Self / ally arts cast on the hero when pointed at an enemy

Arts with launch type 2 (buffs, auras, heals) are only valid on allies
or without a target; with an enemy under the cursor the game dropped
the order. Orders of a player hero for such arts lose a non-ally target,
which casts them on the hero. The launch type comes from the art
definition tables (game/engine/arts.h, tools/arttable.mjs).

Also: skill keys check the relocated taskbar slots (all 7), Ghidra
data labels (g_ names in names.txt).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

CMakeLists.txt

@@ -40,6 +40,7 @@ add_library(sacred_re SHARED
     src/mods/skillslots.cpp
     src/mods/inventory_save.cpp
     src/mods/skillbar.cpp
+    src/mods/arttarget.cpp
 )
 target_include_directories(sacred_re PRIVATE src)
 target_compile_options(sacred_re PRIVATE ${SACRED_RE_CXX_FLAGS})

src/game/engine/arts.h

@@ -0,0 +1,48 @@
+#pragma once
+// Combat arts: the definition tables and how they are targeted.
+
+#include <cstdint>
+
+namespace game {
+
+// How an art is launched (byte +0x3c of a g_spellDefs entry, +0x4c of a
+// g_combatMoveDefs entry; cCreature::IsValidArtTarget 0x51d680 switches on it).
+enum class LaunchType : uint8_t {
+    Target0 = 0,  // aimed (e.g. Feuerball)
+    Enemy = 1,  // aimed at an enemy (attacks, Blitzschlag)
+    SelfOrAlly = 2,  // buffs, auras, heals: an ally, or the caster without a target
+    Ground = 3,  // a point / area, summons
+    Corpse = 4,  // a dead ally (resurrection)
+    AroundSelf = 5,  // centred on the caster
+    Unknown = 0xff,
+};
+
+// SpellDef::Find (0x4d2150) / CombatMoveDef::Find (0x4d1930): the definition
+// entry of art `id` (spells: small ids, combat moves: 0x3e8+), or null.
+inline const uint8_t* FindSpellDef(uint16_t id) {
+    using Fn = const uint8_t*(__cdecl*)(uint32_t);
+    return reinterpret_cast<Fn>(0x004d2150)(id);
+}
+inline const uint8_t* FindCombatMoveDef(uint16_t id) {
+    using Fn = const uint8_t*(__cdecl*)(uint32_t);
+    return reinterpret_cast<Fn>(0x004d1930)(id);
+}
+
+// The launch type of art `id`, looked up as cEngine::UpdateCursorPick does.
+inline LaunchType ArtLaunchType(uint16_t id) {
+    if (const uint8_t* spell = FindSpellDef(id)) {
+        return static_cast<LaunchType>(spell[0x3c]);
+    }
+    if (const uint8_t* move = FindCombatMoveDef(id)) {
+        return static_cast<LaunchType>(move[0x4c]);
+    }
+    return LaunchType::Unknown;
+}
+
+// cCreature::IsAlly (0x548f20): whether object `id` is an ally of `creature`.
+inline bool IsAlly(void* creature, uint32_t id) {
+    using Fn = char(__fastcall*)(void*, void*, uint32_t);
+    return reinterpret_cast<Fn>(0x00548f20)(creature, nullptr, id) != 0;
+}
+
+} // namespace game

src/mods/arttarget.cpp

@@ -0,0 +1,56 @@
+// Self / ally arts cast on the caster when pointed at an enemy.
+//
+// Using an art sends the hero a cEvent_creature 0x105 with the object under
+// the cursor as target (+0x10, 0 for the ground or the hero itself) and the
+// art id (+0x30). Arts with launch type SelfOrAlly (buffs, auras, heals) are
+// only valid on allies or without a target (cCreature::IsValidArtTarget,
+// 0x51d680); with an enemy under the cursor the game drops the order and
+// nothing happens. For a player hero such an order loses its target instead,
+// which casts the art on the hero, as a click on the hero does.
+
+#include <cstdint>
+
+#include "game/engine/arts.h"
+#include "re/hook.h"
+
+namespace game {
+namespace {
+
+constexpr uint32_t kOrderUseArt = 0x105;
+constexpr uint32_t kPlayerIds = 0x11;  // object ids below this are player heroes
+
+// cEvent_creature fields used here.
+constexpr size_t kOrderCommand = 0x4;
+constexpr size_t kOrderTarget = 0x10;  // object id
+constexpr size_t kOrderArt = 0x30;  // art id (cCreature::ResolveArtId)
+
+uint32_t& Field(void* event, size_t offset) {
+    return *reinterpret_cast<uint32_t*>(static_cast<uint8_t*>(event) + offset);
+}
+
+void RetargetSelfArt(void* creature, void* event) {
+    if (!creature || !event || Field(event, kOrderCommand) != kOrderUseArt) {
+        return;
+    }
+    const uint32_t target = Field(event, kOrderTarget);
+    const uint32_t casterId = *reinterpret_cast<uint32_t*>(static_cast<uint8_t*>(creature) + 0xc);
+    if (target == 0 || casterId >= kPlayerIds) {
+        return;
+    }
+    if (ArtLaunchType(static_cast<uint16_t>(Field(event, kOrderArt))) == LaunchType::SelfOrAlly &&
+        !IsAlly(creature, target)) {
+        Field(event, kOrderTarget) = 0;
+    }
+}
+
+} // namespace
+
+// cEngine::SendCreatureOrder (0x6170d0): orders for the controlled creature.
+void __fastcall Engine_SendCreatureOrder(void* self, void* edx, void* creature, void* event);
+RE_HOOK(0x006170d0, Engine_SendCreatureOrder);
+void __fastcall Engine_SendCreatureOrder(void* self, void* edx, void* creature, void* event) {
+    RetargetSelfArt(creature, event);
+    Engine_SendCreatureOrder_original(self, edx, creature, event);
+}
+
+} // namespace game

