bufferobj.c

winNT技术操作系统,国外开放的原代码和LIUX一样

/*
 * Mesa 3-D graphics library
 * Version:  6.3
 *
 * Copyright (C) 1999-2004  Brian Paul   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, sublicense,
 * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL 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 bufferobj.c
 * \brief Functions for the GL_ARB_vertex_buffer_object extension.
 * \author Brian Paul, Ian Romanick
 */


#include "glheader.h"
#include "hash.h"
#include "imports.h"
#include "image.h"
#include "context.h"
#include "bufferobj.h"


/**
 * Get the buffer object bound to the specified target in a GL context.
 *
 * \param ctx     GL context
 * \param target  Buffer object target to be retrieved.  Currently this must
 *                be either \c GL_ARRAY_BUFFER or \c GL_ELEMENT_ARRAY_BUFFER.
 * \param str     Name of caller for logging errors.
 * \return   A pointer to the buffer object bound to \c target in the
 *           specified context or \c NULL if \c target is invalid or no
 *           buffer object is bound.
 */
static INLINE struct gl_buffer_object *
buffer_object_get_target( GLcontext *ctx, GLenum target, const char * str )
{
   struct gl_buffer_object * bufObj = NULL;

   switch (target) {
      case GL_ARRAY_BUFFER_ARB:
         bufObj = ctx->Array.ArrayBufferObj;
         break;
      case GL_ELEMENT_ARRAY_BUFFER_ARB:
         bufObj = ctx->Array.ElementArrayBufferObj;
         break;
      case GL_PIXEL_PACK_BUFFER_EXT:
         bufObj = ctx->Pack.BufferObj;
         break;
      case GL_PIXEL_UNPACK_BUFFER_EXT:
         bufObj = ctx->Unpack.BufferObj;
         break;
      default:
         _mesa_error(ctx, GL_INVALID_ENUM, "gl%s(target)", str);
         return NULL;
   }

   if (bufObj->Name == 0)
      return NULL;

   return bufObj;
}


/**
 * Tests the subdata range parameters and sets the GL error code for
 * \c glBufferSubDataARB and \c glGetBufferSubDataARB.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param offset  Offset of the first byte of the subdata range.
 * \param size    Size, in bytes, of the subdata range.
 * \param str     Name of caller for logging errors.
 * \return   A pointer to the buffer object bound to \c target in the
 *           specified context or \c NULL if any of the parameter or state
 *           conditions for \c glBufferSubDataARB or \c glGetBufferSubDataARB
 *           are invalid.
 *
 * \sa glBufferSubDataARB, glGetBufferSubDataARB
 */
static struct gl_buffer_object *
buffer_object_subdata_range_good( GLcontext * ctx, GLenum target, 
                                  GLintptrARB offset, GLsizeiptrARB size,
                                  const char * str )
{
   struct gl_buffer_object *bufObj;

   if (size < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "%s(size < 0)", str);
      return NULL;
   }

   if (offset < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "%s(offset < 0)", str);
      return NULL;
   }

   bufObj = buffer_object_get_target( ctx, target, str );
   if (!bufObj || bufObj->Name == 0) {
      return NULL;
   }

   if ((GLuint) (offset + size) > bufObj->Size) {
      _mesa_error(ctx, GL_INVALID_VALUE,
		  "%s(size + offset > buffer size)", str);
      return NULL;
   }

   if (bufObj->Pointer) {
      /* Buffer is currently mapped */
      _mesa_error(ctx, GL_INVALID_OPERATION, "%s", str);
      return NULL;
   }

   return bufObj;
}


/**
 * Allocate and initialize a new buffer object.
 * 
 * This function is intended to be called via
 * \c dd_function_table::NewBufferObject.
 */
struct gl_buffer_object *
_mesa_new_buffer_object( GLcontext *ctx, GLuint name, GLenum target )
{
   struct gl_buffer_object *obj;

   (void) ctx;

   obj = MALLOC_STRUCT(gl_buffer_object);
   _mesa_initialize_buffer_object(obj, name, target);
   return obj;
}


/**
 * Delete a buffer object.
 * 
 * This function is intended to be called via
 * \c dd_function_table::DeleteBuffer.
 */
void
_mesa_delete_buffer_object( GLcontext *ctx, struct gl_buffer_object *bufObj )
{
   (void) ctx;

   if (bufObj->Data)
      _mesa_free(bufObj->Data);
   _mesa_free(bufObj);
}


/**
 * Initialize a buffer object to default values.
 */
void
_mesa_initialize_buffer_object( struct gl_buffer_object *obj,
				GLuint name, GLenum target )
{
   (void) target;

   _mesa_bzero(obj, sizeof(struct gl_buffer_object));
   obj->RefCount = 1;
   obj->Name = name;
   obj->Usage = GL_STATIC_DRAW_ARB;
   obj->Access = GL_READ_WRITE_ARB;
}


