Add toggle to allow building on overlays

- Also add doc section for OverlayTypes and move existing changes there from the misc. list

Author: Starkku

CREDITS.md

@@ -287,6 +287,7 @@ This page lists all the individual contributions to the project by their author.
   - Deploy priority filtering
   - Customizable paradrop missions
   - Guard range customizations
+  - Buildable-upon OverlayTypes
 - **Morton (MortonPL)**:
   - `XDrawOffset` for animations
   - Shield passthrough & absorption

docs/Fixed-or-Improved-Logics.md

@@ -118,7 +118,6 @@ This page describes all ingame logics that are fixed or improved in Phobos witho
 - Fixed `DeployToFire` not considering building placement rules for `DeploysInto` buildings and as a result not working properly with `WaterBound` buildings.
 - Fixed `DeployToFire` not recalculating firer's position on land if it cannot currently deploy.
 - `Arcing=true` projectile elevation inaccuracy can now be fixed by setting `Arcing.AllowElevationInaccuracy=false`.
-- Wall overlays are now drawn with the custom palette defined in `Palette` in `artmd.ini` if possible.
 - Setting `ReloadInTransport` to true on units with `Ammo` will allow the ammo to be reloaded according to `Reload` or `EmptyReload` timers even while the unit is inside a transport.
 - It is now possible to enable `Verses` and `PercentAtMax` to be applied on negative damage by setting `ApplyModifiersOnNegativeDamage` to true on the Warhead.
 - Attached animations on flying units now have their layer updated immediately after the parent unit, if on same layer they always draw above the parent.
@@ -146,7 +145,6 @@ This page describes all ingame logics that are fixed or improved in Phobos witho
 - Units & buildings with `DecloakToFire=false` weapons now cloak while targeting & reloading.
 - Units with `Sensors=true` will no longer reveal ally buildings.
 - Air units are now reliably included by target scan with large range and Warhead detonation by large `CellSpread`.
-- OverlayTypes now read and use `ZAdjust` if specified in their `artmd.ini` entry.
 - Weapons with `AA=true` Projectile can now correctly fire at air units when both firer and target are over a bridge.
 - Fixed disguised units not using the correct palette if target has custom palette.
 - Building upgrades now consistently use building's `PowerUpN` animation settings corresponding to the upgrade's `PowersUpToLevel` where possible.
@@ -221,7 +219,6 @@ This page describes all ingame logics that are fixed or improved in Phobos witho
 - Fixed the bug that infantry ignored `Passengers` and `SizeLimit` when entering buildings.
 - Fixed `VoiceDeploy` not played, when deployed through hot-key/command bar.
 - Fixed the bug that ships can travel on elevated bridges.
-- Dehardcoded 255 limit of `OverlayType`.
 - Fixed an issue where airstrike flare line drawn to target at lower elevation would clip.
 - Elite technos no longer scatter by default, behaviour is controlled by `SCATTER` veterancy ability now.
 - Second weapon with `ElectricAssault=yes` will not unconditionally attack your building with `Overpowerable=yes`.
@@ -1176,9 +1173,43 @@ ProneSpeed.NoCrawls=1.5       ; floating point value, multiplier
