context.c

winNT技术操作系统,国外开放的原代码和LIUX一样

#if FEATURE_ATI_fragment_shader
   _mesa_delete_program(ctx, ss->DefaultFragmentShader);
#endif

#if FEATURE_ARB_vertex_buffer_object
   _mesa_DeleteHashTable(ss->BufferObjects);
#endif

   _mesa_DeleteHashTable (ss->GL2Objects);

#if FEATURE_EXT_framebuffer_object
   _mesa_DeleteHashTable(ss->FrameBuffers);
   _mesa_DeleteHashTable(ss->RenderBuffers);
#endif

   _glthread_DESTROY_MUTEX(ss->Mutex);

   FREE(ss);
}


/**
 * Initialize fields of gl_current_attrib (aka ctx->Current.*)
 */
static void
_mesa_init_current( GLcontext *ctx )
{
   GLuint i;

   /* Current group */
   for (i = 0; i < VERT_ATTRIB_MAX; i++) {
      ASSIGN_4V( ctx->Current.Attrib[i], 0.0, 0.0, 0.0, 1.0 );
   }
   /* special cases: */
   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_WEIGHT], 1.0, 0.0, 0.0, 1.0 );
   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_NORMAL], 0.0, 0.0, 1.0, 1.0 );
   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR0], 1.0, 1.0, 1.0, 1.0 );
   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_COLOR1], 0.0, 0.0, 0.0, 1.0 );
   ASSIGN_4V( ctx->Current.Attrib[VERT_ATTRIB_FOG], 0.0, 0.0, 0.0, 0.0 );

   ctx->Current.Index = 1;
   ctx->Current.EdgeFlag = GL_TRUE;
}


/**
 * Initialize fields of gl_constants (aka ctx->Const.*).
 * Use defaults from config.h.  The device drivers will often override
 * some of these values (such as number of texture units).
 */
static void 
_mesa_init_constants( GLcontext *ctx )
{
   assert(ctx);

   assert(MAX_TEXTURE_LEVELS >= MAX_3D_TEXTURE_LEVELS);
   assert(MAX_TEXTURE_LEVELS >= MAX_CUBE_TEXTURE_LEVELS);

