renderer that supports point splatting More...

#include <volume_renderer.h>

Inheritance diagram for cgv::render::volume_renderer:

Public Member Functions
	volume_renderer ()
	initializes position_is_center to true

bool	init (context &ctx)
	construct shader programs and return whether this was successful, call inside of init method of drawable

virtual void	clear (const context &ctx)
	clean up

bool	set_volume_texture (texture *tex)
	sets the 3D volume texture containing scalar values (density or other measured quantities)

bool	set_transfer_function_texture (texture *tex)
	sets the transfer function used for classification; must be 1D or 2D (as loaded from an image)

bool	set_gradient_texture (texture *tex)
	sets the gradient texture used for lighting

bool	set_depth_texture (texture *tex)
	sets the depth texture needed for rendering with additional opaque geometry

void	set_bounding_box (const box3 &bbox)

void	transform_to_bounding_box (bool flag)

void	set_noise_offset (const vec2 &offset)

bool	enable (context &ctx)
	enables renderer

bool	validate_attributes (const context &ctx) const
	call to validate, whether essential position attribute is defined

bool	disable (context &ctx)
	disable renderer

void	draw (context &ctx, size_t start, size_t count, bool use_strips=false, bool use_adjacency=false, uint32_t strip_restart_index=-1)
	Draw a range of vertices or indexed elements.

Public Member Functions inherited from cgv::render::renderer
shader_define_map &	ref_defines ()
	access to shader define map to update defines not handled by render style

shader_program &	ref_prog ()
	derived renderer classes have access to shader program

void	set_prog (shader_program &one_shot_prog)
	set external shader program up to next call to disable() or render()

void	draw_impl (context &ctx, PrimitiveType pt, size_t start, size_t count, bool use_strips=false, bool use_adjacency=false, uint32_t strip_restart_index=-1)
	default implementation of draw method with support for indexed rendering and different primitive types

void	draw_impl_instanced (context &ctx, PrimitiveType type, size_t start, size_t count, size_t instance_count, bool use_strips=false, bool use_adjacency=false, uint32_t strip_restart_index=-1)
	default implementation of instanced draw method with support for indexed rendering and different primitive types

	renderer ()
	construct and init attribute tracking flags

virtual	~renderer ()
	destructor deletes default renderer style

void	manage_singleton (context &ctx, const std::string &renderer_name, int &ref_count, int ref_count_change)
	used by derived classes to manage singletons

virtual void	enable_attribute_array_manager (const context &ctx, attribute_array_manager &aam)
	call this before setting attribute arrays to manage attribute array in given manager

virtual void	disable_attribute_array_manager (const context &ctx, attribute_array_manager &aam)
	call this after last render/draw call to ensure that no other users of renderer change attribute arrays of given manager

virtual void	set_attribute_array_manager (const context &ctx, attribute_array_manager *_aam_ptr=0)
	this function is deprecated, please use enable_attribute_array_manager() and disable_attribute_manager() instead

void	set_render_style (const render_style &rs)
	reference given render style

bool	build_program (context &ctx, shader_program &prog, const render_style &rs)
	build shader program for specific render style

template<typename T >
void	set_position (const context &ctx, const T &position)
	templated method to set the position attribute from a single position of type T

template<typename T >
void	set_position_array (const context &ctx, const std::vector< T > &positions)
	templated method to set the position attribute from a vector of positions of type T

template<typename T >
void	set_position_array (const context &ctx, const T *positions, size_t nr_elements, unsigned stride_in_bytes=0)
	templated method to set the position attribute from a vector of positions of type T

void	set_position_array (const context &ctx, type_descriptor element_type, const vertex_buffer &vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes)
	method to set the position attribute from a vertex buffer object

template<typename T >
void	set_position_array (const context &ctx, const vertex_buffer &vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes=0)
	template method to set the position attribute from a vertex buffer object, the element type must be given as explicit template parameter

