Mass: implement BL attachment writing.

Needs testing, though.

src/Mass/Mass_Armour.cpp

@@ -237,7 +237,95 @@ void Mass::getBulletLauncherAttachments() {
 }
 
 auto Mass::writeBulletLauncherAttachments() -> bool {
-    return false;
+    auto unit_data = _mass->at<GenericStructProperty>("UnitData"_s);
+    if(!unit_data) {
+        _state = State::Invalid;
+        _lastError = "No unit data in " + _filename;
+        return false;
+    }
+
+    auto attach_style_prop = unit_data->at<ByteProperty>("WeaponBLAttachmentStyle_65_5943FCE8406F18D2C3F69285EB23A699"_s);
+    auto attach_array = unit_data->at<ArrayProperty>("WeaponBLAttachment_61_442D08F547510A4CEE1501BBAF297BA0"_s);
+
+    if(!attach_style_prop && !attach_array) {
+        _armour.blAttachmentStyle = BulletLauncherAttachmentStyle::NotFound;
+        _lastError = "No attachment properties to write to in " + _filename;
+        return false;
+    }
+
+    if(attach_style_prop && !attach_array) {
+        _armour.blAttachmentStyle = BulletLauncherAttachmentStyle::NotFound;
+        _state = State::Invalid;
+        _lastError = "Couldn't find the attachments in " + _filename;
+        return false;
+    }
+
+    if(attach_array->items.size() == _weapons.bulletLaunchers.size() &&
+       attach_array->items.size() == _armour.blAttachment.size())
+    {
+        for(UnsignedInt i = 0; i < attach_array->items.size(); i++) {
+            auto attachment_prop = attach_array->at<GenericStructProperty>(i);
+            auto& attachment = _armour.blAttachment[i];
+
+            auto& socket = attachment_prop->at<StringProperty>("Socket_9_B9DBF30D4A1F0032A2BE2F8B342B35A9"_s)->value;
+            switch(attachment.socket) {
+                #define c(enumerator, strenum, name) case BulletLauncherSocket::enumerator: socket = strenum; break;
+                #include "../Maps/BulletLauncherSockets.hpp"
+                #undef c
+                default:
+                    _lastError = "Invalid socket type."_s;
+                    return false;
+            }
+
+            auto rel_loc_prop = attachment_prop->at<VectorStructProperty>("RelativeLocation_10_2F6E75DF4C40622658340E9A22D38B02"_s);
+            rel_loc_prop->x = attachment.relativeLocation.x();
+            rel_loc_prop->y = attachment.relativeLocation.y();
+            rel_loc_prop->z = attachment.relativeLocation.z();
+            auto off_loc_prop = attachment_prop->at<VectorStructProperty>("OffsetLocation_11_F42B3DA3436948FF85752DB33722382F"_s);
+            off_loc_prop->x = attachment.offsetLocation.x();
+            off_loc_prop->y = attachment.offsetLocation.y();
+            off_loc_prop->z = attachment.offsetLocation.z();
+            auto rel_rot_prop = attachment_prop->at<VectorStructProperty>("RelativeRotation_12_578140464621245132CFF2A2AD85E735"_s);
+            rel_rot_prop->x = attachment.relativeRotation.x();
+            rel_rot_prop->y = attachment.relativeRotation.y();
+            rel_rot_prop->z = attachment.relativeRotation.z();
+            auto off_rot_prop = attachment_prop->at<VectorStructProperty>("OffsetRotation_13_B5980BCD47905D842D1490A1A520B064"_s);
+            off_rot_prop->x = attachment.offsetRotation.x();
+            off_rot_prop->y = attachment.offsetRotation.y();
+            off_rot_prop->z = attachment.offsetRotation.z();
+            auto rel_scale_prop = attachment_prop->at<VectorStructProperty>("RelativeScale_16_37BC80EF42699F79533F7AA7B3094E38"_s);
+            rel_scale_prop->x = attachment.relativeScale.x();
+            rel_scale_prop->y = attachment.relativeScale.y();
+            rel_scale_prop->z = attachment.relativeScale.z();
+        }
+    }
+
+    if(!attach_style_prop) {
+        attach_style_prop = new ByteProperty;
+        attach_style_prop->name.emplace("WeaponBLAttachmentStyle_65_5943FCE8406F18D2C3F69285EB23A699"_s);
+        attach_style_prop->enumType = "enuBLAttachmentStyle"_s;
+        ByteProperty::ptr prop{attach_style_prop};
+        arrayAppend(unit_data->properties, std::move(prop));
+    }
+
+    auto& attach_style = attach_style_prop->enumValue;
+    switch(_armour.blAttachmentStyle) {
+        #define c(enumerator, strenum) case BulletLauncherAttachmentStyle::enumerator: \
+                                           attach_style = strenum;                     \
+                                           break;
+        #include "../Maps/BulletLauncherAttachmentStyles.hpp"
+        #undef c
+        default:
+            _lastError = "Unknown BL attachment style.";
+            return false;
+    }
+
+    if(!_mass->saveToFile()) {
+        _lastError = _mass->lastError();
+        return false;
+    }
+
+    return true;
 }
 
 auto Mass::armourCustomStyles() -> Containers::ArrayView<CustomStyle> {