
 
+    enum MBPhysics
+    {
+        MBU,
+        MBG,
+        XNA
+    };
+
     enum UpdateMaskBits
     {
         ActiveModeBits = 0x4,
@@ -216,6 +223,8 @@ class Marble : public ShapeBase
     bool mShadowGenerated;
     MatInstance* mStencilMaterial;
 
+    U32 mPhysics;
+
 public:
     DECLARE_CONOBJECT(Marble);
 
@@ -253,6 +262,7 @@ class Marble : public ShapeBase
     Point3F& getPosition();
     void victorySequence();
     void setMode(U32 mode);
+    void setPhysics(U32 physics);
     U32 getMode() { return mMode; }
     void setOOB(bool isOOB);
     virtual void interpolateTick(F32 delta);
diff --git a/engine/source/game/marble/marblephysics.cpp b/engine/source/game/marble/marblephysics.cpp
index a276a67c..2b439ba0 100644
--- a/engine/source/game/marble/marblephysics.cpp
+++ b/engine/source/game/marble/marblephysics.cpp
@@ -360,9 +360,9 @@ void Marble::velocityCancel(bool surfaceSlide, bool noBounce, bool& bouncedYet,
                     contact->surfaceVelocity = otherMarble->getVelocityD();
                 } else
                 {
-                    if (contact->surfaceVelocity.len() == 0.0 && !surfaceSlide && surfaceDot > -mDataBlock->maxDotSlide * velLen)
+                    // XNA has contact->surfaceVelocity.len() > 0.0001f while MBU360 has contact->surfaceVelocity.len() == 0.0
+                    if (((mPhysics == XNA && contact->surfaceVelocity.len() > 0.0001f) || (mPhysics != XNA && contact->surfaceVelocity.len() == 0.0)) && !surfaceSlide && surfaceDot > -mDataBlock->maxDotSlide * velLen)
                     {
-
                         mVelocity -= surfaceVel;
                         m_point3D_normalize(mVelocity);
                         mVelocity *= velLen;
@@ -454,6 +454,7 @@ void Marble::velocityCancel(bool surfaceSlide, bool noBounce, bool& bouncedYet,
             {
                 Contact* contact = &mContacts[j];
 
+                // TODO: should contactDistance have mRadius added to it in this check? (comparing to XNA)
                 if (mRadius > contact->contactDistance)
                 {
                     Point3F normal = contact->normal;
@@ -633,8 +634,10 @@ void Marble::advancePhysics(const Move* move, U32 timeDelta)
 
         F64 moveTime = timeStep;
         computeFirstPlatformIntersect(moveTime, smPathItrVec);
-        testMove(mVelocity, mPosition, moveTime, mRadius, sCollisionMask, false);
-        //mPosition += mVelocity * moveTime;
+        if (mPhysics == XNA)
+            mPosition += mVelocity * moveTime; // XNA
+        else
+            testMove(mVelocity, mPosition, moveTime, mRadius, sCollisionMask, false); // MBU
 
         if (!mMovePathSize && timeStep * 0.99 > moveTime && moveTime > 0.001000000047497451)
         {