src/mods/skillbar.cpp

@@ -83,6 +83,13 @@ void SelectWeaponSet(unsigned slot) {
     }
 }
 
+bool HasSkillSlot(const void* taskbar, unsigned slot) {
+    const auto* p = static_cast<const uint8_t*>(taskbar);
+    constexpr size_t kSlotCount = 0x15c;  // u16: slots shown, from SetSlotCount
+    return slot < kSlots && slot < *reinterpret_cast<const uint16_t*>(p + kSlotCount) &&
+           reinterpret_cast<void* const*>(p + kSkillSlots)[slot] != nullptr;
+}
+
 void OnTaskbar(void* taskbar) {
     g_taskbar = static_cast<uint8_t*>(taskbar);
 }

src/mods/skillbar.h

@@ -7,4 +7,7 @@ namespace mods::skillbar {
 void SelectSkillSlot(unsigned slot);
 void SelectWeaponSet(unsigned slot);
 
+// Whether the taskbar shows combat-art slot `slot` (unlocked, control exists).
+bool HasSkillSlot(const void* taskbar, unsigned slot);
+
 } // namespace mods::skillbar

src/mods/skillkeys.cpp

@@ -11,6 +11,8 @@
 
 #include "mods/skillkeys.h"
 
+#include "mods/skillbar.h"
+
 #include <cstdint>
 #include <mutex>
 
@@ -21,11 +23,6 @@
 namespace mods::skillkeys {
 namespace {
 
-// cUI_Taskbar2 fields.
-constexpr size_t kTaskbarSlotCount = 0x15c;  // uint16: combat-art slots the hero has
-constexpr size_t kTaskbarSkillSlots = 0x178;  // 5 slot controls (null: none)
-constexpr unsigned kSlots = 5;
-
 // The game window, if it has the focus (it does while a skill key is used).
 HWND GameWindow() {
     HWND window = GetForegroundWindow();
@@ -84,9 +81,7 @@ void OnSlotSelected(void* taskbar, unsigned slot) {
     }
     const int key = g_state.pendingKey;
     g_state.pendingKey = 0;
-    const auto* bar = static_cast<const uint8_t*>(taskbar);
-    if (slot >= kSlots || slot >= *reinterpret_cast<const uint16_t*>(bar + kTaskbarSlotCount) ||
-        !reinterpret_cast<void* const*>(bar + kTaskbarSkillSlots)[slot]) {
+    if (!mods::skillbar::HasSkillSlot(taskbar, slot)) {
         return;  // empty slot: nothing was selected
     }
     HWND window = GameWindow();
@@ -118,3 +113,4 @@ void __fastcall UiTaskbar_SelectSkillSlot(void* self, void* edx, unsigned slot,
 }
 
