Remove deadcode for sRGB image shading.

Change-Id: I9d98da67d97b64ab55cf44b9ae447882dccda1ca
Reviewed-on: https://skia-review.googlesource.com/20695
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Herb Derby <herb@google.com>

1 files changed, 0 insertions, 1041 deletions

diff --git a/src/core/SkLinearBitmapPipeline_sample.h b/src/core/SkLinearBitmapPipeline_sample.h
deleted file mode 100644
index a7f5d7383e..0000000000
--- a/src/core/SkLinearBitmapPipeline_sample.h
+++ /dev/null
@@ -1,1041 +0,0 @@
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkLinearBitmapPipeline_sampler_DEFINED
-#define SkLinearBitmapPipeline_sampler_DEFINED
-
-#include <tuple>
-
-#include "SkAutoMalloc.h"
-#include "SkColor.h"
-#include "SkColorPriv.h"
-#include "SkFixed.h"  // for SkFixed1 only. Don't use SkFixed in this file.
-#include "SkHalf.h"
-#include "SkLinearBitmapPipeline_core.h"
-#include "SkNx.h"
-#include "SkPM4fPriv.h"
-
-namespace {
-// Explaination of the math:
-//              1 - x      x
-//           +--------+--------+
-//           |        |        |
-//  1 - y    |  px00  |  px10  |
-//           |        |        |
-//           +--------+--------+
-//           |        |        |
-//    y      |  px01  |  px11  |
-//           |        |        |
-//           +--------+--------+
-//
-//
-// Given a pixelxy each is multiplied by a different factor derived from the fractional part of x
-// and y:
-// * px00 -> (1 - x)(1 - y) = 1 - x - y + xy
-// * px10 -> x(1 - y) = x - xy
-// * px01 -> (1 - x)y = y - xy
-// * px11 -> xy
-// So x * y is calculated first and then used to calculate all the other factors.
-static Sk4s SK_VECTORCALL bilerp4(Sk4s xs, Sk4s ys, Sk4f px00, Sk4f px10,
-                                                    Sk4f px01, Sk4f px11) {
-    // Calculate fractional xs and ys.
-    Sk4s fxs = xs - xs.floor();
-    Sk4s fys = ys - ys.floor();
-    Sk4s fxys{fxs * fys};
-    Sk4f sum = px11 * fxys;
-    sum = sum + px01 * (fys - fxys);
-    sum = sum + px10 * (fxs - fxys);
-    sum = sum + px00 * (Sk4f{1.0f} - fxs - fys + fxys);
-    return sum;
-}
-
-////////////////////////////////////////////////////////////////////////////////////////////////////
-// PixelGetter is the lowest level interface to the source data. There is a PixelConverter for each
-// of the different SkColorTypes.
-template <SkColorType, SkGammaType> class PixelConverter;
-
-// Alpha handling:
-//   The alpha from the paint (tintColor) is used in the blend part of the pipeline to modulate
-// the entire bitmap. So, the tint color is given an alpha of 1.0 so that the later alpha can
-// modulate this color later.
-template <>
-class PixelConverter<kAlpha_8_SkColorType, kLinear_SkGammaType> {
-public:
-    using Element = uint8_t;
-    PixelConverter(const SkPixmap& srcPixmap, SkColor tintColor) {
-        fTintColor = SkColor4f::FromColor(tintColor);
-        fTintColor.fA = 1.0f;
-    }
-
-    Sk4f toSk4f(const Element pixel) const {
-        return Sk4f::Load(&fTintColor) * (pixel * (1.0f/255.0f));
-    }
-
-private:
-    SkColor4f fTintColor;
-};
-
-template <SkGammaType gammaType>
-static inline Sk4f pmcolor_to_rgba(SkPMColor pixel) {
-    return swizzle_rb_if_bgra(
-            (gammaType == kSRGB_SkGammaType) ? Sk4f_fromS32(pixel)
-                                             : Sk4f_fromL32(pixel));
-}
-
-template <SkGammaType gammaType>
-class PixelConverter<kRGB_565_SkColorType, gammaType> {
-public:
-    using Element = uint16_t;
-    PixelConverter(const SkPixmap& srcPixmap) { }
-
-    Sk4f toSk4f(Element pixel) const {
-        return pmcolor_to_rgba<gammaType>(SkPixel16ToPixel32(pixel));
-    }
-};
-
-template <SkGammaType gammaType>
-class PixelConverter<kARGB_4444_SkColorType, gammaType> {
-public:
-    using Element = uint16_t;
-    PixelConverter(const SkPixmap& srcPixmap) { }
-
-    Sk4f toSk4f(Element pixel) const {
-        return pmcolor_to_rgba<gammaType>(SkPixel4444ToPixel32(pixel));
-    }
-};
-
-template <SkGammaType gammaType>
-class PixelConverter<kRGBA_8888_SkColorType, gammaType> {
-public:
-    using Element = uint32_t;
-    PixelConverter(const SkPixmap& srcPixmap) { }
-
-    Sk4f toSk4f(Element pixel) const {
-        return gammaType == kSRGB_SkGammaType
-               ? Sk4f_fromS32(pixel)
-               : Sk4f_fromL32(pixel);
-    }
-};
-
-template <SkGammaType gammaType>
-class PixelConverter<kBGRA_8888_SkColorType, gammaType> {
-public:
-    using Element = uint32_t;
-    PixelConverter(const SkPixmap& srcPixmap) { }
-
-    Sk4f toSk4f(Element pixel) const {
-        return swizzle_rb(
-                   gammaType == kSRGB_SkGammaType ? Sk4f_fromS32(pixel) : Sk4f_fromL32(pixel));
-    }
-};
-
-template <SkGammaType gammaType>
-class PixelConverter<kIndex_8_SkColorType, gammaType> {
-public:
-    using Element = uint8_t;
-    PixelConverter(const SkPixmap& srcPixmap)
-    : fColorTableSize(srcPixmap.ctable()->count()){
-        SkColorTable* skColorTable = srcPixmap.ctable();
-        SkASSERT(skColorTable != nullptr);
-
-        fColorTable = (Sk4f*)SkAlign16((intptr_t)fColorTableStorage.get());
