Sub Textures

Sub Textures — Functions for creating and manipulating sub-textures.

Synopsis

                    CoglSubTexture;
CoglSubTexture *    cogl_sub_texture_new                (CoglContext *ctx,
                                                         CoglTexture *parent_texture,
                                                         int sub_x,
                                                         int sub_y,
                                                         int sub_width,
                                                         int sub_height);
CoglBool            cogl_is_sub_texture                 (void *object);

Description

These functions allow high-level textures to be created that represent a sub-region of another texture. For example these can be used to implement custom texture atlasing schemes.

Details

CoglSubTexture

typedef struct _CoglSubTexture CoglSubTexture;

cogl_sub_texture_new ()

CoglSubTexture *    cogl_sub_texture_new                (CoglContext *ctx,
                                                         CoglTexture *parent_texture,
                                                         int sub_x,
                                                         int sub_y,
                                                         int sub_width,
                                                         int sub_height);

Creates a high-level CoglSubTexture representing a sub-region of any other CoglTexture. The sub-region must strictly lye within the bounds of the parent_texture. The returned texture implements the CoglMetaTexture interface because it's not a low level texture that hardware can understand natively.

Note

Remember: Unless you are using high level drawing APIs such as cogl_rectangle() or other APIs documented to understand the CoglMetaTexture interface then you need to use the CoglMetaTexture interface to resolve a CoglSubTexture into a low-level texture before drawing.

`ctx` :	A CoglContext pointer
`parent_texture` :	The full texture containing a sub-region you want to make a CoglSubTexture from.
`sub_x` :	The top-left x coordinate of the parent region to make a texture from.
`sub_y` :	The top-left y coordinate of the parent region to make a texture from.
`sub_width` :	The width of the parent region to make a texture from.
`sub_height` :	The height of the parent region to make a texture from.
Returns :	A newly allocated CoglSubTexture representing a sub-region of `parent_texture`. [transfer full]

Since 1.10

Stability Level: Unstable

cogl_is_sub_texture ()

CoglBool            cogl_is_sub_texture                 (void *object);

Checks whether object is a CoglSubTexture.

`object` :	a CoglObject
Returns :	`TRUE` if the passed `object` represents a CoglSubTexture and `FALSE` otherwise.

Since 1.10

Stability Level: Unstable

			Cogl 2.0 Reference Manual
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