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, 139 insertions, 0 deletions

diff --git a/tools/viewer/StatsLayer.cpp b/tools/viewer/StatsLayer.cpp
new file mode 100644
index 0000000000..75226fd7db
--- /dev/null
+++ b/tools/viewer/StatsLayer.cpp
@@ -0,0 +1,139 @@
+/*
+* Copyright 2017 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+
+#include "StatsLayer.h"
+
+#include "SkCanvas.h"
+#include "SkString.h"
+#include "SkTime.h"
+
+StatsLayer::StatsLayer()
+    : fCurrentMeasurement(0)
+    , fCumulativeMeasurementTime(0)
+    , fCumulativeMeasurementCount(0) {}
+
+void StatsLayer::resetMeasurements() {
+    for (int i = 0; i < fTimers.count(); ++i) {
+        memset(fTimers[i].fTimes, 0, sizeof(fTimers[i].fTimes));
+    }
+    fCurrentMeasurement = 0;
+    fCumulativeMeasurementTime = 0;
+    fCumulativeMeasurementCount = 0;
+}
+
+StatsLayer::Timer StatsLayer::addTimer(const char* label, SkColor color, SkColor labelColor) {
+    Timer newTimer = fTimers.count();
+    TimerData& newData = fTimers.push_back();
+    memset(newData.fTimes, 0, sizeof(newData.fTimes));
+    newData.fLabel = label;
+    newData.fColor = color;
+    newData.fLabelColor = labelColor ? labelColor : color;
+    return newTimer;
+}
+
+void StatsLayer::beginTiming(Timer timer) {
+    fTimers[timer].fTimes[fCurrentMeasurement] -= SkTime::GetMSecs();
+}
+
+void StatsLayer::endTiming(Timer timer) {
+    fTimers[timer].fTimes[fCurrentMeasurement] += SkTime::GetMSecs();
+}
+
+double StatsLayer::getLastTime(Timer timer) {
+    int idx = (fCurrentMeasurement + (kMeasurementCount - 1)) & (kMeasurementCount - 1);
+    return fTimers[timer].fTimes[idx];
+}
+
+void StatsLayer::onPaint(SkCanvas* canvas) {
+    // Advance our timing bookkeeping
+    for (int i = 0; i < fTimers.count(); ++i) {
+        fCumulativeMeasurementTime += fTimers[i].fTimes[fCurrentMeasurement];
+    }
+    fCumulativeMeasurementCount++;
+    fCurrentMeasurement = (fCurrentMeasurement + 1) & (kMeasurementCount - 1);
+    SkASSERT(fCurrentMeasurement < kMeasurementCount);
+    for (int i = 0; i < fTimers.count(); ++i) {
+        fTimers[i].fTimes[fCurrentMeasurement] = 0;
+    }
+
+    // Now draw everything
+    static const float kPixelPerMS = 2.0f;
+    static const int kDisplayWidth = 192;
+    static const int kGraphHeight = 100;
+    static const int kTextHeight = 60;
+    static const int kDisplayHeight = kGraphHeight + kTextHeight;
+    static const int kDisplayPadding = 10;
+    static const int kGraphPadding = 3;
+    static const SkScalar kBaseMS = 1000.f / 60.f;  // ms/frame to hit 60 fps
+
+    SkISize canvasSize = canvas->getBaseLayerSize();
+    SkRect rect = SkRect::MakeXYWH(SkIntToScalar(canvasSize.fWidth-kDisplayWidth-kDisplayPadding),
+                                   SkIntToScalar(kDisplayPadding),
+                                   SkIntToScalar(kDisplayWidth), SkIntToScalar(kDisplayHeight));
+    SkPaint paint;
+    canvas->save();
+
+    paint.setColor(SK_ColorBLACK);
+    canvas->drawRect(rect, paint);
+    // draw the 16ms line
+    paint.setColor(SK_ColorLTGRAY);
+    canvas->drawLine(rect.fLeft, rect.fBottom - kBaseMS*kPixelPerMS,
+                     rect.fRight, rect.fBottom - kBaseMS*kPixelPerMS, paint);
+    paint.setColor(SK_ColorRED);
+    paint.setStyle(SkPaint::kStroke_Style);
+    canvas->drawRect(rect, paint);
+    paint.setStyle(SkPaint::kFill_Style);
+
+    int x = SkScalarTruncToInt(rect.fLeft) + kGraphPadding;
+    const int xStep = 3;
+    int i = fCurrentMeasurement;
+    double ms = 0;
+    SkTDArray<double> sumTimes;
+    sumTimes.setCount(fTimers.count());
+    memset(sumTimes.begin(), 0, sumTimes.count() * sizeof(double));
+    int count = 0;
+    do {
+        int startY = SkScalarTruncToInt(rect.fBottom);
+        double inc = 0;
+        for (int timer = 0; timer < fTimers.count(); ++timer) {
+            int height = (int)(fTimers[timer].fTimes[i] * kPixelPerMS + 0.5);
+            int endY = SkTMax(startY - height, kDisplayPadding + kTextHeight);
+            paint.setColor(fTimers[timer].fColor);
+            canvas->drawLine(SkIntToScalar(x), SkIntToScalar(startY),
+                             SkIntToScalar(x), SkIntToScalar(endY), paint);
+            startY = endY;
+            inc += fTimers[timer].fTimes[i];
+            sumTimes[timer] += fTimers[timer].fTimes[i];
+        }
+
+        if (inc > 0) {
+            ms += inc;
+            ++count;
+        }
+
+        i++;
+        i &= (kMeasurementCount - 1);  // fast mod
+        x += xStep;
+    } while (i != fCurrentMeasurement);
+
+    paint.setTextSize(16);
+    SkString mainString;
+    mainString.appendf("%4.3f ms -> %4.3f ms", ms / SkTMax(1, count),
+                  fCumulativeMeasurementTime / SkTMax(1, fCumulativeMeasurementCount));
+    paint.setColor(SK_ColorWHITE);
+    canvas->drawString(mainString.c_str(), rect.fLeft + 3, rect.fTop + 14, paint);
+
+    for (int timer = 0; timer < fTimers.count(); ++timer) {
+        SkString str;
+        str.appendf("%s: %4.3f ms", fTimers[timer].fLabel.c_str(),
+                    sumTimes[timer] / SkTMax(1, count));
+        paint.setColor(fTimers[timer].fLabelColor);
+        canvas->drawString(str, rect.fLeft + 3, rect.fTop + 28 + (14 * timer), paint);
+    }
+
+    canvas->restore();
+}