   /* Constants, may be overriden (usually only reduced) by device drivers */
   ctx->Const.MaxTextureLevels = MAX_TEXTURE_LEVELS;
   ctx->Const.Max3DTextureLevels = MAX_3D_TEXTURE_LEVELS;
   ctx->Const.MaxCubeTextureLevels = MAX_CUBE_TEXTURE_LEVELS;
   ctx->Const.MaxTextureRectSize = MAX_TEXTURE_RECT_SIZE;
   ctx->Const.MaxTextureUnits = MAX_TEXTURE_UNITS;
   ctx->Const.MaxTextureCoordUnits = MAX_TEXTURE_COORD_UNITS;
   ctx->Const.MaxTextureImageUnits = MAX_TEXTURE_IMAGE_UNITS;
   ctx->Const.MaxTextureMaxAnisotropy = MAX_TEXTURE_MAX_ANISOTROPY;
   ctx->Const.MaxTextureLodBias = MAX_TEXTURE_LOD_BIAS;
   ctx->Const.MaxArrayLockSize = MAX_ARRAY_LOCK_SIZE;
   ctx->Const.SubPixelBits = SUB_PIXEL_BITS;
   ctx->Const.MinPointSize = MIN_POINT_SIZE;
   ctx->Const.MaxPointSize = MAX_POINT_SIZE;
   ctx->Const.MinPointSizeAA = MIN_POINT_SIZE;
   ctx->Const.MaxPointSizeAA = MAX_POINT_SIZE;
   ctx->Const.PointSizeGranularity = (GLfloat) POINT_SIZE_GRANULARITY;
   ctx->Const.MinLineWidth = MIN_LINE_WIDTH;
   ctx->Const.MaxLineWidth = MAX_LINE_WIDTH;
   ctx->Const.MinLineWidthAA = MIN_LINE_WIDTH;
   ctx->Const.MaxLineWidthAA = MAX_LINE_WIDTH;
   ctx->Const.LineWidthGranularity = (GLfloat) LINE_WIDTH_GRANULARITY;
   ctx->Const.MaxColorTableSize = MAX_COLOR_TABLE_SIZE;
   ctx->Const.MaxConvolutionWidth = MAX_CONVOLUTION_WIDTH;
   ctx->Const.MaxConvolutionHeight = MAX_CONVOLUTION_HEIGHT;
   ctx->Const.MaxClipPlanes = MAX_CLIP_PLANES;
   ctx->Const.MaxLights = MAX_LIGHTS;
   ctx->Const.MaxShininess = 128.0;
   ctx->Const.MaxSpotExponent = 128.0;
   ctx->Const.MaxViewportWidth = MAX_WIDTH;
   ctx->Const.MaxViewportHeight = MAX_HEIGHT;
#if FEATURE_ARB_vertex_program
   ctx->Const.MaxVertexProgramInstructions = MAX_NV_VERTEX_PROGRAM_INSTRUCTIONS;
   ctx->Const.MaxVertexProgramAttribs = MAX_NV_VERTEX_PROGRAM_INPUTS;
   ctx->Const.MaxVertexProgramTemps = MAX_NV_VERTEX_PROGRAM_TEMPS;
   ctx->Const.MaxVertexProgramLocalParams = MAX_NV_VERTEX_PROGRAM_PARAMS;
   ctx->Const.MaxVertexProgramEnvParams = MAX_NV_VERTEX_PROGRAM_PARAMS;/*XXX*/
   ctx->Const.MaxVertexProgramAddressRegs = MAX_VERTEX_PROGRAM_ADDRESS_REGS;
#endif
#if FEATURE_ARB_fragment_program
   ctx->Const.MaxFragmentProgramInstructions = MAX_NV_FRAGMENT_PROGRAM_INSTRUCTIONS;
   ctx->Const.MaxFragmentProgramAttribs = MAX_NV_FRAGMENT_PROGRAM_INPUTS;
   ctx->Const.MaxFragmentProgramTemps = MAX_NV_FRAGMENT_PROGRAM_TEMPS;
   ctx->Const.MaxFragmentProgramLocalParams = MAX_NV_FRAGMENT_PROGRAM_PARAMS;
   ctx->Const.MaxFragmentProgramEnvParams = MAX_NV_FRAGMENT_PROGRAM_PARAMS;/*XXX*/
   ctx->Const.MaxFragmentProgramAddressRegs = MAX_FRAGMENT_PROGRAM_ADDRESS_REGS;
   ctx->Const.MaxFragmentProgramAluInstructions = MAX_FRAGMENT_PROGRAM_ALU_INSTRUCTIONS;
   ctx->Const.MaxFragmentProgramTexInstructions = MAX_FRAGMENT_PROGRAM_TEX_INSTRUCTIONS;
   ctx->Const.MaxFragmentProgramTexIndirections = MAX_FRAGMENT_PROGRAM_TEX_INDIRECTIONS;
#endif

   ctx->Const.MaxProgramMatrices = MAX_PROGRAM_MATRICES;
   ctx->Const.MaxProgramMatrixStackDepth = MAX_PROGRAM_MATRIX_STACK_DEPTH;

   /* If we're running in the X server, do bounds checking to prevent
    * segfaults and server crashes!
    */
#if defined(XFree86LOADER) && defined(IN_MODULE)
   ctx->Const.CheckArrayBounds = GL_TRUE;
#else
   ctx->Const.CheckArrayBounds = GL_FALSE;
#endif

   ctx->Const.MaxDrawBuffers = MAX_DRAW_BUFFERS;

   /* GL_OES_read_format */
   ctx->Const.ColorReadFormat = GL_RGBA;
   ctx->Const.ColorReadType = GL_UNSIGNED_BYTE;

#if FEATURE_EXT_framebuffer_object
   ctx->Const.MaxColorAttachments = MAX_COLOR_ATTACHMENTS;
   ctx->Const.MaxRenderbufferSize = MAX_WIDTH;
#endif

   /* sanity checks */
   ASSERT(ctx->Const.MaxTextureUnits == MAX2(ctx->Const.MaxTextureImageUnits, ctx->Const.MaxTextureCoordUnits));
}


/**
 * Initialize the attribute groups in a GL context.
 *
 * \param ctx GL context.
 *
 * Initializes all the attributes, calling the respective <tt>init*</tt>
 * functions for the more complex data structures.
 */
static GLboolean
init_attrib_groups( GLcontext *ctx )
{
   assert(ctx);

   /* Constants */
   _mesa_init_constants( ctx );

   /* Extensions */
   _mesa_init_extensions( ctx );

