TAB map content centred again; key bindings no longer pass on Ctrl/Alt

- megamap: the zoomed view (0x6cc950) is shared by the large map and the
  TAB overview map; its centre is now set per call from the drawing
  window's offset (hud::DrawOffsetX) instead of fixed to the render width
- input: drop the Ctrl/Alt pass-through; GetKeyState reports Alt as held
  after Alt+Tab, which switched all bindings back to the game's handling

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

src/mods/hud.cpp

@@ -431,6 +431,10 @@ int CursorOffsetX() {
     return g_cursorDx;
 }
 
+int DrawOffsetX() {
+    return g_offsetX;
+}
+
 void* CursorFor(void* cursor) {
     return g_cursorDx != 0 && cursor == g_cursorShadow.real ? g_cursorShadow.bytes : cursor;
 }

src/mods/hud.h

@@ -9,6 +9,10 @@ void OnDevice(void* device);
 // the current thread (0 outside): polled mouse positions are reduced by it.
 int CursorOffsetX();
 
+// Horizontal offset the current thread's UI drawing is shifted by (the
+// outermost hooked window's; 0 outside).
+int DrawOffsetX();
+
 // The mouse cursor object as the current thread should see it: inside a moved
 // window, a private copy with x shifted by CursorOffsetX().
 void* CursorFor(void* cursor);

src/mods/input.cpp

@@ -10,8 +10,10 @@
 // hotkey post that hotkey's key event to the game's event kernel, the way the window
 // procedure does (the kernel dispatches it right away, on the window thread).
 //
-// While a text field has the keyboard, or Ctrl / Alt is held, keys pass
+// While a text field has the keyboard, keys pass through unchanged. (Keys
-// through unchanged.
+// with Ctrl / Alt held used to pass too; GetKeyState reports Alt as held after
+// Alt+Tab until it is pressed again in the game, which switched the bindings
+// off. Alt+key arrives as WM_SYSKEYDOWN and is not handled here anyway.)
 //
 // sacred_re.ini (key names: A-Z, 0-9, F1-F24, Space, None):
 //   [keys]
@@ -173,10 +175,6 @@ void Release(const Binding& binding, int vk) {
     }
 }
 
-bool ModifierHeld() {
-    return (GetKeyState(VK_CONTROL) & 0x8000) != 0 || (GetKeyState(VK_MENU) & 0x8000) != 0;
-}
-
 // Virtual keys whose WM_KEYDOWN was taken: their WM_CHAR / WM_KEYUP are
 // swallowed too, even if the state changed in between.
 bool g_taken[256] = {};
@@ -212,7 +210,7 @@ bool HandleWindowMessage(HWND, UINT message, WPARAM wParam, LPARAM lParam) {
         const bool repeat = (lParam & (1 << 30)) != 0;
         if (!repeat) {
             g_taken[vk] = false;
-            if (ModifierHeld() || TypingIntoTextField()) {
+            if (TypingIntoTextField()) {
                 return false;
             }
             const Binding* binding = BindingFor(vk);

src/mods/megamap.cpp

@@ -10,11 +10,13 @@
 // the zoom buttons at the bottom stay centred. The window is drawn and clicked
 // unshifted (mods/hud.cpp, Anchor::Screen). See docs/hud.md.
 
+#include <algorithm>
 #include <cstdint>
 #include <cstring>
 #include <unordered_map>
 
