tree a5b81819648880b2dbbb52d05cb2edf6bcd7b0e7
parent 1ab9e59da057e02ece707d736032c756fb3ce9cf
author halcanary <halcanary@google.com> 1469480370 -0700
committer Commit bot <commit-bot@chromium.org> 1469480370 -0700

SkPDF: re-work SkPDFUtils::FloatToDecimal

  * do a lot less floating-point math by converting to
    an integer as early as possible [faster].
  * round rather than truncate.
  * use 8 significant digits rather than 9 when possible.
  * remove trailing zeros in fractions.

before:
      0.12 !    PDFScalar   nonrendering
after:
      0.07 !    PDFScalar   nonrendering

Accuracy guaranteed by existing unit test.

Example diffs:

    -/Shading <</Function <</C0 [.321568638 .333333343 .321568638]
    +/Shading <</Function <</C0 [.32156864 .33333334 .32156864]

    -/C1 [.258823543 .270588248 .258823543]
    +/C1 [.25882354 .27058825 .25882354]

    -1 0 0 -1 20 120.394500 Tm
    +1 0 0 -1 20 120.394501 Tm

    -1 0 0 -1 20 184.789001 Tm
    +1 0 0 -1 20 184.789 Tm

    -291.503997 0 l
    +291.504 0 l

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2146103004

Review-Url: https://codereview.chromium.org/2146103004