tree d155d846ad63c613b0554c881c55ef40883f9a6a
parent 3a59665099da62835f54192ae9a4f2480e91c8ff
author Hal Canary <halcanary@google.com> 1499268342 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1499275674 +0000

SkPDF: Refactor PDFShader to use ShTHashMap<>

my tests run ~14% faster.

  - Split out gradient shaders from image shaders.  new compilation
    unit: SkPDFGradientShader
  - Common functions InverseTransformBBox and PopulateTilingPatternDict
    moved to SkPDFUtils
  - Split SkPDFShader::State into image and gradient structures.
  - SkPDFCanon is now a simpler structure, with no logic of its own.
    I am considering just moving all of its fields into SkPDFDocument
  - SkPDFShader::State (the image/fallback shader) now is POD, making
    the use of a hashmap for canonicalization straightforward.
    Formerly, we used a linear search.
  - Do not bother trying to canonicalize the falback image shader.
  - SkPDFGradientShader::Key is not POD; comparison of two objects
    requires looking at the contents of two variable-sized arrays.
    We now pre-calculate the hash of the arrays using SkOpts::hash and
    store a hash for the object in the fHash field.
    Using that hash, we can now canonicalize using a hashmap instead
    of a linar search!
  - several static functions renamed to follow style guidelines
  - stop using codeFunction function pointer; I find that less
    clear than it could be.
  - operator==() for SkPDFShader::State and SkPDFGradientShader::Key is
    now much simpler and can now be inlined.
  - SkArrayEqual template in SkPDFUtils.h

No change to PDF output.

BUG=skia:3585
Change-Id: I354ad1b600be6d6749abccb58d13db257370bc0b
Reviewed-on: https://skia-review.googlesource.com/21376
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>