/// <summary>
/// Setup this matrix to view the universe in a certain direction.
/// </summary>
/// <param name="eyePosition">
/// A <see cref="Vertex3f"/> that specify the eye position, in local coordinates.
/// </param>
/// <param name="forwardVector">
/// A <see cref="Vertex3f"/> that specify the direction of the view. It will be normalized.
/// </param>
/// <param name="upVector">
/// A <see cref="Vertex3f"/> that specify the up vector of the view camera abstraction. It will be normalized
/// </param>
/// <returns>
/// It returns a view transformation matrix used to transform the world coordinate, in order to view
/// the world from <paramref name="eyePosition"/>, looking at <paramref name="forwardVector"/> having
/// an up direction equal to <paramref name="upVector"/>.
/// </returns>
public void LookAtDirection(Vertex3d eyePosition, Vertex3d forwardVector, Vertex3d upVector)
{
Vertex3d rightVector;
// Normalize forward vector
forwardVector.Normalize();
// Normalize up vector (it should already be normalized)
upVector.Normalize();
// Compute the right vector (cross-product between forward and up vectors; right is perperndicular to the plane)
rightVector = forwardVector ^ upVector;
rightVector.Normalize();
// Derive up vector
upVector = rightVector ^ forwardVector;
// Compute view matrix
ModelMatrixDouble lookatMatrix = new ModelMatrixDouble(), positionMatrix = new ModelMatrixDouble();
// Row 0: right vector
lookatMatrix[0, 0] = rightVector.x;
lookatMatrix[0, 1] = rightVector.y;
lookatMatrix[0, 2] = rightVector.z;
// Row 1: up vector
lookatMatrix[1, 0] = upVector.x;
lookatMatrix[1, 1] = upVector.y;
lookatMatrix[1, 2] = upVector.z;
// Row 2: opposite of forward vector
lookatMatrix[2, 0] = -forwardVector.x;
lookatMatrix[2, 1] = -forwardVector.y;
lookatMatrix[2, 2] = -forwardVector.z;
// Eye position
positionMatrix.Translate(eyePosition);
// Complete look-at matrix
Set(positionMatrix * lookatMatrix);
}
/// <summary>
/// Setup this matrix to view the universe in a certain direction.
/// </summary>
/// <param name="eyePosition">
/// A <see cref="Vertex3f"/> that specify the eye position, in local coordinates.
/// </param>
/// <param name="forwardVector">
/// A <see cref="Vertex3f"/> that specify the direction of the view. It will be normalized.
/// </param>
/// <param name="upVector">
/// A <see cref="Vertex3f"/> that specify the up vector of the view camera abstraction. It will be normalized
/// </param>
/// <returns>
/// It returns a view transformation matrix used to transform the world coordinate, in order to view
/// the world from <paramref name="eyePosition"/>, looking at <paramref name="forwardVector"/> having
/// an up direction equal to <paramref name="upVector"/>.
/// </returns>
public void LookAtDirection(Vertex3d eyePosition, Vertex3d forwardVector, Vertex3d upVector)
{
Vertex3d rightVector;
forwardVector.Normalize();
upVector.Normalize();
rightVector = forwardVector ^ upVector;
rightVector.Normalize();
if (rightVector.Module() <= 0.0f)
{
rightVector = Vertex3f.UnitX;
}
upVector = rightVector ^ forwardVector;
// Compute view matrix
ModelMatrixDouble lookatMatrix = new ModelMatrixDouble();
// Row 0: right vector
lookatMatrix[0, 0] = rightVector.x;
lookatMatrix[0, 1] = rightVector.y;
lookatMatrix[0, 2] = rightVector.z;
// Row 1: up vector
lookatMatrix[1, 0] = upVector.x;
lookatMatrix[1, 1] = upVector.y;
lookatMatrix[1, 2] = upVector.z;
// Row 2: opposite of forward vector
lookatMatrix[2, 0] = -forwardVector.x;
lookatMatrix[2, 1] = -forwardVector.y;
lookatMatrix[2, 2] = -forwardVector.z;
// Eye position
lookatMatrix.Translate(eyePosition);
// Complete look-at matrix
Set(lookatMatrix);
}
/// <summary>
/// Setup this matrix to view the universe in a certain direction.
/// </summary>
/// <param name="eyePosition">
/// A <see cref="Vertex3f"/> that specify the eye position, in local coordinates.
/// </param>
/// <param name="forwardVector">
/// A <see cref="Vertex3f"/> that specify the direction of the view. It will be normalized.
/// </param>
/// <param name="upVector">
/// A <see cref="Vertex3f"/> that specify the up vector of the view camera abstraction. It will be normalized
/// </param>
/// <returns>
/// It returns a view transformation matrix used to transform the world coordinate, in order to view
/// the world from <paramref name="eyePosition"/>, looking at <paramref name="forwardVector"/> having
/// an up direction equal to <paramref name="upVector"/>.
/// </returns>
public void LookAtDirection(Vertex3d eyePosition, Vertex3d forwardVector, Vertex3d upVector)
{
Vertex3d rightVector;
// Normalize forward vector
forwardVector.Normalize();
// Normalize up vector (it should already be normalized)
upVector.Normalize();
// Compute the right vector (cross-product between forward and up vectors; right is perperndicular to the plane)
rightVector = forwardVector ^ upVector;
rightVector.Normalize();
// Derive up vector
upVector = rightVector ^ forwardVector;
// Compute view matrix
ModelMatrixDouble lookatMatrix = new ModelMatrixDouble(), positionMatrix = new ModelMatrixDouble();
// Row 0: right vector
lookatMatrix[0, 0] = rightVector.x;
lookatMatrix[0, 1] = rightVector.y;
lookatMatrix[0, 2] = rightVector.z;
// Row 1: up vector
lookatMatrix[1, 0] = upVector.x;
lookatMatrix[1, 1] = upVector.y;
lookatMatrix[1, 2] = upVector.z;
// Row 2: opposite of forward vector
lookatMatrix[2, 0] = -forwardVector.x;
lookatMatrix[2, 1] = -forwardVector.y;
lookatMatrix[2, 2] = -forwardVector.z;
// Eye position
positionMatrix.Translate(eyePosition);
// Complete look-at matrix
Set(positionMatrix * lookatMatrix);
}