[Impeller] Add Quaternion to Matrix conversion

impeller/geometry/geometry_unittests.cc

@@ -265,6 +265,26 @@ TEST(GeometryTest, MatrixVectorMultiplication) {
   }
 }
 
+TEST(GeometryTest, MatrixMakeRotationFromQuaternion) {
+  {
+    auto matrix = Matrix::MakeRotation(Quaternion({1, 0, 0}, kPiOver2));
+    auto expected = Matrix::MakeRotationX(Radians(kPiOver2));
+    ASSERT_MATRIX_NEAR(matrix, expected);
+  }
+
+  {
+    auto matrix = Matrix::MakeRotation(Quaternion({0, 1, 0}, kPiOver2));
+    auto expected = Matrix::MakeRotationY(Radians(kPiOver2));
+    ASSERT_MATRIX_NEAR(matrix, expected);
+  }
+
+  {
+    auto matrix = Matrix::MakeRotation(Quaternion({0, 0, 1}, kPiOver2));
+    auto expected = Matrix::MakeRotationZ(Radians(kPiOver2));
+    ASSERT_MATRIX_NEAR(matrix, expected);
+  }
+}
+
 TEST(GeometryTest, MatrixTransformDirection) {
   {
     auto matrix = Matrix::MakeTranslation({100, 100, 100}) *

impeller/geometry/matrix.h

@@ -122,6 +122,31 @@ struct Matrix {
     // clang-format on
   }
 
+  static Matrix MakeRotation(Quaternion q) {
+    // clang-format off
+    return Matrix(
+      1.0 - 2.0 * q.y * q.y - 2.0 * q.z * q.z,
+      2.0 * q.x * q.y + 2.0 * q.z * q.w,
+      2.0 * q.x * q.z - 2.0 * q.y * q.w,
+      0.0,
+
+      2.0 * q.x * q.y - 2.0 * q.z * q.w,
+      1.0 - 2.0 * q.x * q.x - 2.0 * q.z * q.z,
+      2.0 * q.y * q.z + 2.0 * q.x * q.w,
+      0.0,
+
+      2.0 * q.x * q.z + 2.0 * q.y * q.w,
+      2.0 * q.y * q.z - 2.0 * q.x * q.w,
+      1.0 - 2.0 * q.x * q.x - 2.0 * q.y * q.y,
+      0.0,
+
+      0.0,
+      0.0,
+      0.0,
+      1.0);
+    // clang-format on
+  }
+
   static Matrix MakeRotation(Scalar radians, const Vector4& r) {
     const Vector4 v = r.Normalize();