feat: lightmap integration

[michaeleggers]

• Define new data formats for the MAP parser so that the lightmapper is able to get UVs and surface-textures.
• Define and create binary format that holds the processes triangles by the lightmapper, ready for in engine use.
• Define new data formats for the in-engine static geometry so it can reference albedo textures and the lightmap.
• Edit the shader for static geometry.

[michaeleggers]

The Quake MAP data structures have changed a bit:

struct QuakeMapVertex {
    glm::f64vec3  pos;
    glm::vec2     uv;
};

struct MapPolygon
{
    std::vector<QuakeMapVertex> vertices;
    glm::f64vec3                normal;
    std::string                 textureName;  // located in /game/textures/<*.png>
    uint64_t                    surfaceFlags; // eg. transparency, emissiveness, ...
    uint64_t                    contentFlags; // eg. water, slime, lava, ...
};

The functions

std::vector<MapPolygon> createPolysoup(Map map, SoupFlags soupFlags = SOUP_GET_WORLDSPAWN_ONLY); 
std::vector<MapPolygon> createPolysoup(const Brush& brush);

To get the polygons just for static MAP geometry (which is needed for the lightmapper) just call the first of the two functions with the default flag. If you want all of the geometry (including brush entities and invisible stuff) call it with SOUP_GET_ALL. A function to get only brush entities could be added but probably not very useful because they will be available by iterating over the entity list anyways.

Now process the Polygons in a way so they include both the texturename and UV coordinates that have already been converted from 3d relative texture space to concrete UVs, ranged from 0..1 on both axis.

Important

• Only VALVE_220 MAP format is supported (the one we want anyways)
• Map textures have to be present in /assets/textures/ in PNG format. Other image files will be supported once the virtual filesystem is done.