Revert "Remove deadcode for sRGB image shading."

This reverts commit 51f6a0f89e55b2c0f102aa7963320a23c586e71d.

Reason for revert: try to fix chrome roll

Original change's description:
> 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>

TBR=mtklein@chromium.org,mtklein@google.com,herb@google.com,reed@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I90409a08409177d9dc3b094d736af0fdaf7d6cdd
Reviewed-on: https://skia-review.googlesource.com/20824
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 257 insertions, 0 deletions

diff --git a/tests/SkLinearBitmapPipelineTest.cpp b/tests/SkLinearBitmapPipelineTest.cpp
new file mode 100644
index 0000000000..4b54641eca
--- /dev/null
+++ b/tests/SkLinearBitmapPipelineTest.cpp
@@ -0,0 +1,257 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <algorithm>
+#include <array>
+#include <tuple>
+#include <vector>
+#include "SkLinearBitmapPipeline.h"
+#include "SkColor.h"
+#include "SkNx.h"
+#include "SkPoint.h"
+#include "SkPM4f.h"
+#include "Test.h"
+#include "SkLinearBitmapPipeline_tile.h"
+
+
+DEF_TEST(LBPBilerpEdge, reporter) {
+
+}
+
+static SkString dump(SkScalar cut, Span prefix, Span remainder) {
+    SkPoint prefixStart; SkScalar prefixLen; int prefixCount;
+    std::tie(prefixStart, prefixLen, prefixCount) = prefix;
+    SkPoint remainderStart; SkScalar remainderLen; int remainderCount;
+    std::tie(remainderStart, remainderLen, remainderCount) = remainder;
+    return SkStringPrintf("cut: %f prefix: (%f, %f), %f, %d - remainder: (%f, %f), %f, %d",
+                          cut,
+                          prefixStart.fX, prefixStart.fY, prefixLen, prefixCount,
+                          remainderStart.fX, remainderStart.fY, remainderLen, remainderCount);
+}
+
+static void check_span_result(
+    skiatest::Reporter* reporter,
+    Span span, SkScalar dx, SkScalar cut, SkPoint start, SkScalar len, int count) {
+    SkPoint originalStart; SkScalar originalLen; int originalCount;
+    std::tie(originalStart, originalLen, originalCount) = span;
+
+    Span prefix = span.breakAt(cut, dx);
+
+    SkPoint prefixStart; SkScalar prefixLen; int prefixCount;
+    std::tie(prefixStart, prefixLen, prefixCount) = prefix;
+
+    REPORTER_ASSERT_MESSAGE(reporter, prefixStart == start, dump(cut, prefix, span));
+    REPORTER_ASSERT_MESSAGE(reporter, prefixLen == len, dump(cut, prefix, span));
+    REPORTER_ASSERT_MESSAGE(reporter, prefixCount == count, dump(cut, prefix, span));
+    SkPoint expectedRemainderStart;
+    SkScalar expectedRemainderLen;
+    int expectedRemainderCount;
+    if (prefix.isEmpty()) {
+        expectedRemainderStart = originalStart;
+        expectedRemainderLen = originalLen;
+        expectedRemainderCount = originalCount;
+    } else {
+        expectedRemainderStart = SkPoint::Make(originalStart.fX + prefixLen + dx, originalStart.fY);
+        expectedRemainderLen = originalLen - prefixLen - dx;
+        expectedRemainderCount = originalCount - prefixCount;
+    }
+
+    if (!span.isEmpty()) {
+        SkPoint remainderStart;
+        SkScalar remainderLen;
+        int remainderCount;
+        std::tie(remainderStart, remainderLen, remainderCount) = span;
+        // Remainder span
+        REPORTER_ASSERT_MESSAGE(reporter, expectedRemainderStart == remainderStart,
+                                dump(cut, prefix, span));
+        REPORTER_ASSERT_MESSAGE(reporter,
+                                expectedRemainderLen == remainderLen,
+                                dump(cut, prefix, span));
+        REPORTER_ASSERT_MESSAGE(reporter,
