Matrix tests and fix

Author: ClickerMonkey

pkg/core.go

@@ -294,7 +294,7 @@ func (m *Matrix[A]) Cofactor(other Matrix[A]) {
 	for c := 0; c < n; c++ {
 		col := m.columns[c]
 		for r := 0; r < n; r++ {
-			negative := (r*n+c)&1 == 1
+			negative := (r+c)&1 == 1
 			if negative {
 				col.SetComponent(r, -col.GetComponent(r), &m.columns[c])
 			}

pkg/core_test.go

@@ -54,6 +54,143 @@ func TestMatrix(t *testing.T) {
 				{6, 3},
 			},
 		},
+		{
+			name: "minor 3x3",
+			getActual: func() any {
+				m := InitMatrix(Matrix3f{})
+				m.SetValues([][]float32{
+					{2, -1, 3},
+					{0, 5, 2},
+					{1, -1, -2},
+				})
+
+				actual := InitMatrix(Matrix3f{})
+				actual.Minor(m)
+				return actual.GetValues()
+			},
+			expected: [][]float32{
+				{-8, -2, -5},
+				{5, -7, -1},
+				{-17, 4, 10},
+			},
+		},
+		{
+			name: "cofactor 3x3",
+			getActual: func() any {
+				m := InitMatrix(Matrix3f{})
+				m.SetValues([][]float32{
+					{2, -1, 3},
+					{0, 5, 2},
+					{1, -1, -2},
+				})
+
+				actual := InitMatrix(Matrix3f{})
+				actual.Cofactor(m)
+				return actual.GetValues()
+			},
+			expected: [][]float32{
+				{-8, 2, -5},
+				{-5, -7, 1},
+				{-17, -4, 10},
+			},
+		},
+		{
+			name: "cofactor 3x3 #2",
+			getActual: func() any {
+				m := InitMatrix(Matrix3f{})
+				m.SetValues([][]float32{
+					{1, 2, -1},
+					{2, 1, 2},
+					{-1, 2, 1},
+				})
+
+				actual := InitMatrix(Matrix3f{})
+				actual.Cofactor(m)
+				return actual.GetValues()
+			},
+			expected: [][]float32{
+				{-3, -4, 5},
+				{-4, 0, -4},
+				{5, -4, -3},
+			},
+		},
+		{
+			name: "transpose 3x3",
+			getActual: func() any {
+				m := InitMatrix(Matrix3f{})
+				m.SetValues([][]float32{
+					{2, -1, 3},
+					{0, 5, 2},
+					{1, -1, -2},
+				})
+
+				actual := InitMatrix(Matrix3f{})
+				actual.Transpose(m)
+				return actual.GetValues()
+			},
+			expected: [][]float32{
+				{2, 0, 1},
+				{-1, 5, -1},
+				{3, 2, -2},
+			},
+		},
+		{
+			name: "adjoint 2x2",
+			getActual: func() any {
+				m := InitMatrix(Matrix2f{})
+				m.SetValues([][]float32{
+					{3, 6},
+					{-4, 8},
+				})
+				// minor = 8, -4, 6, 3
+				//
+				actual := InitMatrix(Matrix2f{})
+				actual.Adjoint(m)
+				return actual.GetValues()
+			},
+			expected: [][]float32{
+				{8, -6},
+				{4, 3},
+			},
+		},
+		{
+			name: "adjoint 3x3",
+			getActual: func() any {
+				m := InitMatrix(Matrix3f{})
+				m.SetValues([][]float32{
+					{2, -1, 3},
+					{0, 5, 2},
+					{1, -1, -2},
+				})
+
+				actual := InitMatrix(Matrix3f{})
+				actual.Adjoint(m)
+				return actual.GetValues()
+			},
+			expected: [][]float32{
+				{-8, -5, -17},
+				{2, -7, -4},
+				{-5, 1, 10},
+			},
+		},
+		{
+			name: "inverse 2x2",
+			getActual: func() any {
+				m := InitMatrix(Matrix2f{})
+				m.SetValues([][]float32{
+					{3, 6},
+					{-4, 8},
+				})
+
+				actual := InitMatrix(Matrix2f{})
+				actual.Invert(m)
+				return actual.GetValues()
+			},
+			expected: [][]float32{
+				{1.0 / 6, -1.0 / 8},
+				{1.0 / 12, 1.0 / 16},
+			},
+		},
 	}
 
 	for _, test := range tests {