public virtual void BuildTree()
{
if (RandomSeed == 0)
{
rnd = new Random();
}
else
{
rnd = new Random(RandomSeed);
}
particles.Clear();
Particle3D trunk = new Particle3D()
{
Location = InitialPosition,
Direction = new Vector3D(0, 1, 0),
Life = maxLife,
MaxLife = maxLife,
Color = trunkColor,
Behaviour = TrunkBehaviour
};
particles.Add(trunk);
}
/// <summary>
/// Describes what happens in a trunk particle
/// </summary>
/// <param name="trunk">The trunk particle</param>
private void TrunkBehaviour(Particle3D trunk)
{
int depth = 1;
// stimulate branching where life is low
if (stimulateBranchingAtEndOfLife)
{
BranchingBehaviour((float)LineairScaleTo((((float)trunk.MaxLife - trunk.Life) / (float)trunk.MaxLife), 0.0f, 1f) * branchingPercent, trunk, depth);
}
else
{
BranchingBehaviour(branchingPercent, trunk, depth);
}
// leaves behaviour
LeavesBehaviour(trunk);
// zigzag the tree a little
TrunkNudgeBehaviour(trunk);
// make the tree thicker
TrunkThickingBehaviour(trunk);
// make the trunk split sometimes
TrunkSplittingBehaviour(trunk);
}
protected virtual void OnPixelSet(Particle3D p)
{
//bmp.SetPixel((int)p.Location.X, pic.Height - 1 - (int)p.Location.Y, p.Color);
PixelSetHandler temp = PixelSet;
if (temp != null)
{
temp((int)p.OldLocation.X, (int)p.OldLocation.Y, (int)p.OldLocation.Z, (int)p.Location.X, (int)p.Location.Y, (int)p.Location.Z, p.Color);
}
//}
}
/// <summary>
/// Nudge the tree to create a zig-zag effect (so that the tree isn't dead straight)
/// </summary>
/// <param name="trunk">A trunk particle</param>
private void TrunkNudgeBehaviour(Particle3D trunk)
{
// subtle x nudgings
if (rnd.NextDouble() < zigzagTrunkPercentage)
{
trunk.Direction = trunk.Direction.RotateZ(LineairScaleTo(rnd.NextDouble(), -zigzagTrunkStrength, zigzagTrunkStrength))
.RotateY(rnd.Next(0, 2 * Math.PI));
}
//if (trunk.Direction.Y < 1)
//{
// trunk.Direction.Y += 0.1f;
//}
//if (trunk.Direction.Y > 1)
// trunk.Direction.Y = 1;
}
/// <summary>
/// Describes the behaviour of spawning leaves on branches
/// </summary>
/// <param name="b"></param>
private void LeavesBehaviour(Particle3D b)
{
if (b.Life < leavesPercentage * b.MaxLife)
{
// create leaves
for (int i = 0; i < leavesNrSpawned; i++)
{
Particle3D l = new Particle3D()
{
Direction = new Vector3D(rnd.Next(-1f, 1f), rnd.Next(-1f, 1f), rnd.Next(-1f, 1f)),
Location = b.Location,
Color = leavesColor,
Life = leafLife,
MaxLife = leafLife
};
particles.Add(l);
}
}
}
/// <summary>
/// Describes the branching and general behaviour of a branch
/// </summary>
/// <param name="branchingPercent"></param>
/// <param name="branch"></param>
/// <param name="depth"></param>
private void BranchingBehaviour(float branchingPercent, Particle3D t, int depth)
{
if (rnd.NextDouble() < branchingPercent)//* (Math.Pow(0.5f, depth)))
{
// 90 * 2 ^ depth-1
// [-90, 90] degrees => depth =1
// [-45, 45] degrees => depth = 2
// [-22.5,
double narrower = (Math.Pow(branchNarrowing, depth));
// branch in a random direction but decrease the range based on the depth of the recursion
// still branch in a random direction around the Y axis
Vector3D initialDirection = t.Direction.RotateZ(rnd.Next(-Math.PI * narrower, Math.PI * narrower))
.RotateY(rnd.Next(0, Math.PI * 2));
Particle3D branch = new Particle3D()
{
Location = t.Location,
Direction = initialDirection,
MaxLife = (int)(t.Life * branchSizeDecrease),
Life = (int)(t.Life * branchSizeDecrease),
Color = branchColor,
};
branch.Behaviour = b =>
{
LeavesBehaviour(b);
BranchingBehaviour(branchingPercent, b, depth + 1);
// weight behaviour
if (applyWeightOnBranches)
{
b.Direction = new Vector3D(initialDirection.X, initialDirection.Y * LineairScaleTo((double)b.Life / (double)branch.MaxLife, -1f, 1f), initialDirection.Z);// +(2 * (((double)b.Life / (double)maxLife)) - 1);
}
};
particles.Add(branch);
}
}
/// <summary>
/// Make the trunk of the tree bigger
/// </summary>
/// <param name="trunk"></param>
private void TrunkThickingBehaviour(Particle3D trunk)
{
// thicking
int maxTrunkLife = (int)(((float)trunk.Life / (float)trunk.MaxLife) * (thickHeightRatio * trunk.MaxLife));
double piTimes2 = (2 * Math.PI);
var trunkRotatedOnZ = trunk.Direction.RotateZ(-Math.PI / 2);
// spawn particles in every possible direction
int nrSpawn = 720;
for (int i = 0; i < nrSpawn; i++)
{
Particle3D t1 = new Particle3D()
{
Location = trunk.Location,
Direction = trunkRotatedOnZ.RotateY((i / (float)nrSpawn) * piTimes2)
.RotateZ((i / (float)nrSpawn) * piTimes2),
Life = maxTrunkLife,
MaxLife = maxTrunkLife,
Color = trunk.Color
};
particles.Add(t1);
}
//Particle3D t2 = new Particle3D()
//{
// Location = trunk.Location,
// Direction = trunk.Direction.RotateZ(Math.PI / 2),
// Life = maxTrunkLife,
// MaxLife = maxTrunkLife,
// Color = trunk.Color
//};
//particles.Add(t2);
}
/// <summary>
/// Describes how a trunk splits
/// </summary>
/// <param name="trunk">The trunk particle</param>
private void TrunkSplittingBehaviour(Particle3D trunk)
{
// trunk split
if (rnd.NextDouble() < trunkSplitPercentage)
{
Vector3D newDirection = trunk.Direction.RotateZ(rnd.Next(-Math.PI, Math.PI))
.RotateY(rnd.Next(0, 2 * Math.PI));
Particle3D secondTrunk = new Particle3D()
{
Location = trunk.Location,
Direction = newDirection,
Color = trunk.Color,
Life = (int)(trunk.Life * trunkSplitSpawnLifeDecrease),
MaxLife = (int)(trunk.Life * trunkSplitSpawnLifeDecrease),
Behaviour = trunk.Behaviour
};
particles.Add(secondTrunk);
if (secondTrunk.Direction.Y < 0)
{
secondTrunk.Direction.Y *= -1;
}
trunk.Life = (int)(trunk.Life * trunkSplitOrigLifeDecrease);
// TODO
trunk.Direction = new Vector3D(-newDirection.X, newDirection.Y, newDirection.Z); //trunk.Direction.Rotate(-Math.PI / 2 * rnd.NextDouble());
if (trunk.Direction.Y < 0)
{
trunk.Direction.Y *= -1;
}
}
}