Main menu (state 0)¶

This page documents the classic Crimsonland.exe main menu (game state 0) from decompiled code (Ghidra + Binary Ninja cross-checks). The goal is a faithful reimplementation: same layout math, timings, and render passes.

Frame pipeline (state 0)¶

In the main frame renderer, state 0 follows the "menu/world" render path:

1. Terrain background render.
2. Optional fullscreen fade overlay (screen_fade_alpha).
3. UI element timeline update + draw (ui_elements_update_and_render).
4. Perk prompt (usually inactive in menu).
5. Cursor draw.

Terrain regeneration notes¶

The main menu does not regenerate terrain when you navigate between menu screens (Options/Statistics/etc). State 0 just renders whatever terrain texture is already active.

Terrain generation is triggered elsewhere:

• Startup: game_startup_init_prelude calls terrain_generate_random().

• Demo → Menu: ui_elements_update_and_render calls terrain_generate_random() when demo_mode_active != 0 and game_state_pending == 0, right before game_state_set(0).

• Debug: console_hotkey_update checks config var 0x57 and calls terrain_generate_random() (or terrain_generate(desc) in quest mode), then clears the config var.

Menu terrain selection (terrain_generate_random)¶

When menu terrain is regenerated, terrain_generate_random() chooses a descriptor based on progression (quest_unlock_index) and random checks:

• default descriptor: terrain ids (0, 1, 0) (q1 base/overlay/base)
• if quest_unlock_index >= 0x28 (40) and (crt_rand() & 7) == 3: terrain ids (6, 7, 6) (q4)
• else if quest_unlock_index >= 0x1e (30) and (crt_rand() & 7) == 3: terrain ids (4, 5, 4) (q3)
• else if quest_unlock_index >= 0x14 (20) and (crt_rand() & 7) == 3: terrain ids (2, 3, 2) (q2)
• else keep default (0, 1, 0)

Important parity detail: these are sequential if/else if checks with separate crt_rand() calls, so higher unlock levels still allow lower-tier outcomes.

Shareware/demo behavior note: the frame loop clamps quest_unlock_index to 10 (if !game_is_full_version() && quest_unlock_index > 10) after processing menu frame input. In practice this prevents q2/q3/q4 menu terrain variants in the demo build.

Keyboard navigation (state 0)¶

Main-menu focus navigation is Tab-based (not arrow keys):

• Tab cycles focus forward; Shift+Tab cycles focus backward (ui_focus_update @ 0x0043d830).
• Enter activates the focused element (ui_element_render @ 0x00446c40), but only once the element is enabled (fully visible).

UI element table and ordering¶

UI elements live in a fixed pointer table:

• Range: 0x0048f168 .. 0x0048f20b (0xA4 bytes)
• Count: 41 pointers

ui_elements_update_and_render iterates backwards:

• starts at ui_element_table_start
• decrements down to ui_element_table_end

So earlier pointers in the table draw last (on top).

Assets and template rects (ui_menu_assets_init @ 0x00419dd0)¶

Menu UI templates are loaded once and then copied into per-screen elements.

ui_signCrimson.jaz (logo sign)¶

ui_element_set_rect(width, height, offsetX, offsetY):

• width = 573.44
• height = 143.36
• offset = (-577.44, -62.0)

The quad lives mostly in negative X, so placing the element at pos_x = screen_width + 4 anchors it to the right.

Animation note:

• The logo sign is UI element table index 0 (sub_446150 returns 0), so ui_element_update forces its rotation angle negative (clockwise) during timeline transitions.

• It uses the same default start_time_ms=300 / end_time_ms=0 window as other UI elements, but it is locked to a steady 0° pose during normal menu navigation.

• When ui_elements_timeline overshoots ui_elements_max_timeline() and is clamped, ui_elements_update_and_render writes 1 to ui_sign_crimson_update_disabled (absolute 0x00487292). When this byte is 1, ui_element_update early-returns and the sign does not pivot during transitions to Play Game / Options / etc.