-        for (int i = 0; i < fColorTableSize; i++) {
-            fColorTable[i] = pmcolor_to_rgba<gammaType>((*skColorTable)[i]);
-        }
-    }
-
-    PixelConverter(const PixelConverter& strategy)
-    : fColorTableSize{strategy.fColorTableSize}{
-        fColorTable = (Sk4f*)SkAlign16((intptr_t)fColorTableStorage.get());
-        for (int i = 0; i < fColorTableSize; i++) {
-            fColorTable[i] = strategy.fColorTable[i];
-        }
-    }
-
-    Sk4f toSk4f(Element index) const {
-        return fColorTable[index];
-    }
-
-private:
-    static const size_t kColorTableSize = sizeof(Sk4f[256]) + 12;
-    const int           fColorTableSize;
-    SkAutoMalloc        fColorTableStorage{kColorTableSize};
-    Sk4f*               fColorTable;
-};
-
-template <SkGammaType gammaType>
-class PixelConverter<kGray_8_SkColorType, gammaType> {
-public:
-    using Element = uint8_t;
-    PixelConverter(const SkPixmap& srcPixmap) { }
-
-    Sk4f toSk4f(Element pixel) const {
-        float gray = (gammaType == kSRGB_SkGammaType)
-            ? sk_linear_from_srgb[pixel]
-            : pixel * (1/255.0f);
-        return {gray, gray, gray, 1.0f};
-    }
-};
-
-template <>
-class PixelConverter<kRGBA_F16_SkColorType, kLinear_SkGammaType> {
-public:
-    using Element = uint64_t;
-    PixelConverter(const SkPixmap& srcPixmap) { }
-
-    Sk4f toSk4f(const Element pixel) const {
-        return SkHalfToFloat_finite_ftz(pixel);
-    }
-};
-
-class PixelAccessorShim {
-public:
-    explicit PixelAccessorShim(SkLinearBitmapPipeline::PixelAccessorInterface* accessor)
-        : fPixelAccessor(accessor) { }
-
-    void SK_VECTORCALL getFewPixels(
-        int n, Sk4i xs, Sk4i ys, Sk4f* px0, Sk4f* px1, Sk4f* px2) const {
-        fPixelAccessor->getFewPixels(n, xs, ys, px0, px1, px2);
-    }
-
-    void SK_VECTORCALL get4Pixels(
-        Sk4i xs, Sk4i ys, Sk4f* px0, Sk4f* px1, Sk4f* px2, Sk4f* px3) const {
-        fPixelAccessor->get4Pixels(xs, ys, px0, px1, px2, px3);
-    }
-
-    void get4Pixels(
-        const void* src, int index, Sk4f* px0, Sk4f* px1, Sk4f* px2, Sk4f* px3) const {
-        fPixelAccessor->get4Pixels(src, index, px0, px1, px2, px3);
-    }
-
-    Sk4f getPixelFromRow(const void* row, int index) const {
-        return fPixelAccessor->getPixelFromRow(row, index);
-    }
-
-    Sk4f getPixelAt(int index) const {
-        return fPixelAccessor->getPixelAt(index);
-    }
-
-    const void* row(int y) const {
-        return fPixelAccessor->row(y);
-    }
-
-private:
-    SkLinearBitmapPipeline::PixelAccessorInterface* const fPixelAccessor;
-};
-
-////////////////////////////////////////////////////////////////////////////////////////////////////
-// PixelAccessor handles all the same plumbing for all the PixelGetters.
-template <SkColorType colorType, SkGammaType gammaType>
-class PixelAccessor final : public SkLinearBitmapPipeline::PixelAccessorInterface {
-    using Element = typename PixelConverter<colorType, gammaType>::Element;
-public:
-    template <typename... Args>
-    PixelAccessor(const SkPixmap& srcPixmap, Args&&... args)
-        : fSrc{static_cast<const Element*>(srcPixmap.addr())}
-        , fWidth{srcPixmap.rowBytesAsPixels()}
-        , fConverter{srcPixmap, std::move<Args>(args)...} { }
-
-    void SK_VECTORCALL getFewPixels (
-        int n, Sk4i xs, Sk4i ys, Sk4f* px0, Sk4f* px1, Sk4f* px2) const override {
-        Sk4i bufferLoc = ys * fWidth + xs;
-        switch (n) {
-            case 3:
-                *px2 = this->getPixelAt(bufferLoc[2]);
-            case 2:
-                *px1 = this->getPixelAt(bufferLoc[1]);
-            case 1:
-                *px0 = this->getPixelAt(bufferLoc[0]);
-            default:
-                break;
-        }
-    }
-
-    void SK_VECTORCALL get4Pixels(
-        Sk4i xs, Sk4i ys, Sk4f* px0, Sk4f* px1, Sk4f* px2, Sk4f* px3) const override {
-        Sk4i bufferLoc = ys * fWidth + xs;
-        *px0 = this->getPixelAt(bufferLoc[0]);
-        *px1 = this->getPixelAt(bufferLoc[1]);
-        *px2 = this->getPixelAt(bufferLoc[2]);
-        *px3 = this->getPixelAt(bufferLoc[3]);
-    }
-
-    void get4Pixels(
-        const void* src, int index, Sk4f* px0, Sk4f* px1, Sk4f* px2, Sk4f* px3) const override {
-        *px0 = this->getPixelFromRow(src, index + 0);
-        *px1 = this->getPixelFromRow(src, index + 1);
-        *px2 = this->getPixelFromRow(src, index + 2);
-        *px3 = this->getPixelFromRow(src, index + 3);
-    }
-
-    Sk4f getPixelFromRow(const void* row, int index) const override {
-        const Element* src = static_cast<const Element*>(row);
-        return fConverter.toSk4f(src[index]);
-    }
-
-    Sk4f getPixelAt(int index) const override {
-        return this->getPixelFromRow(fSrc, index);
-    }
-
-    const void* row(int y) const override { return fSrc + y * fWidth; }
-
-private:
-    const Element* const                 fSrc;
-    const int                            fWidth;
-    PixelConverter<colorType, gammaType> fConverter;
-};
-
-// We're moving through source space at a rate of 1 source pixel per 1 dst pixel.
