Implement manual particle emission and particle sub emitters.

Author: reduz

scene/3d/gpu_particles_3d.cpp

@@ -301,6 +301,36 @@ void GPUParticles3D::_validate_property(PropertyInfo &property) const {
 	}
 }
 
+void GPUParticles3D::emit_particle(const Transform &p_transform, const Vector3 &p_velocity, const Color &p_color, const Color &p_custom, uint32_t p_emit_flags) {
+	RS::get_singleton()->particles_emit(particles, p_transform, p_velocity, p_color, p_custom, p_emit_flags);
+}
+
+void GPUParticles3D::_attach_sub_emitter() {
+	Node *n = get_node_or_null(sub_emitter);
+	if (n) {
+		GPUParticles3D *sen = Object::cast_to<GPUParticles3D>(n);
+		if (sen && sen != this) {
+			RS::get_singleton()->particles_set_subemitter(particles, sen->particles);
+		}
+	}
+}
+
+void GPUParticles3D::set_sub_emitter(const NodePath &p_path) {
+	if (is_inside_tree()) {
+		RS::get_singleton()->particles_set_subemitter(particles, RID());
+	}
+
+	sub_emitter = p_path;
+
+	if (is_inside_tree() && sub_emitter != NodePath()) {
+		_attach_sub_emitter();
+	}
+}
+
+NodePath GPUParticles3D::get_sub_emitter() const {
+	return sub_emitter;
+}
+
 void GPUParticles3D::_notification(int p_what) {
 	if (p_what == NOTIFICATION_PAUSED || p_what == NOTIFICATION_UNPAUSED) {
 		if (can_process()) {
@@ -319,6 +349,16 @@ void GPUParticles3D::_notification(int p_what) {
 		}
 	}
 
+	if (p_what == NOTIFICATION_ENTER_TREE) {
+		if (sub_emitter != NodePath()) {
+			_attach_sub_emitter();
+		}
+	}
+
+	if (p_what == NOTIFICATION_EXIT_TREE) {
+		RS::get_singleton()->particles_set_subemitter(particles, RID());
+	}
+
 	if (p_what == NOTIFICATION_VISIBILITY_CHANGED) {
 		// make sure particles are updated before rendering occurs if they were active before
 		if (is_visible_in_tree() && !RS::get_singleton()->particles_is_inactive(particles)) {
@@ -369,8 +409,14 @@ void GPUParticles3D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("restart"), &GPUParticles3D::restart);
 	ClassDB::bind_method(D_METHOD("capture_aabb"), &GPUParticles3D::capture_aabb);
 
+	ClassDB::bind_method(D_METHOD("set_sub_emitter", "path"), &GPUParticles3D::set_sub_emitter);
+	ClassDB::bind_method(D_METHOD("get_sub_emitter"), &GPUParticles3D::get_sub_emitter);
+
+	ClassDB::bind_method(D_METHOD("emit_particle", "xform", "velocity", "color", "custom", "flags"), &GPUParticles3D::emit_particle);
+
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "emitting"), "set_emitting", "is_emitting");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "amount", PROPERTY_HINT_EXP_RANGE, "1,1000000,1"), "set_amount", "get_amount");
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "sub_emitter", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "GPUParticles3D"), "set_sub_emitter", "get_sub_emitter");
 	ADD_GROUP("Time", "");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "lifetime", PROPERTY_HINT_EXP_RANGE, "0.01,600.0,0.01,or_greater"), "set_lifetime", "get_lifetime");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "one_shot"), "set_one_shot", "get_one_shot");
@@ -396,6 +442,12 @@ void GPUParticles3D::_bind_methods() {
 	BIND_ENUM_CONSTANT(DRAW_ORDER_LIFETIME);
 	BIND_ENUM_CONSTANT(DRAW_ORDER_VIEW_DEPTH);
 
+	BIND_ENUM_CONSTANT(EMIT_FLAG_POSITION);
+	BIND_ENUM_CONSTANT(EMIT_FLAG_ROTATION_SCALE);
+	BIND_ENUM_CONSTANT(EMIT_FLAG_VELOCITY);
+	BIND_ENUM_CONSTANT(EMIT_FLAG_COLOR);
+	BIND_ENUM_CONSTANT(EMIT_FLAG_CUSTOM);
+
 	BIND_CONSTANT(MAX_DRAW_PASSES);
 }
 

scene/3d/gpu_particles_3d.h

@@ -64,13 +64,16 @@ class GPUParticles3D : public GeometryInstance3D {
 	bool local_coords;
 	int fixed_fps;
 	bool fractional_delta;
+	NodePath sub_emitter;
 
 	Ref<Material> process_material;
 
 	DrawOrder draw_order;
 
 	Vector<Ref<Mesh>> draw_passes;
 
+	void _attach_sub_emitter();
+
 protected:
 	static void _bind_methods();
 	void _notification(int p_what);
@@ -121,13 +124,27 @@ class GPUParticles3D : public GeometryInstance3D {
 
 	virtual String get_configuration_warning() const override;
 
+	void set_sub_emitter(const NodePath &p_path);
+	NodePath get_sub_emitter() const;
+
 	void restart();
 
+	enum EmitFlags {
+		EMIT_FLAG_POSITION = RS::PARTICLES_EMIT_FLAG_POSITION,
+		EMIT_FLAG_ROTATION_SCALE = RS::PARTICLES_EMIT_FLAG_ROTATION_SCALE,
+		EMIT_FLAG_VELOCITY = RS::PARTICLES_EMIT_FLAG_VELOCITY,
+		EMIT_FLAG_COLOR = RS::PARTICLES_EMIT_FLAG_COLOR,
+		EMIT_FLAG_CUSTOM = RS::PARTICLES_EMIT_FLAG_CUSTOM
+	};
+
+	void emit_particle(const Transform &p_transform, const Vector3 &p_velocity, const Color &p_color, const Color &p_custom, uint32_t p_emit_flags);
+
 	AABB capture_aabb() const;
 	GPUParticles3D();
 	~GPUParticles3D();
 };
 
 VARIANT_ENUM_CAST(GPUParticles3D::DrawOrder)
+VARIANT_ENUM_CAST(GPUParticles3D::EmitFlags)
 
 #endif // PARTICLES_H