mutter/cogl/driver/gl/cogl-texture-2d-gl.c
Robert Bragg cbd6951134 introduce texture loaders to make allocations lazy
This introduces the internal idea of texture loaders that track the
state for loading and allocating a texture. This defers a lot more work
until the texture is allocated.

There are several intentions to this change:

- provides a means for extending how textures are allocated without
  requiring all the parameters to be supplied in a single _texture_new()
  function call.

- allow us to remove the internal_format argument from all
  _texture_new() apis since using CoglPixelFormat is bad way of
  expressing the internal format constraints because it is too specific.

  For now the internal_format arguments haven't actually been removed
  but this patch does introduce replacement apis for controlling the
  internal format:

    cogl_texture_set_components() lets you specify what components your
    texture needs when it is allocated.
    cogl_texture_set_premultiplied() lets you specify whether a texture
    data should be interpreted as premultiplied or not.

- Enable us to support asynchronous texture loading + allocation in the
  future.

Of note, the _new_from_data() texture constructors all continue to
allocate textures immediately so that existing code doesn't need to be
adapted to manage the lifetime of the data being uploaded.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 6a83de9ef4210f380a31f410797447b365a8d02c)

Note: Compared to the original patch, the ->premultipled state for
textures isn't forced to be %TRUE in _cogl_texture_init since that
effectively ignores the users explicitly given internal_format which was
a mistake and on master that change should have been made in the patch
that followed. The gtk-doc comments for cogl_texture_set_premultiplied()
and cogl_texture_set_components() have also been updated in-line with
this fix.
2014-01-09 15:49:46 +00:00

751 lines
26 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2009,2010,2011,2012 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/>.
*
*
*
* Authors:
* Neil Roberts <neil@linux.intel.com>
* Robert Bragg <robert@linux.intel.com>
*/
#include <config.h>
#include <string.h>
#include "cogl-private.h"
#include "cogl-texture-private.h"
#include "cogl-texture-2d-gl.h"
#include "cogl-texture-2d-gl-private.h"
#include "cogl-texture-2d-private.h"
#include "cogl-texture-gl-private.h"
#include "cogl-pipeline-opengl-private.h"
#include "cogl-error-private.h"
#include "cogl-util-gl-private.h"
void
_cogl_texture_2d_gl_free (CoglTexture2D *tex_2d)
{
if (!tex_2d->is_foreign && tex_2d->gl_texture)
_cogl_delete_gl_texture (tex_2d->gl_texture);
}
CoglBool
_cogl_texture_2d_gl_can_create (CoglContext *ctx,
int width,
int height,
CoglPixelFormat internal_format)
{
GLenum gl_intformat;
GLenum gl_format;
GLenum gl_type;
/* If NPOT textures aren't supported then the size must be a power
of two */
if (!cogl_has_feature (ctx, COGL_FEATURE_ID_TEXTURE_NPOT_BASIC) &&
(!_cogl_util_is_pot (width) ||
!_cogl_util_is_pot (height)))
return FALSE;
ctx->driver_vtable->pixel_format_to_gl (ctx,
internal_format,
&gl_intformat,
&gl_format,
&gl_type);
/* Check that the driver can create a texture with that size */