-// We'll never re-use pixels, but we can at least load contiguous pixels.
-template <typename Next, typename Strategy>
-static void src_strategy_blend(Span span, Next* next, Strategy* strategy) {
-    SkPoint start;
-    SkScalar length;
-    int count;
-    std::tie(start, length, count) = span;
-    int ix = SkScalarFloorToInt(X(start));
-    const void* row = strategy->row((int)std::floor(Y(start)));
-    if (length > 0) {
-        while (count >= 4) {
-            Sk4f px0, px1, px2, px3;
-            strategy->get4Pixels(row, ix, &px0, &px1, &px2, &px3);
-            next->blend4Pixels(px0, px1, px2, px3);
-            ix += 4;
-            count -= 4;
-        }
-
-        while (count > 0) {
-            next->blendPixel(strategy->getPixelFromRow(row, ix));
-            ix += 1;
-            count -= 1;
-        }
-    } else {
-        while (count >= 4) {
-            Sk4f px0, px1, px2, px3;
-            strategy->get4Pixels(row, ix - 3, &px3, &px2, &px1, &px0);
-            next->blend4Pixels(px0, px1, px2, px3);
-            ix -= 4;
-            count -= 4;
-        }
-
-        while (count > 0) {
-            next->blendPixel(strategy->getPixelFromRow(row, ix));
-            ix -= 1;
-            count -= 1;
-        }
-    }
-}
-
-// -- NearestNeighborSampler -----------------------------------------------------------------------
-// NearestNeighborSampler - use nearest neighbor filtering to create runs of destination pixels.
-template<typename Accessor, typename Next>
-class NearestNeighborSampler : public SkLinearBitmapPipeline::SampleProcessorInterface {
-public:
-    template<typename... Args>
-    NearestNeighborSampler(SkLinearBitmapPipeline::BlendProcessorInterface* next, Args&& ... args)
-    : fNext{next}, fAccessor{std::forward<Args>(args)...} { }
-
-    NearestNeighborSampler(SkLinearBitmapPipeline::BlendProcessorInterface* next,
-    const NearestNeighborSampler& sampler)
-    : fNext{next}, fAccessor{sampler.fAccessor} { }
-
-    void SK_VECTORCALL pointListFew(int n, Sk4s xs, Sk4s ys) override {
-        SkASSERT(0 < n && n < 4);
-        Sk4f px0, px1, px2;
-        fAccessor.getFewPixels(n, SkNx_cast<int>(xs), SkNx_cast<int>(ys), &px0, &px1, &px2);
-        if (n >= 1) fNext->blendPixel(px0);
-        if (n >= 2) fNext->blendPixel(px1);
-        if (n >= 3) fNext->blendPixel(px2);
-    }
-
-    void SK_VECTORCALL pointList4(Sk4s xs, Sk4s ys) override {
-        Sk4f px0, px1, px2, px3;
-        fAccessor.get4Pixels(SkNx_cast<int>(xs), SkNx_cast<int>(ys), &px0, &px1, &px2, &px3);
-        fNext->blend4Pixels(px0, px1, px2, px3);
-    }
-
-    void pointSpan(Span span) override {
-        SkASSERT(!span.isEmpty());
-        SkPoint start;
-        SkScalar length;
-        int count;
-        std::tie(start, length, count) = span;
-        SkScalar absLength = SkScalarAbs(length);
-        if (absLength < (count - 1)) {
-            this->spanSlowRate(span);
-        } else if (absLength == (count - 1)) {
-            src_strategy_blend(span, fNext, &fAccessor);
-        } else {
-            this->spanFastRate(span);
-        }
-    }
-
-    void repeatSpan(Span span, int32_t repeatCount) override {
-        while (repeatCount > 0) {
-            this->pointSpan(span);
-            repeatCount--;
-        }
-    }
-
-private:
-    // When moving through source space more slowly than dst space (zoomed in),
-    // we'll be sampling from the same source pixel more than once.
-    void spanSlowRate(Span span) {
-        SkPoint start; SkScalar length; int count;
-        std::tie(start, length, count) = span;
-        SkScalar x = X(start);
-        // fx is a fixed 48.16 number.
-        int64_t fx = static_cast<int64_t>(x * SK_Fixed1);
-        SkScalar dx = length / (count - 1);
-        // fdx is a fixed 48.16 number.
