Texturing

[afonsolage]

This PR adds texture capabilities to the game. I've made some basic textures on GIMP and added just 4 basic textures to get things done.

[afonsolage]

Next step is load the atlas onto the AssetServer and update the shader to render the correct UV

[afonsolage]

Now that I'm reading my own PR, I think doesn't make sense to have multiple atlases for KindDescription, since it should be a single atlas always.

I'll change this...

[afonsolage]

A very primitive texturing is working:

There are some issues to be solved: 1- Fix texture rotation; 2- Add texture tiling; 3- Check if texture is working for different kinds;

[afonsolage]

In order to do the texture tiling, the following steps needs to be done, if I'm not mistaken:

• [x] Calculate TileTextureSize which is the TileSize in texture coordinates [0.0, 1.0]. This is just a matter of 1.0 / TileSize
• [x] Convert UV, which is [0, N] where N < TileCount, to tiled UV UV * TileTextureSize
• [x] Calculate BaseTextCoord which is the starting point of the tile in texture coordinates. This one can be calculated using TileOffset * TileTextureSize
• [x] Send TileTextureSize, TiledUV and BaseTextCoord to the shader. The first one can be a UniformBuffer, second and third may be a Vertex Data
• [x] Update fragment shader to calculate the final UV using uv = baseTextCoord + mod(tiledUV, tileTextureSize)

[afonsolage]

Texture tiling is working fine.

Next steps:

• [x] Fix texture rotation;
• [x] Do some cleanup and code organization;
• [ ] Fix chunks sometimes not rendering (maybe something related to system ordering);
• [x] Add back commented tests generate_vertices and update_chunk

[afonsolage]

Texture rotation fixed

[afonsolage]

Found a bug were sometime the mesh::merge_faces ignores the voxel kind:

Edit: Fixed!

[afonsolage]

I wasn't able to reproduce: Fix chunks sometimes not rendering (maybe something related to system ordering)

Skipping it for now

[afonsolage]

Ok I think everything is good now.