if (!ctx->texture_driver->size_supported (ctx,
GL_TEXTURE_2D,
gl_intformat,
gl_format,
gl_type,
width,
height))
return FALSE;
return TRUE;
}
void
_cogl_texture_2d_gl_init (CoglTexture2D *tex_2d)
{
tex_2d->gl_texture = 0;
/* We default to GL_LINEAR for both filters */
tex_2d->gl_legacy_texobj_min_filter = GL_LINEAR;
tex_2d->gl_legacy_texobj_mag_filter = GL_LINEAR;
/* Wrap mode not yet set */
tex_2d->gl_legacy_texobj_wrap_mode_s = GL_FALSE;
tex_2d->gl_legacy_texobj_wrap_mode_t = GL_FALSE;
}
static CoglBool
allocate_with_size (CoglTexture2D *tex_2d,
CoglTextureLoader *loader,
CoglError **error)
{
CoglTexture *tex = COGL_TEXTURE (tex_2d);
CoglPixelFormat internal_format;
int width = loader->src.sized.width;
int height = loader->src.sized.height;
CoglContext *ctx = tex->context;
GLenum gl_intformat;
GLenum gl_format;
GLenum gl_type;
GLenum gl_error;
GLenum gl_texture;
internal_format =
_cogl_texture_determine_internal_format (tex, COGL_PIXEL_FORMAT_ANY);
if (!_cogl_texture_2d_gl_can_create (ctx,
width,
height,
internal_format))
{
_cogl_set_error (error, COGL_TEXTURE_ERROR,
COGL_TEXTURE_ERROR_SIZE,
"Failed to create texture 2d due to size/format"
" constraints");
return FALSE;
}
ctx->driver_vtable->pixel_format_to_gl (ctx,
internal_format,
&gl_intformat,
&gl_format,
&gl_type);
gl_texture = ctx->texture_driver->gen (ctx, GL_TEXTURE_2D, internal_format);
tex_2d->gl_internal_format = gl_intformat;
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
gl_texture,
tex_2d->is_foreign);
/* Clear any GL errors */
while ((gl_error = ctx->glGetError ()) != GL_NO_ERROR)
;
ctx->glTexImage2D (GL_TEXTURE_2D, 0, gl_intformat,
width, height, 0, gl_format, gl_type, NULL);
if (_cogl_gl_util_catch_out_of_memory (ctx, error))
{
GE( ctx, glDeleteTextures (1, &gl_texture) );
return FALSE;
}
tex_2d->gl_texture = gl_texture;
tex_2d->gl_internal_format = gl_intformat;
tex_2d->internal_format = internal_format;
_cogl_texture_set_allocated (tex, internal_format, width, height);
return TRUE;
}
static CoglBool
allocate_from_bitmap (CoglTexture2D *tex_2d,
CoglTextureLoader *loader,
CoglError **error)
{
CoglTexture *tex = COGL_TEXTURE (tex_2d);
CoglBitmap *bmp = loader->src.bitmap.bitmap;
CoglContext *ctx = _cogl_bitmap_get_context (bmp);
CoglPixelFormat internal_format;
int width = cogl_bitmap_get_width (bmp);
int height = cogl_bitmap_get_height (bmp);
CoglBool can_convert_in_place = loader->src.bitmap.can_convert_in_place;
CoglBitmap *upload_bmp;
GLenum gl_intformat;
GLenum gl_format;
GLenum gl_type;
internal_format =
_cogl_texture_determine_internal_format (tex, cogl_bitmap_get_format (bmp));
if (!_cogl_texture_2d_gl_can_create (ctx,
width,
height,
internal_format))
{
_cogl_set_error (error, COGL_TEXTURE_ERROR,
COGL_TEXTURE_ERROR_SIZE,
"Failed to create texture 2d due to size/format"
" constraints");
return FALSE;
}
upload_bmp = _cogl_bitmap_convert_for_upload (bmp,
internal_format,
can_convert_in_place,
error);
if (upload_bmp == NULL)
return FALSE;
ctx->driver_vtable->pixel_format_to_gl (ctx,
cogl_bitmap_get_format (upload_bmp),
NULL, /* internal format */
&gl_format,
&gl_type);
ctx->driver_vtable->pixel_format_to_gl (ctx,
internal_format,
&gl_intformat,
NULL,
NULL);
/* Keep a copy of the first pixel so that if glGenerateMipmap isn't