-        int64_t fdx = static_cast<int64_t>(dx * SK_Fixed1);
-
-        const void* row = fAccessor.row((int)std::floor(Y(start)));
-        Next* next = fNext;
-
-        int64_t ix = fx >> 16;
-        int64_t prevIX = ix;
-        Sk4f fpixel = fAccessor.getPixelFromRow(row, ix);
-
-        // When dx is less than one, each pixel is used more than once. Using the fixed point fx
-        // allows the code to quickly check that the same pixel is being used. The code uses this
-        // same pixel check to do the sRGB and normalization only once.
-        auto getNextPixel = [&]() {
-            if (ix != prevIX) {
-                fpixel = fAccessor.getPixelFromRow(row, ix);
-                prevIX = ix;
-            }
-            fx += fdx;
-            ix = fx >> 16;
-            return fpixel;
-        };
-
-        while (count >= 4) {
-            Sk4f px0 = getNextPixel();
-            Sk4f px1 = getNextPixel();
-            Sk4f px2 = getNextPixel();
-            Sk4f px3 = getNextPixel();
-            next->blend4Pixels(px0, px1, px2, px3);
-            count -= 4;
-        }
-        while (count > 0) {
-            next->blendPixel(getNextPixel());
-            count -= 1;
-        }
-    }
-
-    // We're moving through source space at a rate of 1 source pixel per 1 dst pixel.
-    // We'll never re-use pixels, but we can at least load contiguous pixels.
-    void spanUnitRate(Span span) {
-        src_strategy_blend(span, fNext, &fAccessor);
-    }
-
-    // We're moving through source space faster than dst (zoomed out),
-    // so we'll never reuse a source pixel or be able to do contiguous loads.
-    void spanFastRate(Span span) {
-        span_fallback(span, this);
-    }
-
-    Next* const fNext;
-    Accessor    fAccessor;
-};
-
-// From an edgeType, the integer value of a pixel vs, and the integer value of the extreme edge
-// vMax, take the point which might be off the tile by one pixel and either wrap it or pin it to
-// generate the right pixel. The value vs is on the interval [-1, vMax + 1]. It produces a value
-// on the interval [0, vMax].
-// Note: vMax is not width or height, but width-1 or height-1 because it is the largest valid pixel.
-static inline int adjust_edge(SkShader::TileMode edgeType, int vs, int vMax) {
-    SkASSERT(-1 <= vs && vs <= vMax + 1);
-    switch (edgeType) {
-        case SkShader::kClamp_TileMode:
-        case SkShader::kMirror_TileMode:
-            vs = std::max(vs, 0);
-            vs = std::min(vs, vMax);
-            break;
-        case SkShader::kRepeat_TileMode:
-            vs = (vs <= vMax) ? vs : 0;
-            vs =    (vs >= 0) ? vs : vMax;
-            break;
-    }
-    SkASSERT(0 <= vs && vs <= vMax);
-    return vs;
-}
-
-// From a sample point on the tile, return the top or left filter value.
-// The result r should be in the range (0, 1]. Since this represents the weight given to the top
-// left element, then if x == 0.5 the filter value should be 1.0.
-// The input sample point must be on the tile, therefore it must be >= 0.
-static SkScalar sample_to_filter(SkScalar x) {
-    SkASSERT(x >= 0.0f);
-    // The usual form of the top or left edge is x - .5, but since we are working on the unit
-    // square, then x + .5 works just as well. This also guarantees that v > 0.0 allowing the use
-    // of trunc.
-    SkScalar v = x + 0.5f;
-    // Produce the top or left offset a value on the range [0, 1).
-    SkScalar f = v - SkScalarTruncToScalar(v);
-    // Produce the filter value which is on the range (0, 1].
-    SkScalar r =  1.0f - f;
-    SkASSERT(0.0f < r && r <= 1.0f);
-    return r;
-}
-
-// -- BilerpSampler --------------------------------------------------------------------------------
-// BilerpSampler - use a bilerp filter to create runs of destination pixels.
-// Note: in the code below, there are two types of points
-//       * sample points - these are the points passed in by pointList* and Spans.
-//       * filter points - are created from a sample point to form the coordinates of the points
-//                         to use in the filter and to generate the filter values.
-template<typename Accessor, typename Next>
-class BilerpSampler : public SkLinearBitmapPipeline::SampleProcessorInterface {
-public:
-    template<typename... Args>
-    BilerpSampler(
-        SkLinearBitmapPipeline::BlendProcessorInterface* next,
-        SkISize dimensions,
-        SkShader::TileMode xTile, SkShader::TileMode yTile,
-        Args&& ... args
-    )
-        : fNext{next}
-        , fXEdgeType{xTile}
-        , fXMax{dimensions.width() - 1}
-        , fYEdgeType{yTile}
-        , fYMax{dimensions.height() - 1}
-        , fAccessor{std::forward<Args>(args)...} { }
-
-    BilerpSampler(SkLinearBitmapPipeline::BlendProcessorInterface* next,
-                   const BilerpSampler& sampler)
-        : fNext{next}
-        , fXEdgeType{sampler.fXEdgeType}
-        , fXMax{sampler.fXMax}
-        , fYEdgeType{sampler.fYEdgeType}
-        , fYMax{sampler.fYMax}
-        , fAccessor{sampler.fAccessor} { }
-
-    void SK_VECTORCALL pointListFew(int n, Sk4s xs, Sk4s ys) override {
-        SkASSERT(0 < n && n < 4);
-        auto bilerpPixel = [&](int index) {
-            return this->bilerpSamplePoint(SkPoint{xs[index], ys[index]});
-        };
-
-        if (n >= 1) fNext->blendPixel(bilerpPixel(0));
-        if (n >= 2) fNext->blendPixel(bilerpPixel(1));
-        if (n >= 3) fNext->blendPixel(bilerpPixel(2));
-    }
-
-    void SK_VECTORCALL pointList4(Sk4s xs, Sk4s ys) override {
-        auto bilerpPixel = [&](int index) {
-            return this->bilerpSamplePoint(SkPoint{xs[index], ys[index]});
-        };
-        fNext->blend4Pixels(bilerpPixel(0), bilerpPixel(1), bilerpPixel(2), bilerpPixel(3));
-    }
-
-    void pointSpan(Span span) override {
-        SkASSERT(!span.isEmpty());
-        SkPoint start;
-        SkScalar length;
-        int count;
-        std::tie(start, length, count) = span;
-
-        // Nothing to do.
