2D textures

## 2D textures 2D textures — Functions for creating and manipulating 2D textures |

## Synopsis

                        CoglTexture2D;
    #define             cogl_texture_2d_new_with_size
    #define             cogl_texture_2d_new_from_data
    #define             cogl_texture_2d_new_from_foreign
    #define             cogl_is_texture_rectangle

## Description

These functions allow low-level 2D textures to be allocated. These differ from sliced textures for example which may internally be made up of multiple 2D textures, or atlas textures where Cogl must internally modify user texture coordinates before they can be used by the GPU.

You should be aware that many GPUs only support power of two sizes for CoglTexture2D textures. You can check support for non power of two textures by checking for the `COGL_FEATURE_ID_TEXTURE_NPOT` feature via `cogl_has_feature()`.

## Details

### CoglTexture2D

    typedef struct _CoglTexture2D CoglTexture2D;

### cogl_texture_2d_new_with_size

    #define cogl_texture_2d_new_with_size cogl_texture_2d_new_with_size_EXP

Allocates a low-level CoglTexture2D texture that your GPU can texture from directly. This is unlike sliced textures for example which may be comprised of multiple internal textures, or atlas textures where Cogl has to modify texture coordinates before they may be used by the GPU.

### Note

Many GPUs only support power of two sizes for CoglTexture2D textures. You can check support for non power of two textures by checking for the `COGL_FEATURE_ID_TEXTURE_NPOT` feature via `cogl_has_feature()`.

`ctx` : | A CoglContext
`width` : | Width of the texture to allocate
`height` : | Height of the texture to allocate
`internal_format` : | The format of the texture
`error` : | A GError for exceptions
Returns : | A newly allocated CoglTexture2D, or if the size is not supported (because it is too large or a non-power-of-two size that the hardware doesn't support) it will return `NULL` and set `error`.

Since 2.0

### cogl_texture_2d_new_from_data

    #define cogl_texture_2d_new_from_data cogl_texture_2d_new_from_data_EXP

Creates a new CoglTexture2D texture based on data residing in memory. These are unlike sliced textures for example which may be comprised of multiple internal textures, or atlas textures where Cogl has to modify texture coordinates before they may be used by the GPU.

### Note

Many GPUs only support power of two sizes for CoglTexture2D textures. You can check support for non power of two textures by checking for the `COGL_FEATURE_ID_TEXTURE_NPOT` feature via `cogl_has_feature()`.

`ctx` : | A CoglContext
`width` : | width of texture in pixels
`height` : | height of texture in pixels
`format` : | the CoglPixelFormat the buffer is stored in in RAM
`internal_format` : | the CoglPixelFormat that will be used for storing the buffer on the GPU. If COGL_PIXEL_FORMAT_ANY is given then a premultiplied format similar to the format of the source data will be used. The default blending equations of Cogl expect premultiplied color data; the main use of passing a non-premultiplied format here is if you have non-premultiplied source data and are going to adjust the blend mode (see `cogl_material_set_blend()`) or use the data for something other than straight blending.
`rowstride` : | the memory offset in bytes between the starts of scanlines in `data`. A value of 0 will make Cogl automatically calculate `rowstride` from `width` and `format`.
`data` : | pointer the memory region where the source buffer resides
`error` : | A GError for exceptions
Returns : | A newly allocated CoglTexture2D, or if the size is not supported (because it is too large or a non-power-of-two size that the hardware doesn't support) it will return `NULL` and set `error`.

Since 2.0

### cogl_texture_2d_new_from_foreign

    #define cogl_texture_2d_new_from_foreign cogl_texture_2d_new_from_foreign_EXP

Wraps an existing GL_TEXTURE_2D texture object as a CoglTexture2D. This can be used for integrating Cogl with software using OpenGL directly.

### Note

The results are undefined for passing an invalid `gl_handle` or if `width` or `height` don't have the correct texture geometry.

`ctx` : | A CoglContext
`gl_handle` : | A GL handle for a GL_TEXTURE_2D texture object
`width` : | Width of the foreign GL texture
`height` : | Height of the foreign GL texture
`internal_format` : | The format of the texture
`error` : | A GError for exceptions
Returns : | A newly allocated CoglTexture2D, or if Cogl could not validate the `gl_handle` in some way (perhaps because of an unsupported format) it will return `NULL` and set `error`.

Since 2.0

### cogl_is_texture_rectangle

    #define cogl_is_texture_rectangle cogl_is_texture_rectangle_EXP

Gets whether the given object references an existing CoglTextureRectangle object.

`object` : | A CoglObject
Returns : | `TRUE` if the object references a CoglTextureRectangle, `FALSE` otherwise.