public static GsMatrix operator /(GsMatrix matrix1, GsMatrix matrix2)
{
GsMatrix inverse = GsMatrix.Invert(matrix2), result;
result.M11 = matrix1.M11 * inverse.M11 + matrix1.M12 * inverse.M21 + matrix1.M13 * inverse.M31 + matrix1.M14 * inverse.M41;
result.M12 = matrix1.M11 * inverse.M12 + matrix1.M12 * inverse.M22 + matrix1.M13 * inverse.M32 + matrix1.M14 * inverse.M42;
result.M13 = matrix1.M11 * inverse.M13 + matrix1.M12 * inverse.M23 + matrix1.M13 * inverse.M33 + matrix1.M14 * inverse.M43;
result.M14 = matrix1.M11 * inverse.M14 + matrix1.M12 * inverse.M24 + matrix1.M13 * inverse.M34 + matrix1.M14 * inverse.M44;
result.M21 = matrix1.M21 * inverse.M11 + matrix1.M22 * inverse.M21 + matrix1.M23 * inverse.M31 + matrix1.M24 * inverse.M41;
result.M22 = matrix1.M21 * inverse.M12 + matrix1.M22 * inverse.M22 + matrix1.M23 * inverse.M32 + matrix1.M24 * inverse.M42;
result.M23 = matrix1.M21 * inverse.M13 + matrix1.M22 * inverse.M23 + matrix1.M23 * inverse.M33 + matrix1.M24 * inverse.M43;
result.M24 = matrix1.M21 * inverse.M14 + matrix1.M22 * inverse.M24 + matrix1.M23 * inverse.M34 + matrix1.M24 * inverse.M44;
result.M31 = matrix1.M31 * inverse.M11 + matrix1.M32 * inverse.M21 + matrix1.M33 * inverse.M31 + matrix1.M34 * inverse.M41;
result.M32 = matrix1.M31 * inverse.M12 + matrix1.M32 * inverse.M22 + matrix1.M33 * inverse.M32 + matrix1.M34 * inverse.M42;
result.M33 = matrix1.M31 * inverse.M13 + matrix1.M32 * inverse.M23 + matrix1.M33 * inverse.M33 + matrix1.M34 * inverse.M43;
result.M34 = matrix1.M31 * inverse.M14 + matrix1.M32 * inverse.M24 + matrix1.M33 * inverse.M34 + matrix1.M34 * inverse.M44;
result.M41 = matrix1.M41 * inverse.M11 + matrix1.M42 * inverse.M21 + matrix1.M43 * inverse.M31 + matrix1.M44 * inverse.M41;
result.M42 = matrix1.M41 * inverse.M12 + matrix1.M42 * inverse.M22 + matrix1.M43 * inverse.M32 + matrix1.M44 * inverse.M42;
result.M43 = matrix1.M41 * inverse.M13 + matrix1.M42 * inverse.M23 + matrix1.M43 * inverse.M33 + matrix1.M44 * inverse.M43;
result.M44 = matrix1.M41 * inverse.M14 + matrix1.M42 * inverse.M24 + matrix1.M43 * inverse.M34 + matrix1.M44 * inverse.M44;
return(result);
}
public static GsMatrix CreateTranslation(float xPosition, float yPosition, float zPosition)
{
GsMatrix returnMatrix = GsMatrix.Identity;
returnMatrix.M41 = xPosition;
returnMatrix.M42 = yPosition;
returnMatrix.M43 = zPosition;
return(returnMatrix);
}
public static GsMatrix CreateScale(float xScale, float yScale, float zScale)
{
GsMatrix returnMatrix = GsMatrix.Identity;
returnMatrix.M11 = xScale;
returnMatrix.M22 = yScale;
returnMatrix.M33 = zScale;
return(returnMatrix);
}
public static GsMatrix CreateScale(float scale)
{
GsMatrix returnMatrix = GsMatrix.Identity;
returnMatrix.M11 = scale;
returnMatrix.M22 = scale;
returnMatrix.M33 = scale;
return(returnMatrix);
}
public static GsMatrix CreateRotationY(float radians)
{
GsMatrix returnMatrix = GsMatrix.Identity;
returnMatrix.M11 = (float)Math.Cos(radians);
returnMatrix.M13 = (float)Math.Sin(radians);
returnMatrix.M31 = -returnMatrix.M13;
returnMatrix.M33 = returnMatrix.M11;
return(returnMatrix);
}
public static GsMatrix CreateRotationX(float radians)
{
GsMatrix returnMatrix = GsMatrix.Identity;
returnMatrix.M22 = (float)Math.Cos(radians);
returnMatrix.M23 = (float)Math.Sin(radians);
returnMatrix.M32 = -returnMatrix.M23;
returnMatrix.M33 = returnMatrix.M22;
return(returnMatrix);
}
public static GsMatrix CreateRotationZ(float radians)
{
GsMatrix returnMatrix = GsMatrix.Identity;
returnMatrix.M11 = (float)Math.Cos(radians);
returnMatrix.M12 = (float)Math.Sin(radians);
returnMatrix.M21 = -returnMatrix.M12;
returnMatrix.M22 = returnMatrix.M11;
return(returnMatrix);
}
public static void Invert(ref GsMatrix matrix, out GsMatrix result)
{
//
// Use Laplace expansion theorem to calculate the inverse of a 4x4 matrix
//
// 1. Calculate the 2x2 determinants needed and the 4x4 determinant based on the 2x2 determinants