-        if (count == 0) {
-            return;
-        }
-
-        // Trivial case. No sample points are generated other than start.
-        if (count == 1) {
-            fNext->blendPixel(this->bilerpSamplePoint(start));
-            return;
-        }
-
-        // Note: the following code could be done in terms of dx = length / (count -1), but that
-        // would introduce a divide that is not needed for the most common dx == 1 cases.
-        SkScalar absLength = SkScalarAbs(length);
-        if (absLength == 0.0f) {
-            // |dx| == 0
-            // length is zero, so clamp an edge pixel.
-            this->spanZeroRate(span);
-        } else if (absLength < (count - 1)) {
-            // 0 < |dx| < 1.
-            this->spanSlowRate(span);
-        } else if (absLength == (count - 1)) {
-            // |dx| == 1.
-            if (sample_to_filter(span.startX()) == 1.0f
-                && sample_to_filter(span.startY()) == 1.0f) {
-                // All the pixels are aligned with the dest; go fast.
-                src_strategy_blend(span, fNext, &fAccessor);
-            } else {
-                // There is some sub-pixel offsets, so bilerp.
-                this->spanUnitRate(span);
-            }
-        } else if (absLength < 2.0f * (count - 1)) {
-            // 1 < |dx| < 2.
-            this->spanMediumRate(span);
-        } else {
-            // |dx| >= 2.
-            this->spanFastRate(span);
-        }
-    }
-
-    void repeatSpan(Span span, int32_t repeatCount) override {
-        while (repeatCount > 0) {
-            this->pointSpan(span);
-            repeatCount--;
-        }
-    }
-
-private:
-
-    // Convert a sample point to the points used by the filter.
-    void filterPoints(SkPoint sample, Sk4i* filterXs, Sk4i* filterYs) {
-        // May be less than zero. Be careful to use Floor.
-        int x0 = adjust_edge(fXEdgeType, SkScalarFloorToInt(X(sample) - 0.5), fXMax);
-        // Always greater than zero. Use the faster Trunc.
-        int x1 = adjust_edge(fXEdgeType, SkScalarTruncToInt(X(sample) + 0.5), fXMax);
-        int y0 = adjust_edge(fYEdgeType, SkScalarFloorToInt(Y(sample) - 0.5), fYMax);
-        int y1 = adjust_edge(fYEdgeType, SkScalarTruncToInt(Y(sample) + 0.5), fYMax);
-
-        *filterXs = Sk4i{x0, x1, x0, x1};
-        *filterYs = Sk4i{y0, y0, y1, y1};
-    }
-
-    // Given a sample point, generate a color by bilerping the four filter points.
-    Sk4f bilerpSamplePoint(SkPoint sample) {
-        Sk4i iXs, iYs;
-        filterPoints(sample, &iXs, &iYs);
-        Sk4f px00, px10, px01, px11;
-        fAccessor.get4Pixels(iXs, iYs, &px00, &px10, &px01, &px11);
-        return bilerp4(Sk4f{X(sample) - 0.5f}, Sk4f{Y(sample) - 0.5f}, px00, px10, px01, px11);
-    }
-
-    // Get two pixels at x from row0 and row1.
-    void get2PixelColumn(const void* row0, const void* row1, int x, Sk4f* px0, Sk4f* px1) {
-        *px0 = fAccessor.getPixelFromRow(row0, x);
-        *px1 = fAccessor.getPixelFromRow(row1, x);
-    }
-
-    // |dx| == 0. This code assumes that length is zero.
-    void spanZeroRate(Span span) {
-        SkPoint start; SkScalar length; int count;
-        std::tie(start, length, count) = span;
-        SkASSERT(length == 0.0f);
-
-        // Filter for the blending of the top and bottom pixels.
-        SkScalar filterY = sample_to_filter(Y(start));
-
-        // Generate the four filter points from the sample point start. Generate the row* values.
-        Sk4i iXs, iYs;
-        this->filterPoints(start, &iXs, &iYs);
-        const void* const row0 = fAccessor.row(iYs[0]);
-        const void* const row1 = fAccessor.row(iYs[2]);
-
-        // Get the two pixels that make up the clamping pixel.
-        Sk4f pxTop, pxBottom;
-        this->get2PixelColumn(row0, row1, SkScalarFloorToInt(X(start)), &pxTop, &pxBottom);
-        Sk4f pixel = pxTop * filterY + (1.0f - filterY) * pxBottom;
-
-        while (count >= 4) {
-            fNext->blend4Pixels(pixel, pixel, pixel, pixel);
-            count -= 4;
-        }
-        while (count > 0) {
-            fNext->blendPixel(pixel);
-            count -= 1;
-        }
-    }
-
-    // 0 < |dx| < 1. This code reuses the calculations from previous pixels to reduce
-    // computation. In particular, several destination pixels maybe generated from the same four
-    // source pixels.