   /* Attribute Groups */
   _mesa_init_accum( ctx );
   _mesa_init_attrib( ctx );
   _mesa_init_buffer_objects( ctx );
   _mesa_init_color( ctx );
   _mesa_init_colortables( ctx );
   _mesa_init_current( ctx );
   _mesa_init_depth( ctx );
   _mesa_init_debug( ctx );
   _mesa_init_display_list( ctx );
   _mesa_init_eval( ctx );
   _mesa_init_feedback( ctx );
   _mesa_init_fog( ctx );
   _mesa_init_histogram( ctx );
   _mesa_init_hint( ctx );
   _mesa_init_line( ctx );
   _mesa_init_lighting( ctx );
   _mesa_init_matrix( ctx );
   _mesa_init_multisample( ctx );
   _mesa_init_occlude( ctx );
   _mesa_init_pixel( ctx );
   _mesa_init_point( ctx );
   _mesa_init_polygon( ctx );
   _mesa_init_program( ctx );
   _mesa_init_rastpos( ctx );
   _mesa_init_scissor( ctx );
   _mesa_init_shaderobjects (ctx);
   _mesa_init_stencil( ctx );
   _mesa_init_transform( ctx );
   _mesa_init_varray( ctx );
   _mesa_init_viewport( ctx );

   if (!_mesa_init_texture( ctx ))
      return GL_FALSE;

   _mesa_init_texture_s3tc( ctx );
   _mesa_init_texture_fxt1( ctx );

   /* Miscellaneous */
   ctx->NewState = _NEW_ALL;
   ctx->ErrorValue = (GLenum) GL_NO_ERROR;
   ctx->_Facing = 0;
#if CHAN_TYPE == GL_FLOAT
   ctx->ClampFragmentColors = GL_FALSE; /* XXX temporary */
#else
   ctx->ClampFragmentColors = GL_TRUE;
#endif
   ctx->ClampVertexColors = GL_TRUE;

   return GL_TRUE;
}


/**
 * This is the default function we plug into all dispatch table slots
 * This helps prevents a segfault when someone calls a GL function without
 * first checking if the extension's supported.
 */
static int
generic_nop(void)
{
   _mesa_problem(NULL, "User called no-op dispatch function (an unsupported extension function?)");
   return 0;
}


/**
 * Allocate and initialize a new dispatch table.
 */
static struct _glapi_table *
alloc_dispatch_table(void)
{
   /* Find the larger of Mesa's dispatch table and libGL's dispatch table.
    * In practice, this'll be the same for stand-alone Mesa.  But for DRI
    * Mesa we do this to accomodate different versions of libGL and various
    * DRI drivers.
    */
   GLint numEntries = MAX2(_glapi_get_dispatch_table_size(),
                           sizeof(struct _glapi_table) / sizeof(_glapi_proc));
   struct _glapi_table *table =
      (struct _glapi_table *) _mesa_malloc(numEntries * sizeof(_glapi_proc));
   if (table) {
      _glapi_proc *entry = (_glapi_proc *) table;
      GLint i;
      for (i = 0; i < numEntries; i++) {
         entry[i] = (_glapi_proc) generic_nop;
      }
   }
   return table;
}


/**
 * Initialize a GLcontext struct (rendering context).
 *
 * This includes allocating all the other structs and arrays which hang off of
 * the context by pointers.
 * Note that the driver needs to pass in its dd_function_table here since
 * we need to at least call driverFunctions->NewTextureObject to create the
 * default texture objects.
 * 
 * Called by _mesa_create_context().
 *
 * Performs the imports and exports callback tables initialization, and
 * miscellaneous one-time initializations. If no shared context is supplied one
 * is allocated, and increase its reference count.  Setups the GL API dispatch
 * tables.  Initialize the TNL module. Sets the maximum Z buffer depth.
 * Finally queries the \c MESA_DEBUG and \c MESA_VERBOSE environment variables
 * for debug flags.
 *
 * \param ctx the context to initialize
 * \param visual describes the visual attributes for this context
 * \param share_list points to context to share textures, display lists,
 *        etc with, or NULL
 * \param driverFunctions table of device driver functions for this context
 *        to use
 * \param driverContext pointer to driver-specific context data
 */
GLboolean
_mesa_initialize_context( GLcontext *ctx,
                          const GLvisual *visual,
                          GLcontext *share_list,
                          const struct dd_function_table *driverFunctions,
                          void *driverContext )
{
   ASSERT(driverContext);
   assert(driverFunctions->NewTextureObject);
   assert(driverFunctions->FreeTexImageData);

   /* If the driver wants core Mesa to use special imports, it'll have to
    * override these defaults.
    */
   _mesa_init_default_imports( &(ctx->imports), driverContext );

   /* initialize the exports (Mesa functions called by the window system) */
   _mesa_init_default_exports( &(ctx->exports) );

