#include <glfft.hpp>

Classes
struct	Pass

Public Member Functions
	FFT (unsigned Nx, unsigned Ny, Type type, Direction direction, Target input_target, Target output_target, std::shared_ptr< ProgramCache > cache, const FFTOptions &options, const FFTWisdom &wisdom=FFTWisdom())
	Creates a full FFT. More...

	FFT (unsigned Nx, unsigned Ny, unsigned radix, unsigned p, Mode mode, Target input_target, Target output_target, std::shared_ptr< ProgramCache > cache, const FFTOptions &options)
	Creates a single stage FFT. Used mostly internally for benchmarking partial FFTs. More...

void	process (GLuint output, GLuint input, GLuint input_aux=0)
	Process the FFT. More...

double	bench (GLuint output, GLuint input, unsigned warmup_iterations, unsigned iterations, unsigned dispatches_per_iteration, double max_time=std::numeric_limits< double >::max())
	Run process() multiple times, timing the results. More...

double	get_cost () const
	Returns cost for a process() call. Only used for debugging. More...

unsigned	get_num_passes () const
	Returns number of passes (glDispatchCompute) in a process() call. More...

unsigned	get_dimension_x () const
	Returns Nx. More...

unsigned	get_dimension_y () const
	Returns Ny. More...

void	set_texture_offset_scale (float offset_x, float offset_y, float scale_x, float scale_y)
	Sets offset and scale parameters for normalized texel coordinates when sampling textures. More...

void	set_input_buffer_range (GLintptr offset, GLsizei size)
	Set binding range for input. More...

void	set_input_aux_buffer_range (GLintptr offset, GLsizei size)
	Set binding range for input_aux. More...

void	set_output_buffer_range (GLintptr offset, GLsizei size)
	Set binding range for output. More...

void	set_samplers (GLuint sampler0, GLuint sampler1=0)
	Set samplers for input textures. More...

Private Member Functions
GLuint	build_program (const Parameters &params)

GLuint	compile_compute_shader (const char *src)

GLuint	get_program (const Parameters &params)

Static Private Member Functions
static std::string	load_shader_string (const char *path)

static void	store_shader_string (const char *path, const std::string &source)

Private Attributes
double	cost = 0.0

Buffer	temp_buffer

Buffer	temp_buffer_image

std::vector< Pass >	passes

std::shared_ptr< ProgramCache >	cache

struct {
float offset_x = 0.0f

float offset_y = 0.0f

float scale_x = 1.0f

float scale_y = 1.0f

GLuint samplers [2] = { 0, 0 }

}	texture

struct {
struct {
GLintptr offset = 0

GLsizei size = 0

} input

struct {
GLintptr offset = 0

GLsizei size = 0

} input_aux

struct {
GLintptr offset = 0

GLsizei size = 0

} output

}	ssbo

unsigned	size_x

unsigned	size_y

Detailed Description

Definition at line 36 of file glfft.hpp.

Constructor & Destructor Documentation

FFT::FFT	(	unsigned	Nx,
		unsigned	Ny,
		Type	type,
		Direction	direction,
		Target	input_target,
		Target	output_target,
		std::shared_ptr< ProgramCache >	cache,
		const FFTOptions &	options,
		const FFTWisdom &	wisdom = `FFTWisdom()`
	)

Creates a full FFT.

All buffer allocation done by GLFFT will be done in constructor. Will throw if invalid parameters are passed.

Parameters

Nx	Number of samples in horizontal dimension.
Ny	Number of samples in vertical dimension.
type	The transform type.
direction	Forward, inverse or inverse with convolution. For real-to-complex and complex-to-real transforms, the transform type must match.
input_target	GL object type of input target. For real-to-complex with texture as input, ImageReal is used.
output_target	GL object type of output target. For complex-to-real with texture as output, ImageReal is used.
cache	A program cache for caching the GLFFT programs created.
options	FFT options such as performance related parameters and types.
wisdom	GLFFT wisdom which can override performance related options (options.performance is used as a fallback).

