public void InvalidateFrame(int frame)
{
if (frame <= 0)
{
throw new Exception("Cannot invalidate frame 0 for camera");
}
if (frame < _frames.Count)
{
_frames.RemoveRange(
frame,
_frames.Count - frame);
if (_prevframe <= frame)
{
_prevframe = -1;
}
}
var cachepos = (frame / cacherate);
if (frame % cacherate != 0)
{
cachepos++;
}
if (cachepos < _framecache.Count)
{
_framecache.RemoveRange(cachepos, _framecache.Count - cachepos);
}
if (frame == 1)
{
Rider firstframe = _timeline.GetFrame(0);
var entry = new CameraEntry(firstframe.CalculateCenter());
_frames[0] = entry;
_framecache[0] = Vector2d.Zero;
}
}
protected override Vector2d StepCamera(CameraBoundingBox box, ref Vector2d prev, int frame)
{
const double push = 0.8;
const double pull = 0.01;
CameraEntry entry = _frames[frame];
var ret = box.Clamp(prev + entry.CameraOffset);
Angle a = Angle.FromVector(ret);
double length = ret.Length;
double prevlength = prev.Length;
var edge = a.MovePoint(
Vector2d.Zero,
Math.Max(box.Bounds.Width, box.Bounds.Height));
double maxlength = box.Clamp(edge).Length;
double lengthratio = length / maxlength;
double prevratio = prevlength / maxlength;
double diffratio = Math.Abs(lengthratio - prevratio);
if (length > prevlength)
{
var dr = lengthratio - prevratio;
var damper = lengthratio - (dr / 2);
var delta = length - prevlength;
delta *= Math.Max(0.05, push * (1 - Math.Max(0, damper)));
length = prevlength + delta;
}
length -= length * pull;
return(box.Clamp(a.MovePoint(Vector2d.Zero, length)));
}
private CameraEntry GetNext(CameraEntry prev, Rider rider)
{
// todo i really wish this cared about angles
// it shouldnt center if the next step is going towards the center
// of the previous
// something like that
var center = rider.CalculateCenter();
var prevoffs = prev.Position;
var offset = (center - prev.Position);
offset = Vector2d.Lerp(prevoffs, center, 0.15);
return(new CameraEntry(center, offset, rider.CalculateMomentum()));
}
private void EnsureFrame(int frame)
{
//ensure timeline has the frames for us
//also timeline might invalidate our prev frames when calling
//so we do this at the top so it doesnt invalidate while calculating
_timeline.GetFrame(frame);
if (frame >= _frames.Count)
{
var diff = frame - (_frames.Count - 1);
var frames = _timeline.GetFrames(_frames.Count, diff);
for (int i = 0; i < diff; i++)
{
var rider = frames[i];
var center = rider.CalculateCenter();
var entry = new CameraEntry(center, center, rider.CalculateMomentum());
_frames.Add(entry);
}
}
}
public override void InvalidateFrame(int frame)
{
if (frame <= 0)
{
throw new Exception("Cannot invalidate frame 0 for camera");
}
if (frame < _frames.Count)
{
_frames.RemoveRange(
frame,
_frames.Count - frame);
}
if (frame == 1)
{
var firstframe = _timeline.GetFrame(0);
var entry = new CameraEntry(firstframe.CalculateCenter());
_frames[0] = entry;
}
}
protected void EnsureFrame(int frame)
{
//ensure timeline has the frames for us
//also timeline might invalidate our prev frames when calling
//so we do this at the top so it doesnt invalidate while calculating
_timeline.GetFrame(frame);
if (frame >= _frames.Count)
{
var diff = frame - (_frames.Count - 1);
var frames = _timeline.GetFrames(_frames.Count, diff);
var camoffset = _frames[_frames.Count - 1];
for (int i = 0; i < diff; i++)
{
var center = frames[i].CalculateCenter();
var offset = camoffset.RiderCenter - center;
camoffset = new CameraEntry(center, offset, Vector2d.Zero);
_frames.Add(camoffset);
}
}
}
private Vector2d Clamp(Vector2d pos, CameraEntry entry)
{
return(Clamp(pos, entry.RiderCenter, entry.ppf));
}