 } // namespace game
+

tools/arttable.mjs

@@ -0,0 +1,37 @@
+// Dump sacred.exe's combat-art definition tables (see docs/skill-slots.md).
+//   node tools/arttable.mjs <exe> [id...]   (ids hex, e.g. 3f7; none: all)
+import { readFileSync } from "node:fs";
+
+const [exePath, ...ids] = process.argv.slice(2);
+const file = readFileSync(exePath);
+const pe = file.readUInt32LE(0x3c);
+const sections = file.readUInt16LE(pe + 6);
+const optional = file.readUInt16LE(pe + 20);
+const imageBase = file.readUInt32LE(pe + 52);
+const table = pe + 24 + optional;
+function offset(va) {
+  for (let i = 0; i < sections; i++) {
+    const s = table + i * 40;
+    const vsize = file.readUInt32LE(s + 8), vaddr = file.readUInt32LE(s + 12);
+    const raw = file.readUInt32LE(s + 20), rawSize = file.readUInt32LE(s + 16);
+    const rva = va - imageBase;
+    if (rva >= vaddr && rva < vaddr + vsize) return rva - vaddr < rawSize ? rva - vaddr + raw : -1;
+  }
+  return -1;
+}
+const tables = [
+  { name: "A", base: 0x94ddb0, stride: 0x78, end: 0x950a38 },
+  { name: "B", base: 0x950a38, stride: 0x94, end: 0x953344 },
+];
+const wanted = new Set(ids.map((t) => parseInt(t, 16)));
+for (const t of tables) {
+  for (let va = t.base; va < t.end; va += t.stride) {
+    const o = offset(va);
+    if (o < 0) { console.log(t.name, va.toString(16), "(no file data: filled at runtime)"); break; }
+    const id = file.readUInt16LE(o);
+    if (wanted.size && !wanted.has(id)) continue;
+    const words = [];
+    for (let k = 0; k < t.stride; k += 4) words.push(file.readUInt32LE(o + k).toString(16).padStart(8, "0"));
+    console.log(`${t.name} ${va.toString(16)} id ${id.toString(16)}: ${words.join(" ")}`);
+  }
+}

tools/ghidra/Rename.java

@@ -7,7 +7,8 @@
 //
 // names.txt: one "0xADDRESS Name" per line, "Class::Method" puts the function
 // into a class namespace; "#" starts a comment. Functions are created where
-// none starts at the address yet.
+// none starts at the address yet. Names starting with "g_" label data
+// (globals, tables) instead of functions.
 // @category sacred_re
 
 import java.nio.charset.StandardCharsets;
@@ -33,6 +34,7 @@ public class Rename extends GhidraScript {
         }
         SymbolTable symbols = currentProgram.getSymbolTable();
         int renamed = 0;
+        int labelled = 0;
         for (String raw : Files.readAllLines(Paths.get(args[0]), StandardCharsets.UTF_8)) {
             String line = raw.replaceAll("#.*", "").trim();
             if (line.isEmpty()) {
@@ -44,6 +46,11 @@ public class Rename extends GhidraScript {
                 continue;
             }
             Address address = toAddr(parts[0]);
+            if (parts[1].startsWith("g_")) {
+                createLabel(address, parts[1], true, SourceType.USER_DEFINED);
+                labelled++;
+                continue;
+            }
             Function function = getFunctionAt(address);
             if (function == null) {
                 new DisassembleCommand(address, null, true).applyTo(currentProgram, monitor);
@@ -69,6 +76,6 @@ public class Rename extends GhidraScript {
             function.setName(name, SourceType.USER_DEFINED);
             renamed++;
         }
-        println("renamed " + renamed + " functions");
+        println("renamed " + renamed + " functions, labelled " + labelled + " data addresses");
     }
 }

tools/names.txt

@@ -119,3 +119,25 @@
 0x006e31e0 cUI_Taskbar2::RenderArtSlots
 0x006e4310 cUI_Taskbar2::UpdateTooltips
 0x0081c020 Options::CombineSlots              # COMBINE_SLOTS: weapon set also selects the art slot
+# combat arts
+0x0052e400 cCreature::ReceiveOrder           # vf18; order 0x105 (use art) at 0x52fc58
+0x006170d0 cEngine::SendCreatureOrder
+0x005521e0 cCreature::ResolveArtId           # art variant for the creature class (+0x10)
+0x00580cb0 cArtCooldowns::IsReady            # (art): cooldown <= 0.01
+0x00548ef0 cCreature::IsAlive
+0x004d1930 CombatMoveDef::Find              # (id) -> g_combatMoveDefs entry
+0x004d2150 SpellDef::Find                   # (id) -> g_spellDefs entry
+0x004d1a20 CombatMoveDef::UsableMounted     # flags +0x74
+0x004d23e0 SpellDef::UsableMounted          # flags +0x90
+0x0094ddb0 g_combatMoveDefs                 # 95 x 0x78: id +0, icon name +0xc, target type +0x4c
+0x00950a38 g_spellDefs                      # 71 x 0x94: id +0, icon name +0xc, target type u16 +0x3c
+0x0095503c g_slotCountByLevel               # (level, slots) u16 pairs
+0x009ed058 g_taskbarSlotColors
+0x00ad23c8 g_inventoryManager
+0x00ad3bc0 g_objectManager
+0x0051d680 cCreature::IsValidArtTarget     # (pick, launch type): can the art be used on the picked object
+0x0051d670 NormalizeArtId
+0x00548f20 cCreature::IsAlly               # (object id)
+0x00548e70 cCreature::IsEnemy              # (object id)
+0x00611f10 cEngine::UpdateCursorPick         # cursor target for the selected art
+0x00548060 cCreature::ChooseAiArt          # monsters: art per creature class