• The quit callback (ui_menu_main_click_quit @ 0x00447450) clears 0x00487292 back to 0, allowing the sign to pivot out during the last 300ms of the close.

• When fx_detail is enabled (config_blob.reserved0[0xe] != 0), ui_element_render also draws a shadow pass with +7,+7 offset and tint 0x44444444 using the same transform (rotation matrix).

Runtime verification (Frida):

• Script: scripts/frida/menu_logo_pivot_trace.js
• Output: C:\share\frida\menu_logo_pivot_trace.jsonl (raw logs are gitignored; see analysis/frida/menu_logo_pivot_trace_summary.json for this run)
• Logs logo_update / logo_render while ui_elements_timeline <= 350 (or when the logo angle is non-zero).
• Observed:
• Play / Options: logo_update.update_disabled == 1 and angle_deg == 0 for the whole close (no pivot).
• Quit: logo_update.update_disabled == 0 and angle_deg ramps from 0 to -90 as timeline goes 299 -> 0.

ui_menuItem.jaz (menu item button)¶

• width = 512.0
• height = 64.0
• offset = (-72.0, -60.0)
• Template global: ui_menu_item_element (0x0048fba8) with mode/texture fields ui_menu_item_element_mode (0x0048fc8c) and ui_menu_item_element_texture_handle (0x0048fc88).

The pivot is intentionally offset so the element can rotate in from the left.

ui_menuPanel.jaz (panel)¶

This is not used in state 0 (but used by other menus/screens):

• width = 512.0
• height = 256.0
• offset = (20.0, -82.0)
• Template global: ui_menu_panel_template (0x0048fc90) with mode/texture fields ui_menu_panel_template_mode (0x0048fd74) and ui_menu_panel_template_texture_handle (0x0048fd70).

Panel screen animation (Play Game / Options)¶

Panel-based screens (e.g. Play Game, Options) use the panel template plus a single BACK menu item, but they do not rotate in like the main-menu items.

In ui_menu_layout_init these elements have render_mode = 1 (element+0x4 == 1, offset mode), so ui_element_render draws them using pos + offset_xy instead of the rotation matrix. ui_element_update animates the X offset from +/-abs(width) to 0 over the default [end_time_ms .. start_time_ms] = [0 .. 300] ms window.

Known positions (before widescreen shift):

• Play Game (state 1, screen update play_game_menu_update):
• panel: (-45, 210)
• back: (-55, 462)
• Options (state 2, screen update options_menu_update):
• panel: (-45, 210)
• back: (-55, 430)

Label overlay rect (inside ui_menuItem)¶

Each menu item has an overlay quad (later given UVs into ui_itemTexts):

• width = 124.0
• height = 30.0
• offset = (270.0, -38.0)

Main menu composition (state 0)¶

game_state_set(0) activates:

• the logo sign
• menu item buttons (some conditional)
• no panel

The relevant table indices are:

Notes:

• mods_any_available() gates the MODS button in full version builds.
• A string config entry grim_get_config_var(100) controls whether the OTHER GAMES slot is present, and swaps table indices 6 and 7.
• main_menu_full_version_layout_latch (0x00486faa) prevents reapplying the full-version position/UV adjustments after they have run once.

Base positions and timings (ui_menu_layout_init @ 0x0044fcb0)¶

Logo position¶

• pos_x = screen_width + 4
• pos_y = 70 (or 60 when screen_width < 641)

Menu item positions (before adjustments)¶

All menu items start at pos_x = -60 and:

• slot 0: y = 210
• slot 1: y = 270
• slot 2: y = 330
• slot 3: y = 390
• slot 4: y = 450
• slot 5: y = 510 (only when OTHER GAMES is present; otherwise QUIT is at 450)

Stagger timing + diagonal X shift (table idx 1..7)¶

All elements default to:

• start_time_ms = 300
• end_time_ms = 0

Then the layout loop adds +100, +200, ... +700 ms to both start_time_ms and end_time_ms (for table indices 1..7). This keeps the interval length at 300ms while staggering each item by 100ms.