void	remove_position_array (const context &ctx)
	remove the position attribute

template<typename T >
void	set_color (const context &ctx, const T &color)
	templated method to set the color attribute from a single color of type T

template<typename T >
void	set_color_array (const context &ctx, const std::vector< T > &colors)
	template method to set the color attribute from a vector of colors of type T

template<typename T >
void	set_color_array (const context &ctx, const T *colors, size_t nr_elements, unsigned stride_in_bytes=0)
	template method to set the color attribute from a vector of colors of type T

void	set_color_array (const context &ctx, type_descriptor element_type, const vertex_buffer &vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes=0)
	method to set the color attribute from a vertex buffer object, the element type must be given as explicit template parameter

template<typename T >
void	set_color_array (const context &ctx, const vertex_buffer &vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes=0)
	template method to set the color attribute from a vertex buffer object, the element type must be given as explicit template parameter

void	remove_color_array (const context &ctx)
	remove the color attribute

template<typename T >
bool	set_indices (const context &ctx, const std::vector< T > &indices, bool keep_on_cpu=false)
	Set the indices for indexed rendering from a vector.

template<typename T >
bool	set_indices (const context &ctx, const T *indices, size_t nr_indices, bool keep_on_cpu=false)
	Set the indices for indexed rendering from an array given as a pointer.

template<typename T >
bool	set_indices (const context &ctx, const vertex_buffer &vbo, size_t count)
	Set the indices for indexed rendering from a GPU buffer.

bool	has_indices () const
	return whether indices have been defined

void	remove_indices (const context &ctx)
	remove previously set indices

const vertex_buffer *	get_vertex_buffer_ptr (const context &ctx, const attribute_array_manager &aam, const std::string &attr_name)

const vertex_buffer *	get_index_buffer_ptr (const attribute_array_manager &aam)

bool	validate_and_enable (context &ctx)
	validate attributes and if successful, enable renderer

virtual bool	render (context &ctx, size_t start, size_t count, bool use_strips=false, bool use_adjacency=false, uint32_t strip_restart_index=-1)
	Convenience function that draws vertex or indexed element with this renderer.

Protected Member Functions
render_style *	create_render_style () const
	overload to allow instantiation of volume_renderer

void	update_defines (shader_define_map &defines)
	update shader defines based on render style

bool	build_shader_program (context &ctx, shader_program &prog, const shader_define_map &defines)
	build volume program

void	init_noise_texture (context &ctx)
	initializes the noise texture with random values

Protected Member Functions inherited from cgv::render::renderer
bool	has_aam () const
	check for attribute array manager

bool	has_attribute (const context &ctx, const std::string &name)
	check for attribute

const render_style *	get_style_ptr () const
	access to render style

bool	attributes_persist () const
	return whether attributes persist after a call to disable

template<typename T >
const T &	get_style () const
	access to style

int	get_prog_attribute_location (const context &ctx, const std::string &name, bool error_check=true)

template<typename T >
bool	set_attribute_array (const context &ctx, const std::string &name, const T &array)

template<typename T >
bool	set_attribute_array (const context &ctx, const std::string &name, const T *array_ptr, size_t nr_elements, unsigned stride)

bool	set_attribute_array (const context &ctx, const std::string &name, type_descriptor element_type, const vertex_buffer &vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes)

template<typename C , typename T >
bool	set_composed_attribute_array (const context &ctx, const std::string &name, const C *array_ptr, size_t nr_elements, const T &elem)
	in case that several attributes are stored interleaved, call this function for the first and ref_composed_attribute_array() for all others

template<typename C , typename T >
bool	ref_composed_attribute_array (const context &ctx, const std::string &name, const std::string &name_ref, const C *array_ptr, size_t nr_elements, const T &elem)
	in case that several attributes are stored interleaved, call set_composed_attribute_array() for the first and this function for all others

bool	remove_attribute_array (const context &ctx, const std::string &name)

