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Implement Mat4x4::Swaps

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josh
2024-02-01 17:49:05 -05:00
parent 69ca7c5c05
commit 0597b4c937
4 changed files with 106 additions and 20 deletions
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75
include/J3ML/LinearAlgebra/Matrix4x4.h
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@@ -44,9 +44,9 @@ namespace LinearAlgebra {
/// The elements are specified in row-major format, i.e. the first row first followed by the second and third row.
/// E.g. The element _10 denotes the scalar at second (index 1) row, first (index 0) column.
Matrix4x4(float m00, float m01, float m02, float m03,
float m10, float m11, float m12, float m13,
float m20, float m21, float m22, float m23,
float m30, float m31, float m32, float m33);
float m10, float m11, float m12, float m13,
float m20, float m21, float m22, float m23,
float m30, float m31, float m32, float m33);
/// Constructs the matrix by explicitly specifying the four column vectors.
/** @param col0 The first column. If this matrix represents a change-of-basis transformation, this parameter is the world-space
direction of the local X axis.
@@ -116,15 +116,77 @@ namespace LinearAlgebra {
void SetRow(int row, const Vector4& rowVector);
void SetRow(int row, float m_r0, float m_r1, float m_r2, float m_r3);
Vector4 GetRow(int index) const;
Vector4 GetColumn(int index) const;
Vector3 GetRow3(int index) const;
Vector3 GetColumn3(int index) const;
float &At(int row, int col);
float At(int x, int y) const;
template <typename T>
void Swap(T &a, T &b)
{
T temp = std::move(a);
a = std::move(b);
b = std::move(temp);
}
void SwapColumns(int col1, int col2)
{
Swap(At(0, col1), At(0, col2));
Swap(At(1, col1), At(1, col2));
Swap(At(2, col1), At(2, col2));
Swap(At(3, col1), At(3, col2));
}
/// Swaps two rows.
void SwapRows(int row1, int row2)
{
Swap(At(row1, 0), At(row2, 0));
Swap(At(row1, 1), At(row2, 1));
Swap(At(row1, 2), At(row2, 2));
Swap(At(row1, 3), At(row2, 3));
}
/// Swapsthe xyz-parts of two rows element-by-element
void SwapRows3(int row1, int row2)
{
Swap(At(row1, 0), At(row2, 0));
Swap(At(row1, 1), At(row2, 1));
Swap(At(row1, 2), At(row2, 2));
}
/// Algorithm from Eric Lengyel's Mathematics for 3D Game Programming & Computer Graphics, 2nd Ed.
void Pivot()
{
int rowIndex = 0;
for(int col = 0; col < Cols; ++col)
{
int greatest = rowIndex;
// find the rowIndex k with k >= 1 for which Mkj has the largest absolute value.
for(int i = rowIndex; i < Rows; ++i)
if (std::abs(At(i, col)) > std::abs(At(greatest, col)))
greatest = i;
if (std::abs(At(greatest, col)) != 0)
{
if (rowIndex != greatest)
SwapRows(rowIndex, greatest); // the greatest now in rowIndex
ScaleRow(rowIndex, 1.f/At(rowIndex, col));
for(int r = 0; r < Rows; ++r)
if (r != rowIndex)
SetRow(r, GetRow(r) - GetRow(rowIndex) * At(r, col));
++rowIndex;
}
}
}
/// Tests if this matrix does not contain any NaNs or infs.
/** @return Returns true if the entries of this float4x4 are all finite, and do not contain NaN or infs. */
bool IsFinite() const;
@@ -190,9 +252,6 @@ namespace LinearAlgebra {
static Matrix4x4 OpenGLPerspProjLH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
static Matrix4x4 OpenGLPerspProjRH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
Vector4 GetRow() const;
Vector4 GetColumn() const;
Vector4 operator[](int row);
Matrix4x4 operator-() const;