Ticket #2951: template_subsets.diff

new file inaries/data/mods/_test.sim/simulation/templates/special_filter/foundation.xml

@@ +1 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Entity filtered="">
+  <AIProxy merge=""/>
+  <Armour merge=""/>
+  <BuildRestrictions merge=""/>
+  <!-- Don't provide population bonuses yet (but still do take up population cost) -->
+  <Cost merge="">
+    <PopulationBonus>0</PopulationBonus>
+  </Cost>
+  <Decay merge=""/>
+  <!-- Initialise health to 1 -->
+  <Health>
+    <Initial>1</Initial>
+  </Health>
+  <Fogging merge=""/>
+  <Footprint merge=""/>
+  <!-- Add the Foundation component, to deal with the construction process -->
+  <Foundation replace=""/>
+  <Health merge=""/>
+  <Identity merge=""/>
+  <!-- Foundations shouldn't initially block unit movement -->
+  <Obstruction merge="">
+    <DisableBlockMovement>true</DisableBlockMovement>
+    <DisableBlockPathfinding>true</DisableBlockPathfinding>
+  </Obstruction>
+  <OverlayRenderer merge=""/>
+  <Ownership merge=""/>
+  <Position merge=""/>
+  <RallyPoint merge=""/>
+  <RallyPointRenderer merge=""/>
+  <Selectable merge=""/>
+  <Sound merge=""/>
+  <StatusBars merge=""/>
+  <Visibility merge=""/>
+  <!-- Foundations should be visible themselves in fog-of-war if their base template is,
+       but shouldn't have any vision range -->
+  <Vision merge="">
+    <Range>0</Range>
+    <RevealShore merge="">false</RevealShore>
+  </Vision>
+  <!-- Switch the actor to foundation mode -->
+  <VisualActor>
+    <Foundation/>
+  </VisualActor>
+</Entity>

new file inaries/data/mods/public/simulation/templates/special_filter/construction.xml

@@ +1 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Entity filtered="">
+  <Footprint merge=""/>
+  <Ownership merge=""/>
+  <Position merge=""/>
+  <VisualActor merge=""/>
+</Entity>

new file inaries/data/mods/public/simulation/templates/special_filter/corpse.xml

@@ +1 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Entity filtered="">
+  <!-- We only want to include components which are necessary (for the visual previewing of an entity)
+       and safe (i.e. won't do anything that affects the synchronised simulation state), so additions
+       to this list should be carefully considered -->
+  <Attack merge=""/> <!-- Needed for the Actor Viewer -->
+  <BuildRestrictions merge=""/>
+  <!-- Corpses should include decay components and activate them -->
+  <Decay merge="">
+    <Active>true</Active>
+  </Decay>
+  <Footprint merge=""/>
+  <Identity merge=""/>
+  <!-- Disable the Obstruction component (if there is one) so it doesn't affect pathfinding
+       (but can still be used for testing this entity for collisions against others) -->
+  <Obstruction merge="">
+    <Active>false</Active>
+  </Obstruction>
+  <Ownership merge=""/>
+  <Position merge=""/>
+  <Sound merge=""/> <!-- Needed for the Actor Viewer -->
+  <UnitMotion merge=""/> <!-- Needed for the Actor Viewer -->
+  <!-- Corpses should remain visible in fog-of-war (for the owner only) -->
+  <Visibility>
+    <Corpse>true</Corpse>
+  </Visibility>
+  <!-- Corpses shouldn't display silhouettes (especially since they're often half underground) -->
+  <VisualActor merge="">
+    <SilhouetteDisplay>false</SilhouetteDisplay>
+  </VisualActor>
+</Entity>

new file inaries/data/mods/public/simulation/templates/special_filter/foundation.xml

