sacred_k/docs/hud.md

HUD layout in widened views (src/mods/hud.cpp)

The UI is laid out for 1024x768. In a widened render target (e.g. 1835x768) the windows are moved as a whole, without touching their own coordinates: the bottom bar and all dialogs are centred, the party panel (portrait, health) sits at the right edge. Main menu and loading screen keep the classic 1024x768 frame (see widescreen.md).

How a window is moved

A window's render and event methods are hooked (HUD_RENDER, HUD_RENDER3, HUD_EVENT). While one of them runs on a thread, everything the window sees or draws is translated by its offset dx (outermost window wins, children and shared base methods are inside the scope):

What	Where	Translation
screen-space vertices (XYZRHW)	IDirect3DDevice7::DrawPrimitive / DrawIndexedPrimitive (vtable 25 / 26)	x + dx
3D items (belt, equipment)	ortho projection centred on the screen	none needed
mouse events	cEvent_mouseMove x at +4 (previous) and +0xc; button down / up x at +8	x - dx, restored afterwards
mouse cursor object (*0xcdbadc)	x at +4, previous x at +0xc (polled for hover, item pick-up 0x6559a0)	x - dx, restored unless the window thread stored a new position
GetMouseClientPos (0x66e500)	polled position	x - dx

Calls outside a window's scope

• Tooltips (cUI_Tooltip::vf14 0x6e7300) are separate windows that the hovered window positions in its own layout: they draw with the offset of the moved window under the cursor (noted while windows render, expires after 150 ms).
• Hit tests (vf1c: 0x731d40, taskbar 0x6dfb10) are also called by the UI manager with plain render coordinates, e.g. "is UI under the cursor" for world picking (0x75a370). They use the offset the top-level window (parent chain at +0x50) was last drawn with.
• The item carried by the cursor (0x6555e0, drawn by the render loop) and the manager's status line / message box (0x75bbf0, 0x75c200, laid out around x = 512) draw with the centre offset.

UI events

vf04 of an event is its category: 1 mouse move, 2 button down, 3 button up, 4 key (code at +8), 5 UI command (cEventUI2: id at +4, vf08 subtype). Only mouse events carry positions; category 5 events with subtype 0x10 test a point at +0x48 in cUI_Window2::vf10, but commands such as "open ESC menu" (0x11) keep unrelated data there.