(svn r23146) -Change: [NewGRF v8] Make callback 22 return a probability to use instead of property 18.

7 files changed, 33 insertions, 23 deletions

diff --git a/src/ai/api/ai_industrytype.cpp b/src/ai/api/ai_industrytype.cpp
index 121a7756f..bd28df289 100644
--- a/src/ai/api/ai_industrytype.cpp
+++ b/src/ai/api/ai_industrytype.cpp
@@ -91,7 +91,7 @@
 {
 	if (!IsValidIndustryType(industry_type)) return false;
 
-	if (!::CheckIfCallBackAllowsAvailability(industry_type, IACT_USERCREATION)) return false;
+	if (::GetIndustryProbabilityCallback(industry_type, IACT_USERCREATION, 1) == 0) return false;
 	if (!::GetIndustrySpec(industry_type)->IsRawIndustry()) return true;
 
 	/* raw_industry_construction == 1 means "Build as other industries" */
@@ -103,7 +103,7 @@
 	if (!IsValidIndustryType(industry_type)) return false;
 
 	if (!::GetIndustrySpec(industry_type)->IsRawIndustry()) return false;
-	if (!::CheckIfCallBackAllowsAvailability(industry_type, IACT_USERCREATION)) return false;
+	if (::GetIndustryProbabilityCallback(industry_type, IACT_USERCREATION, 1) == 0) return false;
 
 	/* raw_industry_construction == 2 means "prospect" */
 	return _settings_game.construction.raw_industry_construction == 2;
diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index 5309135f1..c7ed3f7a6 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -1777,7 +1777,7 @@ CommandCost CmdBuildIndustry(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 		return CMD_ERROR;
 	}
 
-	if (_game_mode != GM_EDITOR && !CheckIfCallBackAllowsAvailability(it, IACT_USERCREATION)) {
+	if (_game_mode != GM_EDITOR && GetIndustryProbabilityCallback(it, IACT_USERCREATION, 1) == 0) {
 		return CMD_ERROR;
 	}
 
@@ -1876,9 +1876,9 @@ static uint32 GetScaledIndustryGenerationProbability(IndustryType it, bool *forc
 {
 	const IndustrySpec *ind_spc = GetIndustrySpec(it);
 	uint32 chance = ind_spc->appear_creation[_settings_game.game_creation.landscape] * 16; // * 16 to increase precision
-	if (!ind_spc->enabled || chance == 0 || ind_spc->num_table == 0 ||
-			!CheckIfCallBackAllowsAvailability(it, IACT_MAPGENERATION) ||
-			(_game_mode != GM_EDITOR && _settings_game.difficulty.industry_density == ID_FUND_ONLY)) {
+	if (!ind_spc->enabled || ind_spc->num_table == 0 ||
+			(_game_mode != GM_EDITOR && _settings_game.difficulty.industry_density == ID_FUND_ONLY) ||
+			(chance = GetIndustryProbabilityCallback(it, IACT_MAPGENERATION, chance)) == 0) {
 		*force_at_least_one = false;
 		return 0;
 	} else {
@@ -1906,10 +1906,10 @@ static uint16 GetIndustryGamePlayProbability(IndustryType it, byte *min_number)
 
 	const IndustrySpec *ind_spc = GetIndustrySpec(it);
 	byte chance = ind_spc->appear_ingame[_settings_game.game_creation.landscape];
-	if (!ind_spc->enabled || chance == 0 || ind_spc->num_table == 0 ||
+	if (!ind_spc->enabled || ind_spc->num_table == 0 ||
 			((ind_spc->behaviour & INDUSTRYBEH_BEFORE_1950) && _cur_year > 1950) ||
 			((ind_spc->behaviour & INDUSTRYBEH_AFTER_1960) && _cur_year < 1960) ||
-			!CheckIfCallBackAllowsAvailability(it, IACT_RANDOMCREATION)) {
+			(chance = GetIndustryProbabilityCallback(it, IACT_RANDOMCREATION, chance)) == 0) {
 		*min_number = 0;
 		return 0;
 	}
diff --git a/src/industry_gui.cpp b/src/industry_gui.cpp
index 1ea3967fd..9c2e825f6 100644
--- a/src/industry_gui.cpp
+++ b/src/industry_gui.cpp
@@ -209,7 +209,7 @@ class BuildIndustryWindow : public Window {
 	bool timer_enabled;                         ///< timer can be used
 	uint16 count;                               ///< How many industries are loaded
 	IndustryType index[NUM_INDUSTRYTYPES + 1];  ///< Type of industry, in the order it was loaded
-	bool enabled[NUM_INDUSTRYTYPES + 1];        ///< availability state, coming from CBID_INDUSTRY_AVAILABLE (if ever)
+	bool enabled[NUM_INDUSTRYTYPES + 1];        ///< availability state, coming from CBID_INDUSTRY_PROBABILITY (if ever)
 	Scrollbar *vscroll;
 