-    // In the following code a "part" is a combination of two pixels from the same column of the
-    // filter.
-    void spanSlowRate(Span span) {
-        SkPoint start; SkScalar length; int count;
-        std::tie(start, length, count) = span;
-
-        // Calculate the distance between each sample point.
-        const SkScalar dx = length / (count - 1);
-        SkASSERT(-1.0f < dx && dx < 1.0f && dx != 0.0f);
-
-        // Generate the filter values for the top-left corner.
-        // Note: these values are in filter space; this has implications about how to adjust
-        // these values at each step. For example, as the sample point increases, the filter
-        // value decreases, this is because the filter and position are related by
-        // (1 - (X(sample) - .5)) % 1. The (1 - stuff) causes the filter to move in the opposite
-        // direction of the sample point which is increasing by dx.
-        SkScalar filterX = sample_to_filter(X(start));
-        SkScalar filterY = sample_to_filter(Y(start));
-
-        // Generate the four filter points from the sample point start. Generate the row* values.
-        Sk4i iXs, iYs;
-        this->filterPoints(start, &iXs, &iYs);
-        const void* const row0 = fAccessor.row(iYs[0]);
-        const void* const row1 = fAccessor.row(iYs[2]);
-
-        // Generate part of the filter value at xColumn.
-        auto partAtColumn = [&](int xColumn) {
-            int adjustedColumn = adjust_edge(fXEdgeType, xColumn, fXMax);
-            Sk4f pxTop, pxBottom;
-            this->get2PixelColumn(row0, row1, adjustedColumn, &pxTop, &pxBottom);
-            return pxTop * filterY + (1.0f - filterY) * pxBottom;
-        };
-
-        // The leftPart is made up of two pixels from the left column of the filter, right part
-        // is similar. The top and bottom pixels in the *Part are created as a linear blend of
-        // the top and bottom pixels using filterY. See the partAtColumn function above.
-        Sk4f leftPart  = partAtColumn(iXs[0]);
-        Sk4f rightPart = partAtColumn(iXs[1]);
-
-        // Create a destination color by blending together a left and right part using filterX.
-        auto bilerp = [&](const Sk4f& leftPart, const Sk4f& rightPart) {
-            Sk4f pixel = leftPart * filterX + rightPart * (1.0f - filterX);
-            return check_pixel(pixel);
-        };
-
-        // Send the first pixel to the destination. This simplifies the loop structure so that no
-        // extra pixels are fetched for the last iteration of the loop.
-        fNext->blendPixel(bilerp(leftPart, rightPart));
-        count -= 1;
-
-        if (dx > 0.0f) {
-            // * positive direction - generate destination pixels by sliding the filter from left
-            //                        to right.
-            int rightPartCursor = iXs[1];
-
-            // Advance the filter from left to right. Remember that moving the top-left corner of
-            // the filter to the right actually makes the filter value smaller.
-            auto advanceFilter = [&]() {
-                filterX -= dx;
-                if (filterX <= 0.0f) {
-                    filterX += 1.0f;
-                    leftPart = rightPart;
-                    rightPartCursor += 1;
-                    rightPart = partAtColumn(rightPartCursor);
-                }
-                SkASSERT(0.0f < filterX && filterX <= 1.0f);
-
-                return bilerp(leftPart, rightPart);
-            };
-
-            while (count >= 4) {
-                Sk4f px0 = advanceFilter(),
-                     px1 = advanceFilter(),
-                     px2 = advanceFilter(),
-                     px3 = advanceFilter();
-                fNext->blend4Pixels(px0, px1, px2, px3);
-                count -= 4;
-            }
-
-            while (count > 0) {
-                fNext->blendPixel(advanceFilter());
-                count -= 1;
-            }
-        } else {
-            // * negative direction - generate destination pixels by sliding the filter from
-            //                        right to left.
-            int leftPartCursor = iXs[0];
-
-            // Advance the filter from right to left. Remember that moving the top-left corner of
-            // the filter to the left actually makes the filter value larger.
-            auto advanceFilter = [&]() {
-                // Remember, dx < 0 therefore this adds |dx| to filterX.
-                filterX -= dx;
-                // At this point filterX may be > 1, and needs to be wrapped back on to the filter
-                // interval, and the next column in the filter is calculated.
-                if (filterX > 1.0f) {
-                    filterX -= 1.0f;
-                    rightPart = leftPart;
-                    leftPartCursor -= 1;
-                    leftPart = partAtColumn(leftPartCursor);
-                }
-                SkASSERT(0.0f < filterX && filterX <= 1.0f);
-
-                return bilerp(leftPart, rightPart);
-            };
-
-            while (count >= 4) {
-                Sk4f px0 = advanceFilter(),
-                     px1 = advanceFilter(),
-                     px2 = advanceFilter(),
-                     px3 = advanceFilter();
-                fNext->blend4Pixels(px0, px1, px2, px3);
-                count -= 4;
-            }
-
-            while (count > 0) {
-                fNext->blendPixel(advanceFilter());
-                count -= 1;
-            }
-        }
-    }
-
-    // |dx| == 1. Moving through source space at a rate of 1 source pixel per 1 dst pixel.
-    // Every filter part is used for two destination pixels, and the code can bulk load four
-    // pixels at a time.
