Add opReadByte

See #200

src/combat.cc

@@ -6002,6 +6002,11 @@ void _combatKillCritterOutsideCombat(Object* critter_obj, char* msg)
     }
 }
 
+int combatGetTargetHighlight()
+{
+    return _combat_highlight;
+}
+
 static void criticalsInit()
 {
     int mode = 2;

src/combat.h

@@ -58,6 +58,7 @@ int _combat_explode_scenery(Object* a1, Object* a2);
 void _combat_delete_critter(Object* obj);
 void _combatKillCritterOutsideCombat(Object* critter_obj, char* msg);
 
+int combatGetTargetHighlight();
 int criticalsGetValue(int killType, int hitLocation, int effect, int dataMember);
 void criticalsSetValue(int killType, int hitLocation, int effect, int dataMember, int value);
 void criticalsResetValue(int killType, int hitLocation, int effect, int dataMember);

src/sfall_opcodes.cc

@@ -1,6 +1,8 @@
 #include "sfall_opcodes.h"
 
 #include "art.h"
+#include "combat.h"
+#include "debug.h"
 #include "interface.h"
 #include "interpreter.h"
 #include "item.h"
@@ -13,6 +15,24 @@
 
 namespace fallout {
 
+// read_byte
+static void opReadByte(Program* program)
+{
+    int addr = programStackPopInteger(program);
+
+    int value = 0;
+    switch (addr) {
+    case 0x56D38C:
+        value = combatGetTargetHighlight();
+        break;
+    default:
+        debugPrint("%s: attempt to 'read_byte' at 0x%x", program->name, addr);
+        break;
+    }
+
+    programStackPushInteger(program, value);
+}
+
 // set_pc_extra_stat
 static void opSetPcBonusStat(Program* program)
 {
@@ -224,6 +244,7 @@ static void opArtExists(Program* program)
 
 void sfallOpcodesInit()
 {
+    interpreterRegisterOpcode(0x8156, opReadByte);
     interpreterRegisterOpcode(0x815B, opSetPcBonusStat);
     interpreterRegisterOpcode(0x815D, opGetPcBonusStat);
     interpreterRegisterOpcode(0x8193, opGetCurrentHand);