cappah78 / sdlgame

Simple high performance work in progress Minecraft like Voxel Renderer with lua scripting.

Runs immediately on a fresh installation of windows using VS2013 without any other installations. Requires a shader model 4.0 GPU (gl3.3) and Visual C++ Redistributable 2012.

Press F1 to print controls in console

Random screenshot of last finished features: https://dl.dropboxusercontent.com/u/18555381/Permanent/moarrenderdistances.png https://dl.dropboxusercontent.com/u/18555381/Permanent/blocktypes.png https://dl.dropboxusercontent.com/u/18555381/Permanent/viewdistance.png https://dl.dropboxusercontent.com/u/18555381/Permanent/libnoise.png https://dl.dropboxusercontent.com/u/18555381/Permanent/fogandfrustumculling.png https://dl.dropboxusercontent.com/u/18555381/Permanent/GravelBlockScripting.png https://dl.dropboxusercontent.com/u/18555381/Permanent/aowithtextures.png

To run the game as a standalone, copy the sdl2-3d/Assets folder to the Release (or Debug) folder.

Design

The engine will be using a data oriented design, meaning a lot of focus is around making the data easily iterateable with as few cache misses as possible.

All game objects will be Data Driven, e.g. fully created and configurable through scripts and other files without recompiling the engine.

The renderer will be fully opengl based and should be easy to swap out for another render implementation.

Layout

The game loop primarily takes place in GameScreen.cpp, which initializes and renders the VoxelWorld, camera and other things like the skybox. The GameScreen holds a WorldRenderer which can render VoxelWorlds, this makes it easy to swap out renderers without needing to integrate render logic in the VoxelWorld.

VoxelWorld manages block types and properties of every type, contains all the Lua high level lua bindings like World.setBlock(id, x, y, z), and holds a ChunkManager which loads/unloads chunks and allows easy retrieval of specific chunks.

Performance and Rendering

Chunks are 16x16x16 blocks to have a good balance between render calls, time to rebuild a chunk's vertices, and culling.

Chunks hold a list of BlockID's(ushort) and Colors (rgba8888 = 32bits), and an expandable list of bytes which is able to efficiently contain any per-block data needed for logic. Block logic will be done through Lua Scripts, the data will only be stored on the c++ side per chunk in the data list, being efficiently packed in memory so all block scripts can done in one pass while reading the block specific properties once and pushing them to lua.

WorldRenderer handles the high level rendering, iterating chunks, blocks, faces and vertices to calculate Ambient Occlusion and smooth lighting. It uses an instance of the lower level renderer VoxelRenderer which is able to add faces to a container VoxelRenderer::Chunk which holds the render data (VAO and Buffers) of a single chunk. All chunks are sharing a single array of colors, indices and vertex positions to build the chunk with faces before pushing the data to the GPU.

The renderer uses a minimal amount of memory, every vertex only using having 2 integers. The shader (voxelshader.vert/frag), uses

layout(location = 0) in uint in_point;

to contain the block's x/y/z in the first 15 bits of the integer, and 10 bits for the Texture ID which is used to sample the texture from a 3d Texture (OpenGL Texture Array), ID's are managed by a TextureManager to make it easy to retrieve texturesID's cpu side. Vertices are translated by the x/y/z (unpacked from the integer), multiplied by the mvp matrix which is already offset by the Chunk offset cpu side.

Color uses an rgba8888(32 bit integer, Color8888.cpp) buffer, which gets normalized to float for the shader. The alpha component will indicate the light level and ambient occlusion tint, while rgb can be used to tint the block with a color.

The texture coordinate buffer is a static buffer shared by all chunks.

TODO:

• More Lua bindings between c++/lua (to script things like controls and interactions)
• Higher detail Ambient Occlusion like Cube World, sampling from a larger radius.
• Chunk saving/loading
• More efficient block update system
• Fancier chunk generation
• Fancy lighting using shadow mapping and baking the result into the vertex color attribute for free and smooth lighting/shadows

Done:

• Dynamic world generation
• Processing blocks through scripts with configurable values for every block (disabled for now, needs more optimizations)
• Basic World/Chunk layout
• Basic high efficienty voxel renderer
• Basic Ambient occlusion calculations for voxels
• Basic fog / frustum culling
• Basic Lua bindings to setblock and create new block types from scripts.
• Learn OpenGL/GLSL/C++