/**
 * Add the given buffer object to the buffer object pool.
 */
void
_mesa_save_buffer_object( GLcontext *ctx, struct gl_buffer_object *obj )
{
   if (obj->Name > 0) {
      /* insert into hash table */
      _mesa_HashInsert(ctx->Shared->BufferObjects, obj->Name, obj);
   }
}


/**
 * Remove the given buffer object from the buffer object pool.
 * Do not deallocate the buffer object though.
 */
void
_mesa_remove_buffer_object( GLcontext *ctx, struct gl_buffer_object *bufObj )
{
   if (bufObj->Name > 0) {
      /* remove from hash table */
      _mesa_HashRemove(ctx->Shared->BufferObjects, bufObj->Name);
   }
}


/**
 * Allocate space for and store data in a buffer object.  Any data that was
 * previously stored in the buffer object is lost.  If \c data is \c NULL,
 * memory will be allocated, but no copy will occur.
 *
 * This function is intended to be called via
 * \c dd_function_table::BufferData.  This function need not set GL error
 * codes.  The input parameters will have been tested before calling.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param size    Size, in bytes, of the new data store.
 * \param data    Pointer to the data to store in the buffer object.  This
 *                pointer may be \c NULL.
 * \param usage   Hints about how the data will be used.
 * \param bufObj  Object to be used.
 *
 * \sa glBufferDataARB, dd_function_table::BufferData.
 */
void
_mesa_buffer_data( GLcontext *ctx, GLenum target, GLsizeiptrARB size,
		   const GLvoid * data, GLenum usage,
		   struct gl_buffer_object * bufObj )
{
   void * new_data;

   (void) ctx; (void) target;

   new_data = _mesa_realloc( bufObj->Data, bufObj->Size, size );
   if (new_data) {
      bufObj->Data = (GLubyte *) new_data;
      bufObj->Size = size;
      bufObj->Usage = usage;

      if (data) {
	 _mesa_memcpy( bufObj->Data, data, size );
      }
   }
}


/**
 * Replace data in a subrange of buffer object.  If the data range
 * specified by \c size + \c offset extends beyond the end of the buffer or
 * if \c data is \c NULL, no copy is performed.
 *
 * This function is intended to be called by
 * \c dd_function_table::BufferSubData.  This function need not set GL error
 * codes.  The input parameters will have been tested before calling.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param offset  Offset of the first byte to be modified.
 * \param size    Size, in bytes, of the data range.
 * \param data    Pointer to the data to store in the buffer object.
 * \param bufObj  Object to be used.
 *
 * \sa glBufferSubDataARB, dd_function_table::BufferSubData.
 */
void
_mesa_buffer_subdata( GLcontext *ctx, GLenum target, GLintptrARB offset,
		      GLsizeiptrARB size, const GLvoid * data,
		      struct gl_buffer_object * bufObj )
{
   (void) ctx; (void) target;

   if (bufObj->Data && ((GLuint) (size + offset) <= bufObj->Size)) {
      _mesa_memcpy( (GLubyte *) bufObj->Data + offset, data, size );
   }
}


/**
 * Retrieve data from a subrange of buffer object.  If the data range
 * specified by \c size + \c offset extends beyond the end of the buffer or
 * if \c data is \c NULL, no copy is performed.
 *
 * This function is intended to be called by
 * \c dd_function_table::BufferGetSubData.  This function need not set GL error
 * codes.  The input parameters will have been tested before calling.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param offset  Offset of the first byte to be modified.
 * \param size    Size, in bytes, of the data range.
 * \param data    Pointer to the data to store in the buffer object.
 * \param bufObj  Object to be used.
 *
 * \sa glBufferGetSubDataARB, dd_function_table::GetBufferSubData.
 */
void
_mesa_buffer_get_subdata( GLcontext *ctx, GLenum target, GLintptrARB offset,
			  GLsizeiptrARB size, GLvoid * data,
			  struct gl_buffer_object * bufObj )
{
   (void) ctx; (void) target;

   if (bufObj->Data && ((GLsizeiptrARB) (size + offset) <= bufObj->Size)) {
      _mesa_memcpy( data, (GLubyte *) bufObj->Data + offset, size );
   }
}


/**
 * Fallback function called via ctx->Driver.MapBuffer().
 * Hardware drivers that really implement buffer objects should never use
 * function.
 *
 * The input parameters will have been already tested for errors.
 *
 * \param ctx     GL context.
 * \param target  Buffer object target on which to operate.
 * \param access  Information about how the buffer will be accessed.
 * \param bufObj  Object to be mapped.
 * \return  A pointer to the object's internal data store that can be accessed
 *          by the processor
 *
 * \sa glMapBufferARB, dd_function_table::MapBuffer
 */
void *
_mesa_buffer_map( GLcontext *ctx, GLenum target, GLenum access,
		  struct gl_buffer_object *bufObj )
{
   (void) ctx;
   (void) target;
   (void) access;
   ASSERT(!bufObj->OnCard);
   /* Just return a direct pointer to the data */
   if (bufObj->Pointer) {
      /* already mapped! */
      return NULL;
   }
   bufObj->Pointer = bufObj->Data;
   return bufObj->Pointer;
}


