/// <summary>
/// This function is used to scale a list of vertices to the specified
/// size
/// </summary>
/// <param name="listToScale">The list of vertices that should be scaled. Ref is to prevent memory leaks.</param>
/// <param name="scale">The multiplier that should be used to scale the vertices.</param>
static public void rotateVertexList(ref List <VertexPositionColoredNormal> listToScale, float scale)
{
if (listToScale == null)
{
return;
}
//Create the matrix needed to scale each vertex
Matrix scaleMatrix = Matrix.CreateScale(scale);
for (int i = 0; i < listToScale.Count; i++) //got through all the vertices in the list
{
VertexPositionColoredNormal vertex = listToScale[i]; //open the vertex for editing
//apply the final matrix to the podition of the vertex
vertex.Position = Vector3.Transform(vertex.Position, scaleMatrix);
listToScale[i] = vertex;//save the new vertex
}
}
/// <summary>
/// Centres a VertexPositionColoredNormal list around a given x and y point in a Vector3.
/// The z will be moved to have a minimum of the specified point.
/// </summary>
/// <param name="listToCentre">The list of vertices to centre. Ref is to prevent memory leaks</param>
/// <param name="centrePosition">The position they should be centred anround.</param>
static public void centreVertexList(ref List <VertexPositionColoredNormal> listToCentre, Vector3 centrePosition)
{
if (listToCentre == null)
{
return;
}
float xMax = float.NaN; //the maximum x coordinate of the model
float xMin = float.NaN; //the minimum x coordinate of the model
float xCentre = 0.0f; //the centre x coordinate of the model
float xTarget = centrePosition.X; //the target centre x coordinate of the model
float xMove = 0.0f; //the amount that the models needs to move to reach the target position
float yMax = float.NaN; //the maximum y coordinate of the model
float yMin = float.NaN; //the minimum y coordinate of the model
float yCentre = 0.0f; //the centre y coordinate of the model
float yTarget = centrePosition.Y; //the target centre y coordinate of the model
float yMove = 0.0f;
float zMin = float.NaN; //the minimum y coordinate of the model
float zTarget = centrePosition.Z; //the target minimum y coordinate of the model
float zMove = 0.0f; //the amount that the models needs to move to reach the target position
foreach (VertexPositionColoredNormal vertex in listToCentre) //cycle through all the vertices in the list
{
Vector3 vector = vertex.Position; //the position of the current vertice
//just intitialise the values if it has not been done yet
//float.NaN is used to avoid a situation were either the min or max is actually the default value if were to use a real number
if (float.IsNaN(xMax))
{
xMax = vector.X;
}
if (float.IsNaN(xMin))
{
xMin = vector.X;
}
if (float.IsNaN(yMax))
{
yMax = vector.Y;
}
if (float.IsNaN(yMin))
{
yMin = vector.Y;
}
if (float.IsNaN(zMin))
{
zMin = vector.Z;
}
xMax = Math.Max(xMax, vector.X); //set this position to the maximum if it is larger than the previous one
xMin = Math.Min(xMin, vector.X); //set this position to the minimum if it is smaller than the previous one
yMax = Math.Max(yMax, vector.Y); //set this position to the maximum if it is larger than the previous one
yMin = Math.Min(yMin, vector.Y); //set this position to the minimum if it is smaller than the previous one
zMin = Math.Min(zMin, vector.Z); //set this position to the minimum if it is smaller than the previous one
}
xCentre = (xMax + xMin) / 2; //calculate the centre x position
xMove = xTarget - xCentre; //calculate the amount that has to be moved in the x axis
yCentre = (yMax + yMin) / 2; //calculate the centre y position
yMove = yTarget - yCentre; //calculate the amount that has to be moved in the y axis
zMove = zTarget - zMin; //calculate the amount that has to be moved in the z axis
/*
* //Give the caller the centreposition that can be used to move the model back to its previous position
* if (oldCentrePosition != null)
* oldCentrePosition = new Vector3(xCentre, yCentre, zMin);*/
for (int i = 0; i < listToCentre.Count; i++) //got through all the vertices in the list
{
VertexPositionColoredNormal vertex = listToCentre[i]; //Open the vertex for editing
Vector3 vector = vertex.Position; //Oen the vector of thevertex for editing
//move the model to the target positions
vector.X += xMove;
vector.Y += yMove;
vector.Z += zMove;
vertex.Position = vector; //Store the new vector in the vertex
listToCentre[i] = vertex; //store the new vertex in the list
}
}
/// <summary>
/// Rotates a VertexPositionColoredNormal list according to given x, y and z rotations.
