From 14d36ba15e5f0b5524c9791a618a5e9c3e5d00b2 Mon Sep 17 00:00:00 2001
From: jitspoe <jitspoe@yahoo.com>
Date: Fri, 16 Aug 2024 21:30:56 -0400
Subject: [PATCH] Enabled double precision for bullet physics engine and added
 a flag to get more correct raycast results.

---
 SConstruct                      | 2 ++
 modules/bullet/space_bullet.cpp | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/SConstruct b/SConstruct
index d0ffcde3e35b..e03bd1d501cc 100644
--- a/SConstruct
+++ b/SConstruct
@@ -382,6 +382,8 @@ if env_base["rids"] == "tracked_handles":
     env_base.Append(CPPDEFINES=["RID_HANDLE_ALLOCATION_TRACKING_ENABLED"])
     print("WARNING: Building with RIDs as tracked handles.")
 
+env_base.Append(CPPDEFINES=["BT_USE_DOUBLE_PRECISION"])  # Enable double precision in bullet physics engine
+
 if selected_platform in platform_list:
     tmppath = "./platform/" + selected_platform
     sys.path.insert(0, tmppath)
diff --git a/modules/bullet/space_bullet.cpp b/modules/bullet/space_bullet.cpp
index f227e207c253..ac9c8d95d696 100644
--- a/modules/bullet/space_bullet.cpp
+++ b/modules/bullet/space_bullet.cpp
@@ -48,6 +48,7 @@
 #include <BulletCollision/NarrowPhaseCollision/btGjkEpaPenetrationDepthSolver.h>
 #include <BulletCollision/NarrowPhaseCollision/btGjkPairDetector.h>
 #include <BulletCollision/NarrowPhaseCollision/btPointCollector.h>
+#include <BulletCollision/NarrowPhaseCollision/btRaycastCallback.h>
 #include <BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h>
 #include <BulletSoftBody/btSoftRigidDynamicsWorld.h>
 #include <btBulletDynamicsCommon.h>
@@ -97,6 +98,7 @@ bool BulletPhysicsDirectSpaceState::intersect_ray(const Vector3 &p_from, const V
 	btResult.m_collisionFilterGroup = 0;
 	btResult.m_collisionFilterMask = p_collision_mask;
 	btResult.m_pickRay = p_pick_ray;
+	btResult.m_flags |= btTriangleRaycastCallback::kF_UseGjkConvexCastRaytest;
 
 	space->dynamicsWorld->rayTest(btVec_from, btVec_to, btResult);
 	if (btResult.hasHit()) {