   /* misc one-time initializations */
   one_time_init(ctx);

   ctx->Visual = *visual;
   ctx->DrawBuffer = NULL;
   ctx->ReadBuffer = NULL;
   ctx->WinSysDrawBuffer = NULL;
   ctx->WinSysReadBuffer = NULL;

   /* Plug in driver functions and context pointer here.
    * This is important because when we call alloc_shared_state() below
    * we'll call ctx->Driver.NewTextureObject() to create the default
    * textures.
    */
   ctx->Driver = *driverFunctions;
   ctx->DriverCtx = driverContext;

   if (share_list) {
      /* share state with another context */
      ctx->Shared = share_list->Shared;
   }
   else {
      /* allocate new, unshared state */
      if (!alloc_shared_state( ctx )) {
         return GL_FALSE;
      }
   }
   _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
   ctx->Shared->RefCount++;
   _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);

   if (!init_attrib_groups( ctx )) {
      free_shared_state(ctx, ctx->Shared);
      return GL_FALSE;
   }

   /* setup the API dispatch tables */
   ctx->Exec = alloc_dispatch_table();
   ctx->Save = alloc_dispatch_table();
   if (!ctx->Exec || !ctx->Save) {
      free_shared_state(ctx, ctx->Shared);
      if (ctx->Exec)
         _mesa_free(ctx->Exec);
   }
   _mesa_init_exec_table(ctx->Exec);
   ctx->CurrentDispatch = ctx->Exec;
#if _HAVE_FULL_GL
   _mesa_init_dlist_table(ctx->Save);
   _mesa_install_save_vtxfmt( ctx, &ctx->ListState.ListVtxfmt );
   /* Neutral tnl module stuff */
   _mesa_init_exec_vtxfmt( ctx ); 
   ctx->TnlModule.Current = NULL;
   ctx->TnlModule.SwapCount = 0;
#endif

   ctx->_MaintainTexEnvProgram = (_mesa_getenv("MESA_TEX_PROG") != NULL);
   ctx->_MaintainTnlProgram = (_mesa_getenv("MESA_TNL_PROG") != NULL);

   return GL_TRUE;
}


/**
 * Allocate and initialize a GLcontext structure.
 * Note that the driver needs to pass in its dd_function_table here since
 * we need to at least call driverFunctions->NewTextureObject to initialize
 * the rendering context.
 *
 * \param visual a GLvisual pointer (we copy the struct contents)
 * \param share_list another context to share display lists with or NULL
 * \param driverFunctions points to the dd_function_table into which the
 *        driver has plugged in all its special functions.
 * \param driverCtx points to the device driver's private context state
 * 
 * \return pointer to a new __GLcontextRec or NULL if error.
 */
GLcontext *
_mesa_create_context( const GLvisual *visual,
                      GLcontext *share_list,
                      const struct dd_function_table *driverFunctions,
                      void *driverContext )

{
   GLcontext *ctx;

   ASSERT(visual);
   ASSERT(driverContext);

   ctx = (GLcontext *) _mesa_calloc(sizeof(GLcontext));
   if (!ctx)
      return NULL;

   if (_mesa_initialize_context(ctx, visual, share_list,
                                driverFunctions, driverContext)) {
      return ctx;
   }
   else {
      _mesa_free(ctx);
      return NULL;
   }
}


/**
 * Free the data associated with the given context.
 * 
 * But doesn't free the GLcontext struct itself.
 *
 * \sa _mesa_initialize_context() and init_attrib_groups().
 */
void
_mesa_free_context_data( GLcontext *ctx )
{
   /* if we're destroying the current context, unbind it first */
   if (ctx == _mesa_get_current_context()) {
      _mesa_make_current(NULL, NULL, NULL);
   }

   _mesa_free_lighting_data( ctx );
   _mesa_free_eval_data( ctx );
   _mesa_free_texture_data( ctx );
   _mesa_free_matrix_data( ctx );
   _mesa_free_viewport_data( ctx );
   _mesa_free_colortables_data( ctx );
   _mesa_free_program_data(ctx);
   _mesa_free_occlude_data(ctx);

#if FEATURE_ARB_vertex_buffer_object
   _mesa_delete_buffer_object(ctx, ctx->Array.NullBufferObj);
#endif

   /* free dispatch tables */
   _mesa_free(ctx->Exec);
   _mesa_free(ctx->Save);

   /* Shared context state (display lists, textures, etc) */
   _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
   ctx->Shared->RefCount--;
   assert(ctx->Shared->RefCount >= 0);
   _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
   if (ctx->Shared->RefCount == 0) {
      /* free shared state */
      free_shared_state( ctx, ctx->Shared );
   }