Add new benchmark for testing special hard stop gradient cases

bench/HardStopGradientBench_SpecialHardStops.cpp

Index: bench/HardStopGradientBench_SpecialHardStops.cpp
diff --git a/bench/HardStopGradientBench_SpecialHardStops.cpp b/bench/HardStopGradientBench_SpecialHardStops.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..0a9e23e81b2d0934d0b3e0a1b8cc5eaea9e7d9fc
--- /dev/null
+++ b/bench/HardStopGradientBench_SpecialHardStops.cpp
@@ -0,0 +1,131 @@
+/*
+ * 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 "Benchmark.h"
+
+#include "SkCanvas.h"
+#include "SkShader.h"
+#include "SkGradientShader.h"
+#include "SkString.h"
+#include "SkColor.h"
+#include "SkPaint.h"
+
+enum class Kind {
+    k001,
+    k011,
+    kCentered,
+};
+
+const char* kindstr(Kind k) {
+    switch (k) {
+        case Kind::k001:
+            return "001";
+        case Kind::k011:
+            return "011";
+        case Kind::kCentered:
+            return "centered";
+        default:
+            return "Invalid kind";
+    }
+}
+
+class HardStopGradientBench_SpecialHardStops : public Benchmark {
+public:
+    HardStopGradientBench_SpecialHardStops(int w, int h, Kind kind) {
+        fW    = w;
+        fH    = h;
+        fKind = kind;
+
+        fName.printf("hardstop_special_%03dx%03d_%s", fW, fH, kindstr(fKind));
+    }
+
+    const char* onGetName() override {
+        return fName.c_str();
+    }
+
+    SkIPoint onGetSize() override {
+        return SkIPoint::Make(fW, fH);
+    }
+
+    void onPreDraw(SkCanvas* canvas) override {
+        SkPoint points[2] = {
+            SkPoint::Make(   0.0f, fH/2.0f),
+            SkPoint::Make(fW+2.0f, fH/2.0f),
+        };
+
+        SkColor colors[4] = {
+            SK_ColorRED,
+            SK_ColorGREEN,
+            SK_ColorBLUE,
+            SK_ColorYELLOW,
+        };
+
+        SkScalar pos_001[3] = {
+            0.0f,
+            0.0f,
+            1.0f,
+        };
+
+        SkScalar pos_011[3] = {
+            0.0f,
+            1.0f,
+            1.0f,
+        };
+
+        SkScalar pos_centered[4] = {
+            0.0f,
+            0.5f,
+            0.5f,
+            1.0f,
+        };
+
+        SkScalar* positions = fKind == Kind::k001 ? pos_001 :
+                              fKind == Kind::k011 ? pos_011 : 
+                                                    pos_centered;
+
+        int count = fKind == Kind::kCentered ? 4 : 3;
+
+        fPaint.setShader(SkGradientShader::MakeLinear(points,
+                                                      colors,
+                                                      positions,
+                                                      count,
+                                                      SkShader::kClamp_TileMode,
+                                                      0,
+                                                      nullptr));
+    }
+
+    void onDraw(int loops, SkCanvas* canvas) override {
+        for (int i = 0; i < loops; i++) {
+            canvas->drawPaint(fPaint);
+        }
+    }
+
+private:
+    SkString fName;
+    int      fW;
+    int      fH;
+    Kind     fKind;
+    SkPaint  fPaint; 
+};
+
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(100, 100, Kind::k001););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(200, 200, Kind::k001););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(300, 300, Kind::k001););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(400, 400, Kind::k001););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(500, 500, Kind::k001););
+
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(100, 100, Kind::k011););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(200, 200, Kind::k011););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(300, 300, Kind::k011););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(400, 400, Kind::k011););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(500, 500, Kind::k011););
+
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(100, 100, Kind::kCentered););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(200, 200, Kind::kCentered););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(300, 300, Kind::kCentered););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(400, 400, Kind::kCentered););
+DEF_BENCH(return new HardStopGradientBench_SpecialHardStops(500, 500, Kind::kCentered););