Disable useless structures and research

If structure limits are enforced and VTOLs are disabled, disable also
AA structures and related research. This improves the AIs in no-VTOL
games. Likewise, disable useless research for no-cyborg, no-lassat and
no-satlink games.

Closes #510.

src/game.cpp

@@ -6218,10 +6218,7 @@ bool loadSaveResearch(const char *pFileName)
 			psPlRes = &asPlayerResList[plr][statInc];
 			// Copy the research status
 			psPlRes->ResearchStatus = (researched & RESBITS);
-			if (possible != 0)
-			{
-				MakeResearchPossible(psPlRes);
-			}
+			SetResearchPossible(psPlRes, possible);
 			psPlRes->currentPoints = points;
 			//for any research that has been completed - perform so that upgrade values are set up
 			if (researched == RESEARCHED)
@@ -6247,7 +6244,7 @@ static bool writeResearchFile(char *pFileName)
 		std::vector<WzString> possibles, researched, points;
 		for (int player = 0; player < game.maxPlayers; player++)
 		{
-			possibles.push_back(WzString::number(IsResearchPossible(&asPlayerResList[player][i])));
+			possibles.push_back(WzString::number(GetResearchPossible(&asPlayerResList[player][i])));
 			researched.push_back(WzString::number(asPlayerResList[player][i].ResearchStatus & RESBITS));
 			points.push_back(WzString::number(asPlayerResList[player][i].currentPoints));
 			if (IsResearchPossible(&asPlayerResList[player][i]) || (asPlayerResList[player][i].ResearchStatus & RESBITS) || asPlayerResList[player][i].currentPoints)

src/multilimit.cpp

@@ -371,6 +371,7 @@ void applyLimitSet()
 
 	// Get the limits and decode
 	const MULTISTRUCTLIMITS *pEntry = ingame.pStructureLimits;
+	bool no_vtols = false, no_cyborgs = false, no_lassat = false, no_satlink = false;
 	for (int i = 0; i < ingame.numStructureLimits; ++i)
 	{
 		int id = pEntry[i].id;
@@ -398,6 +399,57 @@ void applyLimitSet()
 					}
 				}
 			}
+			if (asStructureStats[id].type == REF_VTOL_FACTORY && pEntry[i].limit == 0)
+			{
+				no_vtols = true;
+			}
+			if (asStructureStats[id].type == REF_CYBORG_FACTORY && pEntry[i].limit == 0)
+			{
+				no_cyborgs = true;
+			}
+			if (asStructureStats[id].type == REF_GENERIC && asStructureStats[id].id == "A0LasSatCommand" && pEntry[i].limit == 0)
+			{
+				no_lassat = true;
+			}
+			if (asStructureStats[id].type == REF_SAT_UPLINK && pEntry[i].limit == 0)
+			{
+				no_satlink = true;
+			}
+		}
+	}
+
+	// If structure limits are enforced and VTOLs are disabled, disable also AA structures
+	if ((ingame.flags & MPFLAGS_FORCELIMITS) && no_vtols)
+	{
+		for (int i = 0; i < numStructureStats; i++)
+		{
+			if (asStructureStats[i].numWeaps > 0 && asStructureStats[i].psWeapStat[0]->surfaceToAir == SHOOT_IN_AIR)
+			{
+				for (int player = 0; player < MAX_PLAYERS; player++)
+				{
+					asStructureStats[i].upgrade[player].limit = 0;
+				}
+			}
+		}
+		// Disable most VTOL and AA research
+		RecursivelyDisableResearch("R-Struc-VTOLPad-Upgrade02", "R-Wpn-AAGun02", "R-Wpn-AAGun03",
+					   "R-Wpn-Sunburst", "R-Wpn-AAGun-Damage01", "R-Wpn-Missile-LtSAM",
+					   "R-Wpn-AALaser", "R-Wpn-Bomb01", "R-Cyborg-Transport",
+					   "R-SuperTransport", nullptr);
+	}
+	if ((ingame.flags & MPFLAGS_FORCELIMITS) && no_cyborgs)
+	{
+		// Disable most cyborg research
+		RecursivelyDisableResearch("R-Cyborg-Metals01", "R-Cyborg-Hvywpn-PulseLsr", nullptr);
+	}
+	if ((ingame.flags & MPFLAGS_FORCELIMITS) && no_lassat)
+	{
+		// Disable Laser Satellite Command Post research
+		RecursivelyDisableResearch("R-Wpn-LasSat", nullptr);
+		// Also Satellite Uplink Center research if it is disabled
+		if (no_satlink)
+		{
+			RecursivelyDisableResearch("R-Sys-Sensor-UpLink", nullptr);
 		}
 	}
 

