fastuidraw::Image Class Reference

An Image represents an image comprising of RGBA8 values. The texel values themselves are stored in a ImageAtlas. More...

#include <image.hpp>

Inheritance diagram for fastuidraw::Image:

Classes
class	ResourceReleaseAction

Public Types
enum	format_t { rgba_format, premultipied_rgba_format }
enum	type_t { on_atlas, bindless_texture2d, context_texture2d }

Public Member Functions
uint64_t	bindless_handle (void) const
ivec2	dimensions (void) const
float	dimensions_index_divisor (void) const
enum format_t	format (void) const
ivec3	master_index_tile (void) const
vec2	master_index_tile_dims (void) const
unsigned int	number_index_lookups (void) const
unsigned int	number_mipmap_levels (void) const
type_t	type (void) const
Public Member Functions inherited from fastuidraw::reference_counted_base< T, Counter >
	reference_counted_base (void)

Protected Member Functions
	Image (ImageAtlas &atlas, int w, int h, unsigned int m, enum type_t type, uint64_t handle, enum format_t fmt, const reference_counted_ptr< ResourceReleaseAction > &action=reference_counted_ptr< ResourceReleaseAction >())

Friends
class	ImageAtlas

Additional Inherited Members
Static Public Member Functions inherited from fastuidraw::reference_counted_base< T, Counter >
static void	add_reference (const reference_counted_base< T, Counter > *p)
static void	remove_reference (const reference_counted_base< T, Counter > *p)

Detailed Description

An Image represents an image comprising of RGBA8 values. The texel values themselves are stored in a ImageAtlas.

Definition at line 44 of file image.hpp.

Member Enumeration Documentation

format_t

enum fastuidraw::Image::format_t

Enumeration to describe the format of an image

Enumerator
rgba_format	Image is non-premultiplied RGBA format (each color channel of each pixel taking 8-bits).
premultipied_rgba_format	Image is RGBA format (each color channel of each pixel taking 8-bits) with the RGB channels pre-multiplied by the alpha channel.

Definition at line 50 of file image.hpp.

type_t

enum fastuidraw::Image::type_t

Gives the image-type of an Image

Enumerator
on_atlas	Indicates that the Image is on an ImageAtlas. Such images will not introcude draw-breaks, but are more complicated to sample from.
bindless_texture2d	Indicates that the Image is backed by a gfx API texture via a bindless interface. Such images do not introduce draw-breaks and are simple from. The only draw back, is that not all 3D API implementations support bindless texruing (for example the GL/GLES backends require that the GL/GLES implementation support an extension.
context_texture2d	Indicates to source the Image data from a currently bound texture of the 3D API context. These image are simple to sample from but introduce draw breaks. Using images of these types should be avoided at all costs since whenever one uses Image objects of these types the 3D API state needs to change which induces a stage change and draw break, harming performance.

Definition at line 69 of file image.hpp.

Constructor & Destructor Documentation

Image()

fastuidraw::Image::Image ( ImageAtlas &  atlas, int  w, int  h, unsigned int  m, enum type_t  type, uint64_t  handle, enum format_t  fmt, const reference_counted_ptr< ResourceReleaseAction > &  action = reference_counted_ptr< ResourceReleaseAction >()  )

protected

Protected ctor for creating an Image backed by a bindless texture; Backends should use this ctor for Image deried classes that do cleanup (for example releasing the handle and/or deleting the texture).

Parameters

atlas	ImageAtlas atlas onto which to place the image.
w	width of underlying texture
h	height of underlying texture
m	number of mipmap levels of the image
type	the type of the bindless texture, must NOT have value on_atlas.
fmt	the format of the image
handle	the bindless handle value used by the Gfx API in shaders to reference the texture.
action	action to call to release backing resources of the created Image.

Member Function Documentation

bindless_handle()

uint64_t fastuidraw::Image::bindless_handle

(

void

)

const

Returns the bindless handle for the Image.

Only applies when type() does NOT return on_atlas.

dimensions()

ivec2 fastuidraw::Image::dimensions

(

void

)

const

Returns the dimensions of the image, i.e the width and height.

dimensions_index_divisor()

float fastuidraw::Image::dimensions_index_divisor

(

void

)

const

Returns the quotient of dimensions() divided by master_index_tile_dims().

Only applies when type() returns on_atlas.

format()

enum format_t fastuidraw::Image::format

(

void

)

const

Returns the format of the image.

master_index_tile()

ivec3 fastuidraw::Image::master_index_tile

(

void

)

const

Returns the "head" index tile as returned by ImageAtlas::add_index_tile() or ImageAtlas::add_index_tile_index_data().

Only applies when type() returns on_atlas.

master_index_tile_dims()

vec2 fastuidraw::Image::master_index_tile_dims

(

void

)

const

If number_index_lookups() > 0, returns the number of texels in each dimension of the master index tile this Image lies. If number_index_lookups() is 0, the returns the same value as dimensions().

Only applies when type() returns on_atlas.

number_index_lookups()

unsigned int fastuidraw::Image::number_index_lookups

(

void

)

const

Returns the number of index look-ups to get to the image data.

Only applies when type() returns on_atlas.

number_mipmap_levels()

unsigned int fastuidraw::Image::number_mipmap_levels

(

void

)

const

Returns the number of mipmap levels the image supports.

type()

type_t fastuidraw::Image::type

(

void

)

const

Returns the image type.

---

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

• /home/kevin/fastuidraw.krogueintel/inc/fastuidraw/image.hpp