/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 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_TEXTURE_DRIVER_H
#define __COGL_TEXTURE_DRIVER_H
typedef struct _CoglTextureDriver CoglTextureDriver;
struct _CoglTextureDriver
{
/*
* A very small wrapper around glGenTextures() that ensures we default to
* non-mipmap filters when creating textures. This is to save some memory as
* the driver will not allocate room for the mipmap tree.
*/
void
(* gen) (GLenum gl_target,
GLsizei n,
GLuint *textures);
/*
* This sets up the glPixelStore state for an upload to a destination with
* the same size, and with no offset.
*/
/* NB: GLES can't upload a sub region of pixel data from a larger source
* buffer which is why this interface is limited. The GL driver has a more
* flexible version of this function that is uses internally */
void
(* prep_gl_for_pixels_upload) (int pixels_rowstride,
int pixels_bpp);
/*
* This uploads a sub-region from source_bmp to a single GL texture
* handle (i.e a single CoglTexture slice)
*
* It also updates the array of tex->first_pixels[slice_index] if
* dst_{x,y} == 0
*
* The driver abstraction is in place because GLES doesn't support the pixel
* store options required to source from a subregion, so for GLES we have
* to manually create a transient source bitmap.
*
* XXX: sorry for the ridiculous number of arguments :-(
*/
void
(* upload_subregion_to_gl) (GLenum gl_target,
GLuint gl_handle,
gboolean is_foreign,
int src_x,
int src_y,
int dst_x,
int dst_y,
int width,
int height,
CoglBitmap *source_bmp,
GLuint source_gl_format,
GLuint source_gl_type);
/*
* Replaces the contents of the GL texture with the entire bitmap. On
* GL this just directly calls glTexImage2D, but under GLES it needs
* to copy the bitmap if the rowstride is not a multiple of a possible
* alignment value because there is no GL_UNPACK_ROW_LENGTH
*/
void
(* upload_to_gl) (GLenum gl_target,
GLuint gl_handle,
gboolean is_foreign,
CoglBitmap *source_bmp,
GLint internal_gl_format,
GLuint source_gl_format,
GLuint source_gl_type);
/*
* Replaces the contents of the GL texture with the entire bitmap. The
* width of the texture is inferred from the bitmap. The height and
* depth of the texture is given directly. The 'image_height' (which
* is the number of rows between images) is inferred by dividing the
* height of the bitmap by the depth.
*/
void
(* upload_to_gl_3d) (GLenum gl_target,
GLuint gl_handle,
gboolean is_foreign,
GLint height,
GLint depth,
CoglBitmap *source_bmp,
GLint internal_gl_format,
GLuint source_gl_format,
GLuint source_gl_type);
/*
* This sets up the glPixelStore state for an download to a destination with
* the same size, and with no offset.
*/
/* NB: GLES can't download pixel data into a sub region of a larger
* destination buffer, the GL driver has a more flexible version of
* this function that it uses internally. */
void
(* prep_gl_for_pixels_download) (int pixels_rowstride,
int pixels_bpp);
/*
* This driver abstraction is needed because GLES doesn't support
* glGetTexImage (). On GLES this currently just returns FALSE which
* will lead to a generic fallback path being used that simply
* renders the texture and reads it back from the framebuffer. (See
* _cogl_texture_draw_and_read () )
*/
gboolean
(* gl_get_tex_image) (GLenum gl_target,
GLenum dest_gl_format,
GLenum dest_gl_type,
guint8 *dest);
/*
* It may depend on the driver as to what texture sizes are supported...
*/
gboolean
(* size_supported) (GLenum gl_target,
GLenum gl_format,
GLenum gl_type,
int width,
int height);
gboolean
(* size_supported_3d) (GLenum gl_target,
GLenum gl_format,
GLenum gl_type,
int width,
int height,
int depth);
/*
* This driver abstraction is needed because GLES doesn't support setting
* a texture border color.
*/
void
(* try_setting_gl_border_color) (
GLuint gl_target,
const GLfloat *transparent_color);
/*
* XXX: this should live in cogl/{gl,gles}/cogl.c
*/
gboolean
(* pixel_format_from_gl_internal) (GLenum gl_int_format,
CoglPixelFormat *out_format);
/*
* XXX: this should live in cogl/{gl,gles}/cogl.c
*/
CoglPixelFormat
(* pixel_format_to_gl) (CoglPixelFormat format,
GLenum *out_glintformat,
GLenum *out_glformat,
GLenum *out_gltype);
/*
* It may depend on the driver as to what texture targets may be used when
* creating a foreign texture. E.g. OpenGL supports ARB_texture_rectangle
* but GLES doesn't
*/
gboolean
(* allows_foreign_gl_target) (GLenum gl_target);
/*
* glGenerateMipmap semantics may need to be emulated for some
* drivers. E.g. by enabling auto mipmap generation an re-loading a
* number of known texels.
*/
void
(* gl_generate_mipmaps) (GLenum texture_target);
/*
* The driver may impose constraints on what formats can be used to store
* texture data read from textures. For example GLES currently only supports
* RGBA_8888, and so we need to manually convert the data if the final
* destination has another format.
*/
CoglPixelFormat
(* find_best_gl_get_data_format) (CoglPixelFormat format,
GLenum *closest_gl_format,
GLenum *closest_gl_type);
};
#endif /* __COGL_TEXTURE_DRIVER_H */