 #include "game/addresses.h"
+#include "mods/hud.h"
 #include "mods/megamap.h"
 #include "mods/widescreen.h"
 #include "re/hook.h"
@@ -37,12 +39,16 @@ constexpr uint32_t kScrollLimit = 0x006c9edd;
 // The view centre 200h: the zoom-in frame (0x6ca53f) and the image centred
 // on it (0x6ca637, 0x6ca645).
 constexpr uint32_t kCentreImmediates[] = {0x006ca53f, 0x006ca637, 0x006ca645};
-// fsub/fld/fadd [512.0]: centring the scroll on the hero (opening the map
+// fsub [512.0]: centring the scroll on the hero (opening the map 0x6c7bfe,
-// 0x6c7bfe, 0x6cb27a), the zoomed view (0x6ccb7f) and its quest markers
+// 0x6cb27a).
-// (0x6cf782).
+constexpr uint32_t kCentreFloatUses[] = {0x006c7bfe, 0x006cb27a};
-constexpr uint32_t kCentreFloatUses[] = {0x006c7bfe, 0x006cb27a, 0x006ccb7f, 0x006cf782};
+// The zoomed view (0x6cc950, cdecl) is drawn by the large map and by the TAB
-// fld [768.0] as an x: markers in the zoomed view at 768 - d (0x6ce156), the
+// overview map (cUI_OverviewMap 0x6c69d0, a centred window: shifted by the
-// centre plus 256.
+// HUD layer). Its centre: fld [512.0] (0x6ccb7f), quest markers fadd [512.0]
+// (0x6cf782), other markers fld [768.0] as an x, 768 - d = centre + 256
+// (0x6ce156). It is set on every call from the window's draw offset.
+constexpr uint32_t kZoomView = 0x006cc950;
+constexpr uint32_t kZoomCentreUses[] = {0x006ccb7f, 0x006cf782};
 constexpr uint32_t kZoomMarkerX = 0x006ce156;
 constexpr float kZoomMarkerFromCentre = 256.0f;
 // The dark band around the view (10 vertices, mov [esp+..], imm32): its right
@@ -52,6 +58,7 @@ constexpr uint32_t kBandRightInner[] = {0x006ca7bc, 0x006ca84c};
 constexpr int kBandWidth = 70;
 
 float g_halfWidth = 512.0f;
+float g_zoomCentre = 512.0f;
 float g_zoomMarkerX = 768.0f;
 
 uint32_t FloatBits(float value) {
@@ -172,7 +179,9 @@ void PatchLayout(int width) {
     for (uint32_t instruction : kCentreFloatUses) {
         failed += !re::RedirectOperand(instruction, game::addr::kScreenHalfWidthF, &g_halfWidth);
     }
-    g_zoomMarkerX = g_halfWidth + kZoomMarkerFromCentre;
+    for (uint32_t instruction : kZoomCentreUses) {
+        failed += !re::RedirectOperand(instruction, game::addr::kScreenHalfWidthF, &g_zoomCentre);
+    }
     failed += !re::RedirectOperand(kZoomMarkerX, game::addr::kScreenHeightF, &g_zoomMarkerX);
     failed += re::PatchAll(kBandRightOuter, FloatBits(1024.0f), FloatBits(static_cast<float>(width)));
     failed += re::PatchAll(kBandRightInner, FloatBits(1024.0f - kBandWidth),
@@ -180,10 +189,31 @@ void PatchLayout(int width) {
     re::Log("megamap: view width %d%s", width, failed ? " (some patches FAILED)" : "");
 }
 
+// Before each zoomed view: its centre in the coordinates of the window that
+// draws it (the large map is unshifted: width / 2; a centred window, which
+// the HUD layer shifts: 512).
+void __cdecl SetZoomCentre() {
+    const int width = std::max(mods::widescreen::RenderWidth(), kLayoutWidth);
+    g_zoomCentre = width / 2.0f - static_cast<float>(mods::hud::DrawOffsetX());
+    g_zoomMarkerX = g_zoomCentre + kZoomMarkerFromCentre;
+}
+
 } // namespace mods::megamap
 
 namespace game {
 
+// The zoomed view (0x6cc950, cdecl): sets its centre, then runs it unchanged.
+void ZoomView();
+RE_HOOK(mods::megamap::kZoomView, ZoomView);
+__declspec(naked) void ZoomView() {
+    __asm {
+        pushad
+        call mods::megamap::SetZoomCentre
+        popad
+        jmp dword ptr [ZoomView_original]
+    }
+}
+
 // cUI_Megamap::Show (vf24 0x6c7930, the argument: show / hide).
 void __fastcall UiMegamap_Show(void* self, void* edx, int show);
 RE_HOOK(0x006c7930, UiMegamap_Show);