Image Class Reference

Raster image resource used for drawing or displaying. More...

#include <image.h>

Public Member Functions
	Image (cairo_surface_t *surface)
	Image (const std::string &uri, float hscale, float vscale)
	Construct a raster image from a URI with an optional scale.
	Image (const std::string &uri={}, float scale=1.0)
	Construct a raster image from a URI with an optional scale.
	Image (const unsigned char *data, size_t len)
	Construct a raster image from memory.
	Image (shared_cairo_surface_t surface)
EGT_NODISCARD Rect	align (const Rect &bounding, const AlignFlags &align)
	Get the position and size of the image once aligned inside the bounding area.
void	copy ()
	This function must be called any time the surface is going to be modified.
Image	crop (const Rect &rect)
Image	crop (const RectF &rect)
void	deserialize (const std::string &name, const std::string &value, const Serializer::Attributes &attrs)
	Deserialized property.
EGT_NODISCARD bool	empty () const
	Returns true if no internal surface is set.
EGT_NODISCARD DefaultDim	height () const
EGT_NODISCARD float	hscale () const
	Get the horizontal scale value.
bool	keep_image_ratio () const
	Get the keep image ratio state.
void	keep_image_ratio (bool enable)
	Enable/disable ratio preservation while scaling the image.
void	load (const std::string &uri, float hscale=1.0, float vscale=1.0, bool approx=false)
	Load a new source image with an optional scale.
EGT_NODISCARD cairo_pattern_t *	pattern () const
	Get internal pattern representation.
void	reset_uri ()
void	resize (const Size &size)
	Resize the image to the specified absolute size.
void	scale (float hscale, float vscale, bool approximate=false)
	Scale the image.
void	scale (float scale, bool approximate=false)
	Scale the image.
void	serialize (const std::string &name, Serializer &serializer) const
	Serialize to the specified serializer.
EGT_NODISCARD Size	size () const
	Get the absolute size of the image.
EGT_NODISCARD Size	size_orig () const
	Get the original size of the image before any Image::resize() or Image::scale() calls.
EGT_NODISCARD shared_cairo_surface_t	surface () const
	Get a reference to the internal image surface.
EGT_NODISCARD std::string	uri () const
void	uri (const std::string &uri)
EGT_NODISCARD float	vscale () const
	Get the vertical scale value.
EGT_NODISCARD DefaultDim	width () const

Protected Member Functions
void	handle_surface_changed ()

Protected Attributes
float	m_hscale {1.0}
	Horizontal scale value, compared to original.
bool	m_keep_image_ratio {true}
	Keep the image ratio when the aligned with AlignFlag::expand.
Size	m_orig_size
	Original image size.
shared_cairo_pattern_t	m_pattern
	Internal pattern representation.
shared_cairo_surface_t	m_surface
	Shared surface pointer.
shared_cairo_surface_t	m_surface_local
	Local surface pointer.
std::string	m_uri
	If a URI was used, the URI.
float	m_vscale {1.0}
	Vertical scale value, compared to original.

Friends
class	SvgImage

Detailed Description

Raster image resource used for drawing or displaying.

This class by default shares the internal surface pointer with anything else using the surface. To force this class to keep its own copy, call the copy() function.

Constructor & Destructor Documentation

Image() [1/5]

Image	(	const std::string &	uri = {},
		float	scale = 1.0
	)

Construct a raster image from a URI with an optional scale.

Image image("file:image.png");

Parameters

uri	Resource path.

See also

Resources

Parameters

scale

Scale of the image, with 1.0 being 100%.

Image() [2/5]

Image	(	const std::string &	uri,
		float	hscale,
		float	vscale
	)

Construct a raster image from a URI with an optional scale.

Parameters

uri	Resource path.

See also

Resources

Parameters

hscale	Horizontal scale of the image, with 1.0 being 100%.
vscale	Vertical scale of the image, with 1.0 being 100%.

Image() [3/5]

Image	(	const unsigned char *	data,
		size_t	len
	)

Construct a raster image from memory.

Parameters

data	Pointer to the data.
len	Length of the data.

Image() [4/5]

Image

(

shared_cairo_surface_t

surface

)

Parameters

surface

A pre-existing surface.

This takes a reference to the passed in image.

Todo:

This is a broken API. It's different from the constructor below. Need consistency.

Image() [5/5]

Image

(

cairo_surface_t *

surface

)

Parameters

surface

A pre-existing surface.

