blazingkin/dtdengine

The disease tower defense engine stripped down and open sourced

DTD Engine

Features

Entity Component System

Rather than using a traditional oriented system, this engine uses a more efficient Entity Component System. The implementation of the ECS system is custom to this engine.

Resource loading

Resources are loaded on startup from the resource directory. Currently the following resources are loaded

• .obj files (and associated .mtl files) are loaded from resources/models (and all subdirectories if you wish to organize your models)
• .png and .jpg files are loaded from resources/textures
• .glsl shader files are loaded from resources/shaders/vertex and resources/shaders/fragment
• Skyboxes are loaded from resources/skyboxes
• global_config.json is loaded from resources/config

Processed models are put into a globally accessible meshes map where the key is the file name (e.g. cube.obj or houses/house1.obj). Models are automatically resized to be between [-1, +1] in all dimensions, and are recentered to the origin.

Similarily, processed textures are put into a globally accessible textures map.

Audio playback is handled by Audio.cpp

Shaders are compiled by calling Program::init with the list of shader file names.

View Frustrum Culling

VFC is a supported optimization out of the box.

Shadow Maps

Shadow mapping code is included in the project in src/Systems/SystemShadow.cpp. The depth map generated in that file is then used by src/Systems/SystemRender.cpp to pass depth information along to shaders.

Immediate mode GUI

ImGui is included in this project to allow for the creation of GUIs.

2D and 3D Audio

irrKlang is included in this project, along with a wrapper in src/Audio.cpp to call the library.

Axis Aligned Bounding Box Colliders

An axis aligned bounding box collision system exists to allow for some basic physics reactions. These bounding boxes can be automatically created from an entities model. Using the resize, move, and setRotationTo methods in src/EntityHelper.cpp updates the bounding boxes in an efficient manner.

Instance Rendering

Optionally, entities can be configured to be instanced rendered. This passes the Model matrix of the object as an attribute in the shader. Additional vec4 attributes can also be passed to an instance rendered object's shader.

Scene System

Entities are contained within a scene. Scenes also contain information about the update function, and key handlers. This allows for easy and efficient swapping between different scenes that have entirely different behavior.

Normal Mapping

The engine allows for a normal / bump map to be configured as part of the renderable component. It will pass along vertex normal / binormal / tangents that were calculated when the model was imported.

Building The Project

1. Clone the repository
2. Create your build directory mkdir build
3. Navigate to your build directory
4. See the steps below about getting irrKlang installed
5. Run cmake .. to generate your makefile and make to build
6. Start the executable with ./blz-3d-engine

Libraries Included

The following libraries are included with the listed licenses from their parent projects

Glad

glad is used to provide an OpenGL context. It is included as licensed under the MIT license.

Dear ImGui

Dear ImGui is used to create simple user interfaces. It is included as licensed under the MIT license.

irrKlang

[irrKlang] is used to play back 2D and 3D audio.

It is not open source :(

The license for the software can be found here

For this reason, it is not included in this repository. You will have to download irrKlang yourself in order to build and run this engine.

Steps for doing so:

Linux

1. Download the irrKlang 1.6 SDK from this page
2. Unzip the download
3. Create an irrKlang folder in the ext folder of this repository
4. Copy the lib, include, and bin folders from your irrKlang zip into the ext/irrKlang folder
5. Copy ext/irrKlang/bin/ikpMP3.so to your build directory
6. Rename ext/irrKlang/bin/ikpMP3.so to ext/irrKlang/bin/libikpMP3.so
7. Build and run

MacOS

Steps are similar

Windows

We got it working, but I'm not sure how. I think the 32 bit version of irrKlang was required

rapidjson

Rapid JSON is used to load in JSON resources at engine startup. It is included as licensed under the BSD license.

stb_image

stb_image is used to load in all image asset files. It is included as a public domain resource.

tiny obj loader

tinyobjloader is used to load in OBJ model files. It is included as licensed under the MIT license.

Contributors

This project includes code by

• Shinjiro Sueda
• Zoe Wood
• Ian Dunn

Most of the work on this engine was done by

• Alex Gravenor
• John Potz
• Evan Zhang
• David Heyer

dtdengine's Issues

Create FBO Pipeline system

There's a nice architecture presented here
https://www.youtube.com/watch?v=uZlwbWqQKpc

Document irrKlang process on Windows

Document irrKlang process on MacOS

Create network stack

This issue just concerns the initial creation of a network stack - this is the architecture stack that I'm envisioning

• application layer - to figure out what to sync
• prioritization layer (this layer should be able to adapt to changing network conditions)
• low level thread that handles IO from a queue