@@ +1 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Entity filtered="">
+  <AIProxy merge=""/>
+  <Armour merge=""/>
+  <BuildRestrictions merge=""/>
+  <!-- Don't provide population bonuses yet (but still do take up population cost) -->
+  <Cost merge="">
+    <PopulationBonus>0</PopulationBonus>
+  </Cost>
+  <Decay merge=""/>
+  <!-- Initialise health to 1 -->
+  <Health>
+    <Initial>1</Initial>
+  </Health>
+  <Fogging merge=""/>
+  <Footprint merge=""/>
+  <!-- Add the Foundation component, to deal with the construction process -->
+  <Foundation replace=""/>
+  <Health merge=""/>
+  <Identity merge=""/>
+  <!-- Foundations shouldn't initially block unit movement -->
+  <Obstruction merge="">
+    <DisableBlockMovement>true</DisableBlockMovement>
+    <DisableBlockPathfinding>true</DisableBlockPathfinding>
+  </Obstruction>
+  <OverlayRenderer merge=""/>
+  <Ownership merge=""/>
+  <Position merge=""/>
+  <RallyPoint merge=""/>
+  <RallyPointRenderer merge=""/>
+  <Selectable merge=""/>
+  <Sound merge=""/>
+  <StatusBars merge=""/>
+  <Visibility merge=""/>
+  <!-- Foundations should be visible themselves in fog-of-war if their base template is,
+       but shouldn't have any vision range -->
+  <Vision merge="">
+    <Range>0</Range>
+    <RevealShore merge="">false</RevealShore>
+  </Vision>
+  <!-- Switch the actor to foundation mode -->
+  <VisualActor>
+    <Foundation/>
+  </VisualActor>
+</Entity>

new file inaries/data/mods/public/simulation/templates/special_filter/mirage.xml

@@ +1 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Entity filtered="">
+  <Footprint merge=""/>
+  <Identity filtered="">
+    <Civ merge=""/>
+    <GenericName merge=""/>
+    <SpecificName merge=""/>
+    <Tooltip merge=""/>
+    <History merge=""/>
+    <Icon merge=""/>
+  </Identity>
+  <Minimap merge=""/>
+  <Mirage replace=""/>
+  <Ownership merge=""/>
+  <OverlayRenderer merge=""/>
+  <Position merge=""/>
+  <Selectable merge=""/>
+  <StatusBars merge=""/>
+  <Visibility merge=""/>
+  <VisualActor merge=""/>
+</Entity>

new file inaries/data/mods/public/simulation/templates/special_filter/preview.xml

@@ +1 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Entity filtered="">
+  <!-- We only want to include components which are necessary (for the visual previewing of an entity)
+       and safe (i.e. won't do anything that affects the synchronised simulation state), so additions
+       to this list should be carefully considered -->
+  <Attack merge=""/> <!-- Needed for the Actor Viewer -->
+  <BuildRestrictions merge=""/>
+  <Decay merge=""/>
+  <Footprint merge=""/>
+  <Identity merge=""/>
+  <!-- Disable the Obstruction component (if there is one) so it doesn't affect pathfinding
+       (but can still be used for testing this entity for collisions against others) -->
+  <Obstruction merge="">
+    <Active>false</Active>
+  </Obstruction>
+  <Ownership merge=""/>
+  <Position merge=""/>
+  <Sound merge=""/> <!-- Needed for the Actor Viewer -->
+  <UnitMotion merge=""/> <!-- Needed for the Actor Viewer -->
+  <!-- Previews should always be visible in fog-of-war/etc -->
+  <Visibility>
+    <AlwaysVisible>true</AlwaysVisible>
+    <Preview>true</Preview>
+  </Visibility>
+  <!-- Previews should not cast shadows -->
+  <VisualActor merge="">
+    <DisableShadows/>
+  </VisualActor>
+</Entity>

new file inaries/data/mods/public/simulation/templates/special_filter/resource.xml

@@ +1 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Entity filtered="">
+  <AIProxy merge=""/>
+  <Footprint merge=""/>
+  <Identity merge=""/>
+  <Minimap merge=""/>
+  <!-- When dying, resources lose the unitMotion component, this causes them to have no clearance.
+       Since unit obstructions no longer have a radius, this makes them unreachable in some cases (see #3530).
+       Instead, create a static, unblocking (see #3530 for why) static obstruction.
+       TODO: this should probably be generalized as a parameter on entity death or something.
+  -->
+  <Obstruction replace="">
+    <Active>true</Active>
+    <BlockMovement>false</BlockMovement>
+    <BlockPathfinding>false</BlockPathfinding>
+    <BlockFoundation>false</BlockFoundation>
+    <BlockConstruction>false</BlockConstruction>
+    <DisableBlockMovement>false</DisableBlockMovement>
+    <DisableBlockPathfinding>false</DisableBlockPathfinding>
+    <Static width="2.0" depth="2.0"/>
+  </Obstruction>
+  <OverlayRenderer merge=""/>
+  <Ownership merge=""/>
+  <Position merge=""/>
+  <ResourceSupply merge=""/>
+  <Selectable merge=""/>
+  <StatusBars merge=""/>
+  <VisualActor merge=""/>
+</Entity>

source/ps/TemplateLoader.cpp

@@ -1 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -29 +29 @@
 
 static CParamNode NULL_NODE(false);
 
