add bench for cubicmap

Bug: skia:
Change-Id: Ie88de751e6f889eed02fba1d13e712345256ac72
Reviewed-on: https://skia-review.googlesource.com/147210
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>

bench/CubicMapBench.cpp

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2018 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 "SkCubicMap.h"
+
+class CubicMapBench : public Benchmark {
+public:
+    CubicMapBench(SkPoint p1, SkPoint p2) : fCMap(p1, p2) {
+        fName.printf("cubicmap_%g_%g_%g_%g", p1.fX, p1.fY, p2.fX, p2.fY);
+    }
+
+    bool isSuitableFor(Backend backend) override {
+        return backend == kNonRendering_Backend;
+    }
+
+    const char* onGetName() override {
+        return fName.c_str();
+    }
+
+    void onDraw(int loops, SkCanvas*) override {
+        for (int i = 0; i < loops * 100; ++i) {
+            for (SkScalar x = 0; x <= 1; x += 1.0f / 512) {
+                fCMap.computeYFromX(x);
+            }
+        }
+    }
+
+private:
+    SkCubicMap  fCMap;
+    SkString    fName;
+
+    typedef Benchmark INHERITED;
+};
+
+DEF_BENCH( return new CubicMapBench({1, 0}, {0,0}); )
+DEF_BENCH( return new CubicMapBench({1, 0}, {0,1}); )
+DEF_BENCH( return new CubicMapBench({1, 0}, {1,0}); )
+DEF_BENCH( return new CubicMapBench({1, 0}, {1,1}); )
+
+DEF_BENCH( return new CubicMapBench({0, 1}, {0,0}); )
+DEF_BENCH( return new CubicMapBench({0, 1}, {0,1}); )
+DEF_BENCH( return new CubicMapBench({0, 1}, {1,0}); )
+DEF_BENCH( return new CubicMapBench({0, 1}, {1,1}); )
+
+DEF_BENCH( return new CubicMapBench({0, 0}, {1,1}); )
+DEF_BENCH( return new CubicMapBench({1, 1}, {0,0}); )

gn/bench.gni

@@ -39,6 +39,7 @@ bench_sources = [
   "$_bench/ControlBench.cpp",
   "$_bench/CoverageBench.cpp",
   "$_bench/CubicKLMBench.cpp",
+  "$_bench/CubicMapBench.cpp",
   "$_bench/DashBench.cpp",
   "$_bench/DisplacementBench.cpp",
   "$_bench/DrawBitmapAABench.cpp",