Function cornertest

source/src/physics.cpp:94–130

}

int cornertest(int x, int y, int &bx, int &by, int &bs, sqr *&s, sqr *&h)    // iteratively collide with a mipmapped corner cube
{
    int mip = 1, res = -1;
    while(SWS(wmip[mip], x>>mip, y>>mip, sfactor-mip)->type==CORNER) mip++;
    mip--;
    x >>= mip;
    y >>= mip;
    int mfactor = sfactor - mip;
    bx = x<<mip;                     // bx, by and bs are the real-world coordinates and size of the corner mip
    by = y<<mip;                     // s is the corner mip and h is the companion mip of a corner between non-solids (to get floor and ceil from)
    bs = 1<<mip;
    sqr *z = SWS(wmip[mip],x - 1, y,mfactor);
    sqr *t = SWS(z,2,0,mfactor);     //   w
    sqr *w = SWS(z,1,-1,mfactor);    //  zst
    sqr *v = SWS(z,1,1,mfactor);     //   v
    s = SWS(z,1,0,mfactor);

    // now, this is _exactly_ how the renderer interprets map geometry...
    if(SOLID(z))
    {
        if(SOLID(w)) res = 2; // corners between solids are solid behind the wall or SPACE in front of it
        else if(SOLID(v)) res = 3;
    }
    else if(SOLID(t))
    {
        if(SOLID(w)) res = 1;
        else if(SOLID(v)) res = 0;
    }
    else
    { // not a corner between solids
        bool wv = w->ceil-w->floor < v->ceil-v->floor;
        h = wv ? v : w;  // in front of the corner, use floor and ceil from h
        if(z->ceil-z->floor < t->ceil-t->floor) res = wv ? 2 : 3;
        else res = wv ? 1 : 0;
    }            //  03
    return res;  //  12
}

static int cornersurface = 0;