src/research.cpp

@@ -368,6 +368,11 @@ bool researchAvailable(int inc, int playerID, QUEUE_MODE mode)
 	{
 		return true;
 	}
+	// Ignore disabled
+	if (IsResearchDisabled(&asPlayerResList[playerID][inc]))
+	{
+		return false;
+	}
 	// if the topic is possible and has not already been researched - add to list
 	if ((IsResearchPossible(&asPlayerResList[playerID][inc])))
 	{
@@ -1395,3 +1400,53 @@ std::vector<AllyResearch> const &listAllyResearch(unsigned ref)
 	}
 	return i->second;
 }
+
+/* Recursively disable research for all players */
+static void RecursivelyDisableResearchByID(UWORD index)
+{
+	if (IsResearchDisabled(&asPlayerResList[0][index]))
+	{
+		return;
+	}
+
+	for (int player = 0; player < MAX_PLAYERS; ++player)
+	{
+		DisableResearch(&asPlayerResList[player][index]);
+	}
+
+	for (size_t inc = 0; inc < asResearch.size(); inc++)
+	{
+		for (size_t prereq = 0; prereq < asResearch[inc].pPRList.size(); prereq++)
+		{
+			if (asResearch[inc].pPRList[prereq] == index)
+			{
+				RecursivelyDisableResearchByID(inc);
+			}
+		}
+	}
+}
+
+static void RecursivelyDisableResearchByName(const char *name)
+{
+	RESEARCH *r = getResearch(name);
+	if (r)
+	{
+		RecursivelyDisableResearchByID(r->index);
+	}
+}
+
+/* Recursively disable a list of research for all players */
+void RecursivelyDisableResearch(const char *names ...)
+{
+	va_list args;
+	va_start(args, names);
+
+	RecursivelyDisableResearchByName(names);
+	const char *name;
+	while ((name = va_arg(args, const char *)))
+	{
+		RecursivelyDisableResearchByName(name);
+	}
+	va_end(args);
+	return;
+}

src/researchdef.h

@@ -78,7 +78,7 @@ struct PLAYER_RESEARCH
 
 	UBYTE		ResearchStatus;			// Bit flags   ...  see below
 
-	bool            possible;                       ///< is the research possible ... so can enable topics vis scripts
+	UBYTE           possible;                       ///< is the research possible ... so can enable topics vis scripts
 };
 
 #define STARTED_RESEARCH           0x01            // research in progress
@@ -90,14 +90,41 @@ struct PLAYER_RESEARCH
 #define RESBITS_PENDING_ONLY (STARTED_RESEARCH_PENDING|CANCELLED_RESEARCH_PENDING)
 #define RESBITS_PENDING (RESBITS|RESBITS_PENDING_ONLY)
 
+#define RESEARCH_IMPOSSIBLE        0x00            // research is (temporarily) not possible
+#define RESEARCH_POSSIBLE          0x01            // research is possible
+#define RESEARCH_DISABLED          0x02            // research is disabled (e.g. most VTOL research in no-VTOL games)
+
 static inline bool IsResearchPossible(const PLAYER_RESEARCH *research)
 {
-	return research->possible;
+	return research->possible == RESEARCH_POSSIBLE;
+}
+
+static inline bool IsResearchDisabled(const PLAYER_RESEARCH *research)
+{
+	return research->possible == RESEARCH_DISABLED;
 }
 
 static inline void MakeResearchPossible(PLAYER_RESEARCH *research)
 {
-	research->possible = true;
+	if (research->possible == RESEARCH_IMPOSSIBLE)
+	{
+		research->possible = RESEARCH_POSSIBLE;
+	}
+}
+
+static inline void DisableResearch(PLAYER_RESEARCH *research)
+{
+	research->possible = RESEARCH_DISABLED;
+}
+
+static inline int GetResearchPossible(const PLAYER_RESEARCH *research)
+{
+	return research->possible;
+}
+
+static inline void SetResearchPossible(PLAYER_RESEARCH *research, UBYTE possible)
+{
+	research->possible = possible;
 }
 
 static inline bool IsResearchCompleted(PLAYER_RESEARCH const *x)
@@ -163,4 +190,6 @@ static inline void ResetResearchStatus(PLAYER_RESEARCH *x)
 	x->ResearchStatus &= ~RESBITS_PENDING;
 }
 
+void RecursivelyDisableResearch(const char *names ...);
+
 #endif // __INCLUDED_RESEARCHDEF_H__