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Implement Mat4x4::FromTranslation

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josh
2024-02-01 20:07:00 -05:00
parent 0597b4c937
commit 432fa32f57
2 changed files with 91 additions and 51 deletions
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61
include/J3ML/LinearAlgebra/Matrix4x4.h
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@@ -58,7 +58,6 @@ namespace LinearAlgebra {
position of the local space pivot. */
Matrix4x4(const Vector4& r1, const Vector4& r2, const Vector4& r3, const Vector4& r4);
explicit Matrix4x4(const Quaternion& orientation);
/// Constructs this float4x4 from the given quaternion and translation.
@@ -96,6 +95,8 @@ namespace LinearAlgebra {
@see RotateFromTo(). */
static Matrix4x4 LookAt(const Vector3& localFwd, const Vector3& targetDir, const Vector3& localUp, const Vector3& worldUp);
static Matrix4x4 FromTranslation(const Vector3& translation);
/// Returns the translation part.
/** The translation part is stored in the fourth column of this matrix.
This is equivalent to decomposing this matrix in the form M = T * M', i.e. this translation is applied last,
@@ -110,8 +111,6 @@ namespace LinearAlgebra {
void SetRotatePart(const Quaternion& q);
void Set3x3Part(const Matrix3x3& r);
void SetRow(int row, const Vector3& rowVector, float m_r3);
void SetRow(int row, const Vector4& rowVector);
void SetRow(int row, float m_r0, float m_r1, float m_r2, float m_r3);
@@ -133,59 +132,19 @@ namespace LinearAlgebra {
}
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));
}
void SwapColumns(int col1, int 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));
}
void SwapRows(int row1, int row2);
/// 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));
}
void SwapRows3(int row1, int row2);
void ScaleRow(int row, float scalar);
void ScaleRow3(int row, float scalar);
void ScaleColumn(int col, float scalar);
void ScaleColumn3(int col, float scalar);
/// 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;
}
}
}
void Pivot();
/// 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. */

81
src/J3ML/LinearAlgebra/Matrix4x4.cpp
View File

@@ -440,4 +440,85 @@ namespace LinearAlgebra {
Vector3 Matrix4x4::GetRow3(int index) const {
return Vector3{ At(index, 0), At(index, 1), At(index, 2)};
}
void Matrix4x4::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));
}
void Matrix4x4::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));
}
void Matrix4x4::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));
}
void Matrix4x4::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;
}
}
}
void Matrix4x4::ScaleColumn3(int col, float scalar) {
At(0, col) *= scalar;
At(1, col) *= scalar;
At(2, col) *= scalar;
}
void Matrix4x4::ScaleColumn(int col, float scalar) {
At(0, col) *= scalar;
At(1, col) *= scalar;
At(2, col) *= scalar;
At(3, col) *= scalar;
}
void Matrix4x4::ScaleRow3(int row, float scalar) {
At(row, 0) *= scalar;
At(row, 1) *= scalar;
At(row, 2) *= scalar;
}
void Matrix4x4::ScaleRow(int row, float scalar) {
At(row, 0) *= scalar;
At(row, 1) *= scalar;
At(row, 2) *= scalar;
At(row, 3) *= scalar;
}
Matrix4x4 Matrix4x4::FromTranslation(const Vector3 &translation) {
Matrix4x4 m;
m.SetTranslatePart(translation);
m.Set3x3Part(Matrix3x3::Identity);
return m;
}
}