OASIS Learn/Case Studies/OQuake
Advanced ⏱ 60 min WEB4 WEB5 C/C++ Vulkan

⚡ Case Study: OQuake

OQuake is a fork of vkQuake — the Vulkan-based Quake source port — extended with full OASIS WEB4 and WEB5 integration via the same OGLib + OGEngine Client stack used by ODOOM. It shares the Key Hunters Trilogy cross-game quest chain and inventory system with ODOOM and Our World. The Blue Key found in Quake's e1m1 is the same item that appears in ODOOM and Our World.

Tech stack

  • Base engine: vkQuake (C, Vulkan) extended with OGEngine OASIS layer
  • OGLib: shared C helper library — same config, beamin, session, and cross-game layer as ODOOM (oglib.h)
  • OASIS integration: OGEngine Client C ABI — identical interface to ODOOM, different game
  • OASIS WEB4: Avatar auth, Karma, cross-game Inventory, HyperDrive save
  • OASIS WEB5: Missions, Quests (Key Hunters chain), Inventory Items (Blue Key), CelestialBody (Nexara Prime)
  • Shared with: ODOOM (quest chain), Our World (inventory)
  • Renderer: Vulkan 1.1+ — fully Vulkan-native, no OpenGL fallback

OQuake vs ODOOM — What's Different?

ODOOMOQuake
Base engineUZDoom (C)vkQuake (C, Vulkan)
RendererSoftware / OpenGLVulkan 1.1+
OGLib✅ same oglib.h✅ same oglib.h
OGEngine Client✅ same DLL✅ same DLL
star_api.h✅ same header✅ same header
Quest chainMission 1 (Crimson Key)Mission 2 (Blue Key)
Inventory itemCrimson KeyBlue Key
Karma eventsDoom monstersQuake monsters
CelestialBodyDoom PlanetNexara Prime

Both games use the identical star_api.h interface and the shared oglib.h helper layer. OGLib eliminates the boilerplate duplication that previously existed between them — config loading, session forwarders, beamin workflow, and cross-game mapping are defined once in OGLib and included by both integration files. Only the engine-specific hooks (monster types, level triggers, HUD rendering) differ per game.

Step 1 — OGEngine Init (Vulkan-aware)

c
// oquake_star_integration.c — OGLib handles all session/config boilerplate
#define OGLIB_SESSION_IMPL
#define OGLIB_CONFIG_IMPL
#define OGLIB_BEAMIN_IMPL
#include "oglib.h"   // config, beamin, session forwarders, cross-game, JSON/str utils
#include "star_api.h"

void Host_Init(void)
{
    VID_Init();       // Vulkan renderer init
    S_Init();         // Audio init

    // OGLib loads oasisstar.json and restores saved session — same as ODOOM
    oglib_config_load(&g_star_config, "oasisstar.json", NULL, NULL);
    star_api_init(g_star_config.star_api_url);
    oglib_beamin_restore_session(&g_star_config);

    // Register Nexara Prime as the CelestialBody for OQuake's world
    star_api_register_celestial_body("Nexara Prime", "Planet");
}

Step 2 — The Blue Key

The Blue Key in Quake's e1m1 is the second item in the Key Hunters Trilogy cross-game quest chain.

c
// sv_phys.c — when player touches the blue key entity
void SV_TouchTrigger(edict_t *ent, edict_t *other)
{
    if (strcmp(ent->classname, "item_key2") == 0)
    {
        // Add Blue Key to cross-game inventory
        star_api_add_inventory_item("blue_key",
                                    "Blue Key",
                                    "Key discovered in Quake e1m1 — completes the second part of the Trilogy.");

        // Complete quest objective 1 of the Key Hunters Trilogy
        star_api_complete_quest_objective(KEY_HUNTERS_QUEST_ID, 1, avatar_id);

        // Award karma for the find
        star_api_award_karma(150, "BlueKeyFound");
    }
}

Step 3 — Karma for Quake Monsters

c
// sv_main.c — entity dies
void ED_EntityDied(edict_t *ent)
{
    static const struct {
        const char *classname;
        int         karma;
    } monster_karma[] = {
        { "monster_zombie",    3  },
        { "monster_dog",       5  },
        { "monster_knight",    15 },
        { "monster_shambler",  75 },
        { "monster_chthon",   500 },  // end boss
    };

    for (int i = 0; i < ARRAY_SIZE(monster_karma); i++) {
        if (!strcmp(ent->classname, monster_karma[i].classname)) {
            star_api_award_karma(monster_karma[i].karma, "Kill");
            break;
        }
    }
}

Step 4 — Cross-Game Door (Crimson Key from ODOOM)

A secret room in OQuake's e2m1 only opens if the player already holds the Crimson Key found in ODOOM.

c
// func_door trigger — checks cross-game inventory
void door_blocked(edict_t *self, edict_t *other)
{
    if (strcmp(self->targetname, "doom_crimson_gate") == 0)
    {
        if (star_api_has_item("crimson_key"))
        {
            door_go_up(self);   // open the secret passage
            star_api_award_karma(200, "SecretUnlocked_DoomCross");
        }
        else
        {
            SV_ClientPrint(other, "This door only opens for those who conquered Doom...\n");
        }
    }
}
💡
Source code

OQuake game code: vkQuake fork ↗ · OASIS OQuake integration: OASIS Omniverse/OQuake ↗ · OGLib: OASIS Omniverse/OGLib ↗ · OGEngine Client: OGEngine Client ↗

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