From 19bcfebe0d9b59088d54d39d28fe352ec062b9bb Mon Sep 17 00:00:00 2001
From: Alexander Batalov <alex.batalov@gmail.com>
Date: Mon, 7 Nov 2022 20:41:33 +0300
Subject: [PATCH] Add ammo/charges opcodes

See #200
---
 src/sfall_opcodes.cc | 72 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/src/sfall_opcodes.cc b/src/sfall_opcodes.cc
index 8cf5954..55d09d9 100644
--- a/src/sfall_opcodes.cc
+++ b/src/sfall_opcodes.cc
@@ -3,6 +3,7 @@
 #include "art.h"
 #include "interface.h"
 #include "interpreter.h"
+#include "item.h"
 #include "mouse.h"
 #include "svga.h"
 
@@ -14,6 +15,74 @@ static void opGetCurrentHand(Program* program)
     programStackPushInteger(program, interfaceGetCurrentHand());
 }
 
+// get_weapon_ammo_pid
+static void opGetWeaponAmmoPid(Program* program)
+{
+    Object* obj = static_cast<Object*>(programStackPopPointer(program));
+
+    int pid = -1;
+    if (obj != nullptr) {
+        if (PID_TYPE(obj->pid) == OBJ_TYPE_ITEM) {
+            switch (itemGetType(obj)) {
+            case ITEM_TYPE_WEAPON:
+                pid = weaponGetAmmoTypePid(obj);
+                break;
+            case ITEM_TYPE_MISC:
+                pid = miscItemGetPowerTypePid(obj);
+                break;
+            }
+        }
+    }
+
+    programStackPushInteger(program, pid);
+}
+
+// get_weapon_ammo_count
+static void opGetWeaponAmmoCount(Program* program)
+{
+    Object* obj = static_cast<Object*>(programStackPopPointer(program));
+
+    // CE: Implementation is different.
+    int ammoQuantityOrCharges = 0;
+    if (obj != nullptr) {
+        if (PID_TYPE(obj->pid) == OBJ_TYPE_ITEM) {
+            switch (itemGetType(obj)) {
+            case ITEM_TYPE_AMMO:
+            case ITEM_TYPE_WEAPON:
+                ammoQuantityOrCharges = ammoGetQuantity(obj);
+                break;
+            case ITEM_TYPE_MISC:
+                ammoQuantityOrCharges = miscItemGetCharges(obj);
+                break;
+            }
+        }
+    }
+
+    programStackPushInteger(program, ammoQuantityOrCharges);
+}
+
+// set_weapon_ammo_count
+static void opSetWeaponAmmoCount(Program* program)
+{
+    int ammoQuantityOrCharges = programStackPopInteger(program);
+    Object* obj = static_cast<Object*>(programStackPopPointer(program));
+
+    // CE: Implementation is different.
+    if (obj != nullptr) {
+        if (PID_TYPE(obj->pid) == OBJ_TYPE_ITEM) {
+            switch (itemGetType(obj)) {
+            case ITEM_TYPE_AMMO:
+            case ITEM_TYPE_WEAPON:
+                ammoSetQuantity(obj, ammoQuantityOrCharges);
+                break;
+            case ITEM_TYPE_MISC:
+                miscItemSetCharges(obj, ammoQuantityOrCharges);
+                break;
+            }
+        }
+    }
+}
+
 // get_mouse_x
 static void opGetMouseX(Program* program)
 {
@@ -80,6 +149,9 @@ static void opArtExists(Program* program)
 void sfallOpcodesInit()
 {
     interpreterRegisterOpcode(0x8193, opGetCurrentHand);
+    interpreterRegisterOpcode(0x8217, opGetWeaponAmmoPid);
+    interpreterRegisterOpcode(0x8219, opGetWeaponAmmoCount);
+    interpreterRegisterOpcode(0x821A, opSetWeaponAmmoCount);
     interpreterRegisterOpcode(0x821C, opGetMouseX);
     interpreterRegisterOpcode(0x821D, opGetMouseY);
     interpreterRegisterOpcode(0x8220, opGetScreenWidth);