/**************************************************************************
 *
 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/

/**
 * \file
 * Implementation of client buffer (also designated as "user buffers"), which
 * are just state-tracker owned data masqueraded as buffers.
 * 
 * \author José Fonseca <jrfonseca@tungstengraphics.com>
 */


#include "pipe/p_winsys.h"
#include "pipe/p_util.h"

#include "pb_buffer.h"


/**
 * User buffers are special buffers that initially reference memory
 * held by the user but which may if necessary copy that memory into
 * device memory behind the scenes, for submission to hardware.
 *
 * These are particularly useful when the referenced data is never
 * submitted to hardware at all, in the particular case of software
 * vertex processing.
 */
struct pb_user_buffer 
{
   struct pb_buffer base;
   void *data;
};


extern const struct pb_vtbl pb_user_buffer_vtbl;


static INLINE struct pb_user_buffer *
pb_user_buffer(struct pb_buffer *buf)
{
   assert(buf);
   assert(buf->vtbl == &pb_user_buffer_vtbl);
   return (struct pb_user_buffer *)buf;
}


static void
pb_user_buffer_destroy(struct pb_buffer *buf)
{
   assert(buf);
   FREE(buf);
}


static void *
pb_user_buffer_map(struct pb_buffer *buf, 
                   unsigned flags)
{
   return pb_user_buffer(buf)->data;
}


static void
pb_user_buffer_unmap(struct pb_buffer *buf)
{
   /* No-op */
}


static void
pb_user_buffer_get_base_buffer(struct pb_buffer *buf,
                               struct pb_buffer **base_buf,
                               unsigned *offset)
{
   *base_buf = buf;
   *offset = 0;
}


const struct pb_vtbl 
pb_user_buffer_vtbl = {
      pb_user_buffer_destroy,
      pb_user_buffer_map,
      pb_user_buffer_unmap,
      pb_user_buffer_get_base_buffer
};


static struct pipe_buffer *
pb_winsys_user_buffer_create(struct pipe_winsys *winsys,
                             void *data, 
                             unsigned bytes) 
{
   struct pb_user_buffer *buf = CALLOC_STRUCT(pb_user_buffer);

   if(!buf)
      return NULL;
   
   buf->base.base.refcount = 1;
   buf->base.base.size = bytes;
   buf->base.base.alignment = 0;
   buf->base.base.usage = 0;

   buf->base.vtbl = &pb_user_buffer_vtbl;   
   buf->data = data;
   
   return &buf->base.base;
}


static void *
pb_winsys_buffer_map(struct pipe_winsys *winsys,
                     struct pipe_buffer *buf,
                     unsigned flags)
{
   (void)winsys;
   return pb_map(pb_buffer(buf), flags);
}


static void
pb_winsys_buffer_unmap(struct pipe_winsys *winsys,
                       struct pipe_buffer *buf)
{
   (void)winsys;
   pb_unmap(pb_buffer(buf));
}


static void
pb_winsys_buffer_destroy(struct pipe_winsys *winsys,
                         struct pipe_buffer *buf)
{
   (void)winsys;
   pb_destroy(pb_buffer(buf));
}


void 
pb_init_winsys(struct pipe_winsys *winsys)
{
   winsys->user_buffer_create = pb_winsys_user_buffer_create;
   winsys->buffer_map = pb_winsys_buffer_map;
   winsys->buffer_unmap = pb_winsys_buffer_unmap;
   winsys->buffer_destroy = pb_winsys_buffer_destroy;
}
