/*
 * Cogl
 *
 * An object oriented GL/GLES Abstraction/Utility Layer
 *
 * Copyright (C) 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/>.
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <strings.h>

#include "cogl-internal.h"
#include "cogl-context-private.h"
#include "cogl-texture-gl-private.h"
#include "cogl-util.h"

static inline int
calculate_alignment (int rowstride)
{
  int alignment = 1 << (_cogl_util_ffs (rowstride) - 1);

  return MIN (alignment, 8);
}

void
_cogl_texture_gl_prep_alignment_for_pixels_upload (CoglContext *ctx,
                                                   int pixels_rowstride)
{
  GE( ctx, glPixelStorei (GL_UNPACK_ALIGNMENT,
                          calculate_alignment (pixels_rowstride)) );
}

void
_cogl_texture_gl_prep_alignment_for_pixels_download (CoglContext *ctx,
                                                     int bpp,
                                                     int width,
                                                     int rowstride)
{
  int alignment;

  /* If no padding is needed then we can always use an alignment of 1.
   * We want to do this even though it is equivalent to the alignment
   * of the rowstride because the Intel driver in Mesa currently has
   * an optimisation when reading data into a PBO that only works if
   * the alignment is exactly 1.
   *
   * https://bugs.freedesktop.org/show_bug.cgi?id=46632
   */

  if (rowstride == bpp * width)
    alignment = 1;
  else
    alignment = calculate_alignment (rowstride);

  GE( ctx, glPixelStorei (GL_PACK_ALIGNMENT, alignment) );
}

void
_cogl_texture_gl_flush_legacy_texobj_wrap_modes (CoglTexture *texture,
                                                 unsigned int wrap_mode_s,
                                                 unsigned int wrap_mode_t,
                                                 unsigned int wrap_mode_p)
{
  texture->vtable->gl_flush_legacy_texobj_wrap_modes (texture,
                                                      wrap_mode_s,
                                                      wrap_mode_t,
                                                      wrap_mode_p);
}

void
_cogl_texture_gl_flush_legacy_texobj_filters (CoglTexture *texture,
                                              unsigned int min_filter,
                                              unsigned int mag_filter)
{
  texture->vtable->gl_flush_legacy_texobj_filters (texture,
                                                   min_filter, mag_filter);
}