context.c

winNT技术操作系统,国外开放的原代码和LIUX一样

   if (ctx->Extensions.String)
      FREE((void *) ctx->Extensions.String);
}


/**
 * Destroy a GLcontext structure.
 *
 * \param ctx GL context.
 * 
 * Calls _mesa_free_context_data() and frees the GLcontext structure itself.
 */
void
_mesa_destroy_context( GLcontext *ctx )
{
   if (ctx) {
      _mesa_free_context_data(ctx);
      FREE( (void *) ctx );
   }
}


#if _HAVE_FULL_GL
/**
 * Copy attribute groups from one context to another.
 * 
 * \param src source context
 * \param dst destination context
 * \param mask bitwise OR of GL_*_BIT flags
 *
 * According to the bits specified in \p mask, copies the corresponding
 * attributes from \p src into \p dst.  For many of the attributes a simple \c
 * memcpy is not enough due to the existence of internal pointers in their data
 * structures.
 */
void
_mesa_copy_context( const GLcontext *src, GLcontext *dst, GLuint mask )
{
   if (mask & GL_ACCUM_BUFFER_BIT) {
      /* OK to memcpy */
      dst->Accum = src->Accum;
   }
   if (mask & GL_COLOR_BUFFER_BIT) {
      /* OK to memcpy */
      dst->Color = src->Color;
   }
   if (mask & GL_CURRENT_BIT) {
      /* OK to memcpy */
      dst->Current = src->Current;
   }
   if (mask & GL_DEPTH_BUFFER_BIT) {
      /* OK to memcpy */
      dst->Depth = src->Depth;
   }
   if (mask & GL_ENABLE_BIT) {
      /* no op */
   }
   if (mask & GL_EVAL_BIT) {
      /* OK to memcpy */
      dst->Eval = src->Eval;
   }
   if (mask & GL_FOG_BIT) {
      /* OK to memcpy */
      dst->Fog = src->Fog;
   }
   if (mask & GL_HINT_BIT) {
      /* OK to memcpy */
      dst->Hint = src->Hint;
   }
   if (mask & GL_LIGHTING_BIT) {
      GLuint i;
      /* begin with memcpy */
      MEMCPY( &dst->Light, &src->Light, sizeof(struct gl_light) );
      /* fixup linked lists to prevent pointer insanity */
      make_empty_list( &(dst->Light.EnabledList) );
      for (i = 0; i < MAX_LIGHTS; i++) {
         if (dst->Light.Light[i].Enabled) {
            insert_at_tail(&(dst->Light.EnabledList), &(dst->Light.Light[i]));
         }
      }
   }
   if (mask & GL_LINE_BIT) {
      /* OK to memcpy */
      dst->Line = src->Line;
   }
   if (mask & GL_LIST_BIT) {
      /* OK to memcpy */
      dst->List = src->List;
   }
   if (mask & GL_PIXEL_MODE_BIT) {
      /* OK to memcpy */
      dst->Pixel = src->Pixel;
   }
   if (mask & GL_POINT_BIT) {
      /* OK to memcpy */
      dst->Point = src->Point;
   }
   if (mask & GL_POLYGON_BIT) {
      /* OK to memcpy */
      dst->Polygon = src->Polygon;
   }
   if (mask & GL_POLYGON_STIPPLE_BIT) {
      /* Use loop instead of MEMCPY due to problem with Portland Group's
       * C compiler.  Reported by John Stone.
       */
      GLuint i;
      for (i = 0; i < 32; i++) {
         dst->PolygonStipple[i] = src->PolygonStipple[i];
      }
   }
   if (mask & GL_SCISSOR_BIT) {
      /* OK to memcpy */
      dst->Scissor = src->Scissor;
   }
   if (mask & GL_STENCIL_BUFFER_BIT) {
      /* OK to memcpy */
      dst->Stencil = src->Stencil;
   }
   if (mask & GL_TEXTURE_BIT) {
      /* Cannot memcpy because of pointers */
      _mesa_copy_texture_state(src, dst);
   }
   if (mask & GL_TRANSFORM_BIT) {
      /* OK to memcpy */
      dst->Transform = src->Transform;
   }
   if (mask & GL_VIEWPORT_BIT) {
      /* Cannot use memcpy, because of pointers in GLmatrix _WindowMap */
      dst->Viewport.X = src->Viewport.X;
      dst->Viewport.Y = src->Viewport.Y;
      dst->Viewport.Width = src->Viewport.Width;
      dst->Viewport.Height = src->Viewport.Height;
      dst->Viewport.Near = src->Viewport.Near;
      dst->Viewport.Far = src->Viewport.Far;
      _math_matrix_copy(&dst->Viewport._WindowMap, &src->Viewport._WindowMap);
   }