 	/** The offset for the text in the matrix. */
@@ -247,7 +247,7 @@ class BuildIndustryWindow : public Window {
 					continue;
 				}
 				this->index[this->count] = ind;
-				this->enabled[this->count] = (_game_mode == GM_EDITOR) || CheckIfCallBackAllowsAvailability(ind, IACT_USERCREATION);
+				this->enabled[this->count] = (_game_mode == GM_EDITOR) || GetIndustryProbabilityCallback(ind, IACT_USERCREATION, 1) > 0;
 				/* Keep the selection to the correct line */
 				if (this->selected_type == ind) this->selected_index = this->count;
 				this->count++;
@@ -582,7 +582,7 @@ public:
 			const IndustrySpec *indsp = GetIndustrySpec(this->selected_type);
 
 			if (indsp->enabled) {
-				bool call_back_result = CheckIfCallBackAllowsAvailability(this->selected_type, IACT_USERCREATION);
+				bool call_back_result = GetIndustryProbabilityCallback(this->selected_type, IACT_USERCREATION, 1) > 0;
 
 				/* Only if result does match the previous state would it require a redraw. */
 				if (call_back_result != this->enabled[this->selected_index]) {
diff --git a/src/newgrf_callbacks.h b/src/newgrf_callbacks.h
index cce00151f..1cc608121 100644
--- a/src/newgrf_callbacks.h
+++ b/src/newgrf_callbacks.h
@@ -85,8 +85,8 @@ enum CallbackID {
 	/** Called periodically to determine if a house should be destroyed. */
 	CBID_HOUSE_DESTRUCTION               = 0x21, // 8 bit callback
 
-	/** Called to determine if the given industry type is available */
-	CBID_INDUSTRY_AVAILABLE              = 0x22, // 15 bit callback
+	/** Called to determine if the given industry type is available. For grf version >= 8 also a probability can be returned. */
+	CBID_INDUSTRY_PROBABILITY            = 0x22, // 15 bit callback
 
 	/**
 	 * This callback is called from vehicle purchase lists. It returns a value to be
@@ -341,7 +341,7 @@ enum CargoCallbackMask {
  * Callback masks for Industries
  */
 enum IndustryCallbackMask {
-	CBM_IND_AVAILABLE                 =  0, ///< industry availability callback
+	CBM_IND_PROBABILITY               =  0, ///< industry availability/probability callback
 	CBM_IND_PRODUCTION_CARGO_ARRIVAL  =  1, ///< call production callback when cargo arrives at the industry
 	CBM_IND_PRODUCTION_256_TICKS      =  2, ///< call production callback every 256 ticks
 	CBM_IND_LOCATION                  =  3, ///< check industry construction on given area
diff --git a/src/newgrf_industries.cpp b/src/newgrf_industries.cpp
index 389bcebfb..2f469dc71 100644
--- a/src/newgrf_industries.cpp
+++ b/src/newgrf_industries.cpp
@@ -550,22 +550,32 @@ CommandCost CheckIfCallBackAllowsCreation(TileIndex tile, IndustryType type, uin
 }
 
 /**
- * Check with callback #CBM_IND_AVAILABLE whether the industry can be built.
+ * Check with callback #CBID_INDUSTRY_PROBABILITY whether the industry can be built.
  * @param type Industry type to check.
  * @param creation_type Reason to construct a new industry.
  * @return If the industry has no callback or allows building, \c true is returned. Otherwise, \c false is returned.
  */
-bool CheckIfCallBackAllowsAvailability(IndustryType type, IndustryAvailabilityCallType creation_type)
+uint32 GetIndustryProbabilityCallback(IndustryType type, IndustryAvailabilityCallType creation_type, uint32 default_prob)
 {
 	const IndustrySpec *indspec = GetIndustrySpec(type);
 