-
 bool CTemplateLoader::LoadTemplateFile(const std::string& templateName, int depth)
 {
     // If this file was already loaded, we don't need to do anything
@@ -50 +49 @@
         return true;
     }
 
-    // Handle special case "preview|foo"
-    if (templateName.find("preview|") == 0)
+    // Handle special case "bar|foo"
+    size_t pos = templateName.find_first_of('|');
+    if (pos != std::string::npos)
     {
-        // Load the base entity template, if it wasn't already loaded
-        std::string baseName = templateName.substr(8);
+        std::string prefix = templateName.substr(0, pos);
+        std::string baseName = templateName.substr(pos+1);
+        
         if (!LoadTemplateFile(baseName, depth+1))
         {
             LOGERROR("Failed to load entity template '%s'", baseName.c_str());
             return false;
         }
-        // Copy a subset to the requested template
-        CopyPreviewSubset(m_TemplateFileData[templateName], m_TemplateFileData[baseName], false);
-        return true;
-    }
 
-    // Handle special case "corpse|foo"
-    if (templateName.find("corpse|") == 0)
-    {
-        // Load the base entity template, if it wasn't already loaded
-        std::string baseName = templateName.substr(7);
-        if (!LoadTemplateFile(baseName, depth+1))
+        VfsPath path = VfsPath(TEMPLATE_ROOT) / L"special_filter" / wstring_from_utf8(prefix + ".xml");
+        if (!VfsFileExists(path))
         {
-            LOGERROR("Failed to load entity template '%s'", baseName.c_str());
+            LOGERROR("Invalid subset '%s'", prefix.c_str());
             return false;
         }
-        // Copy a subset to the requested template
-        CopyPreviewSubset(m_TemplateFileData[templateName], m_TemplateFileData[baseName], true);
-        return true;
-    }
 
-    // Handle special case "mirage|foo"
-    if (templateName.find("mirage|") == 0)
-    {
-        // Load the base entity template, if it wasn't already loaded
-        std::string baseName = templateName.substr(7);
-        if (!LoadTemplateFile(baseName, depth+1))
-        {
-            LOGERROR("Failed to load entity template '%s'", baseName.c_str());
-            return false;
-        }
-        // Copy a subset to the requested template
-        CopyMirageSubset(m_TemplateFileData[templateName], m_TemplateFileData[baseName]);
-        return true;
-    }
+        CXeromyces xero;
+        PSRETURN ok = xero.Load(g_VFS, path);
+        if (ok != PSRETURN_OK)
+            return false; // (Xeromyces already logged an error with the full filename)
 
-    // Handle special case "foundation|foo"
-    if (templateName.find("foundation|") == 0)
-    {
-        // Load the base entity template, if it wasn't already loaded
-        std::string baseName = templateName.substr(11);
-        if (!LoadTemplateFile(baseName, depth+1))
-        {
-            LOGERROR("Failed to load entity template '%s'", baseName.c_str());
-            return false;
-        }
-        // Copy a subset to the requested template
-        CopyFoundationSubset(m_TemplateFileData[templateName], m_TemplateFileData[baseName]);
-        return true;
-    }
-
-    // Handle special case "construction|foo"
-    if (templateName.find("construction|") == 0)
-    {
-        // Load the base entity template, if it wasn't already loaded
-        std::string baseName = templateName.substr(13);
-        if (!LoadTemplateFile(baseName, depth+1))
-        {
-            LOGERROR("Failed to load entity template '%s'", baseName.c_str());
-            return false;
-        }
-        // Copy a subset to the requested template
-        CopyConstructionSubset(m_TemplateFileData[templateName], m_TemplateFileData[baseName]);
-        return true;
-    }
-
-    // Handle special case "resource|foo"
-    if (templateName.find("resource|") == 0)
-    {
-        // Load the base entity template, if it wasn't already loaded
-        std::string baseName = templateName.substr(9);
-        if (!LoadTemplateFile(baseName, depth+1))
-        {
-            LOGERROR("Failed to load entity template '%s'", baseName.c_str());
-            return false;
-        }
-        // Copy a subset to the requested template
-        CopyResourceSubset(m_TemplateFileData[templateName], m_TemplateFileData[baseName]);
+        m_TemplateFileData[templateName] = m_TemplateFileData[baseName];
+        CParamNode::LoadXML(m_TemplateFileData[templateName], xero, path.string().c_str());
         return true;
     }
 