   /* XXX FIXME:  Call callbacks?
    */
   dst->NewState = _NEW_ALL;
}
#endif


/**
 * Check if the given context can render into the given framebuffer
 * by checking visual attributes.
 * \return GL_TRUE if compatible, GL_FALSE otherwise.
 */
static GLboolean 
check_compatible(const GLcontext *ctx, const GLframebuffer *buffer)
{
   const GLvisual *ctxvis = &ctx->Visual;
   const GLvisual *bufvis = &buffer->Visual;

   if (ctxvis == bufvis)
      return GL_TRUE;

   if (ctxvis->rgbMode != bufvis->rgbMode)
      return GL_FALSE;
   if (ctxvis->doubleBufferMode && !bufvis->doubleBufferMode)
      return GL_FALSE;
   if (ctxvis->stereoMode && !bufvis->stereoMode)
      return GL_FALSE;
   if (ctxvis->haveAccumBuffer && !bufvis->haveAccumBuffer)
      return GL_FALSE;
   if (ctxvis->haveDepthBuffer && !bufvis->haveDepthBuffer)
      return GL_FALSE;
   if (ctxvis->haveStencilBuffer && !bufvis->haveStencilBuffer)
      return GL_FALSE;
   if (ctxvis->redMask && ctxvis->redMask != bufvis->redMask)
      return GL_FALSE;
   if (ctxvis->greenMask && ctxvis->greenMask != bufvis->greenMask)
      return GL_FALSE;
   if (ctxvis->blueMask && ctxvis->blueMask != bufvis->blueMask)
      return GL_FALSE;
   if (ctxvis->depthBits && ctxvis->depthBits != bufvis->depthBits)
      return GL_FALSE;
   if (ctxvis->stencilBits && ctxvis->stencilBits != bufvis->stencilBits)
      return GL_FALSE;

   return GL_TRUE;
}


/**
 * Bind the given context to the given draw-buffer and read-buffer and
 * make it the current context for this thread.
 *
 * \param newCtx new GL context. If NULL then there will be no current GL
 * context.
 * \param drawBuffer draw framebuffer.
 * \param readBuffer read framebuffer.
 * 
 * Check that the context's and framebuffer's visuals are compatible, returning
 * immediately otherwise. Sets the glapi current context via
 * _glapi_set_context(). If \p newCtx is not NULL, associates \p drawBuffer and
 * \p readBuffer with it and calls dd_function_table::ResizeBuffers if the buffers size has changed. 
 * Calls dd_function_table::MakeCurrent callback if defined.
 *
 * When a context is bound by the first time and the \c MESA_INFO environment
 * variable is set it calls print_info() as an aid for remote user
 * troubleshooting.
 */
void
_mesa_make_current( GLcontext *newCtx, GLframebuffer *drawBuffer,
                    GLframebuffer *readBuffer )
{
   if (MESA_VERBOSE & VERBOSE_API)
      _mesa_debug(newCtx, "_mesa_make_current()\n");

   /* Check that the context's and framebuffer's visuals are compatible.
    */
   if (newCtx && drawBuffer && newCtx->DrawBuffer != drawBuffer) {
      if (!check_compatible(newCtx, drawBuffer))
         return;
   }
   if (newCtx && readBuffer && newCtx->ReadBuffer != readBuffer) {
      if (!check_compatible(newCtx, readBuffer))
         return;
   }

#if !defined(IN_DRI_DRIVER)
   /* We call this function periodically (just here for now) in
    * order to detect when multithreading has begun.  In a DRI driver, this
    * step is done by the driver loader (e.g., libGL).
    */
   _glapi_check_multithread();
#endif /* !defined(IN_DRI_DRIVER) */

   _glapi_set_context((void *) newCtx);
   ASSERT(_mesa_get_current_context() == newCtx);

   if (!newCtx) {
      _glapi_set_dispatch(NULL);  /* none current */
   }
   else {
      _glapi_set_dispatch(newCtx->CurrentDispatch);

      if (drawBuffer && readBuffer) {
	 /* TODO: check if newCtx and buffer's visual match??? */

         ASSERT(drawBuffer->Name == 0);
         ASSERT(readBuffer->Name == 0);
         newCtx->WinSysDrawBuffer = drawBuffer;
         newCtx->WinSysReadBuffer = readBuffer;
         /* don't replace user-buffer bindings with window system buffer */
         if (!newCtx->DrawBuffer || newCtx->DrawBuffer->Name == 0) {
            newCtx->DrawBuffer = drawBuffer;
            newCtx->ReadBuffer = readBuffer;
         }

	 newCtx->NewState |= _NEW_BUFFERS;

