Add chart bench.

Review URL: https://codereview.appspot.com/7368051

git-svn-id: http://skia.googlecode.com/svn/trunk@7821 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 202 insertions, 0 deletions

diff --git a/bench/ChartBench.cpp b/bench/ChartBench.cpp
new file mode 100644
index 0000000000..0693f49da0
--- /dev/null
+++ b/bench/ChartBench.cpp
@@ -0,0 +1,202 @@
+
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBenchmark.h"
+#include "SkCanvas.h"
+#include "SkPaint.h"
+#include "SkRandom.h"
+
+/**
+ * This is a conversion of samplecode/SampleChart.cpp into a bench. It sure would be nice to be able
+ * to write one subclass that can be a GM, bench, and/or Sample.
+ */
+
+namespace {
+
+// Generates y values for the chart plots.
+void gen_data(SkScalar yAvg, SkScalar ySpread, int count, SkTDArray<SkScalar>* dataPts) {
+    dataPts->setCount(count);
+    static SkMWCRandom gRandom;
+    for (int i = 0; i < count; ++i) {
+        (*dataPts)[i] = gRandom.nextRangeScalar(yAvg - SkScalarHalf(ySpread),
+                                                yAvg + SkScalarHalf(ySpread));
+    }
+}
+
+// Generates a path to stroke along the top of each plot and a fill path for the area below each
+// plot. The fill path is bounded below by the bottomData plot points or a horizontal line at
+// yBase if bottomData == NULL.
+// The plots are animated by rotating the data points by leftShift.
+void gen_paths(const SkTDArray<SkScalar>& topData,
+               const SkTDArray<SkScalar>* bottomData,
+               SkScalar yBase,
+               SkScalar xLeft, SkScalar xDelta,
+               int leftShift,
+               SkPath* plot, SkPath* fill) {
+    plot->rewind();
+    fill->rewind();
+    plot->incReserve(topData.count());
+    if (NULL == bottomData) {
+        fill->incReserve(topData.count() + 2);
+    } else {
+        fill->incReserve(2 * topData.count());
+    }
+
+    leftShift %= topData.count();
+    SkScalar x = xLeft;
+
+    // Account for the leftShift using two loops
+    int shiftToEndCount = topData.count() - leftShift;
+    plot->moveTo(x, topData[leftShift]);
+    fill->moveTo(x, topData[leftShift]);
+
+    for (int i = 1; i < shiftToEndCount; ++i) {
+        plot->lineTo(x, topData[i + leftShift]);
+        fill->lineTo(x, topData[i + leftShift]);
+        x += xDelta;
+    }
+
+    for (int i = 0; i < leftShift; ++i) {
+        plot->lineTo(x, topData[i]);
+        fill->lineTo(x, topData[i]);
+        x += xDelta;
+    }
+
+    if (NULL != bottomData) {
+        SkASSERT(bottomData->count() == topData.count());
+        // iterate backwards over the previous graph's data to generate the bottom of the filled
+        // area (and account for leftShift).
+        for (int i = 0; i < leftShift; ++i) {
+            x -= xDelta;
+            fill->lineTo(x, (*bottomData)[leftShift - 1 - i]);
+        }
+        for (int i = 0; i < shiftToEndCount; ++i) {
+            x -= xDelta;
+            fill->lineTo(x, (*bottomData)[bottomData->count() - 1 - i]);
+        }
+    } else {
+        fill->lineTo(x - xDelta, yBase);
+        fill->lineTo(xLeft, yBase);
+    }
+}
+
+}
+
+// A set of scrolling line plots with the area between each plot filled. Stresses out GPU path
+// filling
+class ChartBench : public SkBenchmark {
+public:
+    ChartBench(void* param, bool aa) : SkBenchmark(param) {
+        fShift = 0;
+        fAA = aa;
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        if (fAA) {
+            return "chart_aa";
+        } else {
+            return "chart_bw";
+        }
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        bool sizeChanged = false;
+        if (canvas->getDeviceSize() != fSize) {
+            fSize = canvas->getDeviceSize();
+            sizeChanged = true;
+        }
+
+        SkScalar ySpread = SkIntToScalar(fSize.fHeight / 20);
+
+        SkScalar height = SkIntToScalar(fSize.fHeight);
+
+        for (int frame = 0; frame < kFramesPerRun; ++frame) {
+            if (sizeChanged) {
+                int dataPointCount = SkMax32(fSize.fWidth / kPixelsPerTick + 1, 2);
+
+                for (int i = 0; i < kNumGraphs; ++i) {
+                    SkScalar y = (kNumGraphs - i) * (height - ySpread) / (kNumGraphs + 1);
+                    fData[i].reset();
+                    gen_data(y, ySpread, dataPointCount, fData + i);
+                }
+                sizeChanged = false;
+            }
+
+            canvas->clear(0xFFE0F0E0);
+
+            static SkMWCRandom colorRand;
+            static SkColor gColors[kNumGraphs] = { 0x0 };
+            if (0 == gColors[0]) {
+                for (int i = 0; i < kNumGraphs; ++i) {
+                    gColors[i] = colorRand.nextU() | 0xff000000;
+                }
+            }
+
+            SkPath plotPath;
+            SkPath fillPath;
+
+            static const SkScalar kStrokeWidth = SkIntToScalar(2);
+            SkPaint plotPaint;
+            SkPaint fillPaint;
+            plotPaint.setAntiAlias(fAA);
+            plotPaint.setStyle(SkPaint::kStroke_Style);
+            plotPaint.setStrokeWidth(kStrokeWidth);
+            plotPaint.setStrokeCap(SkPaint::kRound_Cap);
+            plotPaint.setStrokeJoin(SkPaint::kRound_Join);
+            fillPaint.setAntiAlias(fAA);
+            fillPaint.setStyle(SkPaint::kFill_Style);
+
+            SkTDArray<SkScalar>* prevData = NULL;
+            for (int i = 0; i < kNumGraphs; ++i) {
+                gen_paths(fData[i],
+                          prevData,
+                          height,
+                          0,
+                          SkIntToScalar(kPixelsPerTick),
+                          fShift,
+                          &plotPath,
+                          &fillPath);
+
+                // Make the fills partially transparent
+                fillPaint.setColor((gColors[i] & 0x00ffffff) | 0x80000000);
+                canvas->drawPath(fillPath, fillPaint);
+
+                plotPaint.setColor(gColors[i]);
+                canvas->drawPath(plotPath, plotPaint);
+
+                prevData = fData + i;
+            }
+
+            fShift += kShiftPerFrame;
+        }
+    }
+
+private:
+    enum {
+        kNumGraphs = 5,
+        kPixelsPerTick = 3,
+        kShiftPerFrame = 1,
+
+        kFramesPerRun = SkBENCHLOOP(5),
+    };
+    int                 fShift;
+    SkISize             fSize;
+    SkTDArray<SkScalar> fData[kNumGraphs];
+    bool                fAA;
+
+    typedef SkBenchmark INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkBenchmark* Fact0(void* p) { return new ChartBench(p, true); }
+static SkBenchmark* Fact1(void* p) { return new ChartBench(p, false); }
+
+static BenchRegistry gReg0(Fact0);
+static BenchRegistry gReg1(Fact1);