From 9b149d5848985483d14a3d336d6b0d9b00c49282 Mon Sep 17 00:00:00 2001
From: kobewi <kobewi4e@gmail.com>
Date: Fri, 17 Dec 2021 01:47:17 +0100
Subject: [PATCH] Add physics material to GridMap

(cherry picked from commit 59a9b2192eb1287c4ec2fc99397903199b19df9a)
---
 modules/gridmap/doc_classes/GridMap.xml |  3 +++
 modules/gridmap/grid_map.cpp            | 18 ++++++++++++++++++
 modules/gridmap/grid_map.h              |  6 ++++++
 3 files changed, 27 insertions(+)

diff --git a/modules/gridmap/doc_classes/GridMap.xml b/modules/gridmap/doc_classes/GridMap.xml
index 8e67bc26056..8de0f434194 100644
--- a/modules/gridmap/doc_classes/GridMap.xml
+++ b/modules/gridmap/doc_classes/GridMap.xml
@@ -183,6 +183,9 @@
 		<member name="mesh_library" type="MeshLibrary" setter="set_mesh_library" getter="get_mesh_library">
 			The assigned [MeshLibrary].
 		</member>
+		<member name="physics_material" type="PhysicsMaterial" setter="set_physics_material" getter="get_physics_material">
+			Overrides the default friction and bounce physics properties for the whole [GridMap].
+		</member>
 		<member name="use_in_baked_light" type="bool" setter="set_use_in_baked_light" getter="get_use_in_baked_light" default="false">
 			Controls whether this GridMap will be baked in a [BakedLightmap] or not.
 		</member>
diff --git a/modules/gridmap/grid_map.cpp b/modules/gridmap/grid_map.cpp
index ccac5db6d7f..6bae4607fd9 100644
--- a/modules/gridmap/grid_map.cpp
+++ b/modules/gridmap/grid_map.cpp
@@ -34,6 +34,7 @@
 #include "core/message_queue.h"
 #include "scene/3d/light.h"
 #include "scene/resources/mesh_library.h"
+#include "scene/resources/physics_material.h"
 #include "scene/resources/surface_tool.h"
 #include "scene/scene_string_names.h"
 #include "servers/navigation_server.h"
@@ -183,6 +184,15 @@ bool GridMap::get_collision_layer_bit(int p_bit) const {
 	return get_collision_layer() & (1 << p_bit);
 }
 
+void GridMap::set_physics_material(Ref<PhysicsMaterial> p_material) {
+	physics_material = p_material;
+	_recreate_octant_data();
+}
+
+Ref<PhysicsMaterial> GridMap::get_physics_material() const {
+	return physics_material;
+}
+
 void GridMap::set_mesh_library(const Ref<MeshLibrary> &p_mesh_library) {
 	if (!mesh_library.is_null()) {
 		mesh_library->unregister_owner(this);
@@ -300,6 +310,10 @@ void GridMap::set_cell_item(int p_x, int p_y, int p_z, int p_item, int p_rot) {
 		PhysicsServer::get_singleton()->body_attach_object_instance_id(g->static_body, get_instance_id());
 		PhysicsServer::get_singleton()->body_set_collision_layer(g->static_body, collision_layer);
 		PhysicsServer::get_singleton()->body_set_collision_mask(g->static_body, collision_mask);
+		if (physics_material.is_valid()) {
+			PhysicsServer::get_singleton()->body_set_param(g->static_body, PhysicsServer::BODY_PARAM_FRICTION, physics_material->get_friction());
+			PhysicsServer::get_singleton()->body_set_param(g->static_body, PhysicsServer::BODY_PARAM_BOUNCE, physics_material->get_bounce());
+		}
 		SceneTree *st = SceneTree::get_singleton();
 
 		if (st && st->is_debugging_collisions_hint()) {
@@ -815,6 +829,9 @@ void GridMap::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_collision_layer_bit", "bit", "value"), &GridMap::set_collision_layer_bit);
 	ClassDB::bind_method(D_METHOD("get_collision_layer_bit", "bit"), &GridMap::get_collision_layer_bit);
 
+	ClassDB::bind_method(D_METHOD("set_physics_material", "material"), &GridMap::set_physics_material);
+	ClassDB::bind_method(D_METHOD("get_physics_material"), &GridMap::get_physics_material);
+
 	ClassDB::bind_method(D_METHOD("set_mesh_library", "mesh_library"), &GridMap::set_mesh_library);
 	ClassDB::bind_method(D_METHOD("get_mesh_library"), &GridMap::get_mesh_library);
 
@@ -861,6 +878,7 @@ void GridMap::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_use_in_baked_light"), &GridMap::get_use_in_baked_light);
 
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "mesh_library", PROPERTY_HINT_RESOURCE_TYPE, "MeshLibrary"), "set_mesh_library", "get_mesh_library");
+	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "physics_material", PROPERTY_HINT_RESOURCE_TYPE, "PhysicsMaterial"), "set_physics_material", "get_physics_material");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_in_baked_light"), "set_use_in_baked_light", "get_use_in_baked_light");
 	ADD_GROUP("Cell", "cell_");
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "cell_size"), "set_cell_size", "get_cell_size");
diff --git a/modules/gridmap/grid_map.h b/modules/gridmap/grid_map.h
index a5c2e3b2143..cfad7b302be 100644
--- a/modules/gridmap/grid_map.h
+++ b/modules/gridmap/grid_map.h
@@ -39,6 +39,8 @@
 //heh heh, godotsphir!! this shares no code and the design is completely different with previous projects i've done..
 //should scale better with hardware that supports instancing
 
+class PhysicsMaterial;
+
 class GridMap : public Spatial {
 	GDCLASS(GridMap, Spatial);
 
@@ -132,6 +134,7 @@ class GridMap : public Spatial {
 
 	uint32_t collision_layer;
 	uint32_t collision_mask;
+	Ref<PhysicsMaterial> physics_material;
 
 	Transform last_transform;
 
@@ -219,6 +222,9 @@ public:
 	void set_collision_mask_bit(int p_bit, bool p_value);
 	bool get_collision_mask_bit(int p_bit) const;
 
+	void set_physics_material(Ref<PhysicsMaterial> p_material);
+	Ref<PhysicsMaterial> get_physics_material() const;
+
 	void set_mesh_library(const Ref<MeshLibrary> &p_mesh_library);
 	Ref<MeshLibrary> get_mesh_library() const;