Merge pull request #12403 from AndreaCatania/phymat

Physics material

5 files changed, 82 insertions, 2 deletions

diff --git a/servers/physics/body_pair_sw.cpp b/servers/physics/body_pair_sw.cpp
index 2a6a9e08ae..5a41b621eb 100644
--- a/servers/physics/body_pair_sw.cpp
+++ b/servers/physics/body_pair_sw.cpp
@@ -211,6 +211,44 @@ bool BodyPairSW::_test_ccd(real_t p_step, BodySW *p_A, int p_shape_A, const Tran
 	return true;
 }
 
+real_t combine_bounce(BodySW *A, BodySW *B) {
+	const PhysicsServer::CombineMode cm = A->get_bounce_combine_mode();
+
+	switch (cm) {
+		case PhysicsServer::COMBINE_MODE_INHERIT:
+			if (B->get_bounce_combine_mode() != PhysicsServer::COMBINE_MODE_INHERIT)
+				return combine_bounce(B, A);
+			// else use MAX [This is used when the two bodies doesn't use physical material]
+		case PhysicsServer::COMBINE_MODE_MAX:
+			return MAX(A->get_bounce(), B->get_bounce());
+		case PhysicsServer::COMBINE_MODE_MIN:
+			return MIN(A->get_bounce(), B->get_bounce());
+		case PhysicsServer::COMBINE_MODE_MULTIPLY:
+			return A->get_bounce() * B->get_bounce();
+		default: // Is always PhysicsServer::COMBINE_MODE_AVERAGE:
+			return (A->get_bounce() + B->get_bounce()) / 2;
+	}
+}
+
+real_t combine_friction(BodySW *A, BodySW *B) {
+	const PhysicsServer::CombineMode cm = A->get_friction_combine_mode();
+
+	switch (cm) {
+		case PhysicsServer::COMBINE_MODE_INHERIT:
+			if (B->get_friction_combine_mode() != PhysicsServer::COMBINE_MODE_INHERIT)
+				return combine_friction(B, A);
+			// else use Multiply [This is used when the two bodies doesn't use physical material]
+		case PhysicsServer::COMBINE_MODE_MULTIPLY:
+			return A->get_friction() * B->get_friction();
+		case PhysicsServer::COMBINE_MODE_MAX:
+			return MAX(A->get_friction(), B->get_friction());
+		case PhysicsServer::COMBINE_MODE_MIN:
+			return MIN(A->get_friction(), B->get_friction());
+		default: // Is always PhysicsServer::COMBINE_MODE_AVERAGE:
+			return (A->get_friction() + B->get_friction()) / 2;
+	}
+}
+
 bool BodyPairSW::setup(real_t p_step) {
 
 	//cannot collide
@@ -331,7 +369,7 @@ bool BodyPairSW::setup(real_t p_step) {
 		c.acc_bias_impulse = 0;
 		c.acc_bias_impulse_center_of_mass = 0;
 
-		c.bounce = MAX(A->get_bounce(), B->get_bounce());
+		c.bounce = combine_bounce(A, B);
 		if (c.bounce) {
 
 			Vector3 crA = A->get_angular_velocity().cross(c.rA);
@@ -421,7 +459,7 @@ void BodyPairSW::solve(real_t p_step) {
 
 		//friction impulse
 
-		real_t friction = A->get_friction() * B->get_friction();
+		real_t friction = combine_friction(A, B);
 
 		Vector3 lvA = A->get_linear_velocity() + A->get_angular_velocity().cross(c.rA);
 		Vector3 lvB = B->get_linear_velocity() + B->get_angular_velocity().cross(c.rB);
diff --git a/servers/physics/body_sw.cpp b/servers/physics/body_sw.cpp
index cc9681193c..59f987fc17 100644
--- a/servers/physics/body_sw.cpp
+++ b/servers/physics/body_sw.cpp
@@ -423,6 +423,22 @@ void BodySW::_compute_area_gravity_and_dampenings(const AreaSW *p_area) {
 	area_angular_damp += p_area->get_angular_damp();
 }
 
