From c334d4a0d43fbe0562c1c72ea03f51a8afd0d795 Mon Sep 17 00:00:00 2001
From: Asdow <Asdow@3b4a5df2-a311-0410-b5c6-a8a6f20db521>
Date: Thu, 31 Mar 2022 15:10:19 +0000
Subject: [PATCH] Optimize RandomMagazine() called when deploying to tactical
 sector (by sun_alf)

Timings
Before:
RandomMagazine: 90044 us (total 90044 us)
RandomMagazine: 90007 us (total 180051 us)
RandomMagazine: 100009 us (total 280060 us)

After:
RandomMagazine: 0 us (total 0 us)
RandomMagazine: 0 us (total 0 us)
RandomMagazine: 0 us (total 0 us)


git-svn-id: https://ja2svn.mooo.com/source/ja2/trunk/GameSource/ja2_v1.13/Build@9354 3b4a5df2-a311-0410-b5c6-a8a6f20db521
---
 Init.cpp           |  9 +++++++++
 Tactical/Items.cpp | 27 ++++++---------------------
 Tactical/Weapons.h |  3 ++-
 3 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/Init.cpp b/Init.cpp
index c72f5c28..d11e3354 100644
--- a/Init.cpp
+++ b/Init.cpp
@@ -1461,6 +1461,15 @@ UINT32 InitializeJA2(void)
 	//}
 	SGP_TRYCATCH_RETHROW(LoadExternalGameplayData(TABLEDATA_DIRECTORY, false),L"Loading external data failed");
 
+	// sun_alf: set itemId to each Magazine to avoid searching over Item[] on each MagazineClassIndexToItemType() call.
+	for (int i = 0; i < gMAXITEMS_READ; i++)
+	{
+		if (Item[i].usItemClass == IC_AMMO)
+		{
+			Magazine[Item[i].ubClassIndex].uiIndex = Item[i].uiIndex;
+		}
+	}
+
 	// Load external text
 	LoadAllExternalText();
 
diff --git a/Tactical/Items.cpp b/Tactical/Items.cpp
index 83941cac..7eb25bc3 100644
--- a/Tactical/Items.cpp
+++ b/Tactical/Items.cpp
@@ -7982,25 +7982,8 @@ UINT16 UseKitPoints( OBJECTTYPE * pObj, UINT16 usPoints, SOLDIERTYPE *pSoldier )
 
 UINT16 MagazineClassIndexToItemType(UINT16 usMagIndex)
 {
-	// Note: if any ammo items in the item table are separated from the main group,
-	// this function will have to be rewritten to scan the item table for an item
-	// with item class ammo, which has class index usMagIndex
-	DebugMsg( TOPIC_JA2, DBG_LEVEL_3, String( "MagazineClassIndexToItemType" ) );
-	
-	// WANNE: Now ammo can be inserted anywhere in Items.xml (before only on index > 70 [FIRST_AMMO] (fix by Realist)
-	//for (usLoop = FIRST_AMMO; usLoop < MAXITEMS; usLoop++)
-	UINT16 usLoop;
-	for (usLoop = 0; usLoop < gMAXITEMS_READ; ++usLoop )
-	{
-		if (Item[usLoop].ubClassIndex == usMagIndex && Item[usLoop].usItemClass == IC_AMMO )
-		{
-			DebugMsg( TOPIC_JA2, DBG_LEVEL_3, String( "MagazineClassIndexToItemType: return %d", usLoop ) );
-			return( usLoop );
-		}
-	}
-
-	DebugMsg( TOPIC_JA2, DBG_LEVEL_3, String( "MagazineClassIndexToItemType: return none, got to %d", usLoop ) );
-	return(NONE);
+	// sun_alf: uiIndex is according itemId now 
+	return Magazine[usMagIndex].uiIndex;
 }
 
 
@@ -8133,14 +8116,16 @@ UINT16 RandomMagazine( UINT16 usItem, UINT8 ubPercentStandard, UINT8 maxCoolness
 	usLoop = 0;
 	while ( Magazine[ usLoop ].ubCalibre != NOAMMO )
 	{
+		// make sure we have space for additional possible mag
+		if (usPossibleMagCnt >= MAX_AMMO_TYPES_PER_GUN)
+			break;
+
 		loopItem = MagazineClassIndexToItemType(usLoop);
 
 		if (Magazine[usLoop].ubCalibre == pWeapon->ubCalibre &&
 				Magazine[usLoop].ubMagSize == pWeapon->ubMagSize && ItemIsLegal(loopItem)
 				&& maxCoolness >= Item[loopItem].ubCoolness )
 		{
-			// store it! (make sure array is big enough)
-			Assert(usPossibleMagCnt < MAX_AMMO_TYPES_PER_GUN);
 			// Madd: check to see if allowed by army
 			if ( gArmyItemChoices[bSoldierClass][ENEMYAMMOTYPES].ubChoices > 0 )
 			{
diff --git a/Tactical/Weapons.h b/Tactical/Weapons.h
index 0bad729e..45c9f266 100644
--- a/Tactical/Weapons.h
+++ b/Tactical/Weapons.h
@@ -398,7 +398,8 @@ typedef struct
 	UINT8	ubAmmoType;
 	UINT8   ubMagType;
 
-	UINT32 uiIndex;
+	// sun_alf: once Magazines.xml is parsed, classIndex of a mag is index in Magazine[], and uiIndex field is not in use anymore,
+	UINT32 uiIndex;  // so let's use it as itemId, i.e. back reference to Item[].
 } MAGTYPE;
 
 typedef struct