Definition at line 498 of file glfft.cpp.

FFT::FFT	(	unsigned	Nx,
		unsigned	Ny,
		unsigned	radix,
		unsigned	p,
		Mode	mode,
		Target	input_target,
		Target	output_target,
		std::shared_ptr< ProgramCache >	cache,
		const FFTOptions &	options
	)

Creates a single stage FFT. Used mostly internally for benchmarking partial FFTs.

All buffer allocation done by GLFFT will be done in constructor. Will throw if invalid parameters are passed.

Parameters

Nx	Number of samples in horizontal dimension.
Ny	Number of samples in vertical dimension.
radix	The FFT radix to use.
p	Which P-factor to use. Essentially, p == 1 will trigger "first pass" paths, p > 1 will trigger generic paths.
mode	The transform mode.
input_target	GL object type of input target. For real-to-complex with texture as input, ImageReal is used.
output_target	GL object type of output target. For complex-to-real with texture as output, ImageReal is used.
cache	A program cache for caching the GLFFT programs created.
options	FFT options such as performance related parameters and types.

Definition at line 376 of file glfft.cpp.

Member Function Documentation

double FFT::bench	(	GLuint	output,
		GLuint	input,
		unsigned	warmup_iterations,
		unsigned	iterations,
		unsigned	dispatches_per_iteration,
		double	max_time = `std::numeric_limits<double>::max()`
	)

Run process() multiple times, timing the results.

Mostly used internally by GLFFT wisdom, glfft_cli's bench, and so on.

Parameters

output	Output buffer or image. NOTE: For images, the texture must be using immutable storage, i.e. glTexStorage2D!
input	Input buffer or texture.
warmup_iterations	Number of iterations to run to "warm" up GL, ensures we don't hit recompilations or similar when benching.
iterations	Number of iterations to run the benchmark. Each iteration will ensure timing with a glFinish() followed by timing.
dispatches_per_iteration	Number of calls to process() we should do per iteration.
max_time	The max time the benchmark should run. Will be checked after each iteration is complete.

Returns: Average GPU time per process() call.

Definition at line 997 of file glfft.cpp.

GLuint FFT::build_program ( const Parameters & params )

private

Definition at line 715 of file glfft.cpp.

GLuint FFT::compile_compute_shader ( const char * src )

private

Definition at line 944 of file glfft.cpp.

double GLFFT::FFT::get_cost ( ) const

inline

Returns cost for a process() call. Only used for debugging.

Definition at line 110 of file glfft.hpp.

unsigned GLFFT::FFT::get_dimension_x ( ) const

inline

Returns Nx.

Definition at line 116 of file glfft.hpp.

unsigned GLFFT::FFT::get_dimension_y ( ) const

inline

Returns Ny.

Definition at line 118 of file glfft.hpp.

unsigned GLFFT::FFT::get_num_passes ( ) const

inline

Returns number of passes (glDispatchCompute) in a process() call.

Definition at line 113 of file glfft.hpp.

GLuint FFT::get_program ( const Parameters & params )

private

Definition at line 340 of file glfft.cpp.

string FFT::load_shader_string ( const char * path )

staticprivate

Definition at line 696 of file glfft.cpp.

void FFT::process	(	GLuint	output,
		GLuint	input,
		GLuint	input_aux = `0`
	)

Process the FFT.

The type of object passed here must match what FFT was initialized with.

Parameters

output	Output buffer or image. NOTE: For images, the texture must be using immutable storage, i.e. glTexStorage2D!
input	Input buffer or texture.
input_aux	If using convolution transform type, the content of input and input_aux will be multiplied together.

Definition at line 1028 of file glfft.cpp.

void GLFFT::FFT::set_input_aux_buffer_range	(	GLintptr	offset,
		GLsizei	size
	)

inline

Set binding range for input_aux.

