bench/DashBench.cpp

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "bench/Benchmark.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPath.h"
#include "include/core/SkPathBuilder.h"
#include "include/core/SkPathEffect.h"
#include "include/core/SkString.h"
#include "include/core/SkStrokeRec.h"
#include "include/effects/SkDashPathEffect.h"
#include "include/private/SkTDArray.h"
#include "src/core/SkRandom.h"

#include <array>

/*
 *  Cases to consider:
 *
 *  1. antialiasing on/off (esp. width <= 1)
 *  2. strokewidth == 0, 1, 2
 *  3. hline, vline, diagonal, rect, oval
 *  4. dots [1,1] ([N,N] where N=strokeWidth?) or arbitrary (e.g. [2,1] or [1,2,3,2])
 */
static SkPath path_hline() {
    return SkPath::Line({10, 10}, {600, 10});
}

class DashBench : public Benchmark {
protected:
    SkString            fName;
    SkTDArray<SkScalar> fIntervals;
    int                 fWidth;
    SkPoint             fPts[2];
    bool                fDoClip;

public:
    DashBench(const SkScalar intervals[], int count, int width,
              bool doClip = false)  {
        fIntervals.append(count, intervals);
        for (int i = 0; i < count; ++i) {
            fIntervals[i] *= width;
        }
        fWidth = width;
        fName.printf("dash_%d_%s", width, doClip ? "clipped" : "noclip");
        fDoClip = doClip;

        fPts[0].set(SkIntToScalar(10), SkIntToScalar(10));
        fPts[1].set(SkIntToScalar(600), SkIntToScalar(10));
    }

    virtual SkPath makePath() {
        return path_hline();
    }

protected:
    const char* onGetName() override {
        return fName.c_str();
    }

    void onDraw(int loops, SkCanvas* canvas) override {
        SkPaint paint;
        this->setupPaint(&paint);
        paint.setStyle(SkPaint::kStroke_Style);
        paint.setStrokeWidth(SkIntToScalar(fWidth));
        paint.setAntiAlias(false);

        SkPath path = this->makePath();

        paint.setPathEffect(SkDashPathEffect::Make(fIntervals, 0));

        if (fDoClip) {
            SkRect r = path.getBounds();
            r.inset(-SkIntToScalar(20), -SkIntToScalar(20));
            // now move it so we don't intersect
            r.offset(0, r.height() * 3 / 2);
            canvas->clipRect(r);
        }

        this->handlePath(canvas, path, paint, loops);
    }

    virtual void handlePath(SkCanvas* canvas, const SkPath& path,
                            const SkPaint& paint, int N) {
        for (int i = 0; i < N; ++i) {
//            canvas->drawPoints(SkCanvas::kLines_PointMode, 2, fPts, paint);
            canvas->drawPath(path, paint);
        }
    }

private:
    using INHERITED = Benchmark;
};

class RectDashBench : public DashBench {
public:
    RectDashBench(const SkScalar intervals[], int count, int width)
    : INHERITED(intervals, count, width) {
        fName.append("_rect");
    }

protected:
    void handlePath(SkCanvas* canvas, const SkPath& path, const SkPaint& paint, int N) override {
        SkPoint pts[2];
        if (!path.isLine(pts) || pts[0].fY != pts[1].fY) {
            this->INHERITED::handlePath(canvas, path, paint, N);
        } else {
            SkRect rect;
            rect.fLeft = pts[0].fX;
            rect.fTop = pts[0].fY - paint.getStrokeWidth() / 2;
            rect.fRight = rect.fLeft + SkIntToScalar(fWidth);
            rect.fBottom = rect.fTop + paint.getStrokeWidth();

            SkPaint p(paint);
            p.setStyle(SkPaint::kFill_Style);
            p.setPathEffect(nullptr);

            int count = SkScalarRoundToInt((pts[1].fX - pts[0].fX) / (2*fWidth));
            SkScalar dx = SkIntToScalar(2 * fWidth);

            for (int i = 0; i < N*10; ++i) {
                SkRect r = rect;
                for (int j = 0; j < count; ++j) {
                    canvas->drawRect(r, p);
                    r.offset(dx, 0);
                }
            }
        }
    }

private:
    using INHERITED = DashBench;
};

static SkPath make_unit_star(int n) {
    SkScalar rad = -SK_ScalarPI / 2;
    const SkScalar drad = (n >> 1) * SK_ScalarPI * 2 / n;