 ProneSpeed=                   ; floating point value, multiplier, by default, use the corresponding global value according to Crawls
 ```
 
-<!--
 ## Overlays
--->
+
+### Buildable-upon OverlayTypes
+
+- It is now possible to make OverlayTypes allow buildings to be placed on them by setting `CanBeBuiltOn` to true. This still requires the tile's landtype (which is changed to overlay's land type unless OverlayType has `NoUseTileLandType=false`) to allow buildings to be placed.
+  - If `CanBeBuiltOn.Remove=true`, the overlay will be removed upon the building being placed. If this is not set to true, buildings with `Wall=true` cannot be placed on the overlay and neither does overlay with `Wall=true` allow buildings to be placed on itself regardless of other settings.
+
+In `rulesmd.ini`:
+```ini
+[SOMEOVERLAY]             ; OverlayType
+CanBeBuiltOn=false        ; boolean
+CanBeBuiltOn.Remove=true  ; boolean
+```
+
+### More than 255 OverlayTypes
+
+- Game now supports more than 255 distinct OverlayTypes, up to 65535. For map file/editor support, see [Increased Overlay Limit](AI-Scripting-and-Mapping.md#increased-overlay-limit).
+
+### Custom palette
+
+- You can now specify custom palette for OverlayTypes in similar manner as TechnoTypes can.
+
+In `artmd.ini`:
+```ini
+[SOMETERRAINTYPE]  ; TerrainType
+Palette=           ; filename - excluding .pal extension and three-character theater-specific suffix
+```
+
+### ZAdjust
+
+- OverlayTypes now read and use `ZAdjust`.
+
+In `artmd.ini`:
+```ini
+[SOMEOVERLAY]  ; OverlayType image
+ZAdjust=0
+```
 
 ## Particle systems
 

docs/Whats-New.md

@@ -543,6 +543,7 @@ New:
 - Allow jumpjet climbing ignore building height (by TaranDahl)
 - Allow draw SuperWeapon timer as percentage (by NetsuNegi)
 - Customize particle system of parasite logic (by NetsuNegi)
+- [Buildable-upon OverlayTypes](Fixed-or-Improved-Logics.md#buildable-upon-overlaytypes) (by Starkku)
 
 Vanilla fixes:
 - Fixed sidebar not updating queued unit numbers when adding or removing units when the production is on hold (by CrimRecya)

src/Ext/OverlayType/Body.cpp

@@ -2,13 +2,43 @@
 
 OverlayTypeExt::ExtContainer OverlayTypeExt::ExtMap;
 
+bool OverlayTypeExt::CanBeBuiltOn(int overlayTypeIndex, BuildingTypeClass* pBuildingType, bool requireToBeRemovable)
+{
+	auto const pOverlayType = OverlayTypeClass::Array[overlayTypeIndex];
+	auto const pTypeExt = OverlayTypeExt::ExtMap.Find(pOverlayType);
+
+	if (!pTypeExt->CanBeBuiltOn)
+		return false;
+
+	if (((pBuildingType && pBuildingType->Wall) || pOverlayType->Wall) && !pTypeExt->CanBeBuiltOn_Remove)
+		return false;
+
+	return requireToBeRemovable ? pTypeExt->CanBeBuiltOn_Remove : true;
+}
+
+void OverlayTypeExt::RemoveOverlayFromCell(int overlayTypeIndex, CellClass* pCell)
+{
+	if (overlayTypeIndex != -1 && OverlayTypeClass::Array[overlayTypeIndex]->Wall)
+	{
+		pCell->DamageWall(-1);
+	}
+	else
+	{
+		pCell->OverlayTypeIndex = -1;
+		pCell->OverlayData = 0;
+		pCell->RecalcAttributes(-1);
+	}
+}
+
 // =============================
 // load / save
 
 template <typename T>
 void OverlayTypeExt::ExtData::Serialize(T& Stm)
 {
 	Stm
+		.Process(this->CanBeBuiltOn)
+		.Process(this->CanBeBuiltOn_Remove)
