5 files changed, 49 insertions, 7 deletions

diff --git a/src/common/alignment.h b/src/common/alignment.h
index fa715d497..fc5c26898 100644
--- a/src/common/alignment.h
+++ b/src/common/alignment.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <bit>
 #include <cstddef>
 #include <new>
 #include <type_traits>
@@ -10,8 +11,10 @@
 namespace Common {
 
 template <typename T>
-    requires std::is_unsigned_v<T>
-[[nodiscard]] constexpr T AlignUp(T value, size_t size) {
+    requires std::is_integral_v<T>
+[[nodiscard]] constexpr T AlignUp(T value_, size_t size) {
+    using U = typename std::make_unsigned_t<T>;
+    auto value{static_cast<U>(value_)};
     auto mod{static_cast<T>(value % size)};
     value -= mod;
     return static_cast<T>(mod == T{0} ? value : value + size);
@@ -24,8 +27,10 @@ template <typename T>
 }
 
 template <typename T>
-    requires std::is_unsigned_v<T>
-[[nodiscard]] constexpr T AlignDown(T value, size_t size) {
+    requires std::is_integral_v<T>
+[[nodiscard]] constexpr T AlignDown(T value_, size_t size) {
+    using U = typename std::make_unsigned_t<T>;
+    const auto value{static_cast<U>(value_)};
     return static_cast<T>(value - value % size);
 }
 
@@ -55,6 +60,30 @@ template <typename T, typename U>
     return (x + (y - 1)) / y;
 }
 
+template <typename T>
+    requires std::is_integral_v<T>
+[[nodiscard]] constexpr T LeastSignificantOneBit(T x) {
+    return x & ~(x - 1);
+}
+
+template <typename T>
+    requires std::is_integral_v<T>
+[[nodiscard]] constexpr T ResetLeastSignificantOneBit(T x) {
+    return x & (x - 1);
+}
+
+template <typename T>
+    requires std::is_integral_v<T>
+[[nodiscard]] constexpr bool IsPowerOfTwo(T x) {
+    return x > 0 && ResetLeastSignificantOneBit(x) == 0;
+}
+
+template <typename T>
+    requires std::is_integral_v<T>
+[[nodiscard]] constexpr T FloorPowerOfTwo(T x) {
+    return T{1} << (sizeof(T) * 8 - std::countl_zero(x) - 1);
+}
+
 template <typename T, size_t Align = 16>
 class AlignmentAllocator {
 public:
diff --git a/src/common/lz4_compression.cpp b/src/common/lz4_compression.cpp
index ffb32fecf..d85ab1742 100644
--- a/src/common/lz4_compression.cpp
+++ b/src/common/lz4_compression.cpp
@@ -71,4 +71,10 @@ std::vector<u8> DecompressDataLZ4(std::span<const u8> compressed, std::size_t un
     return uncompressed;
 }
 
+int DecompressDataLZ4(void* dst, size_t dst_size, const void* src, size_t src_size) {
+    // This is just a thin wrapper around LZ4.
+    return LZ4_decompress_safe(reinterpret_cast<const char*>(src), reinterpret_cast<char*>(dst),
+                               static_cast<int>(src_size), static_cast<int>(dst_size));
+}
+
 } // namespace Common::Compression
diff --git a/src/common/lz4_compression.h b/src/common/lz4_compression.h
index 7fd53a960..3ae17c2bb 100644
--- a/src/common/lz4_compression.h
+++ b/src/common/lz4_compression.h
@@ -56,4 +56,6 @@ namespace Common::Compression {
 [[nodiscard]] std::vector<u8> DecompressDataLZ4(std::span<const u8> compressed,
                                                 std::size_t uncompressed_size);
 
+[[nodiscard]] int DecompressDataLZ4(void* dst, size_t dst_size, const void* src, size_t src_size);
+
 } // namespace Common::Compression
diff --git a/src/common/settings.cpp b/src/common/settings.cpp
index 15fd2e222..16a58a750 100644
--- a/src/common/settings.cpp
+++ b/src/common/settings.cpp
@@ -207,9 +207,7 @@ const char* TranslateCategory(Category category) {
     return "Miscellaneous";
 }
 
-void UpdateRescalingInfo() {
-    const auto setup = values.resolution_setup.GetValue();
-    auto& info = values.resolution_info;
+void TranslateResolutionInfo(ResolutionSetup setup, ResolutionScalingInfo& info) {
     info.downscale = false;
     switch (setup) {
     case ResolutionSetup::Res1_2X:
@@ -269,6 +267,12 @@ void UpdateRescalingInfo() {
     info.active = info.up_scale != 1 || info.down_shift != 0;
 }
 
+void UpdateRescalingInfo() {
+    const auto setup = values.resolution_setup.GetValue();
+    auto& info = values.resolution_info;
+    TranslateResolutionInfo(setup, info);
+}
+
 void RestoreGlobalState(bool is_powered_on) {
     // If a game is running, DO NOT restore the global settings state
     if (is_powered_on) {
diff --git a/src/common/settings.h b/src/common/settings.h
index b0bc6519a..4407c1e6d 100644
--- a/src/common/settings.h
+++ b/src/common/settings.h
@@ -525,6 +525,7 @@ std::string GetTimeZoneString(TimeZone time_zone);
 
 void LogSettings();
 
+void TranslateResolutionInfo(ResolutionSetup setup, ResolutionScalingInfo& info);
 void UpdateRescalingInfo();
 
 // Restore the global state of all applicable settings in the Values struct