Protected Attributes
texture *	volume_texture
	the 3D texture used for rendering

texture *	transfer_function_texture
	the 2D transfer function texture used for classification of the volume values

texture	noise_texture
	a 2D texture containing random noise used to offset ray start positions in order to reduce ring artifacts

texture *	gradient_texture
	the 3D texture containing vector gradients used for lighting normal calculation

texture *	depth_texture
	a 2D texture from a frame buffer depth buffer used to combine volume rendering with opaque geometry

box3	bounding_box
	the bounding box of the volume in scene units

bool	apply_bounding_box_transformation
	whether to translate and scale the volume to the given bounding box during rendering

vec2	noise_offset
	offset applied to the noise texture (can be used in conjunction with temporal anti aliasing)

Protected Attributes inherited from cgv::render::renderer
bool	has_colors
	track whether color attribute is defined

bool	has_positions
	track whether position attribute is defined

Detailed Description

renderer that supports point splatting

Definition at line 116 of file volume_renderer.h.

Constructor & Destructor Documentation

◆ volume_renderer()

cgv::render::volume_renderer::volume_renderer ( )

initializes position_is_center to true

Definition at line 64 of file volume_renderer.cxx.

References apply_bounding_box_transformation, bounding_box, depth_texture, gradient_texture, noise_offset, noise_texture, cgv::render::texture::set_mag_filter(), cgv::render::texture::set_min_filter(), cgv::render::texture::set_wrap_s(), cgv::render::texture::set_wrap_t(), transfer_function_texture, and volume_texture.

Member Function Documentation

◆ build_shader_program()

bool cgv::render::volume_renderer::build_shader_program	(	context &	ctx,
		shader_program &	prog,
		const shader_define_map &	defines
	)

protectedvirtual

build volume program

Reimplemented from cgv::render::renderer.

Definition at line 108 of file volume_renderer.cxx.

References cgv::render::shader_program::build_program().

◆ clear()

void cgv::render::volume_renderer::clear ( const context & ctx )

virtual

clean up

Reimplemented from cgv::render::renderer.

Definition at line 163 of file volume_renderer.cxx.

References cgv::render::renderer::clear(), cgv::render::texture::destruct(), cgv::render::renderer::disable_attribute_array_manager(), and noise_texture.

◆ create_render_style()

render_style * cgv::render::volume_renderer::create_render_style ( ) const

protectedvirtual

overload to allow instantiation of volume_renderer

Implements cgv::render::renderer.

Definition at line 22 of file volume_renderer.cxx.

◆ disable()

bool cgv::render::volume_renderer::disable ( context & ctx )

virtual

disable renderer

Reimplemented from cgv::render::renderer.

Definition at line 262 of file volume_renderer.cxx.

References depth_texture, cgv::render::texture::disable(), cgv::render::renderer::disable(), gradient_texture, noise_texture, cgv::render::context::pop_blend_state(), cgv::render::context::pop_cull_state(), cgv::render::context::pop_depth_test_state(), transfer_function_texture, and volume_texture.

◆ draw()

void cgv::render::volume_renderer::draw	(	context &	ctx,
		size_t	start,
		size_t	count,
		bool	use_strips = `false`,
		bool	use_adjacency = `false`,
		uint32_t	strip_restart_index = `-1`
	)

virtual

Draw a range of vertices or indexed elements.

Call this function only successful enabeling via validate_and_enable() or enable(). Capsulates glDrawArrays and glDrawElements calls. Overloaded implementations of specific renderers choose the to be used gl primitive type and whether to use an instanced draw call.

See also: render()

Parameters

count	number of to be drawn vertices/elements
start	index of first to be drawn vertex/element
use_strips	whether to generate primitives in strips (only for line or triangle primitives)
use_adjacency	whether to specify adjacency information (only for line or triangle primitives)
strip_restart_index	extraorindary index used to mark end of strips (only for strip based drawing) Strip based drawing can be combined with the use of adjacency information. Default implementation uses triangle primitives.