-    void spanUnitRate(Span span) {
-        SkPoint start; SkScalar length; int count;
-        std::tie(start, length, count) = span;
-        SkASSERT(SkScalarAbs(length) == (count - 1));
-
-        // Calculate the four filter points of start, and use the two different Y values to
-        // generate the row pointers.
-        Sk4i iXs, iYs;
-        filterPoints(start, &iXs, &iYs);
-        const void* row0 = fAccessor.row(iYs[0]);
-        const void* row1 = fAccessor.row(iYs[2]);
-
-        // Calculate the filter values for the top-left filter element.
-        const SkScalar filterX = sample_to_filter(X(start));
-        const SkScalar filterY = sample_to_filter(Y(start));
-
-        // Generate part of the filter value at xColumn.
-        auto partAtColumn = [&](int xColumn) {
-            int adjustedColumn = adjust_edge(fXEdgeType, xColumn, fXMax);
-            Sk4f pxTop, pxBottom;
-            this->get2PixelColumn(row0, row1, adjustedColumn, &pxTop, &pxBottom);
-            return pxTop * filterY + (1.0f - filterY) * pxBottom;
-        };
-
-        auto get4Parts = [&](int ix, Sk4f* part0, Sk4f* part1, Sk4f* part2, Sk4f* part3) {
-            // Check if the pixels needed are near the edges. If not go fast using bulk pixels,
-            // otherwise be careful.
-            if (0 <= ix && ix <= fXMax - 3) {
-                Sk4f px00, px10, px20, px30,
-                     px01, px11, px21, px31;
-                fAccessor.get4Pixels(row0, ix, &px00, &px10, &px20, &px30);
-                fAccessor.get4Pixels(row1, ix, &px01, &px11, &px21, &px31);
-                *part0 = filterY * px00 + (1.0f - filterY) * px01;
-                *part1 = filterY * px10 + (1.0f - filterY) * px11;
-                *part2 = filterY * px20 + (1.0f - filterY) * px21;
-                *part3 = filterY * px30 + (1.0f - filterY) * px31;
-            } else {
-                *part0 = partAtColumn(ix + 0);
-                *part1 = partAtColumn(ix + 1);
-                *part2 = partAtColumn(ix + 2);
-                *part3 = partAtColumn(ix + 3);
-            }
-        };
-
-        auto bilerp = [&](const Sk4f& part0, const Sk4f& part1) {
-            return part0 * filterX + part1 * (1.0f - filterX);
-        };
-
-        if (length > 0) {
-            // * positive direction - generate destination pixels by sliding the filter from left
-            //                        to right.
-
-            // overlapPart is the filter part from the end of the previous four pixels used at
-            // the start of the next four pixels.
-            Sk4f overlapPart = partAtColumn(iXs[0]);
-            int rightColumnCursor = iXs[1];
-            while (count >= 4) {
-                Sk4f part0, part1, part2, part3;
-                get4Parts(rightColumnCursor, &part0, &part1, &part2, &part3);
-                Sk4f px0 = bilerp(overlapPart, part0);
-                Sk4f px1 = bilerp(part0, part1);
-                Sk4f px2 = bilerp(part1, part2);
-                Sk4f px3 = bilerp(part2, part3);
-                overlapPart = part3;
-                fNext->blend4Pixels(px0, px1, px2, px3);
-                rightColumnCursor += 4;
-                count -= 4;
-            }
-
-            while (count > 0) {
-                Sk4f rightPart = partAtColumn(rightColumnCursor);
-
-                fNext->blendPixel(bilerp(overlapPart, rightPart));
-                overlapPart = rightPart;
-                rightColumnCursor += 1;
-                count -= 1;
-            }
-        } else {
-            // * negative direction - generate destination pixels by sliding the filter from
-            //                        right to left.
-            Sk4f overlapPart = partAtColumn(iXs[1]);
-            int leftColumnCursor = iXs[0];
-
-            while (count >= 4) {
-                Sk4f part0, part1, part2, part3;
-                get4Parts(leftColumnCursor - 3, &part3, &part2, &part1, &part0);
-                Sk4f px0 = bilerp(part0, overlapPart);
-                Sk4f px1 = bilerp(part1, part0);
-                Sk4f px2 = bilerp(part2, part1);
-                Sk4f px3 = bilerp(part3, part2);
-                overlapPart = part3;
-                fNext->blend4Pixels(px0, px1, px2, px3);
-                leftColumnCursor -= 4;
-                count -= 4;
-            }
-
-            while (count > 0) {
-                Sk4f leftPart = partAtColumn(leftColumnCursor);
-
-                fNext->blendPixel(bilerp(leftPart, overlapPart));
-                overlapPart = leftPart;
-                leftColumnCursor -= 1;
-                count -= 1;
-            }
-        }
-    }
-
-    // 1 < |dx| < 2. Going through the source pixels at a faster rate than the dest pixels, but
-    // still slow enough to take advantage of previous calculations.
-    void spanMediumRate(Span span) {
-        SkPoint start; SkScalar length; int count;
-        std::tie(start, length, count) = span;
-
-        // Calculate the distance between each sample point.
-        const SkScalar dx = length / (count - 1);
-        SkASSERT((-2.0f < dx && dx < -1.0f) || (1.0f < dx && dx < 2.0f));
-
-        // Generate the filter values for the top-left corner.
-        // Note: these values are in filter space; this has implications about how to adjust
-        // these values at each step. For example, as the sample point increases, the filter
-        // value decreases, this is because the filter and position are related by
-        // (1 - (X(sample) - .5)) % 1. The (1 - stuff) causes the filter to move in the opposite
-        // direction of the sample point which is increasing by dx.