supported we can fallback to using GL_GENERATE_MIPMAP */
if (!cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
{
CoglError *ignore = NULL;
uint8_t *data = _cogl_bitmap_map (upload_bmp,
COGL_BUFFER_ACCESS_READ, 0,
&ignore);
CoglPixelFormat format = cogl_bitmap_get_format (upload_bmp);
tex_2d->first_pixel.gl_format = gl_format;
tex_2d->first_pixel.gl_type = gl_type;
if (data)
{
memcpy (tex_2d->first_pixel.data, data,
_cogl_pixel_format_get_bytes_per_pixel (format));
_cogl_bitmap_unmap (upload_bmp);
}
else
{
g_warning ("Failed to read first pixel of bitmap for "
"glGenerateMipmap fallback");
cogl_error_free (ignore);
memset (tex_2d->first_pixel.data, 0,
_cogl_pixel_format_get_bytes_per_pixel (format));
}
}
tex_2d->gl_texture =
ctx->texture_driver->gen (ctx, GL_TEXTURE_2D, internal_format);
if (!ctx->texture_driver->upload_to_gl (ctx,
GL_TEXTURE_2D,
tex_2d->gl_texture,
FALSE,
upload_bmp,
gl_intformat,
gl_format,
gl_type,
error))
{
cogl_object_unref (upload_bmp);
return FALSE;
}
tex_2d->gl_internal_format = gl_intformat;
cogl_object_unref (upload_bmp);
tex_2d->internal_format = internal_format;
_cogl_texture_set_allocated (tex, internal_format, width, height);
return TRUE;
}
#if defined (COGL_HAS_EGL_SUPPORT) && defined (EGL_KHR_image_base)
static CoglBool
allocate_from_egl_image (CoglTexture2D *tex_2d,
CoglTextureLoader *loader,
CoglError **error)
{
CoglTexture *tex = COGL_TEXTURE (tex_2d);
CoglContext *ctx = tex->context;
CoglPixelFormat internal_format = loader->src.egl_image.format;
GLenum gl_error;
tex_2d->gl_texture =
ctx->texture_driver->gen (ctx, GL_TEXTURE_2D, internal_format);
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
tex_2d->gl_texture,
FALSE);
while ((gl_error = ctx->glGetError ()) != GL_NO_ERROR)
;
ctx->glEGLImageTargetTexture2D (GL_TEXTURE_2D, loader->src.egl_image.image);
if (ctx->glGetError () != GL_NO_ERROR)
{
_cogl_set_error (error,
COGL_TEXTURE_ERROR,
COGL_TEXTURE_ERROR_BAD_PARAMETER,
"Could not create a CoglTexture2D from a given "
"EGLImage");
GE( ctx, glDeleteTextures (1, &tex_2d->gl_texture) );
return FALSE;
}
tex_2d->internal_format = internal_format;
_cogl_texture_set_allocated (tex,
internal_format,
loader->src.egl_image.width,
loader->src.egl_image.height);
return TRUE;
}
#endif
static CoglBool
allocate_from_gl_foreign (CoglTexture2D *tex_2d,
CoglTextureLoader *loader,
CoglError **error)
{
CoglTexture *tex = COGL_TEXTURE (tex_2d);
CoglContext *ctx = tex->context;
CoglPixelFormat format = loader->src.gl_foreign.format;
GLenum gl_error = 0;
GLint gl_compressed = GL_FALSE;
GLenum gl_int_format = 0;
if (!ctx->texture_driver->allows_foreign_gl_target (ctx, GL_TEXTURE_2D))
{
_cogl_set_error (error,
COGL_SYSTEM_ERROR,
COGL_SYSTEM_ERROR_UNSUPPORTED,
"Foreign GL_TEXTURE_2D textures are not "
"supported by your system");
return FALSE;
}
/* Make sure binding succeeds */
while ((gl_error = ctx->glGetError ()) != GL_NO_ERROR)
;
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
loader->src.gl_foreign.gl_handle, TRUE);
if (ctx->glGetError () != GL_NO_ERROR)
{
_cogl_set_error (error,
COGL_SYSTEM_ERROR,
COGL_SYSTEM_ERROR_UNSUPPORTED,
"Failed to bind foreign GL_TEXTURE_2D texture");
return FALSE;
}
/* Obtain texture parameters
(only level 0 we are interested in) */
#ifdef HAVE_COGL_GL