/// </summary>
/// <param name="listToRotate">The list of vertices to rotate. Ref is to prevent memory leaks.</param>
/// <param name="xRot">The amount of yaw to be applied in Radians</param>
/// <param name="yRot">The amount of pitch to be applied in Radians</param>
/// <param name="zRot">The amount of roll to be applied in Radians</param>
static public void rotateVertexList(ref List <VertexPositionColoredNormal> listToRotate, float xRot, float yRot, float zRot)
{
if (listToRotate == null)
{
return;
}
float xMax = float.NaN; //the maximum x coordinate of the model
float xMin = float.NaN; //the minimum x coordinate of the model
float xCentre = 0.0f; //the centre x coordinate of the model
float yMax = float.NaN; //the maximum y coordinate of the model
float yMin = float.NaN; //the minimum y coordinate of the model
float yCentre = 0.0f; //the centre y coordinate of the model
float zMax = float.NaN; //the maximum y coordinate of the model
float zMin = float.NaN; //the minimum y coordinate of the model
float zCentre = 0.0f; //the centre y coordinate of the model
foreach (VertexPositionColoredNormal vertex in listToRotate) //cycle through all the vertices in the list
{
Vector3 vector = vertex.Position; //the position of the current vertice
//just intitialise the values if it has not been done yet
//float.NaN is used to avoid a situation were either the min or max is actually the default value if were to use a real number
if (float.IsNaN(xMax))
{
xMax = vector.X;
}
if (float.IsNaN(xMin))
{
xMin = vector.X;
}
if (float.IsNaN(yMax))
{
yMax = vector.Y;
}
if (float.IsNaN(yMin))
{
yMin = vector.Y;
}
if (float.IsNaN(zMax))
{
zMax = vector.Z;
}
if (float.IsNaN(zMin))
{
zMin = vector.Z;
}
xMax = Math.Max(xMax, vector.X); //set this position to the maximum if it is larger than the previous one
xMin = Math.Min(xMin, vector.X); //set this position to the minimum if it is smaller than the previous one
yMax = Math.Max(yMax, vector.Y); //set this position to the maximum if it is larger than the previous one
yMin = Math.Min(yMin, vector.Y); //set this position to the minimum if it is smaller than the previous one
zMax = Math.Max(zMax, vector.Z); //set this position to the maximum if it is larger than the previous one
zMin = Math.Min(zMin, vector.Z); //set this position to the minimum if it is smaller than the previous one
}
xCentre = (xMax + xMin) / 2; //calculate the centre x position
yCentre = (yMax + yMin) / 2; //calculate the centre x position
zCentre = (zMax + zMin) / 2; //calculate the centre x position
//We need to translate the model sothat its centre is on 0,0,0 before we can rotate it
Matrix translateToCentreMatrix = Matrix.CreateTranslation(new Vector3(-xCentre, -yCentre, -zCentre));
//We then create the matrix that we will use to apply the requestes rotation
Matrix rotationMatrix = Matrix.CreateFromYawPitchRoll(xRot, yRot, zRot);
//We then create the matrix needed to move the model back to its original position
Matrix translateBackMatrix = Matrix.CreateTranslation(new Vector3(xCentre, yCentre, zCentre));
//Finally we create the matrix thats first centres it, then rotates it and finally takes it back to its original position
Matrix matrixToApply = translateToCentreMatrix * rotationMatrix * translateBackMatrix;
for (int i = 0; i < listToRotate.Count; i++) //got through all the vertices in the list
{
VertexPositionColoredNormal vertex = listToRotate[i]; //Open the vertex for editing
//apply the final matrix to the vector
vertex.Position = Vector3.Transform(vertex.Position, matrixToApply);
listToRotate[i] = vertex;//store the new vertex in the list
}
}
