Add viewer mode to VisualBench.

tools/VisualBench/VisualInteractiveModule.cpp

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ */
+
+#include "VisualInteractiveModule.h"
+
+#include "ProcStats.h"
+#include "SkApplication.h"
+#include "SkCanvas.h"
+#include "SkCommandLineFlags.h"
+#include "SkForceLinking.h"
+#include "SkGraphics.h"
+#include "SkGr.h"
+#include "SkImageDecoder.h"
+#include "SkOSFile.h"
+#include "SkStream.h"
+#include "Stats.h"
+#include "gl/GrGLInterface.h"
+
+__SK_FORCE_IMAGE_DECODER_LINKING;
+
+static const int kGpuFrameLag = 5;
+static const int kFrames = 5;
+static const double kLoopMs = 5;
+
+VisualInteractiveModule::VisualInteractiveModule(VisualBench* owner)
+    : fCurrentFrame(0)
+    , fLoops(1)
+    , fState(kPreWarmLoops_State)
+    , fCurrentMeasurement(0)
+    , fBenchmark(nullptr)
+    , fOwner(SkRef(owner)) {
+    fBenchmarkStream.reset(new VisualBenchmarkStream);
+
+    memset(fMeasurements, 0, sizeof(fMeasurements));
+}
+
+inline void VisualInteractiveModule::renderFrame(SkCanvas* canvas) {
+    fBenchmark->draw(fLoops, canvas);
+    this->drawStats(canvas);
+    canvas->flush();
+    fOwner->present();
+}
+
+void VisualInteractiveModule::drawStats(SkCanvas* canvas) {
+    const float kPixelPerMs = 2.0f;
+    const int kDisplayWidth = 130;
+    const int kDisplayHeight = 100;
+    const int kPadding = 10;
+
+    SkISize canvasSize = canvas->getDeviceSize();
+    SkRect rect = SkRect::MakeXYWH(SkIntToScalar(canvasSize.fWidth - kDisplayWidth - kPadding),
+                                   SkIntToScalar(kPadding),
+                                   SkIntToScalar(kDisplayWidth), SkIntToScalar(kDisplayHeight));
+    SkPaint paint;
+    canvas->clipRect(rect);
+    paint.setColor(SK_ColorBLACK);
+    canvas->drawRect(rect, paint);
+    // draw the 16ms line
+    paint.setColor(SK_ColorLTGRAY);
+    canvas->drawLine(rect.fLeft, rect.fBottom - 16.f*kPixelPerMs, 

[joshualitt, 2015/09/14 14:07:45]

I wonder if we want to make this 1000/60 'exactly.'  also might be kind of nice
to have a GetFrameTimeMs(int FramesPerSecond).

[jvanverth1, 2015/09/14 16:21:38]

Done.

+                     rect.fRight, rect.fBottom - 16.f*kPixelPerMs, paint);
+    paint.setColor(SK_ColorRED);
+    paint.setStyle(SkPaint::kStroke_Style);
+    canvas->drawRect(rect, paint);
+
+    int x = SkScalarTruncToInt(rect.fLeft) + 3;

[joshualitt, 2015/09/14 14:07:45]

Is this some kind of padding?

[jvanverth1, 2015/09/14 16:21:38]

Done.

+    const int xStep = 2;
+    const int startY = SkScalarTruncToInt(rect.fBottom);
+    int i = fCurrentMeasurement;
+    do {
+        int endY = startY - (int)(fMeasurements[i] * kPixelPerMs + 0.5);

[joshualitt, 2015/09/14 14:07:45]

0.5?

[jvanverth1, 2015/09/14 16:21:38]

Added comment

+        canvas->drawLine(SkIntToScalar(x), SkIntToScalar(startY), 
+                         SkIntToScalar(x), SkIntToScalar(endY), paint);
+        i++;
+        i &= (kMeasurementCount - 1);  // fast mod
+        x += xStep;
+    } while (i != fCurrentMeasurement);
+
+}
+
+bool VisualInteractiveModule::advanceRecordIfNecessary(SkCanvas* canvas) {
+    if (fBenchmark) {
+        return true;
+    }
+
+    fBenchmark.reset(fBenchmarkStream->next());
+    if (!fBenchmark) {
+        return false;
+    }
+
+    // clear both buffers
+    canvas->clear(0xffffffff);
+    canvas->flush();
+    fOwner->present();
+    canvas->clear(0xffffffff);

[joshualitt, 2015/09/14 14:07:45]

Hmm, might be nice to have a static function on VisualBench which can do this
clear.  Possibly also taking an N for single, double, or triple buffering.