    SkPathBuilder builder;
    builder.moveTo(0, -SK_Scalar1);
    for (int i = 1; i < n; i++) {
        rad += drad;
        builder.lineTo(SkScalarCos(rad), SkScalarSin(rad));
    }
    builder.close();
    return builder.detach();
}

static SkPath make_poly() {
    return make_unit_star(9).makeTransform(SkMatrix::Scale(100, 100));
}

static SkPath make_quad() {
    SkScalar x0 = SkIntToScalar(10);
    SkScalar y0 = SkIntToScalar(10);
    SkPathBuilder builder;
    builder.moveTo(x0, y0);
    builder.quadTo(x0,                    y0 + 400 * SK_Scalar1,
                   x0 + 600 * SK_Scalar1, y0 + 400 * SK_Scalar1);
    return builder.detach();
}

static SkPath make_cubic() {
    SkScalar x0 = SkIntToScalar(10);
    SkScalar y0 = SkIntToScalar(10);
    SkPathBuilder builder;
    builder.moveTo(x0, y0);
    builder.cubicTo(x0,                    y0 + 400 * SK_Scalar1,
                    x0 + 600 * SK_Scalar1, y0 + 400 * SK_Scalar1,
                    x0 + 600 * SK_Scalar1, y0);
    return builder.detach();
}

class MakeDashBench : public Benchmark {
    SkString fName;
    SkPath   fPath;
    sk_sp<SkPathEffect> fPE;

public:
    MakeDashBench(SkPath(*proc)(), const char name[])  {
        fName.printf("makedash_%s", name);
        fPath = proc();

        SkScalar vals[] = { SkIntToScalar(4), SkIntToScalar(4) };
        fPE = SkDashPathEffect::Make(vals, 0);
    }

protected:
    const char* onGetName() override {
        return fName.c_str();
    }

    void onDraw(int loops, SkCanvas*) override {
        SkPathBuilder dst;
        for (int i = 0; i < loops; ++i) {
            SkStrokeRec rec(SkStrokeRec::kHairline_InitStyle);

            fPE->filterPath(&dst, fPath, &rec);
            dst.reset();
        }
    }

private:
    using INHERITED = Benchmark;
};

/*
 *  We try to special case square dashes (intervals are equal to strokewidth).
 */
class DashLineBench : public Benchmark {
    SkString fName;
    SkScalar fStrokeWidth;
    bool     fIsRound;
    sk_sp<SkPathEffect> fPE;

public:
    DashLineBench(SkScalar width, bool isRound)  {
        fName.printf("dashline_%g_%s", width, isRound ? "circle" : "square");
        fStrokeWidth = width;
        fIsRound = isRound;

        SkScalar vals[] = { SK_Scalar1, SK_Scalar1 };
        fPE = SkDashPathEffect::Make(vals, 0);
    }

protected:
    const char* onGetName() override {
        return fName.c_str();
    }

    void onDraw(int loops, SkCanvas* canvas) override {
        SkPaint paint;
        this->setupPaint(&paint);
        paint.setStrokeWidth(fStrokeWidth);
        paint.setStrokeCap(fIsRound ? SkPaint::kRound_Cap : SkPaint::kSquare_Cap);
        paint.setPathEffect(fPE);
        for (int i = 0; i < loops; ++i) {
            canvas->drawLine(10 * SK_Scalar1, 10 * SK_Scalar1,
                             640 * SK_Scalar1, 10 * SK_Scalar1, paint);
        }
    }

private:
    using INHERITED = Benchmark;
};

class DrawPointsDashingBench : public Benchmark {
    SkString fName;
    int      fStrokeWidth;
    bool     fDoAA;

    sk_sp<SkPathEffect> fPathEffect;

public:
    DrawPointsDashingBench(int dashLength, int strokeWidth, bool doAA)
         {
        fName.printf("drawpointsdash_%d_%d%s", dashLength, strokeWidth, doAA ? "_aa" : "_bw");
        fStrokeWidth = strokeWidth;
        fDoAA = doAA;

        SkScalar vals[] = { SkIntToScalar(dashLength), SkIntToScalar(dashLength) };
        fPathEffect = SkDashPathEffect::Make(vals, SK_Scalar1);
    }

protected:
    const char* onGetName() override {
        return fName.c_str();
    }

    void onDraw(int loops, SkCanvas* canvas) override {
        SkPaint p;
        this->setupPaint(&p);
        p.setColor(SK_ColorBLACK);
        p.setStyle(SkPaint::kStroke_Style);
        p.setStrokeWidth(SkIntToScalar(fStrokeWidth));
        p.setPathEffect(fPathEffect);
        p.setAntiAlias(fDoAA);

        SkPoint pts[2] = {
            { SkIntToScalar(10), 0 },
            { SkIntToScalar(640), 0 }
        };

        for (int i = 0; i < loops; ++i) {
            pts[0].fY = pts[1].fY = SkIntToScalar(i % 480);
            canvas->drawPoints(SkCanvas::kLines_PointMode, pts, p);
        }
    }

private:
    using INHERITED = Benchmark;
};

// Want to test how we handle dashing when 99% of the dash is clipped out
class GiantDashBench : public Benchmark {
    SkString fName;
    SkScalar fStrokeWidth;
    SkPoint  fPts[2];
    sk_sp<SkPathEffect> fPathEffect;

public:
    enum LineType {
        kHori_LineType,
        kVert_LineType,
        kDiag_LineType,
        kLineTypeCount
    };

    static const char* LineTypeName(LineType lt) {
        static constexpr auto gNames = std::to_array<const char*>({"hori", "vert", "diag"});
        static_assert(kLineTypeCount == std::size(gNames), "names_wrong_size");
        return gNames[lt];
    }

