Expose `RS.mesh_surface_update_index_region`

And `mesh_surface_get_format_index_stride`

doc/classes/RenderingServer.xml

@@ -2469,6 +2469,14 @@
 				Returns the stride of the attribute buffer for a mesh with given [param format].
 			</description>
 		</method>
+		<method name="mesh_surface_get_format_index_stride" qualifiers="const">
+			<return type="int" />
+			<param index="0" name="format" type="int" enum="RenderingServer.ArrayFormat" is_bitfield="true" />
+			<param index="1" name="vertex_count" type="int" />
+			<description>
+				Returns the stride of the index buffer for a mesh with the given [param format].
+			</description>
+		</method>
 		<method name="mesh_surface_get_format_normal_tangent_stride" qualifiers="const">
 			<return type="int" />
 			<param index="0" name="format" type="int" enum="RenderingServer.ArrayFormat" is_bitfield="true" />
@@ -2536,6 +2544,16 @@
 			<description>
 			</description>
 		</method>
+		<method name="mesh_surface_update_index_region">
+			<return type="void" />
+			<param index="0" name="mesh" type="RID" />
+			<param index="1" name="surface" type="int" />
+			<param index="2" name="offset" type="int" />
+			<param index="3" name="data" type="PackedByteArray" />
+			<description>
+				Updates the index buffer of the mesh surface with the given [param data]. The expected data are 16 or 32-bit unsigned integers, which can be determined with [method mesh_surface_get_format_index_stride].
+			</description>
+		</method>
 		<method name="mesh_surface_update_skin_region">
 			<return type="void" />
 			<param index="0" name="mesh" type="RID" />

drivers/gles3/storage/mesh_storage.cpp

@@ -534,10 +534,10 @@ RS::BlendShapeMode MeshStorage::mesh_get_blend_shape_mode(RID p_mesh) const {
 }
 
 void MeshStorage::mesh_surface_update_vertex_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);
 	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
-	ERR_FAIL_COND(p_data.is_empty());
 
 	uint64_t data_size = p_data.size();
 	ERR_FAIL_COND(p_offset + data_size > mesh->surfaces[p_surface]->vertex_buffer_size);
@@ -549,10 +549,10 @@ void MeshStorage::mesh_surface_update_vertex_region(RID p_mesh, int p_surface, i
 }
 
 void MeshStorage::mesh_surface_update_attribute_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);
 	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
-	ERR_FAIL_COND(p_data.is_empty());
 
 	uint64_t data_size = p_data.size();
 	ERR_FAIL_COND(p_offset + data_size > mesh->surfaces[p_surface]->attribute_buffer_size);
@@ -564,10 +564,10 @@ void MeshStorage::mesh_surface_update_attribute_region(RID p_mesh, int p_surface
 }
 
 void MeshStorage::mesh_surface_update_skin_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);
 	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
-	ERR_FAIL_COND(p_data.is_empty());
 
 	uint64_t data_size = p_data.size();
 	ERR_FAIL_COND(p_offset + data_size > mesh->surfaces[p_surface]->skin_buffer_size);
@@ -578,6 +578,21 @@ void MeshStorage::mesh_surface_update_skin_region(RID p_mesh, int p_surface, int
 	glBindBuffer(GL_ARRAY_BUFFER, 0);
 }
 
+void MeshStorage::mesh_surface_update_index_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
+	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
+	ERR_FAIL_NULL(mesh);
+	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
+
+	uint64_t data_size = p_data.size();
+	ERR_FAIL_COND(p_offset + data_size > mesh->surfaces[p_surface]->index_buffer_size);
+	const uint8_t *r = p_data.ptr();
+
+	glBindBuffer(GL_ARRAY_BUFFER, mesh->surfaces[p_surface]->index_buffer);
+	glBufferSubData(GL_ARRAY_BUFFER, p_offset, data_size, r);
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+}
+
 void MeshStorage::mesh_surface_set_material(RID p_mesh, int p_surface, RID p_material) {
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);

drivers/gles3/storage/mesh_storage.h

@@ -301,6 +301,7 @@ public:
 	virtual void mesh_surface_update_vertex_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
 	virtual void mesh_surface_update_attribute_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
 	virtual void mesh_surface_update_skin_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
+	virtual void mesh_surface_update_index_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
 
 	virtual void mesh_surface_set_material(RID p_mesh, int p_surface, RID p_material) override;
 	virtual RID mesh_surface_get_material(RID p_mesh, int p_surface) const override;

servers/rendering/dummy/storage/mesh_storage.h

@@ -103,6 +103,7 @@ public:
 	virtual void mesh_surface_update_vertex_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override {}
 	virtual void mesh_surface_update_attribute_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override {}
 	virtual void mesh_surface_update_skin_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override {}
+	virtual void mesh_surface_update_index_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override {}
 
 	virtual void mesh_surface_set_material(RID p_mesh, int p_surface, RID p_material) override {}
 	virtual RID mesh_surface_get_material(RID p_mesh, int p_surface) const override { return RID(); }

servers/rendering/renderer_rd/storage_rd/mesh_storage.cpp

@@ -565,11 +565,12 @@ RS::BlendShapeMode MeshStorage::mesh_get_blend_shape_mode(RID p_mesh) const {
 }
 
 void MeshStorage::mesh_surface_update_vertex_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);
 	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
-	ERR_FAIL_COND(p_data.is_empty());
 	ERR_FAIL_COND(mesh->surfaces[p_surface]->vertex_buffer.is_null());
+
 	uint64_t data_size = p_data.size();
 	const uint8_t *r = p_data.ptr();
 