if (_cogl_has_private_feature
(ctx, COGL_PRIVATE_FEATURE_QUERY_TEXTURE_PARAMETERS))
{
GE( ctx, glGetTexLevelParameteriv (GL_TEXTURE_2D, 0,
GL_TEXTURE_COMPRESSED,
&gl_compressed) );
{
GLint val;
GE( ctx, glGetTexLevelParameteriv (GL_TEXTURE_2D, 0,
GL_TEXTURE_INTERNAL_FORMAT,
&val) );
gl_int_format = val;
}
/* If we can query GL for the actual pixel format then we'll ignore
the passed in format and use that. */
if (!ctx->driver_vtable->pixel_format_from_gl_internal (ctx,
gl_int_format,
&format))
{
_cogl_set_error (error,
COGL_SYSTEM_ERROR,
COGL_SYSTEM_ERROR_UNSUPPORTED,
"Unsupported internal format for foreign texture");
return FALSE;
}
}
else
#endif
{
/* Otherwise we'll assume we can derive the GL format from the
passed in format */
ctx->driver_vtable->pixel_format_to_gl (ctx,
format,
&gl_int_format,
NULL,
NULL);
}
/* Compressed texture images not supported */
if (gl_compressed == GL_TRUE)
{
_cogl_set_error (error,
COGL_SYSTEM_ERROR,
COGL_SYSTEM_ERROR_UNSUPPORTED,
"Compressed foreign textures aren't currently supported");
return FALSE;
}
/* Note: previously this code would query the texture object for
whether it has GL_GENERATE_MIPMAP enabled to determine whether to
auto-generate the mipmap. This doesn't make much sense any more
since Cogl switch to using glGenerateMipmap. Ideally I think
cogl_texture_2d_new_from_foreign should take a flags parameter so
that the application can decide whether it wants
auto-mipmapping. To be compatible with existing code, Cogl now
disables its own auto-mipmapping but leaves the value of
GL_GENERATE_MIPMAP alone so that it would still work but without
the dirtiness tracking that Cogl would do. */
_cogl_texture_2d_set_auto_mipmap (COGL_TEXTURE (tex_2d), FALSE);
/* Setup bitmap info */
tex_2d->is_foreign = TRUE;
tex_2d->mipmaps_dirty = TRUE;
tex_2d->gl_texture = loader->src.gl_foreign.gl_handle;
tex_2d->gl_internal_format = gl_int_format;
/* Unknown filter */
tex_2d->gl_legacy_texobj_min_filter = GL_FALSE;
tex_2d->gl_legacy_texobj_mag_filter = GL_FALSE;
tex_2d->internal_format = format;
_cogl_texture_set_allocated (tex,
format,
loader->src.gl_foreign.width,
loader->src.gl_foreign.height);
return TRUE;
}
CoglBool
_cogl_texture_2d_gl_allocate (CoglTexture *tex,
CoglError **error)
{
CoglTexture2D *tex_2d = COGL_TEXTURE_2D (tex);
CoglTextureLoader *loader = tex->loader;
_COGL_RETURN_VAL_IF_FAIL (loader, FALSE);
switch (loader->src_type)
{
case COGL_TEXTURE_SOURCE_TYPE_SIZED:
return allocate_with_size (tex_2d, loader, error);
case COGL_TEXTURE_SOURCE_TYPE_BITMAP:
return allocate_from_bitmap (tex_2d, loader, error);
case COGL_TEXTURE_SOURCE_TYPE_EGL_IMAGE:
#if defined (COGL_HAS_EGL_SUPPORT) && defined (EGL_KHR_image_base)
return allocate_from_egl_image (tex_2d, loader, error);
#else
g_return_val_if_reached (FALSE);
#endif
case COGL_TEXTURE_SOURCE_TYPE_GL_FOREIGN:
return allocate_from_gl_foreign (tex_2d, loader, error);
}
g_return_val_if_reached (FALSE);
}
void
_cogl_texture_2d_gl_flush_legacy_texobj_filters (CoglTexture *tex,
GLenum min_filter,
GLenum mag_filter)
{
CoglTexture2D *tex_2d = COGL_TEXTURE_2D (tex);
CoglContext *ctx = tex->context;
if (min_filter == tex_2d->gl_legacy_texobj_min_filter
&& mag_filter == tex_2d->gl_legacy_texobj_mag_filter)
return;