// 2. Create the adjugate matrix, which satisfies: A * adj(A) = det(A) * I
// 3. Divide adjugate matrix with the determinant to find the inverse
float det1 = matrix.M11 * matrix.M22 - matrix.M12 * matrix.M21;
float det2 = matrix.M11 * matrix.M23 - matrix.M13 * matrix.M21;
float det3 = matrix.M11 * matrix.M24 - matrix.M14 * matrix.M21;
float det4 = matrix.M12 * matrix.M23 - matrix.M13 * matrix.M22;
float det5 = matrix.M12 * matrix.M24 - matrix.M14 * matrix.M22;
float det6 = matrix.M13 * matrix.M24 - matrix.M14 * matrix.M23;
float det7 = matrix.M31 * matrix.M42 - matrix.M32 * matrix.M41;
float det8 = matrix.M31 * matrix.M43 - matrix.M33 * matrix.M41;
float det9 = matrix.M31 * matrix.M44 - matrix.M34 * matrix.M41;
float det10 = matrix.M32 * matrix.M43 - matrix.M33 * matrix.M42;
float det11 = matrix.M32 * matrix.M44 - matrix.M34 * matrix.M42;
float det12 = matrix.M33 * matrix.M44 - matrix.M34 * matrix.M43;
float detMatrix = (float)(det1 * det12 - det2 * det11 + det3 * det10 + det4 * det9 - det5 * det8 + det6 * det7);
float invDetMatrix = 1f / detMatrix;
GsMatrix ret; // Allow for matrix and result to point to the same structure
ret.M11 = (matrix.M22 * det12 - matrix.M23 * det11 + matrix.M24 * det10) * invDetMatrix;
ret.M12 = (-matrix.M12 * det12 + matrix.M13 * det11 - matrix.M14 * det10) * invDetMatrix;
ret.M13 = (matrix.M42 * det6 - matrix.M43 * det5 + matrix.M44 * det4) * invDetMatrix;
ret.M14 = (-matrix.M32 * det6 + matrix.M33 * det5 - matrix.M34 * det4) * invDetMatrix;
ret.M21 = (-matrix.M21 * det12 + matrix.M23 * det9 - matrix.M24 * det8) * invDetMatrix;
ret.M22 = (matrix.M11 * det12 - matrix.M13 * det9 + matrix.M14 * det8) * invDetMatrix;
ret.M23 = (-matrix.M41 * det6 + matrix.M43 * det3 - matrix.M44 * det2) * invDetMatrix;
ret.M24 = (matrix.M31 * det6 - matrix.M33 * det3 + matrix.M34 * det2) * invDetMatrix;
ret.M31 = (matrix.M21 * det11 - matrix.M22 * det9 + matrix.M24 * det7) * invDetMatrix;
ret.M32 = (-matrix.M11 * det11 + matrix.M12 * det9 - matrix.M14 * det7) * invDetMatrix;
ret.M33 = (matrix.M41 * det5 - matrix.M42 * det3 + matrix.M44 * det1) * invDetMatrix;
ret.M34 = (-matrix.M31 * det5 + matrix.M32 * det3 - matrix.M34 * det1) * invDetMatrix;
ret.M41 = (-matrix.M21 * det10 + matrix.M22 * det8 - matrix.M23 * det7) * invDetMatrix;
ret.M42 = (matrix.M11 * det10 - matrix.M12 * det8 + matrix.M13 * det7) * invDetMatrix;
ret.M43 = (-matrix.M41 * det4 + matrix.M42 * det2 - matrix.M43 * det1) * invDetMatrix;
ret.M44 = (matrix.M31 * det4 - matrix.M32 * det2 + matrix.M33 * det1) * invDetMatrix;
result = ret;
}
private GsVector[] GetPoints(GsVector[] hull, GsMatrix transform)
{
mMinX = float.MaxValue;
mMaxX = float.MinValue;
mMinY = float.MaxValue;
mMaxY = float.MinValue;
List <GsVector> points = new List <GsVector>(hull.Length);
foreach (GsVector pt in hull)
{
points.Add(GsVector.Transform(pt, transform));
float x = points[points.Count - 1].X;
float y = points[points.Count - 1].Y;
mMinX = Math.Min(mMinX, x);
mMinY = Math.Min(mMinY, y);
mMaxX = Math.Max(mMaxX, x);
mMaxY = Math.Max(mMaxY, y);
}
return(points.ToArray());
}
/// <summary>
/// Creates a new polygon from a collection of points (connecting them together) and applies
/// the transformation on the result.
/// </summary>
/// <param name="points">The points to use to construct the polygon.</param>
/// <param name="transform">The transform to apply to the polygon.</param>
public GsPolygon(GsVector[] points, GsMatrix transform)
{
mPoints = GetPoints(points, transform);
mEdges = GetEdges(mPoints);
}
public static GsMatrix Invert(GsMatrix matrix)
{
Invert(ref matrix, out matrix);
return(matrix);
}
public static GsVector Transform(GsVector position, GsMatrix matrix)
{
return(new GsVector((position.X * matrix.M11) + (position.Y * matrix.M21) + matrix.M41,
(position.X * matrix.M12) + (position.Y * matrix.M22) + matrix.M42));
}
