Move stats code to new layer (with configurable list of timers)

Bug: skia:
Change-Id: I3ca5c8c7047309983018339ec7b71b9aea5ee786
Reviewed-on: https://skia-review.googlesource.com/86921
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/tools/viewer/StatsLayer.h b/tools/viewer/StatsLayer.h
new file mode 100644
index 0000000000..a99bd43a99
--- /dev/null
+++ b/tools/viewer/StatsLayer.h
@@ -0,0 +1,43 @@
+/*
+* Copyright 2017 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+
+#ifndef StatsLayer_DEFINED
+#define StatsLayer_DEFINED
+
+#include "SkColor.h"
+#include "SkString.h"
+#include "sk_app/Window.h"
+
+class StatsLayer : public sk_app::Window::Layer {
+public:
+    StatsLayer();
+    void resetMeasurements();
+
+    typedef int Timer;
+
+    Timer addTimer(const char* label, SkColor color, SkColor labelColor = 0);
+    void beginTiming(Timer);
+    void endTiming(Timer);
+    double getLastTime(Timer);
+
+    void onPaint(SkCanvas* canvas) override;
+
+private:
+    static const int kMeasurementCount = 1 << 6;  // should be power of 2 for fast mod
+    struct TimerData {
+        double fTimes[kMeasurementCount];
+        SkString fLabel;
+        SkColor fColor;
+        SkColor fLabelColor;
+    };
+    SkTArray<TimerData> fTimers;
+    int fCurrentMeasurement;
+    double fCumulativeMeasurementTime;
+    int fCumulativeMeasurementCount;
+};
+
+#endif