6 files changed, 54 insertions, 38 deletions

diff --git a/core/os/keyboard.h b/core/os/keyboard.h
index 6315356510..84017e89a6 100644
--- a/core/os/keyboard.h
+++ b/core/os/keyboard.h
@@ -124,8 +124,6 @@ enum class Key {
 	KP_7 = SPECIAL | 0x8D,
 	KP_8 = SPECIAL | 0x8E,
 	KP_9 = SPECIAL | 0x8F,
-	SUPER_L = SPECIAL | 0x40,
-	SUPER_R = SPECIAL | 0x41,
 	MENU = SPECIAL | 0x42,
 	HYPER = SPECIAL | 0x43,
 	HELP = SPECIAL | 0x45,
diff --git a/core/os/mutex.h b/core/os/mutex.h
index c91917a9a1..ceedcb235a 100644
--- a/core/os/mutex.h
+++ b/core/os/mutex.h
@@ -31,7 +31,6 @@
 #ifndef MUTEX_H
 #define MUTEX_H
 
-#include "core/error/error_list.h"
 #include "core/typedefs.h"
 
 #include <mutex>
@@ -49,8 +48,8 @@ public:
 		mutex.unlock();
 	}
 
-	_ALWAYS_INLINE_ Error try_lock() const {
-		return mutex.try_lock() ? OK : ERR_BUSY;
+	_ALWAYS_INLINE_ bool try_lock() const {
+		return mutex.try_lock();
 	}
 };
 
diff --git a/core/os/os.cpp b/core/os/os.cpp
index 86469852e3..ef7d860d19 100644
--- a/core/os/os.cpp
+++ b/core/os/os.cpp
@@ -553,6 +553,16 @@ void OS::add_frame_delay(bool p_can_draw) {
 	}
 }
 
+OS::PreferredTextureFormat OS::get_preferred_texture_format() const {
+#if defined(__arm__) || defined(__aarch64__) || defined(_M_ARM) || defined(_M_ARM64)
+	return PREFERRED_TEXTURE_FORMAT_ETC2_ASTC; // By rule, ARM hardware uses ETC texture compression.
+#elif defined(__x86_64__) || defined(_M_X64) || defined(i386) || defined(__i386__) || defined(__i386) || defined(_M_IX86)
+	return PREFERRED_TEXTURE_FORMAT_S3TC_BPTC; // By rule, X86 hardware prefers S3TC and derivatives.
+#else
+	return PREFERRED_TEXTURE_FORMAT_S3TC_BPTC; // Override in platform if needed.
+#endif
+}
+
 OS::OS() {
 	singleton = this;
 
diff --git a/core/os/os.h b/core/os/os.h
index 436a83eae3..d77890d89d 100644
--- a/core/os/os.h
+++ b/core/os/os.h
@@ -290,6 +290,14 @@ public:
 	virtual Vector<String> get_granted_permissions() const { return Vector<String>(); }
 
 	virtual void process_and_drop_events() {}
+
+	enum PreferredTextureFormat {
+		PREFERRED_TEXTURE_FORMAT_S3TC_BPTC,
+		PREFERRED_TEXTURE_FORMAT_ETC2_ASTC
+	};
+
+	virtual PreferredTextureFormat get_preferred_texture_format() const;
+
 	OS();
 	virtual ~OS();
 };
diff --git a/core/os/rw_lock.h b/core/os/rw_lock.h
index e290b7c00b..a232fcb1ce 100644
--- a/core/os/rw_lock.h
+++ b/core/os/rw_lock.h
@@ -31,7 +31,7 @@
 #ifndef RW_LOCK_H
 #define RW_LOCK_H
 
-#include "core/error/error_list.h"
+#include "core/typedefs.h"
 
 #include <shared_mutex>
 
@@ -39,34 +39,34 @@ class RWLock {
 	mutable std::shared_timed_mutex mutex;
 
 public:
-	// Lock the rwlock, block if locked by someone else
-	void read_lock() const {
+	// Lock the RWLock, block if locked by someone else.
+	_ALWAYS_INLINE_ void read_lock() const {
 		mutex.lock_shared();
 	}
 
