From eedec535e93c797312d0141130f2f02e3bf1171a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Thu, 17 Oct 2019 23:58:19 +0200
Subject: [PATCH] Start AI

---
 constants.h |  6 ++++++
 main.c      | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/constants.h b/constants.h
index c90ccd4..3b6d2b2 100644
--- a/constants.h
+++ b/constants.h
@@ -54,4 +54,10 @@
 */
 #define SFG_LEVEL_ELEMENT_ACTIVE_DISTANCE 8
 
+/**
+  Time in ms after which AI will be recomputing its state (which also affects
+  how quickly death animation plays etc).
+*/
+#define SFG_AI_UPDATE_INTERVAL 500
+
 #endif // guard
diff --git a/main.c b/main.c
index 3eb88a4..b8d2b0a 100755
--- a/main.c
+++ b/main.c
@@ -283,6 +283,13 @@ typedef struct
 
 #define SFG_MAX_MONSTERS 64
 
+#define SFG_AI_UPDATE_FRAME_INTERVAL \
+  (SFG_AI_UPDATE_INTERVAL / SFG_MS_PER_FRAME)
+
+#if SFG_AI_UPDATE_FRAME_INTERVAL == 0
+  #define SFG_AI_UPDATE_FRAME_INTERVAL 1
+#endif
+
 /*
   GLOBAL VARIABLES
 ===============================================================================
@@ -971,6 +978,11 @@ void SFG_playerRotateWeapon(uint8_t next)
   SFG_player.weapon %= 3;
 }
 
+void SFG_monsterPerformAI(SFG_MonsterRecord *monster, int8_t recomputeState)
+{
+  // TODO
+}
+
 /**
   Performs one game step (logic, physics), happening SFG_MS_PER_FRAME after
   previous frame. 
@@ -1269,6 +1281,15 @@ void SFG_gameStep()
       SFG_currentLevel.monsterRecordCount)
       SFG_currentLevel.checkedMonsterIndex = 0;
   }
+
+  int8_t recomputeAIState = ((SFG_gameFrame - SFG_currentLevel.frameStart) %
+    SFG_AI_UPDATE_FRAME_INTERVAL) == 0;
+
+  for (uint8_t i = 0; i < SFG_currentLevel.monsterRecordCount; ++i)
+    if (SFG_currentLevel.monsterRecords[i].stateType !=
+        SFG_MONSTER_STATE_INACTIVE)
+      SFG_monsterPerformAI(
+        &(SFG_currentLevel.monsterRecords[i]),recomputeAIState);
 }
 
 void SFG_clearScreen(uint8_t color)