-	if (HasBit(indspec->callback_mask, CBM_IND_AVAILABLE)) {
-		uint16 res = GetIndustryCallback(CBID_INDUSTRY_AVAILABLE, 0, creation_type, NULL, type, INVALID_TILE);
+	if (HasBit(indspec->callback_mask, CBM_IND_PROBABILITY)) {
+		uint16 res = GetIndustryCallback(CBID_INDUSTRY_PROBABILITY, 0, creation_type, NULL, type, INVALID_TILE);
 		if (res != CALLBACK_FAILED) {
-			return (res == 0);
+			if (indspec->grf_prop.grffile->grf_version < 8) {
+				/* Disallow if result != 0 */
+				if (res != 0) default_prob = 0;
+			} else {
+				/* Use returned probability. 0x100 to use default */
+				if (res < 0x100) {
+					default_prob = res;
+				} else if (res > 0x100) {
+					ErrorUnknownCallbackResult(indspec->grf_prop.grffile->grfid, CBID_INDUSTRY_PROBABILITY, res);
+				}
+			}
 		}
 	}
-	return true;
+	return default_prob;
 }
 
 static int32 DerefIndProd(int field, bool use_register)
diff --git a/src/newgrf_industries.h b/src/newgrf_industries.h
index 91a0fe963..4132e51e9 100644
--- a/src/newgrf_industries.h
+++ b/src/newgrf_industries.h
@@ -26,7 +26,7 @@ enum IndustryTrigger {
 	INDUSTRY_TRIGGER_CARGO_DELIVERY   = 4,
 };
 
-/** From where is callback CBID_INDUSTRY_AVAILABLE been called */
+/** From where is callback CBID_INDUSTRY_PROBABILITY been called */
 enum IndustryAvailabilityCallType {
 	IACT_MAPGENERATION,    ///< during random map generation
 	IACT_RANDOMCREATION,   ///< during creation of random ingame industry
@@ -40,7 +40,7 @@ uint16 GetIndustryCallback(CallbackID callback, uint32 param1, uint32 param2, In
 uint32 GetIndustryIDAtOffset(TileIndex new_tile, const Industry *i, uint32 cur_grfid);
 void IndustryProductionCallback(Industry *ind, int reason);
 CommandCost CheckIfCallBackAllowsCreation(TileIndex tile, IndustryType type, uint layout, uint32 seed, uint16 initial_random_bits, Owner founder, IndustryAvailabilityCallType creation_type);
-bool CheckIfCallBackAllowsAvailability(IndustryType type, IndustryAvailabilityCallType creation_type);
+uint32 GetIndustryProbabilityCallback(IndustryType type, IndustryAvailabilityCallType creation_type, uint32 default_prob);
 bool IndustryTemporarilyRefusesCargo(Industry *ind, CargoID cargo_type);
 
 IndustryType MapNewGRFIndustryType(IndustryType grf_type, uint32 grf_id);
diff --git a/src/table/newgrf_debug_data.h b/src/table/newgrf_debug_data.h
index e24a183c8..a07ccc006 100644
--- a/src/table/newgrf_debug_data.h
+++ b/src/table/newgrf_debug_data.h
@@ -253,7 +253,7 @@ static const NIProperty _nip_industries[] = {
 
 #define NICI(cb_id, bit) NIC(cb_id, IndustrySpec, callback_mask, bit)
 static const NICallback _nic_industries[] = {
-	NICI(CBID_INDUSTRY_AVAILABLE,            CBM_IND_AVAILABLE),
+	NICI(CBID_INDUSTRY_PROBABILITY,          CBM_IND_PROBABILITY),
 	NICI(CBID_INDUSTRY_LOCATION,             CBM_IND_LOCATION),
 	NICI(CBID_INDUSTRY_PRODUCTION_CHANGE,    CBM_IND_PRODUCTION_CHANGE),
 	NICI(CBID_INDUSTRY_MONTHLYPROD_CHANGE,   CBM_IND_MONTHLYPROD_CHANGE),