fix CPU particles bug with local_coords and transform

2 files changed, 41 insertions, 6 deletions

diff --git a/scene/2d/cpu_particles_2d.cpp b/scene/2d/cpu_particles_2d.cpp
index ff27e0a29a..08304e1e52 100644
--- a/scene/2d/cpu_particles_2d.cpp
+++ b/scene/2d/cpu_particles_2d.cpp
@@ -85,7 +85,9 @@ void CPUParticles2D::set_randomness_ratio(float p_ratio) {
 void CPUParticles2D::set_use_local_coordinates(bool p_enable) {
 
 	local_coords = p_enable;
+	set_notify_transform(!p_enable);
 }
+
 void CPUParticles2D::set_speed_scale(float p_scale) {
 
 	speed_scale = p_scale;
@@ -865,11 +867,6 @@ void CPUParticles2D::_update_particle_data_buffer() {
 		PoolVector<Particle>::Read r = particles.read();
 		float *ptr = w.ptr();
 
-		Transform2D un_transform;
-		if (!local_coords) {
-			un_transform = get_global_transform().affine_inverse();
-		}
-
 		if (draw_order != DRAW_ORDER_INDEX) {
 			ow = particle_order.write();
 			order = ow.ptr();
@@ -891,7 +888,7 @@ void CPUParticles2D::_update_particle_data_buffer() {
 			Transform2D t = r[idx].transform;
 
 			if (!local_coords) {
-				t = un_transform * t;
+				t = inv_emission_transform * t;
 			}
 
 			if (r[idx].active) {
@@ -1060,6 +1057,42 @@ void CPUParticles2D::_notification(int p_what) {
 
 		_update_particle_data_buffer();
 	}
+
+	if (p_what == NOTIFICATION_TRANSFORM_CHANGED) {
+
+		inv_emission_transform = get_global_transform().affine_inverse();
+
+		if (!local_coords) {
+
+			int pc = particles.size();
+
+			PoolVector<float>::Write w = particle_data.write();
+			PoolVector<Particle>::Read r = particles.read();
+			float *ptr = w.ptr();
+
+			for (int i = 0; i < pc; i++) {
+
+				Transform2D t = inv_emission_transform * r[i].transform;
+
+				if (r[i].active) {
+
+					ptr[0] = t.elements[0][0];
+					ptr[1] = t.elements[1][0];
+					ptr[2] = 0;
+					ptr[3] = t.elements[2][0];
+					ptr[4] = t.elements[0][1];
+					ptr[5] = t.elements[1][1];
+					ptr[6] = 0;
+					ptr[7] = t.elements[2][1];
+
+				} else {
+					zeromem(ptr, sizeof(float) * 8);
+				}
+
+				ptr += 13;
+			}
+		}
+	}
 }
 
 void CPUParticles2D::convert_from_particles(Node *p_particles) {
diff --git a/scene/2d/cpu_particles_2d.h b/scene/2d/cpu_particles_2d.h
index 81343a4604..ccba576cb1 100644
--- a/scene/2d/cpu_particles_2d.h
+++ b/scene/2d/cpu_particles_2d.h
@@ -142,6 +142,8 @@ private:
 	int fixed_fps;
 	bool fractional_delta;
 
+	Transform2D inv_emission_transform;
+
 	DrawOrder draw_order;
 
 	Ref<Texture> texture;