mutter/cogl/cogl-bitmap-private.h
Neil Roberts ccc3068ffd cogl-bitmap: Encapsulate the CoglBitmap even internally
The CoglBitmap struct is now only defined within cogl-bitmap.c so that
all of its members can now only be accessed with accessor
functions. To get to the data pointer for the bitmap image you must
first call _cogl_bitmap_map and later call _cogl_bitmap_unmap. The map
function takes the same arguments as cogl_pixel_array_map so that
eventually we can make a bitmap optionally internally divert to a
pixel array.

There is a _cogl_bitmap_new_from_data function which constructs a new
bitmap object and takes ownership of the data pointer. The function
gets passed a destroy callback which gets called when the bitmap is
freed. This is similar to how gdk_pixbuf_new_from_data
works. Alternatively NULL can be passed for the destroy function which
means that the caller will manage the life of the pointer (but must
guarantee that it stays alive at least until the bitmap is
freed). This mechanism is used instead of the old approach of creating
a CoglBitmap struct on the stack and manually filling in the
members. It could also later be used to create a CoglBitmap that owns
a GdkPixbuf ref so that we don't necessarily have to copy the
GdkPixbuf data when converting to a bitmap.

There is also _cogl_bitmap_new_shared. This creates a bitmap using a
reference to another CoglBitmap for the data. This is a bit of a hack
but it is needed by the atlas texture backend which wants to divert
the set_region virtual to another texture but it needs to override the
format of the bitmap to ignore the premult flag.
2010-07-15 17:24:01 +01:00

177 lines
5.2 KiB
C

/*
* Clutter COGL
*
* A basic GL/GLES Abstraction/Utility Layer
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2007 OpenedHand
*
* 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_BITMAP_H
#define __COGL_BITMAP_H
#include <glib.h>
#include "cogl-handle.h"
#include "cogl-buffer.h"
/*
* CoglBitmapDestroyNotify:
* @data: The image data
* @destroy_data: The callback closure data that was given to
* _cogl_bitmap_new_from_data().
*
* Function prototype that is used to destroy the bitmap data when
* _cogl_bitmap_new_from_data() is called.
*/
typedef void (* CoglBitmapDestroyNotify) (guint8 *data, void *destroy_data);
/*
* _cogl_bitmap_new_from_data:
* @data: A pointer to the data. The bitmap will take ownership of this data.
* @format: The format of the pixel data.
* @width: The width of the bitmap.
* @height: The height of the bitmap.
* @rowstride: The rowstride of the bitmap (the number of bytes from
* the start of one row of the bitmap to the next).
* @destroy_fn: A function to be called when the bitmap is
* destroyed. This should free @data. %NULL can be used instead if
* no free is needed.
* @destroy_fn_data: This pointer will get passed to @destroy_fn.
*
* Creates a bitmap using some existing data. The data is not copied
* so the bitmap will take ownership of the data pointer. When the
* bitmap is freed @destroy_fn will be called to free the data.
*
* Return value: A new %CoglBitmap.
*/
CoglBitmap *
_cogl_bitmap_new_from_data (guint8 *data,
CoglPixelFormat format,
int width,
int height,
int rowstride,
CoglBitmapDestroyNotify destroy_fn,
gpointer destroy_fn_data);
/* The idea of this function is that it will create a bitmap that
shares the actual data with another bitmap. This is needed for the
atlas texture backend because it needs upload a bitmap to a sub
texture but override the format so that it ignores the premult
flag. */
CoglBitmap *
_cogl_bitmap_new_shared (CoglBitmap *shared_bmp,
CoglPixelFormat format,
int width,
int height,
int rowstride);
gboolean
_cogl_bitmap_can_convert (CoglPixelFormat src, CoglPixelFormat dst);
gboolean
_cogl_bitmap_fallback_can_convert (CoglPixelFormat src, CoglPixelFormat dst);
gboolean
_cogl_bitmap_can_unpremult (CoglPixelFormat format);
gboolean
_cogl_bitmap_fallback_can_unpremult (CoglPixelFormat format);
gboolean
_cogl_bitmap_can_premult (CoglPixelFormat format);
gboolean
_cogl_bitmap_fallback_can_premult (CoglPixelFormat format);
CoglBitmap *
_cogl_bitmap_convert (CoglBitmap *bmp,
CoglPixelFormat dst_format);
CoglBitmap *
_cogl_bitmap_fallback_convert (CoglBitmap *bmp,
CoglPixelFormat dst_format);
gboolean
_cogl_bitmap_unpremult (CoglBitmap *dst_bmp);
gboolean
_cogl_bitmap_fallback_unpremult (CoglBitmap *dst_bmp);
gboolean
_cogl_bitmap_premult (CoglBitmap *dst_bmp);
gboolean
_cogl_bitmap_fallback_premult (CoglBitmap *dst_bmp);
CoglBitmap *
_cogl_bitmap_from_file (const char *filename,
GError **error);
CoglBitmap *
_cogl_bitmap_fallback_from_file (const char *filename);
gboolean
_cogl_bitmap_convert_premult_status (CoglBitmap *bmp,
CoglPixelFormat dst_format);
CoglBitmap *
_cogl_bitmap_convert_format_and_premult (CoglBitmap *bmp,
CoglPixelFormat dst_format);
void
_cogl_bitmap_copy_subregion (CoglBitmap *src,
CoglBitmap *dst,
int src_x,
int src_y,
int dst_x,
int dst_y,
int width,
int height);
gboolean
_cogl_bitmap_get_size_from_file (const char *filename,
int *width,
int *height);
CoglPixelFormat
_cogl_bitmap_get_format (CoglBitmap *bitmap);
void
_cogl_bitmap_set_format (CoglBitmap *bitmap,
CoglPixelFormat format);
int
_cogl_bitmap_get_width (CoglBitmap *bitmap);
int
_cogl_bitmap_get_height (CoglBitmap *bitmap);
int
_cogl_bitmap_get_rowstride (CoglBitmap *bitmap);
guint8 *
_cogl_bitmap_map (CoglBitmap *bitmap,
CoglBufferAccess access,
CoglBufferMapHint hints);
void
_cogl_bitmap_unmap (CoglBitmap *bitmap);
#endif /* __COGL_BITMAP_H */