@@ -577,11 +578,12 @@ void MeshStorage::mesh_surface_update_vertex_region(RID p_mesh, int p_surface, i
 }
 
 void MeshStorage::mesh_surface_update_attribute_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);
 	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
-	ERR_FAIL_COND(p_data.is_empty());
 	ERR_FAIL_COND(mesh->surfaces[p_surface]->attribute_buffer.is_null());
+
 	uint64_t data_size = p_data.size();
 	const uint8_t *r = p_data.ptr();
 
@@ -589,17 +591,31 @@ void MeshStorage::mesh_surface_update_attribute_region(RID p_mesh, int p_surface
 }
 
 void MeshStorage::mesh_surface_update_skin_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);
 	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
-	ERR_FAIL_COND(p_data.is_empty());
 	ERR_FAIL_COND(mesh->surfaces[p_surface]->skin_buffer.is_null());
+
 	uint64_t data_size = p_data.size();
 	const uint8_t *r = p_data.ptr();
 
 	RD::get_singleton()->buffer_update(mesh->surfaces[p_surface]->skin_buffer, p_offset, data_size, r);
 }
 
+void RendererRD::MeshStorage::mesh_surface_update_index_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) {
+	ERR_FAIL_COND(p_data.is_empty());
+	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
+	ERR_FAIL_NULL(mesh);
+	ERR_FAIL_UNSIGNED_INDEX((uint32_t)p_surface, mesh->surface_count);
+	ERR_FAIL_COND(mesh->surfaces[p_surface]->index_buffer.is_null());
+
+	uint64_t data_size = p_data.size();
+	const uint8_t *r = p_data.ptr();
+
+	RD::get_singleton()->buffer_update(mesh->surfaces[p_surface]->index_buffer, p_offset, data_size, r);
+}
+
 void MeshStorage::mesh_surface_set_material(RID p_mesh, int p_surface, RID p_material) {
 	Mesh *mesh = mesh_owner.get_or_null(p_mesh);
 	ERR_FAIL_NULL(mesh);

servers/rendering/renderer_rd/storage_rd/mesh_storage.h

@@ -383,6 +383,7 @@ public:
 	virtual void mesh_surface_update_vertex_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
 	virtual void mesh_surface_update_attribute_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
 	virtual void mesh_surface_update_skin_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
+	virtual void mesh_surface_update_index_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) override;
 
 	virtual void mesh_surface_set_material(RID p_mesh, int p_surface, RID p_material) override;
 	virtual RID mesh_surface_get_material(RID p_mesh, int p_surface) const override;

servers/rendering/rendering_server_default.h

@@ -366,6 +366,7 @@ public:
 	FUNC4(mesh_surface_update_vertex_region, RID, int, int, const Vector<uint8_t> &)
 	FUNC4(mesh_surface_update_attribute_region, RID, int, int, const Vector<uint8_t> &)
 	FUNC4(mesh_surface_update_skin_region, RID, int, int, const Vector<uint8_t> &)
+	FUNC4(mesh_surface_update_index_region, RID, int, int, const Vector<uint8_t> &)
 
 	FUNC3(mesh_surface_set_material, RID, int, RID)
 	FUNC2RC(RID, mesh_surface_get_material, RID, int)

servers/rendering/storage/mesh_storage.h

@@ -56,6 +56,7 @@ public:
 	virtual void mesh_surface_update_vertex_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
 	virtual void mesh_surface_update_attribute_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
 	virtual void mesh_surface_update_skin_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
+	virtual void mesh_surface_update_index_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
 
 	virtual void mesh_surface_set_material(RID p_mesh, int p_surface, RID p_material) = 0;
 	virtual RID mesh_surface_get_material(RID p_mesh, int p_surface) const = 0;

servers/rendering_server.cpp

@@ -1022,6 +1022,7 @@ uint32_t RenderingServer::mesh_surface_get_format_attribute_stride(BitField<Arra
 	mesh_surface_make_offsets_from_format(p_format, p_vertex_len, 0, offsets, vstr, ntstr, astr, sstr);
 	return astr;
 }
+
 uint32_t RenderingServer::mesh_surface_get_format_skin_stride(BitField<ArrayFormat> p_format, int p_vertex_len) const {
 	p_format = uint64_t(p_format) & ~ARRAY_FORMAT_INDEX;
 	uint32_t offsets[ARRAY_MAX];
@@ -1033,6 +1034,19 @@ uint32_t RenderingServer::mesh_surface_get_format_skin_stride(BitField<ArrayForm
 	return sstr;
 }
 
