Mgv6 mudflow: Also check for 'ignore' nodes

Previously, when removing decorations we searched upwards and removed until we
found air or water. However, the node above the decoration can be 'ignore' if
a stacked decoration extends into the volume above the mapchunk. The result
could be a problematic column of air placed in the volume of 'ignore'. The
unnecessary placing of air also slows the function.

Add a check for 'ignore' nodes when removing decorations.

diff --git a/src/mapgen_v6.cpp b/src/mapgen_v6.cpp
index 7bf2ea9dbfdeccd40c419216f3d1fdd72c4d23ea..34cc6b0fe2a619f8d1835afaa1ddb86b94dd3c90 100644 (file)
--- a/src/mapgen_v6.cpp
+++ b/src/mapgen_v6.cpp
@@ -913,21 +913,25 @@ void MapgenV6::moveMud(u32 remove_index, u32 place_index,
        // use 'pos.X >= node_max.X' etc.
        if (pos.X >= node_max.X || pos.X <= node_min.X ||
                        pos.Y >= node_max.Z || pos.Y <= node_min.Z) {
-               // 'above remove' node is above removed mud. If it is not air and not
-               // water it is a decoration that needs removing. Also search upwards
-               // for a possible stacked decoration.
+               // 'above remove' node is above removed mud. If it is not air, water or
+               // 'ignore' it is a decoration that needs removing. Also search upwards
+               // to remove a possible stacked decoration.
+               // Check for 'ignore' because stacked decorations can penetrate into
+               // 'ignore' nodes above the mapchunk.
                while (vm->m_area.contains(above_remove_index) &&
                                vm->m_data[above_remove_index].getContent() != CONTENT_AIR &&
-                               vm->m_data[above_remove_index].getContent() != c_water_source) {
+                               vm->m_data[above_remove_index].getContent() != c_water_source &&
+                               vm->m_data[above_remove_index].getContent() != CONTENT_IGNORE) {
                        vm->m_data[above_remove_index] = n_air;
                        vm->m_area.add_y(em, above_remove_index, 1);
                }
-               // Mud placed may have half-buried a tall decoration, search above and
-               // remove.
+               // Mud placed may have partially-buried a stacked decoration, search
+               // above and remove.
                vm->m_area.add_y(em, place_index, 1);
                while (vm->m_area.contains(place_index) &&
                                vm->m_data[place_index].getContent() != CONTENT_AIR &&
-                               vm->m_data[place_index].getContent() != c_water_source) {
+                               vm->m_data[place_index].getContent() != c_water_source &&
+                               vm->m_data[place_index].getContent() != CONTENT_IGNORE) {
                        vm->m_data[place_index] = n_air;
                        vm->m_area.add_y(em, place_index, 1);
                }