inviwo::FragmentListRenderer Class Reference

helper class for rendering perfect alpha-blended shapes using fragment lists. Inspiration taken from http://blog.icare3d.org/2010/07/opengl-40-abuffer-v20-linked-lists-of.html. It requires OpenGL 4.2. More...

#include <fragmentlistrenderer.h>

Classes
struct	IllustrationSettings

Public Member Functions
void	prePass (const size2_t &screenSize)
	Starts the rendering of transparent objects using fragment lists. It resets all counters and allocated the index textures of the given screen size. This has to be called each frame before objects can be rendered with the fragment lists.
void	setShaderUniforms (Shader &shader) const
	Sets the shader uniforms required by the fragment list renderer. The uniforms are defined in oit/abufferlinkedlist.glsl
bool	postPass (bool useIllustration, const Image *background)
	Finishes the fragment list pass and renders the final result. This sorts the fragment lists per pixel and outputs the blended color.
void	beginCount ()
void	endCount ()
void	setIllustrationSettings (const IllustrationSettings &settings)
DispatcherHandle< void()>	onReload (std::function< void()> callback)
void	debugFragmentLists (std::ostream &oss)
void	debugIllustrationBuffer (std::ostream &oss)

Static Public Member Functions
static bool	supportsFragmentLists ()
	Tests if fragment lists are supported by the current opengl context. Fragment lists require OpenGL 4.3.
static bool	supportsIllustration ()
	Tests if the illustration buffer are supported and can therefore be enabled. The Illustration Buffer requires OpenGL 4.6 or OpenGL 4.5 with the extension "GL_ARB_shader_atomic_counter_ops".

Detailed Description

helper class for rendering perfect alpha-blended shapes using fragment lists. Inspiration taken from http://blog.icare3d.org/2010/07/opengl-40-abuffer-v20-linked-lists-of.html. It requires OpenGL 4.2.

Any objects can be rendered with this framework in the following way:

1. Render opaque objects normally
2. Call FragmentListRenderer::prePass(...)
3. For each transparent object: a) Include oit/abufferlinkedlist.glsl in the fragment shader b) Use the following snipped in the fragment shader: abufferRender(ivec2(gl_FragCoord.xy), depth, fragColor); discard; c) Assign additional shader uniforms with FragmentListRenderer::setShaderUniforms(shader) d) Render the object with depth test but without depth write
4. Call FragmentListRenderer::postPass(...) If this returns false, not enough space for all pixels was available. Repeat from step 2.

Member Function Documentation

postPass()

bool inviwo::FragmentListRenderer::postPass	(	bool	useIllustration,
		const Image *	background )

Finishes the fragment list pass and renders the final result. This sorts the fragment lists per pixel and outputs the blended color.

Parameters

useIllustration	Set to true if the illustration buffer should be enabled
background	The background to render on and use depth information from.

Returns

true if successfull, false if not enough space for all fragments was available and the procedure should be repeated.

prePass()

void inviwo::FragmentListRenderer::prePass

(

const size2_t &

screenSize

)

Starts the rendering of transparent objects using fragment lists. It resets all counters and allocated the index textures of the given screen size. This has to be called each frame before objects can be rendered with the fragment lists.

Parameters

screenSize

the current screen size

setShaderUniforms()

void inviwo::FragmentListRenderer::setShaderUniforms

(

Shader &

shader

)

const

Sets the shader uniforms required by the fragment list renderer. The uniforms are defined in oit/abufferlinkedlist.glsl

Parameters

shader

the shader of the object to be rendered

supportsFragmentLists()

static bool inviwo::FragmentListRenderer::supportsFragmentLists ( )

static

Tests if fragment lists are supported by the current opengl context. Fragment lists require OpenGL 4.3.

Returns

true iff they are supported

supportsIllustration()

static bool inviwo::FragmentListRenderer::supportsIllustration ( )

static

Tests if the illustration buffer are supported and can therefore be enabled. The Illustration Buffer requires OpenGL 4.6 or OpenGL 4.5 with the extension "GL_ARB_shader_atomic_counter_ops".

Returns

true iff they are supported

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

• fragmentlistrenderer.h