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  1. JDK
  2. JDK-6248957

Src mode with non-opaque color does not use optimized loops

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P3
    • Resolution: Fixed
    • Affects Version/s: 1.4.0
    • Fix Version/s: 6
    • Component/s: client-libs
    • Labels:
    • Subcomponent:
      2d
    • Introduced In Version:
    • Resolved In Build:
      beta
    • CPU:
      generic
    • OS:
      generic

      Description

      The code to choose a pipeline only chooses the optimized rendering
      code if the alpha mode is Src or SrcOver, with no extra alpha, and
      the color is opaque.

      If the alpha mode is Src (no extra alpha) and the color is non-opaque,
      the same optimized rendering code can be used since this only affects
      the pre-calculated pixel value stored for each rendered pixel, but
      alpha blending code is chosen instead, reducing performance.

      Even worse, for indexed images the alpha blending code does an extremely
      poor job of choosing the best pixel for the results of blending (it only
      examines the opaque pixels in a lookup table for performance reasons)
      and so the blending code will produce much worse results than using the
      optimized rendering code with a carefully chosen pixel in these cases.

      ###@###.### 2005-03-31 21:42:00 GMT

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              • Assignee:
                flar Jim Graham
                Reporter:
                flar Jim Graham
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                • Created:
                  Updated:
                  Resolved:
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