-	// Unlock the rwlock, let other threads continue
-	void read_unlock() const {
+	// Unlock the RWLock, let other threads continue.
+	_ALWAYS_INLINE_ void read_unlock() const {
 		mutex.unlock_shared();
 	}
 
-	// Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock.
-	Error read_try_lock() const {
-		return mutex.try_lock_shared() ? OK : ERR_BUSY;
+	// Attempt to lock the RWLock for reading. True on success, false means it can't lock.
+	_ALWAYS_INLINE_ bool read_try_lock() const {
+		return mutex.try_lock_shared();
 	}
 
-	// Lock the rwlock, block if locked by someone else
-	void write_lock() {
+	// Lock the RWLock, block if locked by someone else.
+	_ALWAYS_INLINE_ void write_lock() {
 		mutex.lock();
 	}
 
-	// Unlock the rwlock, let other thwrites continue
-	void write_unlock() {
+	// Unlock the RWLock, let other threads continue.
+	_ALWAYS_INLINE_ void write_unlock() {
 		mutex.unlock();
 	}
 
-	// Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock.
-	Error write_try_lock() {
-		return mutex.try_lock() ? OK : ERR_BUSY;
+	// Attempt to lock the RWLock for writing. True on success, false means it can't lock.
+	_ALWAYS_INLINE_ bool write_try_lock() {
+		return mutex.try_lock();
 	}
 };
 
@@ -74,11 +74,11 @@ class RWLockRead {
 	const RWLock &lock;
 
 public:
-	RWLockRead(const RWLock &p_lock) :
+	_ALWAYS_INLINE_ RWLockRead(const RWLock &p_lock) :
 			lock(p_lock) {
 		lock.read_lock();
 	}
-	~RWLockRead() {
+	_ALWAYS_INLINE_ ~RWLockRead() {
 		lock.read_unlock();
 	}
 };
@@ -87,11 +87,11 @@ class RWLockWrite {
 	RWLock &lock;
 
 public:
-	RWLockWrite(RWLock &p_lock) :
+	_ALWAYS_INLINE_ RWLockWrite(RWLock &p_lock) :
 			lock(p_lock) {
 		lock.write_lock();
 	}
-	~RWLockWrite() {
+	_ALWAYS_INLINE_ ~RWLockWrite() {
 		lock.write_unlock();
 	}
 };
diff --git a/core/os/semaphore.h b/core/os/semaphore.h
index 6a290f21c6..a992a4587d 100644
--- a/core/os/semaphore.h
+++ b/core/os/semaphore.h
@@ -39,32 +39,33 @@
 
 class Semaphore {
 private:
-	mutable std::mutex mutex_;
-	mutable std::condition_variable condition_;
-	mutable unsigned long count_ = 0; // Initialized as locked.
+	mutable std::mutex mutex;
+	mutable std::condition_variable condition;
+	mutable uint32_t count = 0; // Initialized as locked.
 
 public:
 	_ALWAYS_INLINE_ void post() const {
-		std::lock_guard<decltype(mutex_)> lock(mutex_);
-		++count_;
-		condition_.notify_one();
+		std::lock_guard lock(mutex);
+		count++;
+		condition.notify_one();
 	}
 
 	_ALWAYS_INLINE_ void wait() const {
-		std::unique_lock<decltype(mutex_)> lock(mutex_);
-		while (!count_) { // Handle spurious wake-ups.
-			condition_.wait(lock);
+		std::unique_lock lock(mutex);
+		while (!count) { // Handle spurious wake-ups.
+			condition.wait(lock);
 		}
-		--count_;
+		count--;
 	}
 
 	_ALWAYS_INLINE_ bool try_wait() const {
-		std::lock_guard<decltype(mutex_)> lock(mutex_);
-		if (count_) {
-			--count_;
+		std::lock_guard lock(mutex);
+		if (count) {
+			count--;
 			return true;
+		} else {
+			return false;
 		}
-		return false;
 	}
 };