-        SkScalar filterX = sample_to_filter(X(start));
-        SkScalar filterY = sample_to_filter(Y(start));
-
-        // Generate the four filter points from the sample point start. Generate the row* values.
-        Sk4i iXs, iYs;
-        this->filterPoints(start, &iXs, &iYs);
-        const void* const row0 = fAccessor.row(iYs[0]);
-        const void* const row1 = fAccessor.row(iYs[2]);
-
-        // Generate part of the filter value at xColumn.
-        auto partAtColumn = [&](int xColumn) {
-            int adjustedColumn = adjust_edge(fXEdgeType, xColumn, fXMax);
-            Sk4f pxTop, pxBottom;
-            this->get2PixelColumn(row0, row1, adjustedColumn, &pxTop, &pxBottom);
-            return pxTop * filterY + (1.0f - filterY) * pxBottom;
-        };
-
-        // The leftPart is made up of two pixels from the left column of the filter, right part
-        // is similar. The top and bottom pixels in the *Part are created as a linear blend of
-        // the top and bottom pixels using filterY. See the nextPart function below.
-        Sk4f leftPart  = partAtColumn(iXs[0]);
-        Sk4f rightPart = partAtColumn(iXs[1]);
-
-        // Create a destination color by blending together a left and right part using filterX.
-        auto bilerp = [&](const Sk4f& leftPart, const Sk4f& rightPart) {
-            Sk4f pixel = leftPart * filterX + rightPart * (1.0f - filterX);
-            return check_pixel(pixel);
-        };
-
-        // Send the first pixel to the destination. This simplifies the loop structure so that no
-        // extra pixels are fetched for the last iteration of the loop.
-        fNext->blendPixel(bilerp(leftPart, rightPart));
-        count -= 1;
-
-        if (dx > 0.0f) {
-            // * positive direction - generate destination pixels by sliding the filter from left
-            //                        to right.
-            int rightPartCursor = iXs[1];
-
-            // Advance the filter from left to right. Remember that moving the top-left corner of
-            // the filter to the right actually makes the filter value smaller.
-            auto advanceFilter = [&]() {
-                filterX -= dx;
-                // At this point filterX is less than zero, but might actually be less than -1.
-                if (filterX > -1.0f) {
-                    filterX += 1.0f;
-                    leftPart = rightPart;
-                    rightPartCursor += 1;
-                    rightPart = partAtColumn(rightPartCursor);
-                } else {
-                    filterX += 2.0f;
-                    rightPartCursor += 2;
-                    leftPart = partAtColumn(rightPartCursor - 1);
-                    rightPart = partAtColumn(rightPartCursor);
-                }
-                SkASSERT(0.0f < filterX && filterX <= 1.0f);
-
-                return bilerp(leftPart, rightPart);
-            };
-
-            while (count >= 4) {
-                Sk4f px0 = advanceFilter(),
-                     px1 = advanceFilter(),
-                     px2 = advanceFilter(),
-                     px3 = advanceFilter();
-                fNext->blend4Pixels(px0, px1, px2, px3);
-                count -= 4;
-            }
-
-            while (count > 0) {
-                fNext->blendPixel(advanceFilter());
-                count -= 1;
-            }
-        } else {
-            // * negative direction - generate destination pixels by sliding the filter from
-            //                        right to left.
-            int leftPartCursor = iXs[0];
-
-            auto advanceFilter = [&]() {
-                // Remember, dx < 0 therefore this adds |dx| to filterX.
-                filterX -= dx;
-                // At this point, filterX is greater than one, but may actually be greater than two.
-                if (filterX < 2.0f) {
-                    filterX -= 1.0f;
-                    rightPart = leftPart;
-                    leftPartCursor -= 1;
-                    leftPart = partAtColumn(leftPartCursor);
-                } else {
-                    filterX -= 2.0f;
-                    leftPartCursor -= 2;
-                    rightPart = partAtColumn(leftPartCursor - 1);
-                    leftPart = partAtColumn(leftPartCursor);
-                }
-                SkASSERT(0.0f < filterX && filterX <= 1.0f);
-                return bilerp(leftPart, rightPart);
-            };
-
-            while (count >= 4) {
-                Sk4f px0 = advanceFilter(),
-                     px1 = advanceFilter(),
-                     px2 = advanceFilter(),
-                     px3 = advanceFilter();
-                fNext->blend4Pixels(px0, px1, px2, px3);
-                count -= 4;
-            }
-
-            while (count > 0) {
-                fNext->blendPixel(advanceFilter());
-                count -= 1;
-            }
-        }
-    }
-
-    // We're moving through source space faster than dst (zoomed out),
-    // so we'll never reuse a source pixel or be able to do contiguous loads.
-    void spanFastRate(Span span) {
-        SkPoint start; SkScalar length; int count;
-        std::tie(start, length, count) = span;
-        SkScalar x = X(start);
-        SkScalar y = Y(start);
-
-        SkScalar dx = length / (count - 1);
-        while (count > 0) {
-            fNext->blendPixel(this->bilerpSamplePoint(SkPoint{x, y}));
-            x += dx;
-            count -= 1;
-        }
-    }
-
-    Next* const              fNext;
-    const SkShader::TileMode fXEdgeType;
-    const int                fXMax;
-    const SkShader::TileMode fYEdgeType;
-    const int                fYMax;
-    Accessor                 fAccessor;
-};
-
-}  // namespace
-
-#endif  // SkLinearBitmapPipeline_sampler_DEFINED