 		.Process(this->ZAdjust)
 		.Process(this->PaletteFile)
 		;
@@ -18,12 +48,15 @@ void OverlayTypeExt::ExtData::LoadFromINIFile(CCINIClass* const pINI)
 {
 	auto pThis = this->OwnerObject();
 
-	//const char* pSection = pThis->ID;
-	//
-	//if (!pINI->GetSection(pSection))
-	//	return;
-	//
-	//INI_EX exINI(pINI);
+	const char* pSection = pThis->ID;
+	
+	if (!pINI->GetSection(pSection))
+		return;
+
+	INI_EX exINI(pINI);
+
+	this->CanBeBuiltOn.Read(exINI, pSection, "CanBeBuiltOn");
+	this->CanBeBuiltOn_Remove.Read(exINI, pSection, "CanBeBuiltOn.Remove");
 
 	auto pArtSection = pThis->ImageFile;
 	INI_EX exArtINI(&CCINIClass::INI_Art);

src/Ext/OverlayType/Body.h

@@ -15,11 +15,15 @@ class OverlayTypeExt
 	class ExtData final : public Extension<OverlayTypeClass>
 	{
 	public:
+		Valueable<bool> CanBeBuiltOn;
+		Valueable<bool> CanBeBuiltOn_Remove;
 		Valueable<int> ZAdjust;
 		PhobosFixedString<32u> PaletteFile;
 		DynamicVectorClass<ColorScheme*>* Palette; // Intentionally not serialized - rebuilt from the palette file on load.
 
 		ExtData(OverlayTypeClass* OwnerObject) : Extension<OverlayTypeClass>(OwnerObject)
+			, CanBeBuiltOn { false }
+			, CanBeBuiltOn_Remove { true }
 			, ZAdjust { 0 }
 			, PaletteFile {}
 			, Palette {}
@@ -50,4 +54,7 @@ class OverlayTypeExt
 
 	static bool LoadGlobals(PhobosStreamReader& Stm);
 	static bool SaveGlobals(PhobosStreamWriter& Stm);
+
+	static bool CanBeBuiltOn(int overlayTypeIndex, BuildingTypeClass* pBuildingType, bool requireToBeRemovable);
+	static void RemoveOverlayFromCell(int overlayTypeIndex, CellClass* pCell);
 };

src/Ext/OverlayType/Hooks.cpp

@@ -44,3 +44,38 @@ DEFINE_HOOK(0x47F974, CellClass_DrawOverlay_Walls, 0x5)
 
 	return SkipGameCode;
 }
+
+#pragma region CanBeBuiltOn
+
+DEFINE_HOOK(0x47C9A7, CellClass_IsClearToBuild_Overlays, 0x5)
+{
+	enum { ReturnFromFunction = 0x47C6D1, CheckTileLandType = 0x47C9CD };
+
+	GET(CellClass*, pThis, EDI);
+	GET_STACK(BuildingTypeClass*, pBuildingType, STACK_OFFSET(0x18, 0x8));
+
+	int overlayTypeIndex = pThis->OverlayTypeIndex;
+
+	if (overlayTypeIndex != -1)
+	{
+		if (OverlayTypeExt::CanBeBuiltOn(overlayTypeIndex, pBuildingType, false))
+			return CheckTileLandType;
+	}
+
+	return ReturnFromFunction;
+}
+
+DEFINE_HOOK(0x45EF11, BuildingTypeClass_FlushForPlacement_Overlays, 0x6)
+{
+	enum { Continue = 0x45EF2C };
+
+	GET(BuildingTypeClass*, pThis, EBX);
+	GET(int, overlayTypeIndex, ECX);
+
+	if (OverlayTypeExt::CanBeBuiltOn(overlayTypeIndex, pThis, false))
+		return Continue;
+
+	return 0;
+}
+
+#pragma endregion

src/Ext/TerrainType/Hooks.Passable.cpp

@@ -1,4 +1,5 @@
 #include "Body.h"
+#include <Ext/OverlayType/Body.h>
 
 constexpr bool IS_CELL_OCCUPIED(CellClass* pCell)
 {
@@ -113,6 +114,16 @@ DEFINE_HOOK(0x5684B1, MapClass_PlaceDown_BuildableTerrain, 0x6)
 				TerrainTypeExt::Remove(pTerrain);
 			}
 		}
+
+		int overlayTypeIndex = pCell->OverlayTypeIndex;
+
+		if (overlayTypeIndex != -1)
+		{
+			auto const pBuildingType = static_cast<BuildingTypeClass*>(pObject->GetType());
+
+			if (OverlayTypeExt::CanBeBuiltOn(overlayTypeIndex, pBuildingType, true))
+				OverlayTypeExt::RemoveOverlayFromCell(overlayTypeIndex, pCell);
+		}
 	}
 
 	return 0;