Move all nodes up when a node is placed below the ground

editor.conf.example

@@ -18,7 +18,7 @@ viewport_bottom_right = right
 
 # Lighting
 # 0: no lighting / shadows
-# 1: Depth lighting (things further away from camera are darker)
+# 1: Depth lighting (things further away from camera are darker) (TODO)
 # 2: Normal lighting (like in Minetest)
 lighting = 2
 
@@ -26,6 +26,9 @@ lighting = 2
 # when not in the node tool
 hide_other_nodes = true
 
+# Move all nodes up when a node is placed at negative y
+no_negative_node_y = true
+
 # Driver used to render
 driver = opengl
 

src/main.cpp

@@ -77,6 +77,7 @@ int main(int argc, char *argv[]) {
 	conf->set("viewport_bottom_right", "right");
 	conf->set("lighting", "2");
 	conf->set("hide_other_nodes", "true");
+	conf->set("no_negative_node_y", "true");
 	conf->set("fullscreen", "false");
 	conf->set("width", "896");
 	conf->set("height", "520");

src/modes/NodeEditor.cpp

@@ -222,9 +222,21 @@ void NodeEditor::updateProperties() {
 	try {
 		irr::core::stringc name = prop->getElementFromId(ENG_GUI_PROP_NAME)->getText();
 		node->name = str_replace(std::string(name.c_str(), name.size()), ' ', '_');
+		int y = wcstod(prop->getElementFromId(ENG_GUI_PROP_Y)->getText(), NULL);
+		if (state->settings->getBool("no_negative_node_y") && y < 0) {
+			std::list<Node*> & nodes = state->project->nodes;
+			for (std::list<Node*>::const_iterator it = nodes.begin();
+					it != nodes.end();
+					++it) {
+				(*it)->position.Y -= y; // Remember, y is negative
+			}
+			state->project->remesh();
+			y = 0;
+		}
+
 		node->position = vector3di(
 			wcstod(prop->getElementFromId(ENG_GUI_PROP_X)->getText(), NULL),
-			wcstod(prop->getElementFromId(ENG_GUI_PROP_Y)->getText(), NULL),
+			y,
 			wcstod(prop->getElementFromId(ENG_GUI_PROP_Z)->getText(), NULL)
 		);
 		node->remesh();