Add Sfall list functions

See #200

CMakeLists.txt

@@ -271,6 +271,8 @@ target_sources(${EXECUTABLE_NAME} PUBLIC
     "src/sfall_config.h"
     "src/sfall_global_vars.cc"
     "src/sfall_global_vars.h"
+    "src/sfall_lists.cc"
+    "src/sfall_lists.h"
     "src/sfall_opcodes.cc"
     "src/sfall_opcodes.h"
 )

src/game.cc

@@ -58,6 +58,7 @@
 #include "settings.h"
 #include "sfall_config.h"
 #include "sfall_global_vars.h"
+#include "sfall_lists.h"
 #include "skill.h"
 #include "skilldex.h"
 #include "stat.h"
@@ -352,6 +353,11 @@ int gameInitWithOptions(const char* windowTitle, bool isMapper, int font, int a4
         return -1;
     }
 
+    if (!sfallListsInit()) {
+        debugPrint("Failed on sfallListsInit");
+        return -1;
+    }
+
     return 0;
 }
 
@@ -395,6 +401,7 @@ void gameReset()
 
     // SFALL
     sfallGlobalVarsReset();
+    sfallListsReset();
 }
 
 // 0x442C34
@@ -403,6 +410,7 @@ void gameExit()
     debugPrint("\nGame Exit\n");
 
     // SFALL
+    sfallListsExit();
     sfallGlobalVarsExit();
     premadeCharactersExit();
 

src/sfall_lists.cc

@@ -0,0 +1,134 @@
+#include "sfall_lists.h"
+
+#include <unordered_map>
+#include <vector>
+
+#include "object.h"
+#include "scripts.h"
+
+namespace fallout {
+
+// Due to bad design of |ListType| it's |LIST_ITEMS| and |LIST_CRITTERS| do not
+// match |OBJ_TYPE_CRITTER| and |OBJ_TYPE_ITEM|.
+static constexpr int kObjectTypeToListType[] = {
+    /*    OBJ_TYPE_ITEM */ LIST_ITEMS,
+    /* OBJ_TYPE_CRITTER */ LIST_CRITTERS,
+    /* OBJ_TYPE_SCENERY */ LIST_SCENERY,
+    /*    OBJ_TYPE_WALL */ LIST_WALLS,
+    /*    OBJ_TYPE_TILE */ LIST_TILES,
+    /*    OBJ_TYPE_MISC */ LIST_MISC,
+};
+
+static constexpr int kObjectTypeToListTypeSize = sizeof(kObjectTypeToListType) / sizeof(kObjectTypeToListType[0]);
+
+// As in Sfall.
+static constexpr int kInitialListId = 0xCCCCCC;
+
+// Loosely based on [sList] from Sfall.
+struct List {
+    std::vector<Object*> objects;
+    size_t pos = 0;
+};
+
+struct State {
+    std::unordered_map<int, List> lists;
+    int nextListId = kInitialListId;
+};
+
+static State* _state = nullptr;
+
+bool sfallListsInit()
+{
+    _state = new (std::nothrow) State();
+    if (_state == nullptr) {
+        return false;
+    }
+
+    return true;
+}
+
+void sfallListsReset()
+{
+    _state->nextListId = kInitialListId;
+    _state->lists.clear();
+}
+
+void sfallListsExit()
+{
+    if (_state != nullptr) {
+        delete _state;
+        _state = nullptr;
+    }
+}
+
+int sfallListsCreate(int listType)
+{
+    int listId = _state->nextListId++;
+    List& list = _state->lists[listId];
+
+    if (listType == LIST_TILES) {
+        // For unknown reason this list type is not implemented in Sfall.
+    } else if (listType == LIST_SPATIAL) {
+        for (int elevation = 0; elevation < ELEVATION_COUNT; elevation++) {
+            Script* script = scriptGetFirstSpatialScript(elevation);
+            while (script != nullptr) {
+                Object* obj = script->owner;
+                if (obj == nullptr) {
+                    obj = scriptGetSelf(script->program);
+                }
+                list.objects.push_back(obj);
+                script = scriptGetNextSpatialScript();
+            }
+        }
+    } else {
+        // CE: Implementation is slightly different. Sfall manually loops thru
+        // elevations (3) and hexes (40000) and use |objectFindFirstAtLocation|
+        // (originally |obj_find_first_at_tile|) to obtain next object. This
+        // functionality is already implemented in |objectFindFirst| and
+        // |objectFindNext|.
+        //
+        // As a small optimization |LIST_ALL| is handled separately since there
+        // is no need to check object type.
+        if (listType == LIST_ALL) {
+            Object* obj = objectFindFirst();
+            while (obj != nullptr) {
+                list.objects.push_back(obj);
+                obj = objectFindNext();
+            }
+        } else {
+            Object* obj = objectFindFirst();
+            while (obj != nullptr) {
+                int objectType = PID_TYPE(obj->pid);
+                if (objectType < kObjectTypeToListTypeSize && kObjectTypeToListType[objectType] == listType) {
+                    list.objects.push_back(obj);
+                }
+                obj = objectFindNext();
+            }
+        }
+    }
+
+    return listId;
+}
+
+Object* sfallListsGetNext(int listId)
+{
+    auto it = _state->lists.find(listId);
+    if (it != _state->lists.end()) {
+        List& list = it->second;
+        if (list.pos < list.objects.size()) {
+            return list.objects[list.pos++];
+        }
+    }
+
+    return nullptr;
+}
+
+void sfallListsDestroy(int listId)
+{
+    auto it = _state->lists.find(listId);
+    if (it != _state->lists.end()) {
+        _state->lists.erase(it);
+    }
+}
+
+} // namespace fallout