@@ -215 +154 @@
 
 std::vector<std::string> CTemplateLoader::FindPlaceableTemplates(const std::string& path, bool includeSubdirectories, ETemplatesType templatesType, ScriptInterface& scriptInterface)
 {
+    if (templatesType != SIMULATION_TEMPLATES && templatesType != ACTOR_TEMPLATES && templatesType != ALL_TEMPLATES)
+    {
+        LOGERROR("Undefined template type (valid: all, simulation, actor)");
+        return std::vector<std::string>();
+    }
+
     JSContext* cx = scriptInterface.GetContext();
     JSAutoRequest rq(cx);
     
@@ -222 +167 @@
     Status ok;
     VfsPath templatePath;
 
-
     if (templatesType == SIMULATION_TEMPLATES || templatesType == ALL_TEMPLATES)
     {
         JS::RootedValue placeablesFilter(cx);
@@ -289 +233 @@
         WARN_IF_ERR(ok);
     }
 
-    if (templatesType != SIMULATION_TEMPLATES && templatesType != ACTOR_TEMPLATES && templatesType != ALL_TEMPLATES)
-        LOGERROR("Undefined template type (valid: all, simulation, actor)");
-
     return templates;
 }
 
@@ -299 +240 @@
 {
     std::vector<std::string> templates;
 
+    if (templatesType != SIMULATION_TEMPLATES && templatesType != ACTOR_TEMPLATES && templatesType != ALL_TEMPLATES)
+    {
+        LOGERROR("Undefined template type (valid: all, simulation, actor)");
+        return templates;
+    }
+
     Status ok;
     VfsPath templatePath;
+    size_t flags = includeSubdirectories ? vfs::DIR_RECURSIVE : 0;
 
     if (templatesType == SIMULATION_TEMPLATES || templatesType == ALL_TEMPLATES)
     {
         templatePath = VfsPath(TEMPLATE_ROOT) / path;
-        if (includeSubdirectories)
-            ok = vfs::ForEachFile(g_VFS, templatePath, AddToTemplates, (uintptr_t)&templates, L"*.xml", vfs::DIR_RECURSIVE);
-        else
-            ok = vfs::ForEachFile(g_VFS, templatePath, AddToTemplates, (uintptr_t)&templates, L"*.xml");
+        ok = vfs::ForEachFile(g_VFS, templatePath, AddToTemplates, (uintptr_t)&templates, L"*.xml", flags);
         WARN_IF_ERR(ok);
     }
     if (templatesType == ACTOR_TEMPLATES || templatesType == ALL_TEMPLATES)
     {
         templatePath = VfsPath(ACTOR_ROOT) / path;
-        if (includeSubdirectories)
-            ok = vfs::ForEachFile(g_VFS, templatePath, AddActorToTemplates, (uintptr_t)&templates, L"*.xml", vfs::DIR_RECURSIVE);
-        else
-            ok = vfs::ForEachFile(g_VFS, templatePath, AddActorToTemplates, (uintptr_t)&templates, L"*.xml");
+        ok = vfs::ForEachFile(g_VFS, templatePath, AddActorToTemplates, (uintptr_t)&templates, L"*.xml", flags);
         WARN_IF_ERR(ok);
     }
 
-    if (templatesType != SIMULATION_TEMPLATES && templatesType != ACTOR_TEMPLATES && templatesType != ALL_TEMPLATES)
-        LOGERROR("Undefined template type (valid: all, simulation, actor)");
-
     return templates;
 }
 
