Added interpolation property to GPUParticles2D

doc/classes/GPUParticles2D.xml

@@ -57,6 +57,9 @@
 		<member name="fract_delta" type="bool" setter="set_fractional_delta" getter="get_fractional_delta" default="true">
 			If [code]true[/code], results in fractional delta calculation which has a smoother particles display effect.
 		</member>
+		<member name="interpolate" type="bool" setter="set_interpolate" getter="get_interpolate" default="true">
+			Enables particle interpolation, which makes the particle movement smoother when their [member fixed_fps] is lower than the screen refresh rate.
+		</member>
 		<member name="lifetime" type="float" setter="set_lifetime" getter="get_lifetime" default="1.0">
 			Amount of time each particle will exist.
 		</member>

doc/classes/GPUParticles3D.xml

@@ -90,6 +90,7 @@
 			If [code]true[/code], results in fractional delta calculation which has a smoother particles display effect.
 		</member>
 		<member name="interpolate" type="bool" setter="set_interpolate" getter="get_interpolate" default="true">
+			Enables particle interpolation, which makes the particle movement smoother when their [member fixed_fps] is lower than the screen refresh rate.
 		</member>
 		<member name="lifetime" type="float" setter="set_lifetime" getter="get_lifetime" default="1.0">
 			Amount of time each particle will exist.

scene/2d/gpu_particles_2d.cpp

@@ -287,6 +287,15 @@ bool GPUParticles2D::get_fractional_delta() const {
 	return fractional_delta;
 }
 
+void GPUParticles2D::set_interpolate(bool p_enable) {
+	interpolate = p_enable;
+	RS::get_singleton()->particles_set_interpolate(particles, p_enable);
+}
+
+bool GPUParticles2D::get_interpolate() const {
+	return interpolate;
+}
+
 TypedArray<String> GPUParticles2D::get_configuration_warnings() const {
 	TypedArray<String> warnings = Node::get_configuration_warnings();
 
@@ -543,6 +552,7 @@ void GPUParticles2D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_use_local_coordinates", "enable"), &GPUParticles2D::set_use_local_coordinates);
 	ClassDB::bind_method(D_METHOD("set_fixed_fps", "fps"), &GPUParticles2D::set_fixed_fps);
 	ClassDB::bind_method(D_METHOD("set_fractional_delta", "enable"), &GPUParticles2D::set_fractional_delta);
+	ClassDB::bind_method(D_METHOD("set_interpolate", "enable"), &GPUParticles2D::set_interpolate);
 	ClassDB::bind_method(D_METHOD("set_process_material", "material"), &GPUParticles2D::set_process_material);
 	ClassDB::bind_method(D_METHOD("set_speed_scale", "scale"), &GPUParticles2D::set_speed_scale);
 	ClassDB::bind_method(D_METHOD("set_collision_base_size", "size"), &GPUParticles2D::set_collision_base_size);
@@ -558,6 +568,7 @@ void GPUParticles2D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_use_local_coordinates"), &GPUParticles2D::get_use_local_coordinates);
 	ClassDB::bind_method(D_METHOD("get_fixed_fps"), &GPUParticles2D::get_fixed_fps);
 	ClassDB::bind_method(D_METHOD("get_fractional_delta"), &GPUParticles2D::get_fractional_delta);
+	ClassDB::bind_method(D_METHOD("get_interpolate"), &GPUParticles2D::get_interpolate);
 	ClassDB::bind_method(D_METHOD("get_process_material"), &GPUParticles2D::get_process_material);
 	ClassDB::bind_method(D_METHOD("get_speed_scale"), &GPUParticles2D::get_speed_scale);
 	ClassDB::bind_method(D_METHOD("get_collision_base_size"), &GPUParticles2D::get_collision_base_size);
@@ -601,6 +612,7 @@ void GPUParticles2D::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "explosiveness", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_explosiveness_ratio", "get_explosiveness_ratio");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "randomness", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_randomness_ratio", "get_randomness_ratio");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "fixed_fps", PROPERTY_HINT_RANGE, "0,1000,1"), "set_fixed_fps", "get_fixed_fps");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "interpolate"), "set_interpolate", "get_interpolate");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "fract_delta"), "set_fractional_delta", "get_fractional_delta");
 	ADD_GROUP("Collision", "collision_");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "collision_base_size", PROPERTY_HINT_RANGE, "0,128,0.01,or_greater"), "set_collision_base_size", "get_collision_base_size");
@@ -644,6 +656,7 @@ GPUParticles2D::GPUParticles2D() {
 	set_lifetime(1);
 	set_fixed_fps(0);
 	set_fractional_delta(true);
+	set_interpolate(true);
 	set_pre_process_time(0);
 	set_explosiveness_ratio(0);
 	set_randomness_ratio(0);

scene/2d/gpu_particles_2d.h

@@ -58,6 +58,7 @@ private:
 	bool local_coords;
 	int fixed_fps;
 	bool fractional_delta;
+	bool interpolate = true;
 #ifdef TOOLS_ENABLED
 	bool show_visibility_rect;
 #endif
@@ -133,6 +134,9 @@ public:
 	void set_fractional_delta(bool p_enable);
 	bool get_fractional_delta() const;
 
+	void set_interpolate(bool p_enable);
+	bool get_interpolate() const;
+
 	void set_draw_order(DrawOrder p_order);
 	DrawOrder get_draw_order() const;