+                                expectedRemainderCount == remainderCount,
+                                dump(cut, prefix, span));
+    }
+}
+
+DEF_TEST(LBPSpanOps, reporter) {
+    {
+        SkScalar dx = 1.0f;
+        SkPoint start = SkPoint::Make(-5, -5);
+        Span span{start, 9.0f, 10};
+        check_span_result(reporter, span, dx,  0.0f, start, 4.0f, 5);
+        check_span_result(reporter, span, dx, -6.0f, SkPoint::Make(0, 0), 0.0f, 0);
+        check_span_result(reporter, span, dx, -5.0f, SkPoint::Make(0, 0), 0.0f, 0);
+        check_span_result(reporter, span, dx, -4.0f, SkPoint::Make(-5, -5), 0.0f, 1);
+        check_span_result(reporter, span, dx,  4.0f, SkPoint::Make(-5, -5), 8.0f, 9);
+        check_span_result(reporter, span, dx,  5.0f, SkPoint::Make(-5, -5), 9.0f, 10);
+        check_span_result(reporter, span, dx,  6.0f, SkPoint::Make(-5, -5), 9.0f, 10);
+    }
+    {
+        SkScalar dx = -1.0f;
+        SkPoint start = SkPoint::Make(5, 5);
+        Span span{start, -9.0f, 10};
+        check_span_result(reporter, span, dx,  0.0f, start, -5.0f, 6);
+        check_span_result(reporter, span, dx, -6.0f, SkPoint::Make(5, 5), -9.0f, 10);
+        check_span_result(reporter, span, dx, -5.0f, SkPoint::Make(5, 5), -9.0f, 10);
+        check_span_result(reporter, span, dx, -4.0f, SkPoint::Make(5, 5), -9.0f, 10);
+        check_span_result(reporter, span, dx,  4.0f, SkPoint::Make(5, 5), -1.0f, 2);
+        check_span_result(reporter, span, dx,  5.0f, SkPoint::Make(5, 5), 0.0f, 1);
+        check_span_result(reporter, span, dx,  6.0f, SkPoint::Make(0, 0), 0.0f, 0);
+    }
+}
+
+DEF_TEST(LBPBilerpSpanOps, reporter) {
+
+}
+
+template <typename XTiler, typename YTiler>
+static bool compare_tiler_case(
+    XTiler& xTiler, YTiler& yTiler, Span span, skiatest::Reporter* reporter) {
+    Span originalSpan = span;
+    std::vector<SkPoint> listPoints;
+    std::vector<SkPoint> spanPoints;
+    struct Sink {
+        void SK_VECTORCALL pointListFew(int n, Sk4s xs, Sk4s ys) {
+            SkASSERT(0 < n && n < 4);
+            if (n >= 1) storePoint({xs[0], ys[0]});
+            if (n >= 2) storePoint({xs[1], ys[1]});
+            if (n >= 3) storePoint({xs[2], ys[2]});
+        }
+
+        void SK_VECTORCALL pointList4(Sk4s xs, Sk4s ys) {
+            storePoint({xs[0], ys[0]});
+            storePoint({xs[1], ys[1]});
+            storePoint({xs[2], ys[2]});
+            storePoint({xs[3], ys[3]});
+        }
+
+        void pointSpan(Span span) {
+            span_fallback(span, this);
+        }
+
+        void storePoint(SkPoint pt) {
+            fPoints->push_back({SkScalarFloorToScalar(X(pt)), SkScalarFloorToScalar(Y(pt))});
+        }
+
+        std::vector<SkPoint>* fPoints;
+    };
+
+    Sink listSink = {&listPoints};
+    Sink spanSink = {&spanPoints};
+
+    SkPoint start; SkScalar length; int count;
+    std::tie(start, length, count) = span;
+
+    SkScalar dx = length / (count - 1);
+    Sk4f xs = Sk4f{X(start)} + Sk4f{0.0f, dx, 2 * dx, 3 * dx};
+    Sk4f ys = Sk4f{Y(start)};
+    while (count >= 4) {
+        Sk4f txs = xs;
+        Sk4f tys = ys;
+        xTiler.tileXPoints(&txs);
+        yTiler.tileYPoints(&tys);
+        listSink.pointList4(txs, tys);
+        xs = xs + 4.0f * dx;
+        count -= 4;
+    }
+    if (count > 0) {
+        xTiler.tileXPoints(&xs);
+        yTiler.tileYPoints(&ys);
+        listSink.pointListFew(count, xs, ys);
+    }
+
+    std::tie(start, length, count) = originalSpan;
+    SkScalar x = X(start);
+    SkScalar y = yTiler.tileY(Y(start));
+    Span yAdjustedSpan{{x, y}, length, count};
+