@@ -367 +306 @@
 
     CParamNode::LoadXMLString(out, xml.c_str(), actorNameW.c_str());
 }
-
-void CTemplateLoader::CopyPreviewSubset(CParamNode& out, const CParamNode& in, bool corpse)
-{
-    // We only want to include components which are necessary (for the visual previewing of an entity)
-    // and safe (i.e. won't do anything that affects the synchronised simulation state), so additions
-    // to this list should be carefully considered
-    std::set<std::string> permittedComponentTypes;
-    permittedComponentTypes.insert("Identity");
-    permittedComponentTypes.insert("Ownership");
-    permittedComponentTypes.insert("Position");
-    permittedComponentTypes.insert("Visibility");
-    permittedComponentTypes.insert("VisualActor");
-    permittedComponentTypes.insert("Footprint");
-    permittedComponentTypes.insert("Obstruction");
-    permittedComponentTypes.insert("Decay");
-    permittedComponentTypes.insert("BuildRestrictions");
-
-    // Need these for the Actor Viewer:
-    permittedComponentTypes.insert("Attack");
-    permittedComponentTypes.insert("UnitMotion");
-    permittedComponentTypes.insert("Sound");
-
-    // (This set could be initialised once and reused, but it's not worth the effort)
-
-    CParamNode::LoadXMLString(out, "<Entity/>");
-    out.CopyFilteredChildrenOfChild(in, "Entity", permittedComponentTypes);
-
-    // Disable the Obstruction component (if there is one) so it doesn't affect pathfinding
-    // (but can still be used for testing this entity for collisions against others)
-    if (out.GetChild("Entity").GetChild("Obstruction").IsOk())
-        CParamNode::LoadXMLString(out, "<Entity><Obstruction><Active>false</Active></Obstruction></Entity>");
-
-    if (!corpse)
-    {
-        // Previews should not cast shadows
-        if (out.GetChild("Entity").GetChild("VisualActor").IsOk())
-            CParamNode::LoadXMLString(out, "<Entity><VisualActor><DisableShadows/></VisualActor></Entity>");
-
-        // Previews should always be visible in fog-of-war/etc
-        CParamNode::LoadXMLString(out, "<Entity><Visibility><AlwaysVisible>true</AlwaysVisible><Preview>true</Preview></Visibility></Entity>");
-    }
-
-    if (corpse)
-    {
-        // Corpses should include decay components and activate them
-        if (out.GetChild("Entity").GetChild("Decay").IsOk())
-            CParamNode::LoadXMLString(out, "<Entity><Decay><Active>true</Active></Decay></Entity>");
-
-        // Corpses shouldn't display silhouettes (especially since they're often half underground)
-        if (out.GetChild("Entity").GetChild("VisualActor").IsOk())
-            CParamNode::LoadXMLString(out, "<Entity><VisualActor><SilhouetteDisplay>false</SilhouetteDisplay></VisualActor></Entity>");
-
-        // Corpses should remain visible in fog-of-war (for the owner only)
-        CParamNode::LoadXMLString(out, "<Entity><Visibility><Corpse>true</Corpse></Visibility></Entity>");
-    }
-}
-
-void CTemplateLoader::CopyMirageSubset(CParamNode& out, const CParamNode& in)
-{
-    // Currently used for mirage entities replacing real ones in fog-of-war
-
-    std::set<std::string> permittedComponentTypes;
-    permittedComponentTypes.insert("Footprint");
-    permittedComponentTypes.insert("Minimap");
-    permittedComponentTypes.insert("Ownership");
-    permittedComponentTypes.insert("OverlayRenderer");
-    permittedComponentTypes.insert("Position");
-    permittedComponentTypes.insert("Selectable");
-    permittedComponentTypes.insert("StatusBars");
-    permittedComponentTypes.insert("Visibility");
-    permittedComponentTypes.insert("VisualActor");
-
-    CParamNode::LoadXMLString(out, "<Entity/>");
-    out.CopyFilteredChildrenOfChild(in, "Entity", permittedComponentTypes);
-
-    // Select a subset of identity data. We don't want to have, for example, a CC mirage
-    // that has also the CC class and then prevents construction of other CCs
-    std::set<std::string> identitySubset;
-    identitySubset.insert("Civ");
-    identitySubset.insert("GenericName");
-    identitySubset.insert("SpecificName");
-    identitySubset.insert("Tooltip");
-    identitySubset.insert("History");
-    identitySubset.insert("Icon");
-    CParamNode identity;
-    CParamNode::LoadXMLString(identity, "<Identity/>");
-    identity.CopyFilteredChildrenOfChild(in.GetChild("Entity"), "Identity", identitySubset);
-    CParamNode::LoadXMLString(out, ("<Entity>"+utf8_from_wstring(identity.ToXML())+"</Entity>").c_str());
-
-    // Set the entity as mirage entity
-    CParamNode::LoadXMLString(out, "<Entity><Mirage/></Entity>");
-}
-
-void CTemplateLoader::CopyFoundationSubset(CParamNode& out, const CParamNode& in)
-{
-    // TODO: this is all kind of yucky and hard-coded; it'd be nice to have a more generic
-    // extensible scriptable way to define these subsets
-
-    std::set<std::string> permittedComponentTypes;
-    permittedComponentTypes.insert("Ownership");
-    permittedComponentTypes.insert("Position");
-    permittedComponentTypes.insert("VisualActor");
