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Rendering Context Manager with Rendering Context Extensions

IP.com Disclosure Number: IPCOM000108117D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 108K

Publishing Venue

IBM

Related People

Dilliplane, S: AUTHOR [+3]

Abstract

Disclosed is an improvement to the Rendering Context Manager (RCM) that permits support for a wider range of graphics adapters and more efficient tailoring of the rendering context for any adapter, thus promoting higher performance.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Rendering Context Manager with Rendering Context Extensions

       Disclosed is an improvement to the Rendering Context
Manager (RCM) that permits support for a wider range of graphics
adapters and more efficient tailoring of the rendering context for
any adapter, thus promoting higher performance.

      The Rendering Context Manager switches rendering contexts for
graphics processes running directly on graphics adapters. Rendering
contexts can be defined as fixed entities consisting of various
parts.  The parts include: pipeline state, which roughly corresponds
to the graphics context for a graphics process; incomplete command
content, for example, the content of a FIFO; and clipping
information, for both the graphics process window and the process'
private clipping requirements.

      There are two cases where this fixed definition of the
rendering context is not adequate.  First, some adapters require that
additional information referenced in rendering operations be on the
adapter.  Second, some graphics processes desire to put resources on
the adapter even though the adapter does not require it; generally,
this enhances performance. The improvement disclosed permits graphics
processes to define rendering context extensions, or more simply,
extensions. A rendering context extension is the term for something
referenced by, but not directly part of the pipeline state in a
rendering context, or something considered part of a graphics context
by the graphics process.

      Rendering context extensions are typically referenced
indirectly in the pipeline state, or not referenced at all, and can
be considered independent of the pipeline state to some degree.
Thus, they can be managed independently and somewhat differently from
other parts of a rendering context.

      A font is an example of a rendering context extension. A font
may be referenced by a rendering context and, thus, in some sense, is
an extension of a rendering context.  Some adapters require that the
fonts referenced in rendering operations be on the adapter. When this
is the case, then the fonts become part of the rendering context.

      Fonts belong to a class of rendering context parts that can be
shared among multiple rendering contexts. This class presents some
interesting requirements.  For example, if an adapter has room for
several pipeline states and some fonts, then a steady-state condition
could arise where the adapter contains a number of rendering...