96 lines
3.2 KiB
C
96 lines
3.2 KiB
C
|
// This file is part of Blend2D project <https://blend2d.com>
|
||
|
|
//
|
||
|
|
// See blend2d.h or LICENSE.md for license and copyright information
|
||
|
|
// SPDX-License-Identifier: Zlib
|
||
|
|
|
||
|
|
#ifndef BLEND2D_RUNTIMESCOPE_H_INCLUDED
|
||
|
|
#define BLEND2D_RUNTIMESCOPE_H_INCLUDED
|
||
|
|
|
||
|
|
#include "api.h"
|
||
|
|
|
||
|
|
//! \addtogroup blend2d_api_runtime
|
||
|
|
//! \{
|
||
|
|
|
||
|
|
//! \name BLRuntimeScope - C API
|
||
|
|
//! \{
|
||
|
|
|
||
|
|
//! Blend2D runtime scope [C API].
|
||
|
|
struct BLRuntimeScopeCore {
|
||
|
|
uint32_t data[2];
|
||
|
|
};
|
||
|
|
|
||
|
|
BL_BEGIN_C_DECLS
|
||
|
|
|
||
|
|
BL_API BLResult BL_CDECL blRuntimeScopeBegin(BLRuntimeScopeCore* self) BL_NOEXCEPT_C;
|
||
|
|
BL_API BLResult BL_CDECL blRuntimeScopeEnd(BLRuntimeScopeCore* self) BL_NOEXCEPT_C;
|
||
|
|
BL_API bool BL_CDECL blRuntimeScopeIsActive(const BLRuntimeScopeCore* self) BL_NOEXCEPT_C;
|
||
|
|
|
||
|
|
BL_END_C_DECLS
|
||
|
|
|
||
|
|
//! \}
|
||
|
|
|
||
|
|
#if defined(__cplusplus)
|
||
|
|
//! \name BLRuntimeScope - C++ API
|
||
|
|
//! \{
|
||
|
|
|
||
|
|
//! Blend2D runtime scope [C++ API].
|
||
|
|
//!
|
||
|
|
//! Runtime scope is a totally optional feature that can be used by Blend2D to setup the current thread's control
|
||
|
|
//! word in a way to make the behavior of some floating point computations consistent between platforms. Blend2D
|
||
|
|
//! doesn't rely on any specific behavior, however, for testing purposes and possibly consistency of rendering
|
||
|
|
//! across different architectures some setup may be necessary.
|
||
|
|
//!
|
||
|
|
//! The runtime scope current only changes FPU control word in 32-bit x86 case to 64-bit precision. This means
|
||
|
|
//! that if the FPU control word was set to 80-bits the precision of floating computations would be basically
|
||
|
|
//! lowered, but this is necessary to make sure that intermediate computations match other platforms that don't
|
||
|
|
//! have extended precision. Blend2D doesn't rely on extended precision in any way and this all is needed only
|
||
|
|
//! if 100% consistency is required across different platforms.
|
||
|
|
//!
|
||
|
|
//! At the moment BLRuntimeScope is only used by tests to ensure that we can compare reference implementation
|
||
|
|
//! written in C++ with SIMD optimized implementation written either in C++ or generated at runtime (JIT).
|
||
|
|
//!
|
||
|
|
//! As the name of the class suggests, `BLRuntimeScope` establishes a scope, so the FPU control word would only
|
||
|
|
//! be changed temporarily within the life-time of the scope.
|
||
|
|
//!
|
||
|
|
//! Example:
|
||
|
|
//!
|
||
|
|
//! ```
|
||
|
|
//! void do_something(BLImage& image) noexcept {
|
||
|
|
//! // Establishes a new scope by possibly changing the environment (FPU control word).
|
||
|
|
//! BLRuntimeScope scope;
|
||
|
|
//!
|
||
|
|
//! BLContext ctx(image);
|
||
|
|
//! // ... do something ...
|
||
|
|
//!
|
||
|
|
//! // The scope ends here - the environment is restored.
|
||
|
|
//! }
|
||
|
|
//! ```
|
||
|
|
class BLRuntimeScope final : public BLRuntimeScopeCore {
|
||
|
|
BLRuntimeScope(BLRuntimeScope& other) noexcept = delete;
|
||
|
|
BLRuntimeScope& operator=(BLRuntimeScope& other) noexcept = delete;
|
||
|
|
|
||
|
|
public:
|
||
|
|
//! \name Construction & Destruction
|
||
|
|
//! \{
|
||
|
|
|
||
|
|
//! Establishes a new runtime scope by possibly changing the state of FPU control word.
|
||
|
|
BL_INLINE_NODEBUG BLRuntimeScope() noexcept { blRuntimeScopeBegin(this); }
|
||
|
|
//! Restores the scope to the previous state.
|
||
|
|
BL_INLINE_NODEBUG ~BLRuntimeScope() noexcept { blRuntimeScopeEnd(this); }
|
||
|
|
|
||
|
|
//! \}
|
||
|
|
|
||
|
|
//! \name Accessors
|
||
|
|
//! \{
|
||
|
|
|
||
|
|
BL_INLINE_NODEBUG bool isActive() const noexcept { return blRuntimeScopeIsActive(this); }
|
||
|
|
|
||
|
|
//! \}
|
||
|
|
};
|
||
|
|
//! \}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
//! \}
|
||
|
|
|
||
|
|
#endif // BLEND2D_RUNTIMESCOPE_H_INCLUDED
|