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| author |  fmalita <fmalita@chromium.org> | 2015-12-15 06:48:48 -0800 |
|---|---|---|
| committer |  Commit bot <commit-bot@chromium.org> | 2015-12-15 06:48:48 -0800 |
| commit | aed4d32de937a8f2733924eb848cc287e8d04087 (patch) | |
| tree | 0c7708b50a7459708dc3f9a9613b6900a292d3b5 /src/core/SkBitmapProcState.h | |
| parent | 11f457e1627be775cfa26d71307dbd6073f9269c (diff) | |
SkBitmapProcState rounding bias
Epsilon bias to keep bitmap sample rounding consistent with geometry
rounding.
Also update the GM to draw an outer border + drop uninteresting
scales in favor of negative scale variants.
BUG=skia:4680,skia:4649
R=reed@google.com,caryclark@google.com,mtklein@google.com
Review URL: https://codereview.chromium.org/1527633002
Diffstat (limited to 'src/core/SkBitmapProcState.h')
| -rw-r--r-- | src/core/SkBitmapProcState.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/core/SkBitmapProcState.h b/src/core/SkBitmapProcState.h index 2ce76bc83e..e6e7a3f393 100644 --- a/src/core/SkBitmapProcState.h +++ b/src/core/SkBitmapProcState.h @@ -12,6 +12,7 @@ #include "SkBitmapController.h" #include "SkBitmapFilter.h" #include "SkBitmapProvider.h" +#include "SkFloatBits.h" #include "SkMatrix.h" #include "SkMipMap.h" #include "SkPaint.h" @@ -24,6 +25,17 @@ typedef SkFixed3232 SkFractionalInt; #define SkFixedToFractionalInt(x) SkFixedToFixed3232(x) #define SkFractionalIntToInt(x) SkFixed3232ToInt(x) +// Applying a fixed point (SkFixed, SkFractionalInt) epsilon bias ensures that the inverse-mapped +// bitmap coordinates are rounded consistently WRT geometry. Note that we only have to do this +// when the scale is positive - for negative scales we're already rounding in the right direction. +static inline int bitmap_sampler_inv_bias(SkScalar scale) { +#ifndef SK_SUPPORT_LEGACY_BITMAP_SAMPLER_BIAS + return -(scale > 0); +#else + return 0; +#endif +} + class SkPaint; struct SkBitmapProcState { |