Posted by BitShifter on May 05, 2000 at 11:49:32:
In reply to: RE: Shape of texture fragments posted by E.Popov on May 05, 2000 at 11:32:29:
: > Indeed. Though it took me some time to figure out how they could rotate the
: > texture by defining which is the Hi and which is the Lo coordinate (they are
: > not always in order) because the fourth coord of triangle is always zero but
: > the trinagle is not always the "right" side up so to speak.
: Why do we need to rotate the texture ? In TRViewer I only associate to each vertex of a face (tri / quad) the texture coordinates from the tr2_object_texture_vert structure (I juste add the X or Y -pixel field with the matching X or Y -Coordinate field to have the (u,v) coordinates), and I never saw problems in texturing...
In the level file texture description chunck, the first coordinates is not always the one nearest the upper left corner of the texture tile. Instead, the coordinate type itself has a small flag set to indicate which of the three or four set of coordinate is the Lo (near the upper left corner) or the Hi, farthest away from).
However, the texture itself seems to be mapped so: first coord on the first point of the polygon and one to the last, going clockwise as seen from the visible side (inside the room.)
I guess if you want to make your texture appear flipped, you would rotate it that way, since an area can be set to as amny different set of coordinates as you need.