diff options
author | commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2014-05-22 02:55:59 +0000 |
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committer | commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2014-05-22 02:55:59 +0000 |
commit | 3339ac54a5ed75f2872ab16e9052a8b9ff3564bf (patch) | |
tree | 42852098db6117ad0f15cf332bc2aacffa322e38 /src/utils | |
parent | 8991c67f0c1b9364bb12dfb0f32a53bd5a3357f3 (diff) |
Revert of Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/) (https://codereview.chromium.org/288343009/)
Reason for revert:
required blink change failed to land
Original issue's description:
> Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/)
>
> This reverts commit dd50c83b5b34dab3a077741861b50ed1f2bc6b8f.
>
> BUG=skia:
>
> Committed: http://code.google.com/p/skia/source/detail?r=14830
R=scroggo@google.com, reed@google.com
TBR=reed@google.com, scroggo@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:
Author: reed@chromium.org
Review URL: https://codereview.chromium.org/296823008
git-svn-id: http://skia.googlecode.com/svn/trunk@14838 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'src/utils')
-rw-r--r-- | src/utils/SkUnitMappers.cpp | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/utils/SkUnitMappers.cpp b/src/utils/SkUnitMappers.cpp new file mode 100644 index 0000000000..336a26e164 --- /dev/null +++ b/src/utils/SkUnitMappers.cpp @@ -0,0 +1,61 @@ + +/* + * Copyright 2011 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ +#include "SkUnitMappers.h" +#include "SkReadBuffer.h" +#include "SkWriteBuffer.h" + + +SkDiscreteMapper::SkDiscreteMapper(int segments) { + if (segments < 2) { + fSegments = 0; + fScale = 0; + } else { + if (segments > 0xFFFF) { + segments = 0xFFFF; + } + fSegments = segments; + fScale = (1 << 30) / (segments - 1); + } +} + +uint16_t SkDiscreteMapper::mapUnit16(uint16_t input) { + SkFixed x = input * fSegments >> 16; + x = x * fScale >> 14; + x += x << 15 >> 31; // map 0x10000 to 0xFFFF + return SkToU16(x); +} + +SkDiscreteMapper::SkDiscreteMapper(SkReadBuffer& rb) + : SkUnitMapper(rb) { + fSegments = rb.readInt(); + fScale = rb.read32(); +} + +void SkDiscreteMapper::flatten(SkWriteBuffer& wb) const { + this->INHERITED::flatten(wb); + + wb.writeInt(fSegments); + wb.write32(fScale); +} + +/////////////////////////////////////////////////////////////////////////////// + +uint16_t SkCosineMapper::mapUnit16(uint16_t input) +{ + /* we want to call cosine(input * pi/2) treating input as [0...1) + however, the straight multitply would overflow 32bits since input is + 16bits and pi/2 is 17bits, so we shift down our pi const before we mul + */ + SkFixed rads = (unsigned)(input * (SK_FixedPI >> 2)) >> 15; + SkFixed x = SkFixedCos(rads); + x += x << 15 >> 31; // map 0x10000 to 0xFFFF + return SkToU16(x); +} + +SkCosineMapper::SkCosineMapper(SkReadBuffer& rb) + : SkUnitMapper(rb) {} |