This will not own the passed in pointer or surface, and instead will make a copy of the surface.

Member Function Documentation

align()

EGT_NODISCARD Rect align	(	const Rect &	bounding,
		const AlignFlags &	align
	)

Get the position and size of the image once aligned inside the bounding area.

copy()

void copy

(

)

This function must be called any time the surface is going to be modified.

It's safe to call this function when not necessary, and in any event it will ensure this Image contains a unique copy of the surface.

Todo:

Tricky API.

crop() [1/2]

Image crop ( const Rect &  rect )

inline

crop() [2/2]

Image crop

(

const RectF &

rect

)

deserialize()

void deserialize	(	const std::string &	name,
		const std::string &	value,
		const Serializer::Attributes &	attrs
	)

Deserialized property.

empty()

EGT_NODISCARD bool empty ( ) const

inline

Returns true if no internal surface is set.

handle_surface_changed()

void handle_surface_changed ( )

protected

height()

EGT_NODISCARD DefaultDim height ( ) const

inline

hscale()

EGT_NODISCARD float hscale ( ) const

inline

Get the horizontal scale value.

keep_image_ratio() [1/2]

bool keep_image_ratio ( ) const

inline

Get the keep image ratio state.

keep_image_ratio() [2/2]

void keep_image_ratio ( bool  enable )

inline

Enable/disable ratio preservation while scaling the image.

If enabled, the original image ratio won't be changed during the image auto scale operation. By default, set to true.

load()

void load	(	const std::string &	uri,
		float	hscale = 1.0,
		float	vscale = 1.0,
		bool	approx = false
	)

Load a new source image with an optional scale.

Parameters

uri	Resource path.

See also

Resources

Parameters

hscale	Horizontal scale of the image, with 1.0 being 100%.
vscale	Vertical scale of the image, with 1.0 being 100%.
approx	Approximate the scale to increase image cache hit efficiency.

pattern()

EGT_NODISCARD cairo_pattern_t * pattern ( ) const

inline

Get internal pattern representation.

reset_uri()

void reset_uri ( )

inline

resize()

void resize ( const Size &  size )

inline

Resize the image to the specified absolute size.

Parameters

size	The new size of the image.

scale() [1/2]

void scale	(	float	hscale,
		float	vscale,
		bool	approximate = false
	)

Scale the image.

Change the scale of the image, similar to calling Image::resize().

This scales relative to the original size of the image. Not the result of any subsequent Image::resize() or Image::scale() call.

Parameters

hscale	Horizontal scale of the image, with 1.0 being 100%.
vscale	Vertical scale of the image, with 1.0 being 100%.
approximate	Approximate the scale to increase image cache hit efficiency.

scale() [2/2]

void scale ( float  scale, bool  approximate = false  )

inline

Scale the image.

See also

scale()

serialize()

void serialize	(	const std::string &	name,
		Serializer &	serializer
	)		const

Serialize to the specified serializer.

size()

EGT_NODISCARD Size size ( ) const

inline

Get the absolute size of the image.

size_orig()

EGT_NODISCARD Size size_orig ( ) const

inline

Get the original size of the image before any Image::resize() or Image::scale() calls.

surface()

EGT_NODISCARD shared_cairo_surface_t surface ( ) const

inline

Get a reference to the internal image surface.

uri() [1/2]

EGT_NODISCARD std::string uri ( ) const

inline

uri() [2/2]

void uri ( const std::string &  uri )

inline

vscale()

EGT_NODISCARD float vscale ( ) const

inline

Get the vertical scale value.

width()

EGT_NODISCARD DefaultDim width ( ) const

inline

Friends And Related Symbol Documentation

SvgImage

friend class SvgImage

friend

Member Data Documentation

m_hscale

float m_hscale {1.0}

protected

Horizontal scale value, compared to original.

m_keep_image_ratio

bool m_keep_image_ratio {true}

protected

Keep the image ratio when the aligned with AlignFlag::expand.

m_orig_size

Size m_orig_size

protected

Original image size.

m_pattern

shared_cairo_pattern_t m_pattern

mutableprotected

Internal pattern representation.

m_surface

shared_cairo_surface_t m_surface

protected

Shared surface pointer.

m_surface_local

shared_cairo_surface_t m_surface_local

protected

Local surface pointer.

m_uri

std::string m_uri

protected

If a URI was used, the URI.

m_vscale

float m_vscale {1.0}

protected

Vertical scale value, compared to original.