utils_simd.hpp File Reference

SIMD-accelerated helper functions for image manipulation. More...

#include "game_config.hpp"
#include "preferences/preferences.hpp"
#include "sdl/surface.hpp"
#include <cstdint>
#include <algorithm>

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Namespaces
	simd

Functions
bool	simd::is_enabled ()
	Checks if SIMD hardware acceleration is allowed/enabeled. More...
std::size_t	mask_surface_simd (surface &surf, const surface &mask, bool &empty)
	Modifies the alpha channel of the surface pixels based on the mask. More...
std::size_t	apply_surface_opacity_simd (surface &surf, uint8_t alpha_mod)
	Applies an alpha modification to the whole surface using SIMD. More...
std::size_t	adjust_surface_color_simd (surface &surf, int r, int g, int b)
	Adjusts the color channels of a surface using saturated SIMD arithmetic. More...
std::size_t	flip_image_simd (surface &surf)
	Flips each row of pixels (horizontal mirror) using SIMD. More...

Variables
constexpr std::size_t	simd::SIMD_THRESHOLD = 64
	Minimum number of pixels required to trigger SIMD optimizations. More...

Detailed Description

SIMD-accelerated helper functions for image manipulation.

These functions operate on raw pixel buffers to isolate platform-specific intrinsics (SSE2, NEON) from the main codebase.

Definition in file utils_simd.hpp.

Function Documentation

adjust_surface_color_simd()

std::size_t adjust_surface_color_simd	(	surface &	surf,
		int	r,
		int	g,
		int	b
	)

Adjusts the color channels of a surface using saturated SIMD arithmetic.

Parameters

surf	The surface to modify.
r,g,b	Amounts to add (positive) or subtract (negative) per channel. Clamped to [-255, 255].

Returns

Number of pixels processed via SIMD, or 0 if SIMD was not used.

Definition at line 337 of file utils_simd.cpp.

References surface::area(), b, g, surface_locker< T >::pixels(), simd::SIMD_THRESHOLD, and surf.

Referenced by adjust_surface_color().

apply_surface_opacity_simd()

std::size_t apply_surface_opacity_simd	(	surface &	surf,
		uint8_t	alpha_mod
	)

Applies an alpha modification to the whole surface using SIMD.

Parameters

surf	The surface to modify.
alpha_mod	The 0-255 modifier to multiply the existing alpha by.

Returns

Number of pixels processed via SIMD, or 0 if SIMD was not used.

Definition at line 320 of file utils_simd.cpp.

References surface::area(), surface_locker< T >::pixels(), simd::SIMD_THRESHOLD, and surf.

Referenced by apply_surface_opacity().

flip_image_simd()

std::size_t flip_image_simd

(

surface &

surf

)

Flips each row of pixels (horizontal mirror) using SIMD.

Parameters

surf	The surface to modify.

Returns

Number of columns (per row) processed via SIMD, or 0 if SIMD was not used.

Definition at line 354 of file utils_simd.cpp.

References surface::area(), surface_locker< T >::pixels(), simd::SIMD_THRESHOLD, and surf.

Referenced by flip_surface().

mask_surface_simd()

std::size_t mask_surface_simd	(	surface &	surf,
		const surface &	mask,
		bool &	empty
	)

Modifies the alpha channel of the surface pixels based on the mask.

Parameters

surf	The surface to modify.
mask	The mask surface to read alpha values from.
empty	Output: set to false if any resulting pixel is non-transparent. Should be initialised to true by the caller.

Returns

Number of pixels processed via SIMD (always a multiple of 4), or 0 if SIMD was unavailable / pixel count was below the threshold.

Definition at line 302 of file utils_simd.cpp.

References surface::area(), surface_locker< T >::pixels(), simd::SIMD_THRESHOLD, and surf.

Referenced by mask_surface().