-    permittedComponentTypes.insert("Identity");
-    permittedComponentTypes.insert("BuildRestrictions");
-    permittedComponentTypes.insert("Obstruction");
-    permittedComponentTypes.insert("Selectable");
-    permittedComponentTypes.insert("Footprint");
-    permittedComponentTypes.insert("Fogging");
-    permittedComponentTypes.insert("Armour");
-    permittedComponentTypes.insert("Health");
-    permittedComponentTypes.insert("StatusBars");
-    permittedComponentTypes.insert("OverlayRenderer");
-    permittedComponentTypes.insert("Decay");
-    permittedComponentTypes.insert("Cost");
-    permittedComponentTypes.insert("Sound");
-    permittedComponentTypes.insert("Visibility");
-    permittedComponentTypes.insert("Vision");
-    permittedComponentTypes.insert("AIProxy");
-    permittedComponentTypes.insert("RallyPoint");
-    permittedComponentTypes.insert("RallyPointRenderer");
-
-    CParamNode::LoadXMLString(out, "<Entity/>");
-    out.CopyFilteredChildrenOfChild(in, "Entity", permittedComponentTypes);
-
-    // Switch the actor to foundation mode
-    CParamNode::LoadXMLString(out, "<Entity><VisualActor><Foundation/></VisualActor></Entity>");
-
-    // Add the Foundation component, to deal with the construction process
-    CParamNode::LoadXMLString(out, "<Entity><Foundation/></Entity>");
-
-    // Initialise health to 1
-    CParamNode::LoadXMLString(out, "<Entity><Health><Initial>1</Initial></Health></Entity>");
-
-    // Foundations shouldn't initially block unit movement
-    if (out.GetChild("Entity").GetChild("Obstruction").IsOk())
-        CParamNode::LoadXMLString(out, "<Entity><Obstruction><DisableBlockMovement>true</DisableBlockMovement><DisableBlockPathfinding>true</DisableBlockPathfinding></Obstruction></Entity>");
-
-    // Don't provide population bonuses yet (but still do take up population cost)
-    if (out.GetChild("Entity").GetChild("Cost").IsOk())
-        CParamNode::LoadXMLString(out, "<Entity><Cost><PopulationBonus>0</PopulationBonus></Cost></Entity>");
-
-    // Foundations should be visible themselves in fog-of-war if their base template is,
-    // but shouldn't have any vision range
-    if (out.GetChild("Entity").GetChild("Vision").IsOk())
-    {
-        CParamNode::LoadXMLString(out, "<Entity><Vision><Range>0</Range></Vision></Entity>");
-        // Foundations should not have special vision capabilities either
-        if (out.GetChild("Entity").GetChild("Vision").GetChild("RevealShore").IsOk())
-            CParamNode::LoadXMLString(out, "<Entity><Vision><RevealShore>false</RevealShore></Vision></Entity>");
-    }
-}
-
-void CTemplateLoader::CopyConstructionSubset(CParamNode& out, const CParamNode& in)
-{
-    // Currently used for buildings rising during construction
-    // Mostly serves to filter out components like Vision, UnitAI, etc.
-    std::set<std::string> permittedComponentTypes;
-    permittedComponentTypes.insert("Footprint");
-    permittedComponentTypes.insert("Ownership");
-    permittedComponentTypes.insert("Position");
-    permittedComponentTypes.insert("VisualActor");
-
-    CParamNode::LoadXMLString(out, "<Entity/>");
-    out.CopyFilteredChildrenOfChild(in, "Entity", permittedComponentTypes);
-}
-
-void CTemplateLoader::CopyResourceSubset(CParamNode& out, const CParamNode& in)
-{
-    // Currently used for animals which die and leave a gatherable corpse.
-    // Mostly serves to filter out components like Vision, UnitAI, etc.
-    // Don't emit sound as our samples only apply to living animals.
-    std::set<std::string> permittedComponentTypes;
-    permittedComponentTypes.insert("Ownership");
-    permittedComponentTypes.insert("Position");
-    permittedComponentTypes.insert("VisualActor");
-    permittedComponentTypes.insert("Identity");
-    permittedComponentTypes.insert("Minimap");
-    permittedComponentTypes.insert("ResourceSupply");
-    permittedComponentTypes.insert("Selectable");
-    permittedComponentTypes.insert("Footprint");
-    permittedComponentTypes.insert("StatusBars");
-    permittedComponentTypes.insert("OverlayRenderer");
-    permittedComponentTypes.insert("AIProxy");
-
-    CParamNode::LoadXMLString(out, "<Entity/>");
-    out.CopyFilteredChildrenOfChild(in, "Entity", permittedComponentTypes);
-    
-    // When dying, resources lose the unitMotion component
-    // This causes them to have no clearance. Since unit obstructions no longer have a radius,
-    // this makes them unreachable in some cases (see #3530).
-    // Instead, create a static, unblocking (see #3530 for why) static obstruction.
-    // TODO: this should probably be generalized as a parameter on entity death or something.
-    CParamNode::LoadXMLString(out, "<Entity><Obstruction><Active>true</Active><BlockMovement>false</BlockMovement><BlockPathfinding>false</BlockPathfinding><BlockFoundation>false</BlockFoundation><BlockConstruction>false</BlockConstruction><DisableBlockMovement>false</DisableBlockMovement><DisableBlockPathfinding>false</DisableBlockPathfinding><Static width=\"2.0\" depth=\"2.0\"/></Obstruction></Entity>");
-}

