GaussianBlur Class Reference

Applies an approximate gaussian blur using a dual filtering approach. More...

#include <GaussianBlur.hpp>

Public Member Functions
	GaussianBlur (uint radius, uint downscale, const std::string &name)
void	process (const Texture &src, Texture &dst)

Private Member Functions
void	resize (uint width, uint height)

Private Attributes
Program *	_blurProgramDown
	The downscaling filter.
Program *	_blurProgramUp
	The upscaling filter.
Program *	_passthrough
	The copy program.
std::vector< Texture >	_levels
	Downscaled pyramid textures.
uint	_downscale = 1
	Initial downscaling factor.

Detailed Description

Applies an approximate gaussian blur using a dual filtering approach.

Use a downscaled pyramid approach to approximate a gaussian blur with a large radius. The input texture is downscaled a number of times, using a custom filter as described by Marius Bjørge in the 'Bandwidth-Efficient Rendering' presentation, Siggraph 2015 (https://community.arm.com/cfs-file/__key/communityserver-blogs-components-weblogfiles/00-00-00-20-66/siggraph2015_2D00_mmg_2D00_marius_2D00_slides.pdf). The image is then upscaled again with a second custom filter.

See also

GPU::Frag::Blur-dual-filter-down, GPU::Frag::Blur-dual-filter-up

Constructor & Destructor Documentation

GaussianBlur()

GaussianBlur::GaussianBlur	(	uint	radius,
		uint	downscale,
		const std::string &	name
	)

Constructor. The depth of the gaussian pyramid will determine the strength of the blur, and the computational cost.

Parameters

radius	the number of levels in the downscaling pyramid
downscale	work at a lower resolution than the target texture
name	debug name for internal buffers

Member Function Documentation

process()

void GaussianBlur::process	(	const Texture &	src,
		Texture &	dst
	)

Apply the blurring process to a given texture.

Note

It is possible to use the same texture as input and output.

Parameters

src	the ID of the texture to process
dst	the destination texture

resize()

void GaussianBlur::resize ( uint  width, uint  height  )

private

Handle screen resizing if needed.

Parameters

width	the new width to use
height	the new height to use

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The documentation for this class was generated from the following files:

• src/engine/processing/GaussianBlur.hpp
• src/engine/processing/GaussianBlur.cpp