diff options
author | 2013-06-14 13:38:56 +0000 | |
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committer | 2013-06-14 13:38:56 +0000 | |
commit | 61c49f357a03f68c12c2650ac9915657298352a4 (patch) | |
tree | 6ad8576201ad45375bedce8b0ed853d963c21cba /src/core/SkConfig8888.cpp | |
parent | 68b6eca42ed2bf9b4daaa2f210c9c14d7a5d0e3f (diff) |
Improve the performance of SkConvertConfig8888Pixels using Array lookup
BUG=242097
R=kbr@chromium.org, vangelis@chromium.org, zmo@chromium.org, gman@chromium.org, bsalomon@google.com, reed@google.com, tomhudson@chromium.org, noel@chromium.org
Author: jun.a.jiang@intel.com
Review URL: https://chromiumcodereview.appspot.com/15402003
git-svn-id: http://skia.googlecode.com/svn/trunk@9605 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'src/core/SkConfig8888.cpp')
-rw-r--r-- | src/core/SkConfig8888.cpp | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/src/core/SkConfig8888.cpp b/src/core/SkConfig8888.cpp index f889f20744..dd5cbc4724 100644 --- a/src/core/SkConfig8888.cpp +++ b/src/core/SkConfig8888.cpp @@ -1,5 +1,6 @@ #include "SkConfig8888.h" #include "SkMathPriv.h" +#include "SkUnPreMultiply.h" namespace { @@ -57,23 +58,20 @@ inline uint32_t convert_pixel(uint32_t pixel) { uint32_t a, r, g, b; unpack_config8888<IN_A_IDX, IN_R_IDX, IN_G_IDX, IN_B_IDX>(pixel, &a, &r, &g, &b); if (IN_PM && !OUT_PM) { - // We're doing the explicit divide to match WebKit layout - // test expectations. We can modify and rebaseline if there - // it can be shown that there is a more performant way to - // unpremul. + // Using SkUnPreMultiply::ApplyScale is faster than (value * 0xff) / a. if (a) { - r = r * 0xff / a; - g = g * 0xff / a; - b = b * 0xff / a; + SkUnPreMultiply::Scale scale = SkUnPreMultiply::GetScale(a); + r = SkUnPreMultiply::ApplyScale(scale, r); + g = SkUnPreMultiply::ApplyScale(scale, g); + b = SkUnPreMultiply::ApplyScale(scale, b); } else { return 0; } } else if (!IN_PM && OUT_PM) { - // This matches WebKit's conversion which we are replacing. - // We can consider alternative rounding rules for performance. - r = SkMulDiv255Ceiling(r, a); - g = SkMulDiv255Ceiling(g, a); - b = SkMulDiv255Ceiling(b, a); + // This matches SkUnPreMultiply conversion which we are replacing. + r = SkMulDiv255Round(r, a); + g = SkMulDiv255Round(g, a); + b = SkMulDiv255Round(b, a); } return pack_config8888<OUT_A_IDX, OUT_R_IDX, OUT_G_IDX, OUT_B_IDX>(a, r, g, b); } |