/* Store new values */
tex_2d->gl_legacy_texobj_min_filter = min_filter;
tex_2d->gl_legacy_texobj_mag_filter = mag_filter;
/* Apply new filters to the texture */
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
tex_2d->gl_texture,
tex_2d->is_foreign);
GE( ctx, glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, mag_filter) );
GE( ctx, glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, min_filter) );
}
void
_cogl_texture_2d_gl_flush_legacy_texobj_wrap_modes (CoglTexture *tex,
GLenum wrap_mode_s,
GLenum wrap_mode_t,
GLenum wrap_mode_p)
{
CoglTexture2D *tex_2d = COGL_TEXTURE_2D (tex);
CoglContext *ctx = tex->context;
/* Only set the wrap mode if it's different from the current value
to avoid too many GL calls. Texture 2D doesn't make use of the r
coordinate so we can ignore its wrap mode */
if (tex_2d->gl_legacy_texobj_wrap_mode_s != wrap_mode_s ||
tex_2d->gl_legacy_texobj_wrap_mode_t != wrap_mode_t)
{
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
tex_2d->gl_texture,
tex_2d->is_foreign);
GE( ctx, glTexParameteri (GL_TEXTURE_2D,
GL_TEXTURE_WRAP_S,
wrap_mode_s) );
GE( ctx, glTexParameteri (GL_TEXTURE_2D,
GL_TEXTURE_WRAP_T,
wrap_mode_t) );
tex_2d->gl_legacy_texobj_wrap_mode_s = wrap_mode_s;
tex_2d->gl_legacy_texobj_wrap_mode_t = wrap_mode_t;
}
}
CoglTexture2D *
cogl_texture_2d_new_from_foreign (CoglContext *ctx,
unsigned int gl_handle,
int width,
int height,
CoglPixelFormat format,
CoglError **error)
{
CoglTextureLoader *loader;
/* NOTE: width, height and internal format are not queriable
* in GLES, hence such a function prototype.
*/
/* Note: We always trust the given width and height without querying
* the texture object because the user may be creating a Cogl
* texture for a texture_from_pixmap object where glTexImage2D may
* not have been called and the texture_from_pixmap spec doesn't
* clarify that it is reliable to query back the size from OpenGL.
*/
/* Assert it is a valid GL texture object */
_COGL_RETURN_VAL_IF_FAIL (ctx->glIsTexture (gl_handle), FALSE);
/* Validate width and height */
_COGL_RETURN_VAL_IF_FAIL (width > 0 && height > 0, NULL);
loader = _cogl_texture_create_loader ();
loader->src_type = COGL_TEXTURE_SOURCE_TYPE_GL_FOREIGN;
loader->src.gl_foreign.gl_handle = gl_handle;
loader->src.gl_foreign.width = width;
loader->src.gl_foreign.height = height;
loader->src.gl_foreign.format = format;
return _cogl_texture_2d_create_base (ctx, width, height, format, loader);
}
void
_cogl_texture_2d_gl_copy_from_framebuffer (CoglTexture2D *tex_2d,
int src_x,
int src_y,
int width,
int height,
CoglFramebuffer *src_fb,
int dst_x,
int dst_y,
int level)
{
CoglTexture *tex = COGL_TEXTURE (tex_2d);
CoglContext *ctx = tex->context;
/* Make sure the current framebuffers are bound, though we don't need to
* flush the clip state here since we aren't going to draw to the
* framebuffer. */
_cogl_framebuffer_flush_state (ctx->current_draw_buffer,
src_fb,
COGL_FRAMEBUFFER_STATE_ALL &
~COGL_FRAMEBUFFER_STATE_CLIP);
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
tex_2d->gl_texture,
tex_2d->is_foreign);
ctx->glCopyTexSubImage2D (GL_TEXTURE_2D,
0, /* level */
dst_x, dst_y,
src_x, src_y,
width, height);
}
unsigned int
_cogl_texture_2d_gl_get_gl_handle (CoglTexture2D *tex_2d)
{
return tex_2d->gl_texture;
