Remove (now-dead) SK_LEGACY_SWEEP_GRADIENT code

Behold the first raster pipeline-only gradient!

Change-Id: Ib6f53224e4ff9506aafdae1d2303102fc5235dfc
Reviewed-on: https://skia-review.googlesource.com/17982
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>

2 files changed, 3 insertions, 95 deletions

diff --git a/src/effects/gradients/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index 1e583c2ee0..a138a8e213 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -8,9 +8,6 @@
 #include "SkColorSpaceXformer.h"
 #include "SkSweepGradient.h"
 
-#include <algorithm>
-#include <cmath>
-
 #include "SkPM4fPriv.h"
 #include "SkRasterPipeline.h"
 
@@ -52,84 +49,6 @@ void SkSweepGradient::flatten(SkWriteBuffer& buffer) const {
     buffer.writePoint(fCenter);
 }
 
-SkShaderBase::Context* SkSweepGradient::onMakeContext(
-    const ContextRec& rec, SkArenaAlloc* alloc) const
-{
-    return CheckedMakeContext<SweepGradientContext>(alloc, *this, rec);
-}
-
-SkSweepGradient::SweepGradientContext::SweepGradientContext(
-        const SkSweepGradient& shader, const ContextRec& rec)
-    : INHERITED(shader, rec) {}
-
-bool SkSweepGradient::isRasterPipelineOnly() const {
-#ifdef SK_LEGACY_SWEEP_GRADIENT
-    return false;
-#else
-    return true;
-#endif
-}
-
-//  returns angle in a circle [0..2PI) -> [0..255]
-static unsigned SkATan2_255(float y, float x) {
-    //    static const float g255Over2PI = 255 / (2 * SK_ScalarPI);
-    static const float g255Over2PI = 40.584510488433314f;
-
-    float result = sk_float_atan2(y, x);
-    if (!SkScalarIsFinite(result)) {
-        return 0;
-    }
-    if (result < 0) {
-        result += 2 * SK_ScalarPI;
-    }
-    SkASSERT(result >= 0);
-    // since our value is always >= 0, we can cast to int, which is faster than
-    // calling floorf()
-    int ir = (int)(result * g255Over2PI);
-    SkASSERT(ir >= 0 && ir <= 255);
-    return ir;
-}
-
-void SkSweepGradient::SweepGradientContext::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC,
-                                                      int count) {
-    SkMatrix::MapXYProc proc = fDstToIndexProc;
-    const SkMatrix&     matrix = fDstToIndex;
-    const SkPMColor* SK_RESTRICT cache = fCache->getCache32();
-    int                 toggle = init_dither_toggle(x, y);
-    SkPoint             srcPt;
-
-    if (fDstToIndexClass != kPerspective_MatrixClass) {
-        proc(matrix, SkIntToScalar(x) + SK_ScalarHalf,
-                     SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
-        SkScalar dx, fx = srcPt.fX;
-        SkScalar dy, fy = srcPt.fY;
-
-        if (fDstToIndexClass == kFixedStepInX_MatrixClass) {
-            const auto step = matrix.fixedStepInX(SkIntToScalar(y) + SK_ScalarHalf);
-            dx = step.fX;
-            dy = step.fY;
-        } else {
-            SkASSERT(fDstToIndexClass == kLinear_MatrixClass);
-            dx = matrix.getScaleX();
-            dy = matrix.getSkewY();
-        }
-
-        for (; count > 0; --count) {
-            *dstC++ = cache[toggle + SkATan2_255(fy, fx)];
-            fx += dx;
-            fy += dy;
-            toggle = next_dither_toggle(toggle);
-        }
-    } else {  // perspective case
-        for (int stop = x + count; x < stop; x++) {
-            proc(matrix, SkIntToScalar(x) + SK_ScalarHalf,
-                         SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
-            *dstC++ = cache[toggle + SkATan2_255(srcPt.fY, srcPt.fX)];
-            toggle = next_dither_toggle(toggle);
-        }
-    }
-}
-
 /////////////////////////////////////////////////////////////////////
 
 #if SK_SUPPORT_GPU
diff --git a/src/effects/gradients/SkSweepGradient.h b/src/effects/gradients/SkSweepGradient.h
index b7ed7e5bb9..c30ca4d916 100644
--- a/src/effects/gradients/SkSweepGradient.h
+++ b/src/effects/gradients/SkSweepGradient.h
@@ -10,20 +10,10 @@
 
 #include "SkGradientShaderPriv.h"
 
-class SkSweepGradient : public SkGradientShaderBase {
+class SkSweepGradient final : public SkGradientShaderBase {
 public:
     SkSweepGradient(SkScalar cx, SkScalar cy, const Descriptor&);
 
-    class SweepGradientContext : public SkGradientShaderBase::GradientShaderBaseContext {
-    public:
-        SweepGradientContext(const SkSweepGradient& shader, const ContextRec&);
-
-        void shadeSpan(int x, int y, SkPMColor dstC[], int count) override;
-
-    private:
-        typedef SkGradientShaderBase::GradientShaderBaseContext INHERITED;
-    };
-
     GradientType asAGradient(GradientInfo* info) const override;
 
 #if SK_SUPPORT_GPU
@@ -35,14 +25,13 @@ public:
 
 protected:
     void flatten(SkWriteBuffer& buffer) const override;
-    Context* onMakeContext(const ContextRec&, SkArenaAlloc*) const override;
     sk_sp<SkShader> onMakeColorSpace(SkColorSpaceXformer* xformer) const override;
 
     bool adjustMatrixAndAppendStages(SkArenaAlloc* alloc,
                                      SkMatrix* matrix,
-                                     SkRasterPipeline* p) const final;
+                                     SkRasterPipeline* p) const override;
 
-    bool isRasterPipelineOnly() const final;
+    bool isRasterPipelineOnly() const override { return true; }
 
 private:
     const SkPoint fCenter;