Reimplemented from cgv::render::renderer.

Definition at line 277 of file volume_renderer.cxx.

References apply_bounding_box_transformation, bounding_box, cgv::render::volume_render_style::clip_box, cgv::media::axis_aligned_box< T, N >::get_center(), cgv::media::axis_aligned_box< T, N >::get_extent(), cgv::media::axis_aligned_box< T, N >::get_max_pnt(), cgv::media::axis_aligned_box< T, N >::get_min_pnt(), cgv::render::context::mul_modelview_matrix(), cgv::render::context::pop_modelview_matrix(), and cgv::render::context::push_modelview_matrix().

◆ enable()

bool cgv::render::volume_renderer::enable ( context & ctx )

virtual

enables renderer

if internal program is used, first update defines with update_defines() and rebuild program if it changed due updating or external modification via ref_defines()

Reimplemented from cgv::render::renderer.

Definition at line 213 of file volume_renderer.cxx.

◆ init()

bool cgv::render::volume_renderer::init ( context & ctx )

virtual

construct shader programs and return whether this was successful, call inside of init method of drawable

Reimplemented from cgv::render::renderer.

Definition at line 133 of file volume_renderer.cxx.

References cgv::render::renderer::enable_attribute_array_manager(), cgv::render::renderer::init(), init_noise_texture(), cgv::render::render_component::is_created(), noise_texture, and cgv::render::renderer::set_position_array().

◆ init_noise_texture()

void cgv::render::volume_renderer::init_noise_texture ( context & ctx )

protected

initializes the noise texture with random values

Definition at line 82 of file volume_renderer.cxx.

References cgv::data::CF_R, cgv::render::texture::create(), cgv::render::texture::destruct(), cgv::render::render_component::is_created(), noise_texture, and cgv::type::info::TI_UINT8.

Referenced by init().

◆ set_bounding_box()

void cgv::render::volume_renderer::set_bounding_box ( const box3 & bbox )

Definition at line 198 of file volume_renderer.cxx.

◆ set_depth_texture()

bool cgv::render::volume_renderer::set_depth_texture ( texture * tex )

sets the depth texture needed for rendering with additional opaque geometry

Definition at line 191 of file volume_renderer.cxx.

References depth_texture, and cgv::data::data_format::get_nr_dimensions().

◆ set_gradient_texture()

bool cgv::render::volume_renderer::set_gradient_texture ( texture * tex )

sets the gradient texture used for lighting

Definition at line 184 of file volume_renderer.cxx.

References cgv::data::data_format::get_nr_dimensions(), and gradient_texture.

◆ set_noise_offset()

void cgv::render::volume_renderer::set_noise_offset ( const vec2 & offset )

Definition at line 208 of file volume_renderer.cxx.

◆ set_transfer_function_texture()

bool cgv::render::volume_renderer::set_transfer_function_texture ( texture * tex )

sets the transfer function used for classification; must be 1D or 2D (as loaded from an image)

Definition at line 177 of file volume_renderer.cxx.

References cgv::data::data_format::get_nr_dimensions(), and transfer_function_texture.

◆ set_volume_texture()

bool cgv::render::volume_renderer::set_volume_texture ( texture * tex )

sets the 3D volume texture containing scalar values (density or other measured quantities)

Definition at line 170 of file volume_renderer.cxx.

References cgv::data::data_format::get_nr_dimensions(), and volume_texture.

◆ transform_to_bounding_box()

void cgv::render::volume_renderer::transform_to_bounding_box ( bool flag )

Definition at line 203 of file volume_renderer.cxx.

◆ update_defines()

void cgv::render::volume_renderer::update_defines ( shader_define_map & defines )

protectedvirtual

update shader defines based on render style

Reimplemented from cgv::render::renderer.

Definition at line 112 of file volume_renderer.cxx.