}
void
_cogl_texture_2d_gl_generate_mipmap (CoglTexture2D *tex_2d)
{
CoglContext *ctx = COGL_TEXTURE (tex_2d)->context;
/* glGenerateMipmap is defined in the FBO extension. If it's not
available we'll fallback to temporarily enabling
GL_GENERATE_MIPMAP and reuploading the first pixel */
if (cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
_cogl_texture_gl_generate_mipmaps (COGL_TEXTURE (tex_2d));
#if defined(HAVE_COGL_GLES) || defined(HAVE_COGL_GL)
else
{
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
tex_2d->gl_texture,
tex_2d->is_foreign);
GE( ctx, glTexParameteri (GL_TEXTURE_2D,
GL_GENERATE_MIPMAP,
GL_TRUE) );
GE( ctx, glTexSubImage2D (GL_TEXTURE_2D, 0, 0, 0, 1, 1,
tex_2d->first_pixel.gl_format,
tex_2d->first_pixel.gl_type,
tex_2d->first_pixel.data) );
GE( ctx, glTexParameteri (GL_TEXTURE_2D,
GL_GENERATE_MIPMAP,
GL_FALSE) );
}
#endif
}
CoglBool
_cogl_texture_2d_gl_copy_from_bitmap (CoglTexture2D *tex_2d,
int src_x,
int src_y,
int width,
int height,
CoglBitmap *bmp,
int dst_x,
int dst_y,
int level,
CoglError **error)
{
CoglTexture *tex = COGL_TEXTURE (tex_2d);
CoglContext *ctx = tex->context;
CoglBitmap *upload_bmp;
CoglPixelFormat upload_format;
GLenum gl_format;
GLenum gl_type;
CoglBool status = TRUE;
upload_bmp =
_cogl_bitmap_convert_for_upload (bmp,
_cogl_texture_get_format (tex),
FALSE, /* can't convert in place */
error);
if (upload_bmp == NULL)
return FALSE;
upload_format = cogl_bitmap_get_format (upload_bmp);
ctx->driver_vtable->pixel_format_to_gl (ctx,
upload_format,
NULL, /* internal format */
&gl_format,
&gl_type);
/* If this touches the first pixel then we'll update our copy */
if (dst_x == 0 && dst_y == 0 &&
!cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
{
CoglError *ignore = NULL;
uint8_t *data =
_cogl_bitmap_map (upload_bmp, COGL_BUFFER_ACCESS_READ, 0, &ignore);
CoglPixelFormat bpp =
_cogl_pixel_format_get_bytes_per_pixel (upload_format);
tex_2d->first_pixel.gl_format = gl_format;
tex_2d->first_pixel.gl_type = gl_type;
if (data)
{
memcpy (tex_2d->first_pixel.data,
(data +
cogl_bitmap_get_rowstride (upload_bmp) * src_y +
bpp * src_x),
bpp);
_cogl_bitmap_unmap (bmp);
}
else
{
g_warning ("Failed to read first bitmap pixel for "
"glGenerateMipmap fallback");
cogl_error_free (ignore);
memset (tex_2d->first_pixel.data, 0, bpp);
}
}
status = ctx->texture_driver->upload_subregion_to_gl (ctx,
tex,
FALSE,
src_x, src_y,
dst_x, dst_y,
width, height,
level,
upload_bmp,
gl_format,
gl_type,
error);
cogl_object_unref (upload_bmp);
_cogl_texture_gl_maybe_update_max_level (tex, level);
return status;
}
void
_cogl_texture_2d_gl_get_data (CoglTexture2D *tex_2d,
CoglPixelFormat format,
int rowstride,
uint8_t *data)
{
CoglContext *ctx = COGL_TEXTURE (tex_2d)->context;
int bpp;
int width = COGL_TEXTURE (tex_2d)->width;
GLenum gl_format;
GLenum gl_type;
bpp = _cogl_pixel_format_get_bytes_per_pixel (format);
ctx->driver_vtable->pixel_format_to_gl (ctx,
format,
NULL, /* internal format */
&gl_format,
&gl_type);
ctx->texture_driver->prep_gl_for_pixels_download (ctx,
rowstride,
width,
bpp);
_cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
tex_2d->gl_texture,
tex_2d->is_foreign);
ctx->texture_driver->gl_get_tex_image (ctx,
GL_TEXTURE_2D,
gl_format,
gl_type,
data);
}