Stabilize snapping 2D transforms to pixel

Co-authored-by: Danni <[email protected]>

scene/2d/animated_sprite_2d.cpp

@@ -268,8 +268,9 @@ void AnimatedSprite2D::_notification(int p_what) {
 			}
 
 			if (get_viewport() && get_viewport()->is_snap_2d_transforms_to_pixel_enabled()) {
-				ofs = ofs.floor();
+				ofs = ofs.round();
 			}
+
 			Rect2 dst_rect(ofs, s);
 
 			if (hflip) {

scene/2d/sprite_2d.cpp

@@ -99,7 +99,7 @@ void Sprite2D::_get_rects(Rect2 &r_src_rect, Rect2 &r_dst_rect, bool &r_filter_c
 	}
 
 	if (get_viewport() && get_viewport()->is_snap_2d_transforms_to_pixel_enabled()) {
-		dest_offset = dest_offset.floor();
+		dest_offset = dest_offset.round();
 	}
 
 	r_dst_rect = Rect2(dest_offset, frame_size);
@@ -402,7 +402,7 @@ Rect2 Sprite2D::get_rect() const {
 	}
 
 	if (get_viewport() && get_viewport()->is_snap_2d_transforms_to_pixel_enabled()) {
-		ofs = ofs.floor();
+		ofs = ofs.round();
 	}
 
 	if (s == Size2(0, 0)) {

servers/rendering/renderer_canvas_cull.cpp

@@ -223,7 +223,7 @@ void RendererCanvasCull::_attach_canvas_item_for_draw(RendererCanvasCull::Item *
 	}
 }
 
-void RendererCanvasCull::_cull_canvas_item(Item *p_canvas_item, const Transform2D &p_transform, const Rect2 &p_clip_rect, const Color &p_modulate, int p_z, RendererCanvasRender::Item **r_z_list, RendererCanvasRender::Item **r_z_last_list, Item *p_canvas_clip, Item *p_material_owner, bool p_allow_y_sort, uint32_t p_canvas_cull_mask) {
+void RendererCanvasCull::_cull_canvas_item(Item *p_canvas_item, const Transform2D &p_parent_xform, const Rect2 &p_clip_rect, const Color &p_modulate, int p_z, RendererCanvasRender::Item **r_z_list, RendererCanvasRender::Item **r_z_last_list, Item *p_canvas_clip, Item *p_material_owner, bool p_allow_y_sort, uint32_t p_canvas_cull_mask) {
 	Item *ci = p_canvas_item;
 
 	if (!ci->visible) {
@@ -248,10 +248,14 @@ void RendererCanvasCull::_cull_canvas_item(Item *p_canvas_item, const Transform2
 	}
 
 	Transform2D xform = ci->xform;
+	Transform2D parent_xform = p_parent_xform;
+
 	if (snapping_2d_transforms_to_pixel) {
-		xform.columns[2] = xform.columns[2].floor();
+		xform.columns[2] = xform.columns[2].round();
+		parent_xform.columns[2] = parent_xform.columns[2].round();
 	}
-	xform = p_transform * xform;
+
+	xform = parent_xform * xform;
 
 	Rect2 global_rect = xform.xform(rect);
 	global_rect.position += p_clip_rect.position;

servers/rendering/renderer_canvas_cull.h

@@ -188,7 +188,7 @@ public:
 
 private:
 	void _render_canvas_item_tree(RID p_to_render_target, Canvas::ChildItem *p_child_items, int p_child_item_count, Item *p_canvas_item, const Transform2D &p_transform, const Rect2 &p_clip_rect, const Color &p_modulate, RendererCanvasRender::Light *p_lights, RendererCanvasRender::Light *p_directional_lights, RS::CanvasItemTextureFilter p_default_filter, RS::CanvasItemTextureRepeat p_default_repeat, bool p_snap_2d_vertices_to_pixel, uint32_t p_canvas_cull_mask, RenderingMethod::RenderInfo *r_render_info = nullptr);
-	void _cull_canvas_item(Item *p_canvas_item, const Transform2D &p_transform, const Rect2 &p_clip_rect, const Color &p_modulate, int p_z, RendererCanvasRender::Item **r_z_list, RendererCanvasRender::Item **r_z_last_list, Item *p_canvas_clip, Item *p_material_owner, bool p_allow_y_sort, uint32_t p_canvas_cull_mask);
+	void _cull_canvas_item(Item *p_canvas_item, const Transform2D &p_parent_xform, const Rect2 &p_clip_rect, const Color &p_modulate, int p_z, RendererCanvasRender::Item **r_z_list, RendererCanvasRender::Item **r_z_last_list, Item *p_canvas_clip, Item *p_material_owner, bool p_allow_y_sort, uint32_t p_canvas_cull_mask);
 
 	static constexpr int z_range = RS::CANVAS_ITEM_Z_MAX - RS::CANVAS_ITEM_Z_MIN + 1;
 

servers/rendering/renderer_viewport.cpp

@@ -43,19 +43,11 @@ static Transform2D _canvas_get_transform(RendererViewport::Viewport *p_viewport,
 	float scale = 1.0;
 	if (p_viewport->canvas_map.has(p_canvas->parent)) {
 		Transform2D c_xform = p_viewport->canvas_map[p_canvas->parent].transform;
-		if (p_viewport->snap_2d_transforms_to_pixel) {
-			c_xform.columns[2] = c_xform.columns[2].floor();
-		}
 		xf = xf * c_xform;
 		scale = p_canvas->parent_scale;
 	}
 
 	Transform2D c_xform = p_canvas_data->transform;
-
-	if (p_viewport->snap_2d_transforms_to_pixel) {
-		c_xform.columns[2] = c_xform.columns[2].floor();
-	}
-
 	xf = xf * c_xform;
 
 	if (scale != 1.0 && !RSG::canvas->disable_scale) {