/**************************************************************************
 * 
 * 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.
 * 
 **************************************************************************/


/**
 * Functions for pixel buffer objects and vertex/element buffer objects.
 */


#include "main/imports.h"
#include "main/mtypes.h"
#include "main/arrayobj.h"
#include "main/bufferobj.h"

#include "st_context.h"
#include "st_cb_bufferobjects.h"

#include "pipe/p_context.h"
#include "pipe/p_defines.h"
#include "util/u_inlines.h"


/**
 * There is some duplication between mesa's bufferobjects and our
 * bufmgr buffers.  Both have an integer handle and a hashtable to
 * lookup an opaque structure.  It would be nice if the handles and
 * internal structure where somehow shared.
 */
static struct gl_buffer_object *
st_bufferobj_alloc(GLcontext *ctx, GLuint name, GLenum target)
{
   struct st_buffer_object *st_obj = ST_CALLOC_STRUCT(st_buffer_object);

   if (!st_obj)
      return NULL;

   _mesa_initialize_buffer_object(&st_obj->Base, name, target);

   return &st_obj->Base;
}



/**
 * Deallocate/free a vertex/pixel buffer object.
 * Called via glDeleteBuffersARB().
 */
static void
st_bufferobj_free(GLcontext *ctx, struct gl_buffer_object *obj)
{
   struct st_buffer_object *st_obj = st_buffer_object(obj);

   assert(obj->RefCount == 0);
   assert(st_obj->transfer == NULL);

   if (st_obj->buffer) 
      pipe_resource_reference(&st_obj->buffer, NULL);

   free(st_obj);
}



/**
 * Replace data in a subrange of buffer object.  If the data range
 * specified by size + offset extends beyond the end of the buffer or
 * if data is NULL, no copy is performed.
 * Called via glBufferSubDataARB().
 */
static void
st_bufferobj_subdata(GLcontext *ctx,
		     GLenum target,
		     GLintptrARB offset,
		     GLsizeiptrARB size,
		     const GLvoid * data, struct gl_buffer_object *obj)
{
   struct st_buffer_object *st_obj = st_buffer_object(obj);

   /* we may be called from VBO code, so double-check params here */
   ASSERT(offset >= 0);
   ASSERT(size >= 0);
   ASSERT(offset + size <= obj->Size);

   if (!size)
      return;

   /*
    * According to ARB_vertex_buffer_object specification, if data is null,
    * then the contents of the buffer object's data store is undefined. We just
    * ignore, and leave it unchanged.
    */
   if (!data)
      return;

   /* Now that transfers are per-context, we don't have to figure out
    * flushing here.  Usually drivers won't need to flush in this case
    * even if the buffer is currently referenced by hardware - they
    * just queue the upload as dma rather than mapping the underlying
    * buffer directly.
    */
   pipe_buffer_write(st_context(ctx)->pipe,
		     st_obj->buffer,
		     offset, size, data);
}


/**
 * Called via glGetBufferSubDataARB().
 */
static void
st_bufferobj_get_subdata(GLcontext *ctx,
                         GLenum target,
                         GLintptrARB offset,
                         GLsizeiptrARB size,
                         GLvoid * data, struct gl_buffer_object *obj)
{
   struct st_buffer_object *st_obj = st_buffer_object(obj);

   /* we may be called from VBO code, so double-check params here */
   ASSERT(offset >= 0);
   ASSERT(size >= 0);
   ASSERT(offset + size <= obj->Size);

   if (!size)
      return;

   pipe_buffer_read(st_context(ctx)->pipe, st_obj->buffer,
                    offset, size, data);
}


/**
 * Allocate space for and store data in a buffer object.  Any data that was
 * previously stored in the buffer object is lost.  If data is NULL,
 * memory will be allocated, but no copy will occur.
 * Called via ctx->Driver.BufferData().
 * \return GL_TRUE for success, GL_FALSE if out of memory
 */
static GLboolean
st_bufferobj_data(GLcontext *ctx,
		  GLenum target,
		  GLsizeiptrARB size,
		  const GLvoid * data,
		  GLenum usage, 
		  struct gl_buffer_object *obj)
{
   struct st_context *st = st_context(ctx);
   struct pipe_context *pipe = st->pipe;
   struct st_buffer_object *st_obj = st_buffer_object(obj);
   unsigned buffer_usage;