References cgv::render::volume_render_style::enable_depth_test, cgv::render::volume_render_style::enable_gradient_modulation, cgv::render::volume_render_style::enable_lighting, cgv::render::volume_render_style::enable_noise_offset, cgv::data::data_format::get_nr_dimensions(), cgv::render::volume_render_style::IP_LINEAR, cgv::render::volume_render_style::isosurface_color_from_transfer_function, transfer_function_texture, and cgv::render::volume_render_style::use_gradient_texture.

◆ validate_attributes()

bool cgv::render::volume_renderer::validate_attributes ( const context & ctx ) const

virtual

call to validate, whether essential position attribute is defined

Reimplemented from cgv::render::renderer.

Definition at line 100 of file volume_renderer.cxx.

References cgv::render::renderer::validate_attributes(), and volume_texture.

Member Data Documentation

◆ apply_bounding_box_transformation

bool cgv::render::volume_renderer::apply_bounding_box_transformation

protected

whether to translate and scale the volume to the given bounding box during rendering

Definition at line 135 of file volume_renderer.h.

Referenced by draw(), and volume_renderer().

◆ bounding_box

box3 cgv::render::volume_renderer::bounding_box

protected

the bounding box of the volume in scene units

Definition at line 133 of file volume_renderer.h.

Referenced by draw(), and volume_renderer().

◆ depth_texture

texture* cgv::render::volume_renderer::depth_texture

protected

a 2D texture from a frame buffer depth buffer used to combine volume rendering with opaque geometry

Definition at line 131 of file volume_renderer.h.

Referenced by disable(), enable(), set_depth_texture(), and volume_renderer().

◆ gradient_texture

texture* cgv::render::volume_renderer::gradient_texture

protected

the 3D texture containing vector gradients used for lighting normal calculation

Definition at line 129 of file volume_renderer.h.

Referenced by disable(), enable(), set_gradient_texture(), and volume_renderer().

◆ noise_offset

vec2 cgv::render::volume_renderer::noise_offset

protected

offset applied to the noise texture (can be used in conjunction with temporal anti aliasing)

Definition at line 137 of file volume_renderer.h.

Referenced by enable(), and volume_renderer().

◆ noise_texture

texture cgv::render::volume_renderer::noise_texture

protected

a 2D texture containing random noise used to offset ray start positions in order to reduce ring artifacts

Definition at line 127 of file volume_renderer.h.

Referenced by clear(), disable(), enable(), init(), init_noise_texture(), and volume_renderer().

◆ transfer_function_texture

texture* cgv::render::volume_renderer::transfer_function_texture

protected

the 2D transfer function texture used for classification of the volume values

Definition at line 125 of file volume_renderer.h.

Referenced by disable(), enable(), set_transfer_function_texture(), update_defines(), and volume_renderer().

◆ volume_texture

texture* cgv::render::volume_renderer::volume_texture

protected

the 3D texture used for rendering

Definition at line 123 of file volume_renderer.h.

Referenced by disable(), enable(), set_volume_texture(), validate_attributes(), and volume_renderer().

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

libs/cgv_gl/volume_renderer.h
libs/cgv_gl/volume_renderer.cxx

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ volume_renderer()

Member Function Documentation

◆ build_shader_program()

◆ clear()

◆ create_render_style()

◆ disable()

◆ draw()

◆ enable()

◆ init()

◆ init_noise_texture()

◆ set_bounding_box()

◆ set_depth_texture()

◆ set_gradient_texture()

◆ set_noise_offset()

◆ set_transfer_function_texture()

◆ set_volume_texture()

◆ transform_to_bounding_box()

◆ update_defines()

◆ validate_attributes()

Member Data Documentation

◆ apply_bounding_box_transformation

◆ bounding_box

◆ depth_texture

◆ gradient_texture

◆ noise_offset

◆ noise_texture

◆ transfer_function_texture

◆ volume_texture