/**
 * Fallback function called via ctx->Driver.MapBuffer().
 * Hardware drivers that really implement buffer objects should never use
 * function.
 *
 * The input parameters will have been already tested for errors.
 *
 * \sa glUnmapBufferARB, dd_function_table::UnmapBuffer
 */
GLboolean
_mesa_buffer_unmap( GLcontext *ctx, GLenum target,
                    struct gl_buffer_object *bufObj )
{
   (void) ctx;
   (void) target;
   ASSERT(!bufObj->OnCard);
   /* XXX we might assert here that bufObj->Pointer is non-null */
   bufObj->Pointer = NULL;
   return GL_TRUE;
}


/**
 * Initialize the state associated with buffer objects
 */
void
_mesa_init_buffer_objects( GLcontext *ctx )
{
   GLuint i;

   /* Allocate the default buffer object and set refcount so high that
    * it never gets deleted.
    */
   ctx->Array.NullBufferObj = _mesa_new_buffer_object(ctx, 0, 0);
   if (ctx->Array.NullBufferObj)
      ctx->Array.NullBufferObj->RefCount = 1000;

   ctx->Array.ArrayBufferObj = ctx->Array.NullBufferObj;
   ctx->Array.ElementArrayBufferObj = ctx->Array.NullBufferObj;

   /* Vertex array buffers */
   ctx->Array.Vertex.BufferObj = ctx->Array.NullBufferObj;
   ctx->Array.Normal.BufferObj = ctx->Array.NullBufferObj;
   ctx->Array.Color.BufferObj = ctx->Array.NullBufferObj;
   ctx->Array.SecondaryColor.BufferObj = ctx->Array.NullBufferObj;
   ctx->Array.FogCoord.BufferObj = ctx->Array.NullBufferObj;
   ctx->Array.Index.BufferObj = ctx->Array.NullBufferObj;
   for (i = 0; i < MAX_TEXTURE_UNITS; i++) {
      ctx->Array.TexCoord[i].BufferObj = ctx->Array.NullBufferObj;
   }
   ctx->Array.EdgeFlag.BufferObj = ctx->Array.NullBufferObj;
   for (i = 0; i < VERT_ATTRIB_MAX; i++) {
      ctx->Array.VertexAttrib[i].BufferObj = ctx->Array.NullBufferObj;
   }
}


/**
 * When we're about to read pixel data out of a PBO (via glDrawPixels,
 * glTexImage, etc) or write data into a PBO (via glReadPixels,
 * glGetTexImage, etc) we call this function to check that we're not
 * going to read out of bounds.
 *
 * XXX This would also be a convenient time to check that the PBO isn't
 * currently mapped.  Whoever calls this function should check for that.
 * Remember, we can't use a PBO when it's mapped!
 *
 * \param width  width of image to read/write
 * \param height  height of image to read/write
 * \param depth  depth of image to read/write
 * \param format  format of image to read/write
 * \param type  datatype of image to read/write
 * \param ptr  the user-provided pointer/offset
 * \return GL_TRUE if the PBO access is OK, GL_FALSE if the access would
 *         go out of bounds.
 */
GLboolean
_mesa_validate_pbo_access(GLuint dimensions,
                          const struct gl_pixelstore_attrib *pack,
                          GLsizei width, GLsizei height, GLsizei depth,
                          GLenum format, GLenum type, const GLvoid *ptr)
{
   GLvoid *start, *end;

   ASSERT(pack->BufferObj->Name != 0);

   if (pack->BufferObj->Size == 0)
      /* no buffer! */
      return GL_FALSE;

   /* get address of first pixel we'll read */
   start = _mesa_image_address(dimensions, pack, ptr, width, height,
                               format, type, 0, 0, 0);

   /* get address just past the last pixel we'll read */
   end =  _mesa_image_address(dimensions, pack, ptr, width, height,
                              format, type, depth-1, height-1, width);


   if ((const GLubyte *) start > (const GLubyte *)(uintptr_t) pack->BufferObj->Size) {
      /* This will catch negative values / wrap-around */
      return GL_FALSE;
   }
   if ((const GLubyte *) end > (const GLubyte *)(uintptr_t) pack->BufferObj->Size) {
      /* Image read goes beyond end of buffer */
      return GL_FALSE;
   }

   /* OK! */
   return GL_TRUE;
}




/**********************************************************************/
/* API Functions                                                      */
/**********************************************************************/