/// <summary>
/// Places the end of a bone here, unless the bone level would become too high, or too many bones have been added already.
/// The bone's origin is at the previously added bone (as seen from the current state).
/// </summary>
/// <param name="delta">Amount to adjust the current bone level by</param>
/// <remarks>
/// Branches added between this and the previously added bone will be controlled by the new bone.
///
/// The current bone is part of the crayon's state, like position and rotation, and is affected by PushState and PopState.
/// </remarks>
public void Bone(int delta)
{
if (state.BoneLevel > boneLevels + delta || skeleton.Bones.Count == MaxBones)
return;
// Get index of the parent
int parent = state.ParentBoneIndex;
// Get the parent's absolute transform
Matrix parentTransform = Matrix.Identity;
Matrix parentInverseTransform = Matrix.Identity;
float parentLength = 0.0f;
if (parent != -1)
{
parentTransform = skeleton.Bones[parent].ReferenceTransform;
parentInverseTransform = skeleton.Bones[parent].InverseReferenceTransform;
parentLength = skeleton.Bones[parent].Length;
}
// Find the starting and ending point of the new bone
Vector3 targetLocation = GetTransform().Translation;
Vector3 fromLocation = parentTransform.Translation + parentTransform.Up * parentLength;
// Direction of the bone's Y-axis
Vector3 directionY = Vector3.Normalize(targetLocation - fromLocation);
// Choose arbitrary perpendicular X and Z axes
Vector3 directionX;
Vector3 directionZ;
if (directionY.Y < 0.50f)
{
directionX = Vector3.Normalize(Vector3.Cross(directionY, Vector3.Up));
directionZ = Vector3.Normalize(Vector3.Cross(directionX, directionY));
}
else
{
directionX = Vector3.Normalize(Vector3.Cross(directionY, Vector3.Backward));
directionZ = Vector3.Normalize(Vector3.Cross(directionX, directionY));
}
// Construct the absolute rotation of the child
Matrix childAbsoluteTransform = Matrix.Identity;
childAbsoluteTransform.Right = directionX;
childAbsoluteTransform.Up = directionY;
childAbsoluteTransform.Backward = directionZ;
childAbsoluteTransform.Translation = fromLocation;
// Calculate the relative transformation
Matrix relativeTransformation = childAbsoluteTransform * parentInverseTransform;
Quaternion rotation = Quaternion.CreateFromRotationMatrix(relativeTransformation);
// Create the new bone
TreeBone bone = new TreeBone();
bone.ReferenceTransform = childAbsoluteTransform;
bone.InverseReferenceTransform = Matrix.Invert(bone.ReferenceTransform);
bone.Length = Vector3.Distance(fromLocation, targetLocation);
bone.Rotation = rotation;
bone.ParentIndex = parent;
bone.Stiffness = skeleton.Branches[state.ParentIndex].StartRadius; // 1.0f; // TODO: Set stiffness according to radius
bone.EndBranchIndex = state.ParentIndex;
// Add the bone to the skeleton
skeleton.Bones.Add(bone);
// Set this bone as the parent
int endIndex = (state.ParentBoneIndex == -1? -1 : skeleton.Bones[state.ParentBoneIndex].EndBranchIndex);
int boneIndex = state.ParentBoneIndex = skeleton.Bones.Count - 1;
state.BoneLevel -= delta;
// Update the bone index on branches
int branchIndex = state.ParentIndex;
while (branchIndex != endIndex)
{
TreeBranch branch = skeleton.Branches[branchIndex];
branch.BoneIndex = boneIndex;
skeleton.Branches[branchIndex] = branch;
branchIndex = branch.ParentIndex;
}
}
/// <summary>
/// Places the end of a bone here, unless the bone level would become too high, or too many bones have been added already.
/// The bone's origin is at the previously added bone (as seen from the current state).
/// </summary>
/// <param name="delta">Amount to adjust the current bone level by</param>
/// <remarks>
/// Branches added between this and the previously added bone will be controlled by the new bone.
///
/// The current bone is part of the crayon's state, like position and rotation, and is affected by PushState and PopState.
/// </remarks>
public void Bone(int delta)
{
if (state.BoneLevel > boneLevels + delta || skeleton.Bones.Count == MaxBones)
{
return;
}
// Get index of the parent
int parent = state.ParentBoneIndex;
// Get the parent's absolute transform
Matrix parentTransform = Matrix.Identity;
Matrix parentInverseTransform = Matrix.Identity;
float parentLength = 0.0f;
if (parent != -1)
{
parentTransform = skeleton.Bones[parent].ReferenceTransform;
parentInverseTransform = skeleton.Bones[parent].InverseReferenceTransform;
parentLength = skeleton.Bones[parent].Length;
}
// Find the starting and ending point of the new bone
Vector3 targetLocation = GetTransform().Translation;
Vector3 fromLocation = parentTransform.Translation + parentTransform.Up * parentLength;
// Direction of the bone's Y-axis
Vector3 directionY = Vector3.Normalize(targetLocation - fromLocation);
// Choose arbitrary perpendicular X and Z axes
Vector3 directionX;
Vector3 directionZ;
if (directionY.Y < 0.50f)
{
directionX = Vector3.Normalize(Vector3.Cross(directionY, Vector3.Up));
directionZ = Vector3.Normalize(Vector3.Cross(directionX, directionY));
}
else
{
directionX = Vector3.Normalize(Vector3.Cross(directionY, Vector3.Backward));
directionZ = Vector3.Normalize(Vector3.Cross(directionX, directionY));
}
// Construct the absolute rotation of the child
Matrix childAbsoluteTransform = Matrix.Identity;
childAbsoluteTransform.Right = directionX;
childAbsoluteTransform.Up = directionY;
childAbsoluteTransform.Backward = directionZ;
childAbsoluteTransform.Translation = fromLocation;
// Calculate the relative transformation
Matrix relativeTransformation = childAbsoluteTransform * parentInverseTransform;
Quaternion rotation = Quaternion.CreateFromRotationMatrix(relativeTransformation);
// Create the new bone
var bone = new TreeBone();
bone.ReferenceTransform = childAbsoluteTransform;
bone.InverseReferenceTransform = Matrix.Invert(bone.ReferenceTransform);
bone.Length = Vector3.Distance(fromLocation, targetLocation);
bone.Rotation = rotation;
bone.ParentIndex = parent;
bone.Stiffness = skeleton.Branches[state.ParentIndex].StartRadius;
// 1.0f; // TODO: Set stiffness according to radius
bone.EndBranchIndex = state.ParentIndex;
// Add the bone to the skeleton
skeleton.Bones.Add(bone);
// Set this bone as the parent
int endIndex = (state.ParentBoneIndex == -1 ? -1 : skeleton.Bones[state.ParentBoneIndex].EndBranchIndex);
int boneIndex = state.ParentBoneIndex = skeleton.Bones.Count - 1;
state.BoneLevel -= delta;
// Update the bone index on branches
int branchIndex = state.ParentIndex;
while (branchIndex != endIndex)
{
TreeBranch branch = skeleton.Branches[branchIndex];
branch.BoneIndex = boneIndex;
skeleton.Branches[branchIndex] = branch;
branchIndex = branch.ParentIndex;
}
}