+uint32_t RenderingServer::mesh_surface_get_format_index_stride(BitField<ArrayFormat> p_format, int p_vertex_len) const {
+	if (!(p_format & ARRAY_FORMAT_INDEX)) {
+		return 0;
+	}
+
+	// Determine whether using 16 or 32 bits indices.
+	if (p_vertex_len <= (1 << 16) && p_vertex_len > 0) {
+		return 2;
+	} else {
+		return 4;
+	}
+}
+
 void RenderingServer::mesh_surface_make_offsets_from_format(uint64_t p_format, int p_vertex_len, int p_index_len, uint32_t *r_offsets, uint32_t &r_vertex_element_size, uint32_t &r_normal_element_size, uint32_t &r_attrib_element_size, uint32_t &r_skin_element_size) const {
 	r_vertex_element_size = 0;
 	r_normal_element_size = 0;
@@ -2337,6 +2351,7 @@ void RenderingServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("mesh_surface_get_format_normal_tangent_stride", "format", "vertex_count"), &RenderingServer::mesh_surface_get_format_normal_tangent_stride);
 	ClassDB::bind_method(D_METHOD("mesh_surface_get_format_attribute_stride", "format", "vertex_count"), &RenderingServer::mesh_surface_get_format_attribute_stride);
 	ClassDB::bind_method(D_METHOD("mesh_surface_get_format_skin_stride", "format", "vertex_count"), &RenderingServer::mesh_surface_get_format_skin_stride);
+	ClassDB::bind_method(D_METHOD("mesh_surface_get_format_index_stride", "format", "vertex_count"), &RenderingServer::mesh_surface_get_format_index_stride);
 	ClassDB::bind_method(D_METHOD("mesh_add_surface", "mesh", "surface"), &RenderingServer::_mesh_add_surface);
 	ClassDB::bind_method(D_METHOD("mesh_add_surface_from_arrays", "mesh", "primitive", "arrays", "blend_shapes", "lods", "compress_format"), &RenderingServer::mesh_add_surface_from_arrays, DEFVAL(Array()), DEFVAL(Dictionary()), DEFVAL(0));
 	ClassDB::bind_method(D_METHOD("mesh_get_blend_shape_count", "mesh"), &RenderingServer::mesh_get_blend_shape_count);
@@ -2357,6 +2372,7 @@ void RenderingServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("mesh_surface_update_vertex_region", "mesh", "surface", "offset", "data"), &RenderingServer::mesh_surface_update_vertex_region);
 	ClassDB::bind_method(D_METHOD("mesh_surface_update_attribute_region", "mesh", "surface", "offset", "data"), &RenderingServer::mesh_surface_update_attribute_region);
 	ClassDB::bind_method(D_METHOD("mesh_surface_update_skin_region", "mesh", "surface", "offset", "data"), &RenderingServer::mesh_surface_update_skin_region);
+	ClassDB::bind_method(D_METHOD("mesh_surface_update_index_region", "mesh", "surface", "offset", "data"), &RenderingServer::mesh_surface_update_index_region);
 
 	ClassDB::bind_method(D_METHOD("mesh_set_shadow_mesh", "mesh", "shadow_mesh"), &RenderingServer::mesh_set_shadow_mesh);
 

servers/rendering_server.h

@@ -401,6 +401,7 @@ public:
 	virtual uint32_t mesh_surface_get_format_normal_tangent_stride(BitField<ArrayFormat> p_format, int p_vertex_len) const;
 	virtual uint32_t mesh_surface_get_format_attribute_stride(BitField<ArrayFormat> p_format, int p_vertex_len) const;
 	virtual uint32_t mesh_surface_get_format_skin_stride(BitField<ArrayFormat> p_format, int p_vertex_len) const;
+	virtual uint32_t mesh_surface_get_format_index_stride(BitField<ArrayFormat> p_format, int p_vertex_len) const;
 
 	/// Returns stride
 	virtual void mesh_surface_make_offsets_from_format(uint64_t p_format, int p_vertex_len, int p_index_len, uint32_t *r_offsets, uint32_t &r_vertex_element_size, uint32_t &r_normal_element_size, uint32_t &r_attrib_element_size, uint32_t &r_skin_element_size) const;
@@ -426,6 +427,7 @@ public:
 	virtual void mesh_surface_update_vertex_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
 	virtual void mesh_surface_update_attribute_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
 	virtual void mesh_surface_update_skin_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
+	virtual void mesh_surface_update_index_region(RID p_mesh, int p_surface, int p_offset, const Vector<uint8_t> &p_data) = 0;
 
 	virtual void mesh_surface_set_material(RID p_mesh, int p_surface, RID p_material) = 0;
 	virtual RID mesh_surface_get_material(RID p_mesh, int p_surface) const = 0;