source/ps/TemplateLoader.h

@@ -1 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -48 +48 @@
     CTemplateLoader()
     {
     }
-    
+
     /**
      * Provides the file data for requested template.
      */
@@ -81 +81 @@
      */
     void ConstructTemplateActor(const std::string& actorName, CParamNode& out);
 
-    /** 
-     * Copy the non-interactive components of an entity template (position, actor, etc) into
-     * a new entity template
-     */
-    void CopyPreviewSubset(CParamNode& out, const CParamNode& in, bool corpse);
-
-    /** 
-     * Copy the components of an entity template necessary for a fogged "mirage"
-     * entity (position, actor) into a new entity template
-     */
-    void CopyMirageSubset(CParamNode& out, const CParamNode& in);
-
-    /** 
-     * Copy the components of an entity template necessary for a construction foundation
-     * (position, actor, armour, health, etc) into a new entity template
-     */
-    void CopyFoundationSubset(CParamNode& out, const CParamNode& in);
-
-    /** 
-     * Copy the components of an entity template necessary for a non-foundation construction entity
-     * into a new entity template
-     */
-    void CopyConstructionSubset(CParamNode& out, const CParamNode& in);
-
-    /** 
-     * Copy the components of an entity template necessary for a gatherable resource
-     * into a new entity template
-     */
-    void CopyResourceSubset(CParamNode& out, const CParamNode& in);
-
     /**
      * Map from template name (XML filename or special |-separated string) to the most recently
      * loaded non-broken template data. This includes files that will fail schema validation.

source/simulation2/system/ParamNode.cpp

@@ -1 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -76 +76 @@
     // Look for special attributes
     int at_disable = xmb.GetAttributeID("disable");
     int at_replace = xmb.GetAttributeID("replace");
+    int at_filtered = xmb.GetAttributeID("filtered");
+    int at_merge = xmb.GetAttributeID("merge");
     int at_op = xmb.GetAttributeID("op");
     int at_datatype = xmb.GetAttributeID("datatype");
     enum op {
@@ -84 +86 @@
         MUL
     } op = INVALID;
     bool replacing = false;
+    bool filtering = false;
     {
         XERO_ITER_ATTR(element, attr)
         {
@@ -97 +100 @@
                 m_Childs.erase(name);
                 replacing = true;
             }
+            else if (attr.Name == at_filtered)
+            {
+                filtering = true;
+            }
+            else if (attr.Name == at_merge)
+            {
+                if (m_Childs.find(name) == m_Childs.end())
+                    return;
+            }
             else if (attr.Name == at_op)
             {
                 if (std::wstring(attr.Value.begin(), attr.Value.end()) == L"add") 
@@ -150 +162 @@
         }
     }
 
+    // For the filtered case
+    ChildrenMap childs;
+
     // Add this element as a child node
     CParamNode& node = m_Childs[name];
     if (op != INVALID) 
@@ -175 +190 @@
     XERO_ITER_EL(element, child)
     {
         node.ApplyLayer(xmb, child, sourceIdentifier);
+        if (filtering)
+        {
+            std::string childname = xmb.GetElementString(child.GetNodeName()); // TODO: is GetElementString inefficient? (especially if we call it twice)
+            childs[childname] = std::move(node.m_Childs[childname]);
+        }
     }
 
