Edje Perspective

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Functions that deal with 3D projection of an 2D object.

Perspective is a graphical tool that makes objets represented in 2D look like they have a 3D appearance.

Edje allows us to use perspective on any edje object. This group of functions deal with the use of perspective, by creating and configuring a perspective object that must set to a edje object or a canvas, affecting all the objects inside that have no particular perspective set already.

Functions
Edje_Perspective *	edje_perspective_new (Evas *e)
	Creates a new perspective in the given canvas.
void	edje_perspective_free (Edje_Perspective *ps)
	Deletes the given perspective object.
void	edje_perspective_set (Edje_Perspective *ps, Evas_Coord px, Evas_Coord py, Evas_Coord z0, Evas_Coord foc)
	Sets up the transform for this perspective object.
void	edje_perspective_global_set (Edje_Perspective *ps, Eina_Bool global)
	Makes this perspective object be global for its canvas.
Eina_Bool	edje_perspective_global_get (const Edje_Perspective *ps)
	Gets whether the given perspective object is global or not.
const Edje_Perspective *	edje_evas_global_perspective_get (const Evas *e)
	Gets the global perspective object set for this canvas.

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Function Documentation

const Edje_Perspective* edje_evas_global_perspective_get

(

const Evas *

e

)

Gets the global perspective object set for this canvas.

Parameters:

e	The given canvas (Evas).

Returns:

The perspective object set as global for this canvas. Or NULL if there is no global perspective set and on errors.

This function will return the perspective object that was set as global with edje_perspective_global_set().

See also:

edje_perspective_global_set()

edje_perspective_global_get()

Since :

2.3

void edje_perspective_free

(

Edje_Perspective *

ps

)

Deletes the given perspective object.

Parameters:

ps	A valid perspective object, or NULL.

This function will delete the perspective object. If the perspective effect was being applied to any Edje object or part, this effect won't be applied anymore.

See also:

edje_perspective_new()

Since :

2.3

Eina_Bool edje_perspective_global_get

(

const Edje_Perspective *

ps

)

Gets whether the given perspective object is global or not.

Parameters:

ps	The given perspective object.

Returns:

EINA_TRUE if this perspective object is global, EINA_FALSE otherwise.

See also:

edje_perspective_global_set()

Since :

2.3

void edje_perspective_global_set	(	Edje_Perspective *	ps,
		Eina_Bool	global
	)

Makes this perspective object be global for its canvas.

Parameters:

ps	The given perspective object
global	EINA_TRUE if the perspective should be global, EINA_FALSE otherwise.

The canvas which this perspective object is being set as global is the one given as argument upon the object creation (the evas parameter on the function edje_perspective_new(evas) ).

There can be only one global perspective object set per canvas, and if a perspective object is set to global when there was already another global perspective set, the old one will be set as non-global.

A global perspective just affects a part if its Edje object doesn't have a perspective object set to it, and if the part doesn't point to another part to be used as perspective.

See also:

edje_object_perspective_set()

edje_perspective_global_get()

edje_perspective_new()

Since :

2.3

Examples:

edje-perspective.c.

Edje_Perspective* edje_perspective_new

(

Evas *

e

)

Creates a new perspective in the given canvas.

Parameters:

e	The given canvas (Evas).

Returns:

An Edje Perspective object for this canvas, or NULL on errors.

This function creates a perspective object that can be set on an Edje object, or globally to all Edje objects on this canvas.

See also:

edje_perspective_set()

edje_perspective_free()

Since :

2.3

Examples:

edje-perspective.c.

void edje_perspective_set	(	Edje_Perspective *	ps,
		Evas_Coord	px,
		Evas_Coord	py,
		Evas_Coord	z0,
		Evas_Coord	foc
	)

Sets up the transform for this perspective object.

This sets the parameters of the perspective transformation. X, Y and Z values are used. The px and py points specify the "infinite distance" point in the 3D conversion (where all lines converge to like when artists draw 3D by hand). The z0 value specifies the z value at which there is a 1:1 mapping between spatial coordinates and screen coordinates. Any points on this z value will not have their X and Y values modified in the transform. Those further away (Z value higher) will shrink into the distance, and those less than this value will expand and become bigger. The foc value determines the "focal length" of the camera. This is in reality the distance between the camera lens plane itself (at or closer than this rendering results are undefined) and the "z0" z value. This allows for some "depth" control and foc must be greater than 0.

Parameters:

ps	The perspective object
px	The perspective distance X coordinate
py	The perspective distance Y coordinate
z0	The "0" z plane value
foc	The focal distance

Since :

2.3

Examples:

edje-perspective.c.