[jvanverth1, 2015/09/14 16:21:38]

How do I know what the buffer setup is?

+
+    fBenchmark->preDraw();
+
+    return true;
+}
+
+void VisualInteractiveModule::draw(SkCanvas* canvas) {
+    if (!this->advanceRecordIfNecessary(canvas)) {
+        SkDebugf("Exiting VisualBench successfully\n");
+        fOwner->closeWindow();
+        return;
+    }
+    this->renderFrame(canvas);
+    switch (fState) {
+        case kPreWarmLoopsPerCanvasPreDraw_State: {
+            this->perCanvasPreDraw(canvas, kPreWarmLoops_State);
+            break;
+        }
+        case kPreWarmLoops_State: {
+            this->preWarm(kTuneLoops_State);
+            break;
+        }
+        case kTuneLoops_State: {
+            this->tuneLoops(canvas);
+            break;
+        }
+        case kPreTiming_State: {
+            fBenchmark->perCanvasPreDraw(canvas);
+            fCurrentFrame = 0;
+            fTimer.start();
+            fState = kTiming_State;
+            // fall to next state
+        }
+        case kTiming_State: {
+            this->timing(canvas);
+            break;
+        }
+        case kAdvance_State: {
+            this->postDraw(canvas);
+            this->nextState(kPreWarmLoopsPerCanvasPreDraw_State);
+            break;
+        }
+    }
+}
+
+inline void VisualInteractiveModule::nextState(State nextState) {
+    fState = nextState;
+}
+
+void VisualInteractiveModule::perCanvasPreDraw(SkCanvas* canvas, State nextState) {
+    fBenchmark->perCanvasPreDraw(canvas);
+    fCurrentFrame = 0;
+    this->nextState(nextState);
+}
+
+void VisualInteractiveModule::preWarm(State nextState) {
+    if (fCurrentFrame >= kGpuFrameLag) {
+        // we currently time across all frames to make sure we capture all GPU work
+        this->nextState(nextState);
+        fCurrentFrame = 0;
+        fTimer.start();
+    } else {
+        fCurrentFrame++;
+    }
+}
+
+inline double VisualInteractiveModule::elapsed() {
+    fTimer.end();
+    return fTimer.fWall;
+}
+
+void VisualInteractiveModule::resetTimingState() {
+    fCurrentFrame = 0;
+    fTimer = WallTimer();
+    fOwner->reset();
+}
+
+void VisualInteractiveModule::scaleLoops(double elapsedMs) {
+    // Scale back the number of loops
+    fLoops = (int)ceil(fLoops * kLoopMs / elapsedMs);
+}
+
+inline void VisualInteractiveModule::tuneLoops(SkCanvas* canvas) {

[joshualitt, 2015/09/14 14:07:45]

it'd be nice to figure out how to share this code, but its not really necessary
for this change.

[jvanverth1, 2015/09/14 16:21:38]

Acknowledged.

+    if (1 << 30 == fLoops) {
+        // We're about to wrap.  Something's wrong with the bench.
+        SkDebugf("InnerLoops wrapped\n");
+        fLoops = 0;
+    } else {
+        double elapsedMs = this->elapsed();
+        if (elapsedMs > kLoopMs) {
+            this->scaleLoops(elapsedMs);
+            fBenchmark->perCanvasPostDraw(canvas);
+            this->nextState(kPreTiming_State);
+        } else {
+            fLoops *= 2;
+            this->nextState(kPreWarmLoops_State);
+        }
+        this->resetTimingState();
+    }
+}
+
+void VisualInteractiveModule::recordMeasurement() {
+    double measurement = this->elapsed() / (kFrames * fLoops);
+    fMeasurements[fCurrentMeasurement++] = measurement;
+    fCurrentMeasurement &= (kMeasurementCount-1);  // fast mod
+    SkASSERT(fCurrentMeasurement < kMeasurementCount);
+}
+
+void VisualInteractiveModule::postDraw(SkCanvas* canvas) {
+    fBenchmark->perCanvasPostDraw(canvas);
+    fBenchmark.reset(nullptr);
+    fLoops = 1;
+}
+
+inline void VisualInteractiveModule::timing(SkCanvas* canvas) {
+    if (fCurrentFrame >= kFrames) {
+        this->recordMeasurement();
+        fTimer.start();
+        fCurrentFrame = 0;
+    } else {
+        fCurrentFrame++;
+    }
+}
+
+bool VisualInteractiveModule::onHandleChar(SkUnichar c) {
+    if (' ' == c) {
+        this->nextState(kAdvance_State);
+    }
+
+    return true;
+}