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mutter-performance-source/cogl/cogl-texture-driver.h
Damien Lespiau dbef77cd8b cogl: new textures sould have GL_TEXTURE_MIN_FILTER set to GL_LINEAR
The only way the user has to set the mipmap filters is through the
material/layer API. This API defaults to GL_LINEAR/GL_LINEAR for the max
and min filters. With the main use case of cogl being 2D interfaces, it
makes sense do default to GL_LINEAR for the min filter.

When creating new textures, we did not set any filter on them, using
OpenGL defaults': GL_NEAREST_MIPMAP_LINEAR for the min filter and
GL_LINEAR for the max filter. This will make the driver allocate memory
for the mipmap tree, memory that will not be used in the nominal case
(as the material API defaults to GL_LINEAR).

This patch tries to ensure that the min filter is set to GL_LINEAR
before any glTexImage*() call is done on the texture by setting the
filter when generating new OpenGL handles.
2010-02-08 17:14:49 +00:00

192 lines
7.2 KiB
C

/*
* 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __COGL_TEXTURE_DRIVER_H
#define __COGL_TEXTURE_DRIVER_H
/*
* 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
_cogl_texture_driver_gen (GLenum gl_target,
GLsizei n,
GLuint *textures);
/*
* Basically just a wrapper around glBindTexture, but the GLES2 backend
* for example also wants to know about the internal format so it can
* identify when alpha only textures are bound.
*/
void
_cogl_texture_driver_bind (GLenum gl_target, GLuint gl_handle, GLenum gl_intformat);
/*
* 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
_cogl_texture_driver_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
_cogl_texture_driver_upload_subregion_to_gl (GLenum gl_target,
GLuint gl_handle,
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
_cogl_texture_driver_upload_to_gl (GLenum gl_target,
GLuint gl_handle,
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
_cogl_texture_driver_prep_gl_for_pixels_download (int pixels_rowstride,
int pixels_bpp);
/*
* This driver abstraction is in place because GLES doesn't have a sane way to
* download data from a texture so you litterally render the texture to the
* backbuffer, and retrive the data using glReadPixels :-(
*/
gboolean
_cogl_texture_driver_download_from_gl (CoglTexture *tex,
CoglBitmap *target_bmp,
GLuint target_gl_format,
GLuint target_gl_type);
/*
* 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
_cogl_texture_driver_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
_cogl_texture_driver_size_supported (GLenum gl_target,
GLenum gl_format,
GLenum gl_type,
int width,
int height);
/*
* This driver abstraction is needed because GLES doesn't support setting
* a texture border color.
*/
void
_cogl_texture_driver_try_setting_gl_border_color (
GLuint gl_target,
const GLfloat *transparent_color);
/*
* XXX: this should live in cogl/{gl,gles}/cogl.c
*/
gboolean
_cogl_pixel_format_from_gl_internal (GLenum gl_int_format,
CoglPixelFormat *out_format);
/*
* XXX: this should live in cogl/{gl,gles}/cogl.c
*/
CoglPixelFormat
_cogl_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
_cogl_texture_driver_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
_cogl_texture_driver_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
_cogl_texture_driver_find_best_gl_get_data_format (
CoglPixelFormat format,
GLenum *closest_gl_format,
GLenum *closest_gl_type);
#endif /* __COGL_TEXTURE_DRIVER_H */