public cVector3 direction(cCritter pa, cCritter pb)
{
cVector3 dir = pb.Position - pa.Position;
dir.normalize();
return(dir);
}
public void setViewpoint(cVector3 toViewer, cVector3 lookatPoint,
bool trytoseewholeworld = true)
{
//First do some default setup stuff
cVector3 toviewer = new cVector3();
toviewer.copy(toViewer);
cVector3 lookatpoint = new cVector3();
lookatpoint.copy(lookatPoint);
_fieldofviewangle = cCritterViewer.STARTFIELDOFVIEWANGLE;
Speed = 0.0f;
_attitude = new cMatrix3(new cVector3(0.0f, 0.0f, -1.0f),
new cVector3(-1.0f, 0.0f, 0.0f), new cVector3(0.0f, 1.0f, 0.0f),
new cVector3(0.0f, 0.0f, 0.0f));
/* To get a reasonable default orientation, we arrange the viewer axes so that:
* viewer x axis = world -z axis, viewer y axis = world -x axis, viewer z axis = world y axis.
* We pick this orientation so that if the viewer moves "forward" (along its tangent vector)
* it moves towards the world. (We correct the mismatch between the coordinate systems in the
* cCritterViewer.loadViewMatrix method, which has a long comment about this.)
* Note that we will adjust _position (fourth column) later in this call
* with a moveTo, also we may rotate the _attitude a bit. */
if (!_perspective) //Ortho view, simply move up.
{
_proportionofworldtoshow = 1.0f; //Show all of a flat world.
moveTo(lookatpoint + (new cVector3(0.0f, 0.0f, 1.0f)) * cCritterViewer.ORTHOZOFFSET); // Get above the world
_maxspeed = _maxspeedstandard = 0.5f * cCritterViewer.ORTHOZOFFSET; //Mimic perspective case.
}
else //_perspective
{
if (toviewer.IsPracticallyZero) //Not usable, so pick a real direction.
{
toviewer.copy(new cVector3(0.0f, 0.0f, 1.0f)); //Default is straight up.
}
if (trytoseewholeworld) /* Treat toviewer as a direction, and back off in that direction
* enough to see the whole world */
{
toviewer.normalize(); //Make it a unit vector.
_proportionofworldtoshow = cCritterViewer.PROPORTIONOFWORLDTOSHOW;
//Trying to show all of a world when flying around it, often leaves too big a space around it.
float furthestcornerdistance = Game.Border.maxDistanceToCorner(lookatpoint);
float tanangle = (float)Math.Tan(_fieldofviewangle / 2.0f); /* We work with half the fov in this calculation,
* the tanangle will be the ratio of visible distance to distance above the world,
* that is, tanangle = dr/dz, where
* Our dr is _proportionofworldtoshow * furthestcornerdistance, and
* our dz is the unknown seeallz height we need to back off to.
* Swap tangangle and dz to get the next formula. */
float seeallz = _proportionofworldtoshow * furthestcornerdistance / tanangle;
moveTo(lookatpoint + toviewer * seeallz);
}
else /*Not trytoseewholeworld. In this case we don't normalize toviewer, instead
* we treat it as a displacment from the lookatpoint. */
{
moveTo(lookatpoint + toviewer);
}
lookAt(lookatpoint);
_maxspeed = _maxspeedstandard = 0.5f * (Position - lookatpoint).Magnitude;
/* Define the speed like this so it typically takes two seconds (1/0.5)
* to fly in to lookatpoint. */
_lastgoodplayeroffset = Position - Game.Player.Position;
}
}
