XEngine3D

XEngine3D is a complete C-language game engine for Windows targeting real-time 3D applications and games. It wraps OpenGL 1.1 fixed-function pipeline rendering with a clean procedural API, and integrates DirectSound for audio, DirectInput for joystick/gamepad support, DirectShow for AVI video cutscenes, and the Windows MCI interface for CD audio and MIDI playback.

The engine is composed of independent header modules. Include only what you need. All engine subsystems are initialized individually and should be shut down in reverse order.

Setting up XEngine3D in Microsoft Visual C++ 6.0. Follow these steps to configure your project include paths, library paths, and linker settings before writing your first line of code.

Minimal application skeleton demonstrating engine initialization, the main loop, and shutdown.

#include "xengine.h"
#include "xsound.h"

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrev, LPSTR lpCmd, int nShow)
{
    /* 1. Initialize engine: creates window and OpenGL context */
    if (!xInit(hInst, 800, 600, "My Game"))
        return 1;

    /* 2. Initialize subsystems */
    xSoundInit(xGetWindow());
    x3DInit(xGetWidth(), xGetHeight());

    /* 3. Load assets ... */
    TCamera cam;
    x3DCreateCameraFPS(&cam, x3DVec3(0, 2, 5), 0.0f, 0.0f);

    /* 4. Main loop */
    while (xIsRunning())
    {
        xProcessEvents();
        xTimerUpdate();
        xKeyboardUpdate();
        xMouseUpdate();

        if (xKeyPressed(KEY_ESCAPE)) xQuit();

        xBeginFrame();
        xClear(BLACK);

        x3DBegin();            /* start 3D rendering */
        x3DSetCamera(&cam);
        /* ... draw 3D scene ... */
        x3DEnd();              /* return to 2D mode */

        xEndFrame();
    }

    /* 5. Shutdown */
    xSoundShutdown();
    xShutdown();
    return 0;
}

The engine core handles window creation, the OpenGL rendering context, the main-loop control, and fullscreen/resolution management. It includes xgfx.h, xtimer.h, xkeybrd.h, xmouse.h, xfont.h, xres.h, and x3d.h automatically.

Frame timing utilities. xTimerUpdate() must be called once per frame to refresh delta time and FPS calculations.

System date and time queries (from the OS clock):

Manages the list of supported screen resolutions and aspect ratios.

2D rendering API for primitives, bitmaps, and screen-space effects. All coordinates are in pixels matching the window size.

Two font types are supported: Windows TrueType fonts (rendered via OpenGL display lists) and Bitmap fonts loaded from a .met metrics file paired with a bitmap image.

The core 3D rendering module. Built on the OpenGL 1.1 fixed-function pipeline. Encompasses camera control, lighting, mesh rendering, terrain, skybox, animated MD2 models, billboards, fog, and more.

Up to 8 simultaneous OpenGL lights (GL_LIGHT0–GL_LIGHT7). Supports directional, point, and spot lights with per-light attenuation.

Static 3D meshes and primitive shapes. Meshes can be compiled into OpenGL display lists for optimal performance.

Generates a 3D terrain mesh from a grayscale heightmap image. Brighter pixels = higher terrain.

A six-sided textured cube rendered around the camera to simulate a distant environment.

Supports the Quake II MD2 model format, including per-vertex keyframe animation with smooth interpolation. The standard Quake II animation set is predefined.

Billboards are textured quads that automatically face the camera. Used for sprites, particles, trees, and HUD-in-3D elements.

A parallax-scrolling background rendered as a full-screen quad. Scroll offset is automatically derived from the camera's yaw/pitch angles.

Fake soft shadows projected onto the terrain plane using an oval mesh (blob). Efficient for characters and objects.

Polls the Windows keyboard state each frame. Provides both held-down and edge-detection (just pressed / just released) queries.

Key codes map to Windows virtual keys. Common constants:

Mouse position, delta movement, button state, scroll wheel, and cursor management including FPS-style capture mode.

DirectInput 8 joystick and gamepad support. Supports up to 4 simultaneous devices with full analog axes, POV (D-Pad), buttons, and force feedback.

DirectSound 8-based audio. Supports WAV sound effects (static buffers) and streaming WAV music. Up to 64 simultaneous sound buffers.

MCI-based CD audio playback and MIDI file playback. Automatically links winmm.lib.

DirectShow-based AVI/video playback for cutscenes. Video is displayed in a child window and can be shown fullscreen or positioned over the game window.

A custom binary archive format for bundling game assets. A package file contains a header (control number + file count), followed by a directory of file metadata, followed by the raw file data. The control number is 2903.

/* Example: loading all assets from a package */
  TPackage* pkg = xPackageOpen("data/game.pkg");
  xPackageSetDefault(pkg);

  TBitmap hero;
  xLoadBitmapFromPkgColorKey(pkg, &hero, "hero.bmp", 255, 0, 255);

  TSound jump;
  xLoadSoundFromPkg(pkg, &jump, "jump.wav");

  TMD2Model* enemy = (TMD2Model*)xLoadMD2FromPkg(pkg, "enemy.md2");