+    if (filtering)
+        node.m_Childs.swap(childs);
+
     // Add the element's attributes, prefixing names with "@"
     XERO_ITER_ATTR(element, attr)
     {
         // Skip special attributes
-        if (attr.Name == at_replace || attr.Name == at_op)
+        if (attr.Name == at_replace || attr.Name == at_op || attr.Name == at_merge || attr.Name == at_filtered)
             continue;
         // Add any others
         std::string attrName = xmb.GetAttributeString(attr.Name);

source/simulation2/system/ParamNode.h

@@ -1 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -58 +58 @@
  *   <Example4 datatype="tokens">
  *     one two three
  *   </Example4>
+ *   <Example5>
+ *     <E/>
+ *     <F>
+ *       <I>test</I>
+ *     </F>
+ *     <H>
+ *       <J>example</J>
+ *     </H>
+ *   </Example5>
  * </Entity>
  * @endcode
  * then a second like:
@@ -75 +84 @@
  *     four             <!-- add a token to the parent's set -->
  *     -two             <!-- remove a token from the parent's set -->
  *   </Example4>
+ *   <Example5 filtered=""> <!-- drop all children of this node that are not in this file -->
+ *     <F merge="">  <!-- only add this element if it is also present in the parent -->
+ *       <K>example</K> <!-- if F is present merge its children normally -->
+ *     </F>
+ *     <G merge=""/>  <!-- keep the G element of the parent if it exists -->
+ *     <H>
+ *       <J>text</J>
+ *     </H>
+ *   </Example5>
  * </Entity>
  * @endcode
  * is equivalent to loading a single file like:
@@ -90 +108 @@
  *   <Example4>
  *     one three four
  *   </Example4>
+ *   <Example5>
+ *     <F>
+ *       <I>test</I>
+ *       <K>example</K>
+ *     </F>
+ *     <H>
+ *       <J>text</J>
+ *     </H>
+ *   </Example5>
  * </Entity>
  * @endcode
  *
@@ -103 +130 @@
  *     "Example3": {
  *       "D": "new"
  *     },
- *     "Example4": { "@datatype": "tokens", "_string": "one three four" }
+ *     "Example4": { "@datatype": "tokens", "_string": "one three four" },
+ *     "Example5": {
+ *       "F": {
+ *         "I": "test",
+ *         "K": "example"
+ *       },
+ *       "H": {
+ *         "J": "text"
+ *       }
+ *     }
  *   }
  * }
  * @endcode

source/simulation2/tests/test_ParamNode.h

@@ -1 @@
-/* Copyright (C) 2010 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -135 +135 @@
         TS_ASSERT_WSTR_EQUALS(node.ToXML(), L"<test><a datatype=\"tokens\">Y X</a></test>");
     }
 
+    void test_overlay_filtered()
+    {
+        CParamNode node;
+        TS_ASSERT_EQUALS(CParamNode::LoadXMLString(node, "<test> <a><b/></a> <c>toberemoved</c> <d><e/></d> </test>"), PSRETURN_OK);
+        TS_ASSERT_EQUALS(CParamNode::LoadXMLString(node, "<test filtered=\"\"> <a/> <d><f/></d> <g/> </test>"), PSRETURN_OK);
+        TS_ASSERT_WSTR_EQUALS(node.ToXML(), L"<test><a><b></b></a><d><e></e><f></f></d><g></g></test>");
+    }
+
+    void test_overlay_merge()
+    {
+        CParamNode node;
+        TS_ASSERT_EQUALS(CParamNode::LoadXMLString(node, "<test> <a><b>foo</b><c>bar</c></a> <x><y><z>foo</z></y></x> </test>"), PSRETURN_OK);
+        TS_ASSERT_EQUALS(CParamNode::LoadXMLString(node, "<test> <a merge=\"\"><b>test</b><d>baz</d></a> <i merge=\"\"><j>willnotbeincluded</j></i> <x merge=\"\"><y merge=\"\"><v>text</v></y><w>more text</w></x> </test>"), PSRETURN_OK);
+        TS_ASSERT_WSTR_EQUALS(node.ToXML(), L"<test><a><b>test</b><c>bar</c><d>baz</d></a><x><w>more text</w><y><v>text</v><z>foo</z></y></x></test>");
+    }
+
     void test_types()
     {
         CParamNode node;