If input_aux is an SSBO, set a custom binding range to be passed to glBindBufferRange. By default, the entire buffer is bound.

Definition at line 148 of file glfft.hpp.

void GLFFT::FFT::set_input_buffer_range	(	GLintptr	offset,
		GLsizei	size
	)

inline

Set binding range for input.

If input is an SSBO, set a custom binding range to be passed to glBindBufferRange. By default, the entire buffer is bound.

Definition at line 138 of file glfft.hpp.

void GLFFT::FFT::set_output_buffer_range	(	GLintptr	offset,
		GLsizei	size
	)

inline

Set binding range for output.

If output buffer is an SSBO, set a custom binding range to be passed to glBindBufferRange. By default, the entire buffer is bound.

Definition at line 158 of file glfft.hpp.

void GLFFT::FFT::set_samplers	(	GLuint	sampler0,
		GLuint	sampler1 = `0`
	)

inline

Set samplers for input textures.

Set sampler objects to be used for input and input_aux if textures are used as input. By default, sampler object 0 will be used (inheriting sampler parameters from the texture object itself).

Definition at line 168 of file glfft.hpp.

void GLFFT::FFT::set_texture_offset_scale	(	float	offset_x,
		float	offset_y,
		float	scale_x,
		float	scale_y
	)

inline

Sets offset and scale parameters for normalized texel coordinates when sampling textures.

By default, these values are 0.5 / size (samples in the center of texel (0, 0)). Scale is 1.0 / size, so it steps one texel for each coordinate in the FFT transform. Setting this to something custom is useful to get downsampling with GL_LINEAR -> FFT transform without having to downsample the texture first, then FFT.

Definition at line 126 of file glfft.hpp.

void FFT::store_shader_string	(	const char *	path,
		const std::string &	source
	)

staticprivate

Definition at line 709 of file glfft.cpp.

Member Data Documentation

std::shared_ptr<ProgramCache> GLFFT::FFT::cache

private

Definition at line 191 of file glfft.hpp.

double GLFFT::FFT::cost = 0.0

private

Definition at line 186 of file glfft.hpp.

struct { ... } GLFFT::FFT::input

struct { ... } GLFFT::FFT::input_aux

GLintptr GLFFT::FFT::offset = 0

Definition at line 210 of file glfft.hpp.

float GLFFT::FFT::offset_x = 0.0f

Definition at line 202 of file glfft.hpp.

float GLFFT::FFT::offset_y = 0.0f

Definition at line 202 of file glfft.hpp.

struct { ... } GLFFT::FFT::output

std::vector<Pass> GLFFT::FFT::passes

private

Definition at line 190 of file glfft.hpp.

GLuint GLFFT::FFT::samplers[2] = { 0, 0 }

Definition at line 203 of file glfft.hpp.

float GLFFT::FFT::scale_x = 1.0f

Definition at line 202 of file glfft.hpp.

float GLFFT::FFT::scale_y = 1.0f

Definition at line 202 of file glfft.hpp.

GLsizei GLFFT::FFT::size = 0

Definition at line 211 of file glfft.hpp.

unsigned GLFFT::FFT::size_x

private

Definition at line 214 of file glfft.hpp.

unsigned GLFFT::FFT::size_y

private

Definition at line 214 of file glfft.hpp.

struct { ... } GLFFT::FFT::ssbo

Buffer GLFFT::FFT::temp_buffer

private

Definition at line 188 of file glfft.hpp.

Buffer GLFFT::FFT::temp_buffer_image

private

Definition at line 189 of file glfft.hpp.

struct { ... } GLFFT::FFT::texture

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

/mnt/d/working/gitlab/opengles-sdk-android/samples/advanced_samples/FFTOceanWater/jni/GLFFT/glfft.hpp
/mnt/d/working/gitlab/opengles-sdk-android/samples/advanced_samples/FFTOceanWater/jni/GLFFT/glfft.cpp

Classes

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation