feat: add diagonal mirror of RawCode

src/core/raw_code/internal/mirror.inl

@@ -2,8 +2,6 @@
 
 namespace klotski::codec {
 
-// TODO: add `diagonal_mirror` support
-
 constexpr uint64_t RawCode::get_vertical_mirror(const uint64_t raw_code) {
     uint64_t code = ((raw_code >> 36) & 0x000'000'000'fff'fff) | ((raw_code << 36) & 0xfff'fff'000'000'000);
     code = ((code >> 12) & 0x000'fff'000'000'fff) | ((code << 12) & 0xfff'000'000'fff'000);
@@ -25,6 +23,11 @@ constexpr uint64_t RawCode::get_horizontal_mirror(const uint64_t raw_code) {
     return (code | m1 | m2) & ~(m1 >> 3) & ~(m2 >> 3);
 }
 
+constexpr uint64_t RawCode::get_diagonal_mirror(const uint64_t raw_code) {
+    // TODO: perf it
+    return get_horizontal_mirror(get_vertical_mirror(raw_code));
+}
+
 constexpr bool RawCode::check_mirror(const uint64_t raw_code) {
     const uint64_t m1 = ~raw_code & (raw_code << 1) & 0x492'492'492'492'492;
     const uint64_t m2 = raw_code & 0x924'924'924'924'924;

src/core/raw_code/internal/raw_code.inl

@@ -67,6 +67,10 @@ constexpr bool RawCode::is_horizontal_mirror() const {
     return check_mirror(code_);
 }
 
+constexpr RawCode RawCode::to_diagonal_mirror() const {
+    return unsafe_create(get_diagonal_mirror(code_));
+}
+
 constexpr RawCode RawCode::to_vertical_mirror() const {
     return unsafe_create(get_vertical_mirror(code_));
 }

src/core/raw_code/raw_code.h

@@ -127,6 +127,9 @@ public:
     /// Whether the layout is horizontally symmetrical.
     [[nodiscard]] constexpr bool is_horizontal_mirror() const;
 
+    /// Calculate the diagonally symmetrical klotski layout.
+    [[nodiscard]] constexpr RawCode to_diagonal_mirror() const;
+
     /// Calculate the vertically symmetrical klotski layout.
     [[nodiscard]] constexpr RawCode to_vertical_mirror() const;
 
@@ -161,6 +164,9 @@ private:
     /// Check the horizontally symmetrical.
     static constexpr bool check_mirror(uint64_t raw_code);
 
+    /// Get the diagonally symmetrical layout.
+    static constexpr uint64_t get_diagonal_mirror(uint64_t raw_code);
+
     /// Get the vertically symmetrical layout.
     static constexpr uint64_t get_vertical_mirror(uint64_t raw_code);