src/sfall_lists.h

@@ -0,0 +1,28 @@
+#ifndef FALLOUT_SFALL_LISTS_H_
+#define FALLOUT_SFALL_LISTS_H_
+
+#include "obj_types.h"
+
+namespace fallout {
+
+enum ListType {
+    LIST_CRITTERS = 0,
+    LIST_ITEMS = 1,
+    LIST_SCENERY = 2,
+    LIST_WALLS = 3,
+    LIST_TILES = 4,
+    LIST_MISC = 5,
+    LIST_SPATIAL = 6,
+    LIST_ALL = 9,
+};
+
+bool sfallListsInit();
+void sfallListsReset();
+void sfallListsExit();
+int sfallListsCreate(int listType);
+Object* sfallListsGetNext(int listId);
+void sfallListsDestroy(int listId);
+
+} // namespace fallout
+
+#endif /* FALLOUT_SFALL_LISTS_H_ */

src/sfall_opcodes.cc

@@ -7,6 +7,7 @@
 #include "mouse.h"
 #include "object.h"
 #include "sfall_global_vars.h"
+#include "sfall_lists.h"
 #include "stat.h"
 #include "svga.h"
 
@@ -67,6 +68,29 @@ static void opGetGlobalInt(Program* program)
     programStackPushInteger(program, value);
 }
 
+// list_begin
+static void opListBegin(Program* program)
+{
+    int listType = programStackPopInteger(program);
+    int listId = sfallListsCreate(listType);
+    programStackPushInteger(program, listId);
+}
+
+// list_next
+static void opListNext(Program* program)
+{
+    int listId = programStackPopInteger(program);
+    Object* obj = sfallListsGetNext(listId);
+    programStackPushPointer(program, obj);
+}
+
+// list_end
+static void opListEnd(Program* program)
+{
+    int listId = programStackPopInteger(program);
+    sfallListsDestroy(listId);
+}
+
 // get_weapon_ammo_pid
 static void opGetWeaponAmmoPid(Program* program)
 {
@@ -205,6 +229,9 @@ void sfallOpcodesInit()
     interpreterRegisterOpcode(0x8193, opGetCurrentHand);
     interpreterRegisterOpcode(0x819D, opSetGlobalVar);
     interpreterRegisterOpcode(0x819E, opGetGlobalInt);
+    interpreterRegisterOpcode(0x820D, opListBegin);
+    interpreterRegisterOpcode(0x820E, opListNext);
+    interpreterRegisterOpcode(0x820F, opListEnd);
     interpreterRegisterOpcode(0x8217, opGetWeaponAmmoPid);
     interpreterRegisterOpcode(0x8219, opGetWeaponAmmoCount);
     interpreterRegisterOpcode(0x821A, opSetWeaponAmmoCount);