+    bool handledSpan = xTiler.maybeProcessSpan(yAdjustedSpan, &spanSink);
+    if (handledSpan) {
+        auto firstNotTheSame = std::mismatch(
+            listPoints.begin(), listPoints.end(), spanPoints.begin());
+        if (firstNotTheSame.first != listSink.fPoints->end()) {
+            auto element = std::distance(listPoints.begin(), firstNotTheSame.first);
+            SkASSERT(element >= 0);
+            std::tie(start, length, count) = originalSpan;
+            ERRORF(reporter, "Span: {%f, %f}, %f, %d", start.fX, start.fY, length, count);
+            ERRORF(reporter, "Size points: %d, size span: %d",
+                   listPoints.size(), spanPoints.size());
+            if ((unsigned)element >= spanPoints.size()) {
+                ERRORF(reporter, "Size points: %d, size span: %d",
+                       listPoints.size(), spanPoints.size());
+                // Mismatch off the end
+                ERRORF(reporter,
+                       "The mismatch is at position %d and has value %f, %f - it is off the end "
+                           "of the other.",
+                       element, X(*firstNotTheSame.first), Y(*firstNotTheSame.first));
+            } else {
+                ERRORF(reporter,
+                       "Mismatch at %d - points: %f, %f - span: %f, %f",
+                       element, listPoints[element].fX, listPoints[element].fY,
+                       spanPoints[element].fX, spanPoints[element].fY);
+            }
+            SkFAIL("aha");
+        }
+    }
+    return true;
+}
+
+template <typename XTiler, typename YTiler>
+static bool compare_tiler_spans(int width, int height, skiatest::Reporter* reporter) {
+    XTiler xTiler{width};
+    YTiler yTiler{height};
+    INFOF(reporter, "w: %d, h: %d \n", width, height);
+    std::array<int, 8> interestingX {{-5, -1, 0, 1, width - 1, width, width + 1, width + 5}};
+    std::array<int, 8> interestingY {{-5, -1, 0, 1, height - 1, height, height + 1, height + 5}};
+    std::array<int, 6> interestingCount {{1, 2, 3, 4, 5, 10}};
+    std::array<SkScalar, 7> interestingScale {{0.0f, 1.0f, 0.5f, 2.1f, -2.1f, -1.0f, -0.5f}};
+    for (auto scale : interestingScale) {
+        for (auto startX : interestingX) {
+            for (auto count : interestingCount) {
+                for (auto y : interestingY) {
+                    Span span{
+                        SkPoint::Make((SkScalar)startX, (SkScalar)y), (count-1.0f) * scale, count};
+                    if (!compare_tiler_case(xTiler, yTiler, span, reporter)) {
+                        return false;
+                    }
+                }
+            }
+        }
+    }
+    return true;
+}
+
+template <typename XTiler, typename YTiler>
+static void test_tiler(skiatest::Reporter* reporter) {
+    std::array<int, 6> interestingSize {{1, 2, 3, 4, 5, 10}};
+    for (auto width : interestingSize) {
+        for (auto height : interestingSize) {
+            if (!compare_tiler_spans<XTiler, YTiler>(width, height, reporter)) { return; }
+        }
+    }
+}
+/*
+DEF_TEST(LBPStrategyClampTile, reporter) {
+#if 0
+    ClampStrategy tiler{SkSize::Make(1, 1)};
+    Span span{SkPoint::Make(0, -5), 1.0f, 2};
+    compare_tiler_case<ClampStrategy>(tiler, span, reporter);
+#else
+    test_tiler<XClampStrategy, YClampStrategy>(reporter);
+#endif
+}
+
+DEF_TEST(LBPStrategyRepeatTile, reporter) {
+#if 0
+    RepeatStrategy tiler{SkSize::Make(3, 1)};
+    Span span{SkPoint::Make(-5, -5), 20 * 2.1f, 100};
+    compare_tiler_case<RepeatStrategy>(tiler, span, reporter);
+#else
+    test_tiler<XRepeatStrategy, YRepeatStrategy>(reporter);
+#endif
+}
+*/