   st_obj->Base.Size = size;
   st_obj->Base.Usage = usage;
   
   switch(target) {
   case GL_PIXEL_PACK_BUFFER_ARB:
   case GL_PIXEL_UNPACK_BUFFER_ARB:
      buffer_usage = PIPE_BIND_RENDER_TARGET;
      break;
   case GL_ARRAY_BUFFER_ARB:
      buffer_usage = PIPE_BIND_VERTEX_BUFFER;
      break;
   case GL_ELEMENT_ARRAY_BUFFER_ARB:
      buffer_usage = PIPE_BIND_INDEX_BUFFER;
      break;
   default:
      buffer_usage = 0;
   }

   pipe_resource_reference( &st_obj->buffer, NULL );

   if (size != 0) {
      st_obj->buffer = pipe_buffer_create(pipe->screen, buffer_usage, size);

      if (!st_obj->buffer) {
         return GL_FALSE;
      }

      if (data)
         pipe_buffer_write(st_context(ctx)->pipe, st_obj->buffer, 0,
				       size, data);
      return GL_TRUE;
   }

   return GL_TRUE;
}


/**
 * Dummy data whose's pointer is used for zero size buffers or ranges.
 */
static long st_bufferobj_zero_length = 0;



/**
 * Called via glMapBufferARB().
 */
static void *
st_bufferobj_map(GLcontext *ctx, GLenum target, GLenum access,
                 struct gl_buffer_object *obj)
{
   struct st_buffer_object *st_obj = st_buffer_object(obj);
   uint flags;

   switch (access) {
   case GL_WRITE_ONLY:
      flags = PIPE_TRANSFER_WRITE;
      break;
   case GL_READ_ONLY:
      flags = PIPE_TRANSFER_READ;
      break;
   case GL_READ_WRITE:
   default:
      flags = PIPE_TRANSFER_READ_WRITE;
      break;      
   }

   /* Handle zero-size buffers here rather than in drivers */
   if (obj->Size == 0) {
      obj->Pointer = &st_bufferobj_zero_length;
   }
   else {
      obj->Pointer = pipe_buffer_map(st_context(ctx)->pipe,
                                     st_obj->buffer,
                                     flags,
                                     &st_obj->transfer);
   }

   if (obj->Pointer) {
      obj->Offset = 0;
      obj->Length = obj->Size;
   }
   return obj->Pointer;
}


/**
 * Called via glMapBufferRange().
 */
static void *
st_bufferobj_map_range(GLcontext *ctx, GLenum target, 
                       GLintptr offset, GLsizeiptr length, GLbitfield access,
                       struct gl_buffer_object *obj)
{
   struct pipe_context *pipe = st_context(ctx)->pipe;
   struct st_buffer_object *st_obj = st_buffer_object(obj);
   enum pipe_transfer_usage flags = 0x0;

   if (access & GL_MAP_WRITE_BIT)
      flags |= PIPE_TRANSFER_WRITE;

   if (access & GL_MAP_READ_BIT)
      flags |= PIPE_TRANSFER_READ;

   if (access & GL_MAP_FLUSH_EXPLICIT_BIT)
      flags |= PIPE_TRANSFER_FLUSH_EXPLICIT;
   
   if (access & GL_MAP_UNSYNCHRONIZED_BIT)
      flags |= PIPE_TRANSFER_UNSYNCHRONIZED;

   /* ... other flags ...
    */

   if (access & MESA_MAP_NOWAIT_BIT)
      flags |= PIPE_TRANSFER_DONTBLOCK;

   assert(offset >= 0);
   assert(length >= 0);
   assert(offset < obj->Size);
   assert(offset + length <= obj->Size);

