mutter/cogl/cogl-private.h
Neil Roberts 60812e6a0e Add a vtable for the driver
Cogl already had a vtable for the texture driver. This ended up being
used for some things that are not strictly related to texturing such
as converting between pixel formats and GL enums. Some other functions
that are driver dependent such as updating the features were not
indirected through a vtable but instead switched directly by looking
at the ctx->driver enum value. This patch normalises to the two uses
by adding a separate vtable for driver functions not related to
texturing and moves the pixel format conversion functions to it from
the texture driver vtable. It also adds a context parameter to all of
the functions in the new driver vtable so that they won't have to rely
on the global context.
2012-03-23 13:51:08 +00:00

102 lines
3.1 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, see <http://www.gnu.org/licenses/>.
*
*
*/
#ifndef __COGL_PRIVATE_H__
#define __COGL_PRIVATE_H__
#include <cogl/cogl-pipeline.h>
#include "cogl-context.h"
G_BEGIN_DECLS
gboolean
_cogl_check_extension (const char *name, const char *ext);
void
_cogl_clear (const CoglColor *color, unsigned long buffers);
void
_cogl_init (void);
void
_cogl_push_source (CoglPipeline *pipeline, gboolean enable_legacy);
gboolean
_cogl_get_enable_legacy_state (void);
/*
* _cogl_pixel_format_get_bytes_per_pixel:
* @format: a #CoglPixelFormat
*
* Queries how many bytes a pixel of the given @format takes.
*
* Return value: The number of bytes taken for a pixel of the given
* @format.
*/
int
_cogl_pixel_format_get_bytes_per_pixel (CoglPixelFormat format);
/*
* _cogl_pixel_format_has_aligned_components:
* @format: a #CoglPixelFormat
*
* Queries whether the ordering of the components for the given
* @format depend on the endianness of the host CPU or if the
* components can be accessed using bit shifting and bitmasking by
* loading a whole pixel into a word.
*
* XXX: If we ever consider making something like this public we
* should really try to think of a better name and come up with
* much clearer documentation since it really depends on what
* point of view you consider this from whether a format like
* COGL_PIXEL_FORMAT_RGBA_8888 is endian dependent. E.g. If you
* read an RGBA_8888 pixel into a uint32
* it's endian dependent how you mask out the different channels.
* But If you already have separate color components and you want
* to write them to an RGBA_8888 pixel then the bytes can be
* written sequentially regardless of the endianness.
*
* Return value: %TRUE if you need to consider the host CPU
* endianness when dealing with the given @format
* else %FALSE.
*/
gboolean
_cogl_pixel_format_is_endian_dependant (CoglPixelFormat format);
/*
* COGL_PIXEL_FORMAT_CAN_HAVE_PREMULT(format):
* @format: a #CoglPixelFormat
*
* Returns TRUE if the pixel format can take a premult bit. This is
* currently true for all formats that have an alpha channel except
* COGL_PIXEL_FORMAT_A_8 (because that doesn't have any other
* components to multiply by the alpha).
*/
#define COGL_PIXEL_FORMAT_CAN_HAVE_PREMULT(format) \
(((format) & COGL_A_BIT) && (format) != COGL_PIXEL_FORMAT_A_8)
G_END_DECLS
#endif /* __COGL_PRIVATE_H__ */