/*
 * Cogl
 *
 * An object oriented GL/GLES Abstraction/Utility Layer
 *
 * Copyright (C) 2010 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:
 *   Damien Lespiau <damien.lespiau@intel.com>
 *   Robert Bragg <robert@linux.intel.com>
 */

#ifndef __COGL_BUFFER_PRIVATE_H__
#define __COGL_BUFFER_PRIVATE_H__

#include <glib.h>

#include "cogl.h"
#include "cogl-object-private.h"
#include "cogl-buffer.h"

G_BEGIN_DECLS

#define COGL_BUFFER(buffer)     ((CoglBuffer *)(buffer))

typedef struct _CoglBufferVtable CoglBufferVtable;

struct _CoglBufferVtable
{
  void * (* map) (CoglBuffer       *buffer,
                  CoglBufferAccess  access,
                  CoglBufferMapHint hints);

  void (* unmap) (CoglBuffer *buffer);

  gboolean (* set_data) (CoglBuffer   *buffer,
                         unsigned int  offset,
                         const void   *data,
                         unsigned int  size);
};

typedef enum _CoglBufferFlags
{
  COGL_BUFFER_FLAG_NONE            = 0,
  COGL_BUFFER_FLAG_BUFFER_OBJECT   = 1UL << 0,  /* real openGL buffer object */
  COGL_BUFFER_FLAG_MAPPED          = 1UL << 1,
  COGL_BUFFER_FLAG_MAPPED_FALLBACK = 1UL << 2
} CoglBufferFlags;

typedef enum {
  COGL_BUFFER_USAGE_HINT_TEXTURE,
  COGL_BUFFER_USAGE_HINT_VERTEX_ARRAY,
  COGL_BUFFER_USAGE_HINT_INDEX_ARRAY
} CoglBufferUsageHint;

typedef enum {
  COGL_BUFFER_BIND_TARGET_PIXEL_PACK,
  COGL_BUFFER_BIND_TARGET_PIXEL_UNPACK,
  COGL_BUFFER_BIND_TARGET_VERTEX_ARRAY,
  COGL_BUFFER_BIND_TARGET_INDEX_ARRAY,

  COGL_BUFFER_BIND_TARGET_COUNT
} CoglBufferBindTarget;

struct _CoglBuffer
{
  CoglObject              _parent;
  CoglBufferVtable        vtable;

  CoglBufferBindTarget    last_target;

  CoglBufferFlags         flags;

  GLuint                  gl_handle;  /* OpenGL handle */
  unsigned int            size;       /* size of the buffer, in bytes */
  CoglBufferUsageHint     usage_hint;
  CoglBufferUpdateHint    update_hint;

  guint8                 *data;      /* points to the mapped memory when
                                      * the CoglBuffer is a VBO, PBO, ... or
                                      * points to allocated memory in the
                                      * fallback paths */

  int                     immutable_ref;

  guint                   store_created:1;
};

/* This is used to register a type to the list of handle types that
   will be considered a texture in cogl_is_texture() */
void
_cogl_buffer_register_buffer_type (GQuark type);

#define COGL_BUFFER_DEFINE(TypeName, type_name)                         \
  COGL_OBJECT_DEFINE_WITH_CODE                                          \
  (TypeName, type_name,                                                 \
   _cogl_buffer_register_buffer_type (_cogl_object_                     \
                                      ## type_name ## _get_type ()))

void
_cogl_buffer_initialize (CoglBuffer          *buffer,
                         unsigned int         size,
                         gboolean             use_malloc,
                         CoglBufferBindTarget default_target,
                         CoglBufferUsageHint  usage_hint,
                         CoglBufferUpdateHint update_hint);

void
_cogl_buffer_fini (CoglBuffer *buffer);

void *
_cogl_buffer_bind (CoglBuffer *buffer,
                   CoglBufferBindTarget target);

void
_cogl_buffer_unbind (CoglBuffer *buffer);

CoglBufferUsageHint
_cogl_buffer_get_usage_hint (CoglBuffer *buffer);

GLenum
_cogl_buffer_access_to_gl_enum (CoglBufferAccess access);

GLenum
_cogl_buffer_hints_to_gl_enum (CoglBufferUsageHint  usage_hint,
                               CoglBufferUpdateHint update_hint);

CoglBuffer *
_cogl_buffer_immutable_ref (CoglBuffer *buffer);

void
_cogl_buffer_immutable_unref (CoglBuffer *buffer);

/* This is a wrapper around cogl_buffer_map for internal use when we
   want to map the buffer for write only to replace the entire
   contents. If the map fails then it will fallback to writing to a
   temporary buffer. When _cogl_buffer_unmap_for_fill_or_fallback is
   called the temporary buffer will be copied into the array. Note
   that these calls share a global array so they can not be nested. */
void *
_cogl_buffer_map_for_fill_or_fallback (CoglBuffer *buffer);

void
_cogl_buffer_unmap_for_fill_or_fallback (CoglBuffer *buffer);

G_END_DECLS

#endif /* __COGL_BUFFER_PRIVATE_H__ */