   /*
    * We go out of way here to hide the degenerate yet valid case of zero
    * length range from the pipe driver.
    */
   if (!length) {
      obj->Pointer = &st_bufferobj_zero_length;
   }
   else {
      obj->Pointer = pipe_buffer_map_range(pipe, 
                                           st_obj->buffer,
                                           offset, length,
                                           flags,
                                           &st_obj->transfer);
      if (obj->Pointer) {
         obj->Pointer = (ubyte *) obj->Pointer + offset;
      }
   }
   
   if (obj->Pointer) {
      obj->Offset = offset;
      obj->Length = length;
      obj->AccessFlags = access;
   }

   return obj->Pointer;
}


static void
st_bufferobj_flush_mapped_range(GLcontext *ctx, GLenum target, 
                                GLintptr offset, GLsizeiptr length,
                                struct gl_buffer_object *obj)
{
   struct pipe_context *pipe = st_context(ctx)->pipe;
   struct st_buffer_object *st_obj = st_buffer_object(obj);

   /* Subrange is relative to mapped range */
   assert(offset >= 0);
   assert(length >= 0);
   assert(offset + length <= obj->Length);
   assert(obj->Pointer);
   
   if (!length)
      return;

   pipe_buffer_flush_mapped_range(pipe, st_obj->transfer, 
                                  obj->Offset + offset, length);
}


/**
 * Called via glUnmapBufferARB().
 */
static GLboolean
st_bufferobj_unmap(GLcontext *ctx, GLenum target, struct gl_buffer_object *obj)
{
   struct pipe_context *pipe = st_context(ctx)->pipe;
   struct st_buffer_object *st_obj = st_buffer_object(obj);

   if (obj->Length)
      pipe_buffer_unmap(pipe, st_obj->buffer, st_obj->transfer);

   st_obj->transfer = NULL;
   obj->Pointer = NULL;
   obj->Offset = 0;
   obj->Length = 0;
   return GL_TRUE;
}


/**
 * Called via glCopyBufferSubData().
 */
static void
st_copy_buffer_subdata(GLcontext *ctx,
                       struct gl_buffer_object *src,
                       struct gl_buffer_object *dst,
                       GLintptr readOffset, GLintptr writeOffset,
                       GLsizeiptr size)
{
   struct pipe_context *pipe = st_context(ctx)->pipe;
   struct st_buffer_object *srcObj = st_buffer_object(src);
   struct st_buffer_object *dstObj = st_buffer_object(dst);
   struct pipe_transfer *src_transfer;
   struct pipe_transfer *dst_transfer;
   ubyte *srcPtr, *dstPtr;

   if(!size)
      return;

   /* buffer should not already be mapped */
   assert(!src->Pointer);
   assert(!dst->Pointer);

   srcPtr = (ubyte *) pipe_buffer_map_range(pipe,
                                            srcObj->buffer,
                                            readOffset, size,
                                            PIPE_TRANSFER_READ,
					    &src_transfer);

   dstPtr = (ubyte *) pipe_buffer_map_range(pipe,
                                            dstObj->buffer,
                                            writeOffset, size,
                                            PIPE_TRANSFER_WRITE,
					    &dst_transfer);

   if (srcPtr && dstPtr)
      memcpy(dstPtr + writeOffset, srcPtr + readOffset, size);

   pipe_buffer_unmap(pipe, srcObj->buffer, src_transfer);
   pipe_buffer_unmap(pipe, dstObj->buffer, dst_transfer);
}


/* TODO: if buffer wasn't created with appropriate usage flags, need
 * to recreate it now and copy contents -- or possibly create a
 * gallium entrypoint to extend the usage flags and let the driver
 * decide if a copy is necessary.
 */
void
st_bufferobj_validate_usage(struct st_context *st,
			    struct st_buffer_object *obj,
			    unsigned usage)
{
}


void
st_init_bufferobject_functions(struct dd_function_table *functions)
{
   functions->NewBufferObject = st_bufferobj_alloc;
   functions->DeleteBuffer = st_bufferobj_free;
   functions->BufferData = st_bufferobj_data;
   functions->BufferSubData = st_bufferobj_subdata;
   functions->GetBufferSubData = st_bufferobj_get_subdata;
   functions->MapBuffer = st_bufferobj_map;
   functions->MapBufferRange = st_bufferobj_map_range;
   functions->FlushMappedBufferRange = st_bufferobj_flush_mapped_range;
   functions->UnmapBuffer = st_bufferobj_unmap;
   functions->CopyBufferSubData = st_copy_buffer_subdata;

   /* For GL_APPLE_vertex_array_object */
   functions->NewArrayObject = _mesa_new_array_object;
   functions->DeleteArrayObject = _mesa_delete_array_object;
}
