Rendering pipeline¶

This page summarizes the primary render paths in crimsonland.exe.

Render dispatcher (FUN_00406af0)¶

If render_pass_mode (DAT_00487240) == 0 and game_state_id (DAT_00487270) != 5, it draws terrain only via terrain_render (FUN_004188a0).
Otherwise it runs the full gameplay render pass gameplay_render_world (FUN_00405960).
After either branch it applies a fullscreen fade (DAT_00487264), runs ui_elements_update_and_render, calls perk_prompt_update_and_render (FUN_00403550) (perk prompt), and renders the UI cursor.

Gameplay render pass (gameplay_render_world / FUN_00405960)¶

Order of major passes:

1) fx_queue_render (FUN_00427920) 2) terrain_render (FUN_004188a0) (terrain/backbuffer blit) 3) player_render_overlays (FUN_00428390) for players with player_health (DAT_004908d4) <= 0

4) creature_render_all (FUN_00419680) 5) player_render_overlays for players with player_health (DAT_004908d4) > 0 6) projectile_render (FUN_00422c70) 7) bonus_render (FUN_004295f0) 8) grim_draw_fullscreen_color fade when DAT_00487264 > 0

Notes:

DAT_004aaf0c is used as the player index during the two overlay passes.
ui_transition_alpha (DAT_00487278) is the frame alpha used by multiple render paths.

HUD render (ui_render_hud / FUN_0041aed0)¶

The in-game HUD render is gated by demo_mode_active (DAT_0048700d) and is called from the main UI pass (hud_update_and_render). It binds ui_wicons and uses grim_set_sub_rect for weapon icons, along with health/score overlays.

Terrain generation (terrain_generate / FUN_00417b80)¶

terrain_generate renders the terrain texture into a render target and selects its base texture index from a per-level descriptor.

For the full pipeline (init, procedural stamping, FX decal baking, and final screen draw), see Terrain pipeline.

Runtime evidence (2026-01-20)¶

terrain_trace.jsonl confirms the render path uses config-sized UVs over a 1024×1024 terrain texture:

u0 = -camera_offset_x / terrain_texture_width
v0 = -camera_offset_y / terrain_texture_height
u1 = u0 + (config_screen_width / terrain_texture_width)
v1 = v0 + (config_screen_height / terrain_texture_height)

Example capture (800×600 config, 1024×1024 terrain): u0=0.21875, u1=1.0, v0≈0.2228192, v1≈0.8087567 (deltas match 800/1024 and 600/1024). This matches the decompile and shows camera clamping to the terrain edges.

The same trace confirms quest terrain indices: base/overlay/detail = (0,1,0), (2,3,2), (4,5,4), (6,7,6) for tiers 1–4, matching the quest metadata and terrain_ids_for logic.

UI overlays¶

player_render_overlays draws per-player indicators (aim reticles, shields, weapon indicators). It is gated by game_state_id (DAT_00487270) values (not drawn in modal states like 0x14/0x16) and ui_transition_alpha (DAT_00487278) (transition alpha).