+void BodySW::set_combine_mode(PhysicsServer::BodyParameter p_param, PhysicsServer::CombineMode p_mode) {
+	if (p_param == PhysicsServer::BODY_PARAM_BOUNCE) {
+		bounce_combine_mode = p_mode;
+	} else {
+		friction_combine_mode = p_mode;
+	}
+}
+
+PhysicsServer::CombineMode BodySW::get_combine_mode(PhysicsServer::BodyParameter p_param) const {
+	if (p_param == PhysicsServer::BODY_PARAM_BOUNCE) {
+		return bounce_combine_mode;
+	} else {
+		return friction_combine_mode;
+	}
+}
+
 void BodySW::set_axis_lock(PhysicsServer::BodyAxis p_axis, bool lock) {
 	if (lock) {
 		locked_axis |= p_axis;
diff --git a/servers/physics/body_sw.h b/servers/physics/body_sw.h
index fd2ab16b84..25eb20f5d8 100644
--- a/servers/physics/body_sw.h
+++ b/servers/physics/body_sw.h
@@ -49,6 +49,8 @@ class BodySW : public CollisionObjectSW {
 	real_t mass;
 	real_t bounce;
 	real_t friction;
+	PhysicsServer::CombineMode bounce_combine_mode;
+	PhysicsServer::CombineMode friction_combine_mode;
 
 	real_t linear_damp;
 	real_t angular_damp;
@@ -298,6 +300,12 @@ public:
 	_FORCE_INLINE_ Vector3 get_gravity() const { return gravity; }
 	_FORCE_INLINE_ real_t get_bounce() const { return bounce; }
 
+	void set_combine_mode(PhysicsServer::BodyParameter p_param, PhysicsServer::CombineMode p_mode);
+	PhysicsServer::CombineMode get_combine_mode(PhysicsServer::BodyParameter p_param) const;
+
+	_FORCE_INLINE_ PhysicsServer::CombineMode get_bounce_combine_mode() const { return bounce_combine_mode; }
+	_FORCE_INLINE_ PhysicsServer::CombineMode get_friction_combine_mode() const { return friction_combine_mode; }
+
 	void set_axis_lock(PhysicsServer::BodyAxis p_axis, bool lock);
 	bool is_axis_locked(PhysicsServer::BodyAxis p_axis) const;
 
diff --git a/servers/physics/physics_server_sw.cpp b/servers/physics/physics_server_sw.cpp
index 593218dd5d..f1e0cbef29 100644
--- a/servers/physics/physics_server_sw.cpp
+++ b/servers/physics/physics_server_sw.cpp
@@ -701,6 +701,20 @@ real_t PhysicsServerSW::body_get_param(RID p_body, BodyParameter p_param) const
 	return body->get_param(p_param);
 };
 
+void PhysicsServerSW::body_set_combine_mode(RID p_body, BodyParameter p_param, CombineMode p_mode) {
+	BodySW *body = body_owner.get(p_body);
+	ERR_FAIL_COND(!body);
+
+	body->set_combine_mode(p_param, p_mode);
+}
+
+PhysicsServer::CombineMode PhysicsServerSW::body_get_combine_mode(RID p_body, BodyParameter p_param) const {
+	BodySW *body = body_owner.get(p_body);
+	ERR_FAIL_COND_V(!body, COMBINE_MODE_INHERIT);
+
+	return body->get_combine_mode(p_param);
+}
+
 void PhysicsServerSW::body_set_kinematic_safe_margin(RID p_body, real_t p_margin) {
 	BodySW *body = body_owner.get(p_body);
 	ERR_FAIL_COND(!body);
diff --git a/servers/physics/physics_server_sw.h b/servers/physics/physics_server_sw.h
index 3f56ba26d0..d8c73abb16 100644
--- a/servers/physics/physics_server_sw.h
+++ b/servers/physics/physics_server_sw.h
@@ -188,6 +188,10 @@ public:
 	virtual void body_set_param(RID p_body, BodyParameter p_param, real_t p_value);
 	virtual real_t body_get_param(RID p_body, BodyParameter p_param) const;
 
+	/// p_param accept only Bounce and Friction
+	virtual void body_set_combine_mode(RID p_body, BodyParameter p_param, CombineMode p_mode);
+	virtual CombineMode body_get_combine_mode(RID p_body, BodyParameter p_param) const;
+
 	virtual void body_set_kinematic_safe_margin(RID p_body, real_t p_margin);
 	virtual real_t body_get_kinematic_safe_margin(RID p_body) const;