In the same loop, it applies a diagonal X offset to later entries:

Resolution-dependent adjustments¶

Widescreen vertical shift (applied after layout)¶

After layout, all UI elements except the logo (table idx 0) receive:

pos_y += (screen_width / 640.0) * 150.0 - 150.0

Examples:

• 640 → +0
• 800 → +37.5
• 1024 → +90
• 1280 → +150

Logo scaling (small and 800–1024 widths)¶

The logo quad is scaled in-place:

• when screen_width < 641: multiply vertex coords by 0.8 and add +10 to several X coordinates.

• when 801 <= screen_width <= 1024: multiply by 1.2 and also add +10 to X.

Small-width menu pack (screen_width < 641)¶

For table indices 1..7 the code:

• scales the main + overlay quads by 0.9
• applies a per-element local Y shift to compress the vertical spacing

The per-element shift is f = [-11, 0, 11, 22, 33, 44, 55] (for indices 1..7) and each quad's local Y is adjusted by y -= f.

For menu slots (table idx 2..7) this corresponds to local Y shifts:

• slot 0: 0
• slot 1: 11
• slot 2: 22
• slot 3: 33
• slot 4: 44
• slot 5: 55

Label atlas (ui_itemTexts.jaz)¶

The menu labels are an 8-row atlas (row height = 1/8 = 0.125 in UV space):

When entering state 0, the game assigns overlay UVs for table indices 2..7. Important behavior:

• In full version, the top slot (idx 2) forces row 4 (MODS), then the row sequence resets back to 0 for the next items.

• The normal row sequence skips 4 (so 3 -> 5).

• If config var 100 is empty, table idx 6 is forced to row 6 (QUIT). The remaining row 7 is assigned to an element that is inactive in state 0 and therefore not visible.

Animation (ui_element_update @ 0x00446900)¶

Menu items use render_mode == 0 (element+0x4 == 0, "transform") and animate via rotation:

Note: element+0x2 is an update-disable flag; when non-zero ui_element_update returns immediately (used to lock the logo sign during menu navigation).

• Fully hidden: angle = ±pi/2
• Fully visible: angle = 0
• During transition: linearly lerp angle from pi/2 to 0 over [end_time_ms, start_time_ms]

Rotation matrix:

m00 = cos(angle)
m01 = -sin(angle)
m10 = sin(angle)
m11 = cos(angle)

slide_x is computed for all elements, but is only used when render_mode == 1 (element+0x4 == 1, "offset"). For main menu items (render_mode == 0) it is ignored by the render path.

Hit testing bounds (FUN_0044fb50 @ 0x0044fb50)¶

Bounds are derived from quad0 v0/v2 and pos_x/pos_y:

• w = v2.x - v0.x
• h = v2.y - v0.y

Then:

• left = pos_x + v0.x + w*0.54
• top = pos_y + v0.y + h*0.28
• right = pos_x + v2.x - w*0.05
• bottom = pos_y + v2.y - h*0.10

Per-element render passes (ui_element_render @ 0x00446c40)¶

The element renderer draws, in order:

1. Optional shadow pass (when fx_detail_0 != 0):
2. draw at (pos_x + 7, pos_y + 7) with tint 0x44444444
3. Main quad(s)
4. Overlay label quad
5. "Glow" overlay re-draw in additive blend (clickable + enabled elements):
6. always draws the overlay a second time with a different render state / blend mode
7. if counter_timer is in 0..0xFF, it overrides the glow alpha:
   • alpha_glow = 0xFF - counter_timer/2

Note: counter_timer is initialized to 0x100 in ui_element_init_defaults and (as far as we can tell) only increments in ui_element_update, so this short alpha override may never trigger for main-menu items unless something else resets the timer.

Overlay alpha for clickable elements:

alpha = 100 + floor(hover_amount * 155 / 1000)

Hover amount is updated per frame:

• hovered: += dt_ms * 6
• not hovered: -= dt_ms * 2
• clamp to [0, 1000]