#if _HAVE_FULL_GL
         if (!drawBuffer->Initialized) {
            /* get initial window size */
            GLuint bufWidth, bufHeight;
            /* ask device driver for size of the buffer */
            (*newCtx->Driver.GetBufferSize)(drawBuffer, &bufWidth, &bufHeight);
            /* set initial buffer size */
            if (newCtx->Driver.ResizeBuffers)
               newCtx->Driver.ResizeBuffers(newCtx, drawBuffer,
                                            bufWidth, bufHeight);
            drawBuffer->Initialized = GL_TRUE;
         }

         if (readBuffer != drawBuffer && !readBuffer->Initialized) {
            /* get initial window size */
            GLuint bufWidth, bufHeight;
            /* ask device driver for size of the buffer */
            (*newCtx->Driver.GetBufferSize)(readBuffer, &bufWidth, &bufHeight);
            /* set initial buffer size */
            if (newCtx->Driver.ResizeBuffers)
               newCtx->Driver.ResizeBuffers(newCtx, readBuffer,
                                            bufWidth, bufHeight);
            readBuffer->Initialized = GL_TRUE;
         }
#endif
         if (newCtx->FirstTimeCurrent) {
            /* set initial viewport and scissor size now */
            _mesa_set_viewport(newCtx, 0, 0, drawBuffer->Width, drawBuffer->Height);
            newCtx->Scissor.Width = drawBuffer->Width;
            newCtx->Scissor.Height = drawBuffer->Height;
         }
      }

      /* Alert the driver - usually passed on to the sw t&l module,
       * but also used to detect threaded cases in the radeon codegen
       * hw t&l module.
       */
      if (newCtx->Driver.MakeCurrent)
	 newCtx->Driver.MakeCurrent( newCtx, drawBuffer, readBuffer );

      /* We can use this to help debug user's problems.  Tell them to set
       * the MESA_INFO env variable before running their app.  Then the
       * first time each context is made current we'll print some useful
       * information.
       */
      if (newCtx->FirstTimeCurrent) {
	 if (_mesa_getenv("MESA_INFO")) {
	    _mesa_print_info();
	 }
	 newCtx->FirstTimeCurrent = GL_FALSE;
      }
   }
}


/**
 * Make context 'ctx' share the display lists, textures and programs
 * that are associated with 'ctxToShare'.
 * Any display lists, textures or programs associated with 'ctx' will
 * be deleted if nobody else is sharing them.
 */
GLboolean
_mesa_share_state(GLcontext *ctx, GLcontext *ctxToShare)
{
   if (ctx && ctxToShare && ctx->Shared && ctxToShare->Shared) {
      ctx->Shared->RefCount--;
      if (ctx->Shared->RefCount == 0) {
         free_shared_state(ctx, ctx->Shared);
      }
      ctx->Shared = ctxToShare->Shared;
      ctx->Shared->RefCount++;
      return GL_TRUE;
   }
   else {
      return GL_FALSE;
   }
}



/**
 * Get current context for the calling thread.
 * 
 * \return pointer to the current GL context.
 * 
 * Calls _glapi_get_context(). This isn't the fastest way to get the current
 * context.  If you need speed, see the #GET_CURRENT_CONTEXT macro in context.h.
 */
GLcontext *
_mesa_get_current_context( void )
{
   return (GLcontext *) _glapi_get_context();
}

/**
 * Get context's current API dispatch table.
 *
 * It'll either be the immediate-mode execute dispatcher or the display list
 * compile dispatcher.
 * 
 * \param ctx GL context.
 *
 * \return pointer to dispatch_table.
 *
 * Simply returns __GLcontextRec::CurrentDispatch.
 */
struct _glapi_table *
_mesa_get_dispatch(GLcontext *ctx)
{
   return ctx->CurrentDispatch;
}

/*@}*/


/**********************************************************************/
/** \name Miscellaneous functions                                     */
/**********************************************************************/
/*@{*/

/**
 * Record an error.
 *
 * \param ctx GL context.
 * \param error error code.
 * 
 * Records the given error code and call the driver's dd_function_table::Error
 * function if defined.
 *
 * \sa
 * This is called via _mesa_error().
 */
void
_mesa_record_error( GLcontext *ctx, GLenum error )
{
   if (!ctx)
      return;

   if (ctx->ErrorValue == GL_NO_ERROR) {
      ctx->ErrorValue = error;
   }

   /* Call device driver's error handler, if any.  This is used on the Mac. */
   if (ctx->Driver.Error) {
      (*ctx->Driver.Error)( ctx );
   }
}

/**
 * Execute glFinish().
 *
 * Calls the #ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH macro and the
 * dd_function_table::Finish driver callback, if not NULL.
 */
void GLAPIENTRY
_mesa_Finish( void )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
   if (ctx->Driver.Finish) {
      (*ctx->Driver.Finish)( ctx );
   }
}

/**
 * Execute glFlush().
 *
 * Calls the #ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH macro and the
 * dd_function_table::Flush driver callback, if not NULL.
 */
void GLAPIENTRY
_mesa_Flush( void )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
   if (ctx->Driver.Flush) {
      (*ctx->Driver.Flush)( ctx );
   }
}


/*@}*/