mutter/cogl/cogl-texture-3d.h
Neil Roberts 5288f6d88d Add a Cogl texture 3D backend
This adds a publicly exposed experimental API for a 3D texture
backend. There is a feature flag which can be checked for whether 3D
textures are supported. Although we require OpenGL 1.2 which has 3D
textures in core, GLES only provides them through an extension so the
feature can be used to detect that.

The textures can be created with one of two new API functions :-

cogl_texture_3d_new_with_size

 and

cogl_texture_3d_new_from_data

There is also internally a new_from_bitmap function. new_from_data is
implemented in terms of this function.

The two constructors are effectively the only way to upload data to a
3D texture. It does not work to call glTexImage2D with the
GL_TEXTURE_3D target so the virtual for cogl_texture_set_region does
nothing. It would be possible to make cogl_texture_get_data do
something sensible like returning all of the images as a single long
image but this is not currently implemented and instead the virtual
just always fails. We may want to add API specific to the 3D texture
backend to get and set a sub region of the texture.

All of those three functions can throw a GError. This will happen if
the GPU does not support 3D textures or it does not support NPOTs and
an NPOT size is requested. It will also fail if the FBO extension is
not supported and the COGL_TEXTURE_NO_AUTO_MIPMAP flag is not
given. This could be avoided by copying the code for the
GL_GENERATE_MIPMAP TexParameter fallback, but in the interests of
keeping the code simple this is not yet done.

This adds a couple of functions to cogl-texture-driver for uploading
3D data and querying the 3D proxy
texture. prep_gl_for_pixels_upload_full now also takes sets the
GL_UNPACK_IMAGE_HEIGHT parameter so that 3D textures can have padding
between the images. Whenever 3D texture is uploading, both the height
of the images and the height of all of the data is specified (either
explicitly or implicilty from the CoglBitmap) so that the image height
can be deduced by dividing by the depth.
2010-07-13 14:28:52 +01:00

155 lines
5.8 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2010 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Authors:
* Neil Roberts <neil@linux.intel.com>
*/
#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_TEXTURE_3D_H
#define __COGL_TEXTURE_3D_H
#include <glib.h>
G_BEGIN_DECLS
/**
* SECTION:cogl-texture-3d
* @short_description: Fuctions for creating and manipulating 3D textures
*
* These functions allow 3D textures to be used. 3D textures can be
* thought of as layers of 2D images arranged into a cuboid
* shape. When choosing a texel from the texture, Cogl will take into
* account the 'r' texture coordinate to select one of the images.
*/
/* All of the cogl-texture-3d API is currently experimental so we
* suffix the actual symbols with _EXP so if somone is monitoring for
* ABI changes it will hopefully be clearer to them what's going on if
* any of the symbols dissapear at a later date.
*/
#define cogl_texture_3d_new_with_size cogl_texture_3d_new_with_size_EXP
#define cogl_texture_3d_new_from_data cogl_texture_3d_new_from_data_EXP
#define cogl_is_texture_3d cogl_is_texture_3d_EXP
/**
* cogl_texture_3d_new_with_size:
* @width: width of the texture in pixels.
* @height: height of the texture in pixels.
* @depth: depth of the texture in pixels.
* @flags: Optional flags for the texture, or %COGL_TEXTURE_NONE
* @internal_format: the #CoglPixelFormat to use for the GPU
* storage of the texture.
* @error: A GError return location.
*
* Creates a new Cogl 3D texture with the specified dimensions and
* pixel format.
*
* Note that this function will throw a #GError if
* %COGL_FEATURE_TEXTURE_3D is not advertised. It can also fail if the
* requested dimensions are not supported by the GPU.
*
* Return value: a new handle to a CoglTexture3D object or
* %COGL_INVALID_HANDLE on failure.
* Since: 1.4
* Stability: Unstable
*/
CoglHandle
cogl_texture_3d_new_with_size (unsigned int width,
unsigned int height,
unsigned int depth,
CoglTextureFlags flags,
CoglPixelFormat internal_format,
GError **error);
/**
* cogl_texture_3d_new_from_data:
* @width: width of the texture in pixels.
* @height: height of the texture in pixels.
* @depth: depth of the texture in pixels.
* @flags: Optional flags for the texture, or %COGL_TEXTURE_NONE
* @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 or 0 to infer it from the width and format
* @image_stride: the number of bytes from one image to the next. This
* can be used to add padding between the images in a similar way
* that the rowstride can be used to add padding between
* rows. Alternatively 0 can be passed to infer the @image_stride
* from the @height.
* @data: pointer the memory region where the source buffer resides
* @error: A GError return location.
*
* Creates a new 3D texture and initializes it with @data. The data is
* assumed to be packed array of @depth images. There can be padding
* between the images using @image_stride.
*
* Note that this function will throw a #GError if
* %COGL_FEATURE_TEXTURE_3D is not advertised. It can also fail if the
* requested dimensions are not supported by the GPU.
*
* Return value: the newly created texture or %COGL_INVALID_HANDLE if
* there was an error.
* Since: 1.4
* Stability: Unstable
*/
CoglHandle
cogl_texture_3d_new_from_data (unsigned int width,
unsigned int height,
unsigned int depth,
CoglTextureFlags flags,
CoglPixelFormat format,
CoglPixelFormat internal_format,
unsigned int rowstride,
unsigned int image_stride,
const guint8 *data,
GError **error);
/**
* cogl_is_texture_3d:
* @handle: a #CoglHandle
*
* Checks whether @handle is a #CoglHandle for a 3D texture.
*
* Return value: %TRUE if the passed handle represents a 3D texture
* and %FALSE otherwise
*
* Since: 1.4
* Stability: Unstable
*/
gboolean
cogl_is_texture_3d (CoglHandle handle);
G_END_DECLS
#endif /* __COGL_TEXTURE_3D_H */