Implement Mat4x4::FromTranslation

2024-02-01 20:07:00 -05:00
parent 0597b4c937
commit 432fa32f57
2 changed files with 91 additions and 51 deletions
--- a/src/J3ML/LinearAlgebra/Matrix4x4.cpp
+++ b/src/J3ML/LinearAlgebra/Matrix4x4.cpp
@@ -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;
+    }
 }