    GiantDashBench(LineType lt, SkScalar width)  {
        fName.printf("giantdashline_%s_%g", LineTypeName(lt), width);
        fStrokeWidth = width;

        // deliberately pick intervals that won't be caught by asPoints(), so
        // we can test the filterPath code-path.
        const SkScalar intervals[] = { 20, 10, 10, 10 };
        fPathEffect = SkDashPathEffect::Make(intervals, 0);

        SkScalar cx = 640 / 2;  // center X
        SkScalar cy = 480 / 2;  // center Y
        SkMatrix matrix;

        switch (lt) {
            case kHori_LineType:
                matrix.setIdentity();
                break;
            case kVert_LineType:
                matrix.setRotate(90, cx, cy);
                break;
            case kDiag_LineType:
                matrix.setRotate(45, cx, cy);
                break;
            case kLineTypeCount:
                // Not a real enum value.
                break;
        }

        const SkScalar overshoot = 100*1000;
        const SkPoint pts[2] = {
            { -overshoot, cy }, { 640 + overshoot, cy }
        };
        matrix.mapPoints(fPts, pts);
    }

protected:
    const char* onGetName() override {
        return fName.c_str();
    }

    void onDraw(int loops, SkCanvas* canvas) override {
        SkPaint p;
        this->setupPaint(&p);
        p.setStyle(SkPaint::kStroke_Style);
        p.setStrokeWidth(fStrokeWidth);
        p.setPathEffect(fPathEffect);

        for (int i = 0; i < loops; i++) {
            canvas->drawPoints(SkCanvas::kLines_PointMode, fPts, p);
        }
    }

private:
    using INHERITED = Benchmark;
};

// Want to test how we draw a dashed grid (like what is used in spreadsheets) of many
// small dashed lines switching back and forth between horizontal and vertical
class DashGridBench : public Benchmark {
    SkString fName;
    int      fStrokeWidth;
    bool     fDoAA;

    sk_sp<SkPathEffect> fPathEffect;

public:
    DashGridBench(int dashLength, int strokeWidth, bool doAA) {
        fName.printf("dashgrid_%d_%d%s", dashLength, strokeWidth, doAA ? "_aa" : "_bw");
        fStrokeWidth = strokeWidth;
        fDoAA = doAA;

        SkScalar vals[] = { SkIntToScalar(dashLength), SkIntToScalar(dashLength) };
        fPathEffect = SkDashPathEffect::Make(vals, SK_Scalar1);
    }

protected:
    const char* onGetName() override {
        return fName.c_str();
    }

    void onDraw(int loops, SkCanvas* canvas) override {
        SkPaint p;
        this->setupPaint(&p);
        p.setColor(SK_ColorBLACK);
        p.setStyle(SkPaint::kStroke_Style);
        p.setStrokeWidth(SkIntToScalar(fStrokeWidth));
        p.setPathEffect(fPathEffect);
        p.setAntiAlias(fDoAA);

        SkPoint pts[4] = {
            { SkIntToScalar(0), 20.5f },
            { SkIntToScalar(20), 20.5f },
            { 20.5f, SkIntToScalar(0) },
            { 20.5f, SkIntToScalar(20) }
        };

        for (int i = 0; i < loops; ++i) {
            for (int j = 0; j < 10; ++j) {
                for (int k = 0; k < 10; ++k) {
                    // Horizontal line
                    SkPoint horPts[2];
                    horPts[0].fX = pts[0].fX + k * 22.f;
                    horPts[0].fY = pts[0].fY + j * 22.f;
                    horPts[1].fX = pts[1].fX + k * 22.f;
                    horPts[1].fY = pts[1].fY + j * 22.f;
                    canvas->drawPoints(SkCanvas::kLines_PointMode, horPts, p);

                    // Vertical line
                    SkPoint vertPts[2];
                    vertPts[0].fX = pts[2].fX + k * 22.f;
                    vertPts[0].fY = pts[2].fY + j * 22.f;
                    vertPts[1].fX = pts[3].fX + k * 22.f;
                    vertPts[1].fY = pts[3].fY + j * 22.f;
                    canvas->drawPoints(SkCanvas::kLines_PointMode, vertPts, p);
                }
            }
        }
    }

private:
    using INHERITED = Benchmark;
};

///////////////////////////////////////////////////////////////////////////////

static const SkScalar gDots[] = { SK_Scalar1, SK_Scalar1 };

#define PARAM(array)    array, std::size(array)

DEF_BENCH( return new DashBench(PARAM(gDots), 0); )
DEF_BENCH( return new DashBench(PARAM(gDots), 1); )
DEF_BENCH( return new DashBench(PARAM(gDots), 1, true); )
DEF_BENCH( return new DashBench(PARAM(gDots), 4); )
DEF_BENCH( return new MakeDashBench(make_poly, "poly"); )
DEF_BENCH( return new MakeDashBench(make_quad, "quad"); )
DEF_BENCH( return new MakeDashBench(make_cubic, "cubic"); )
DEF_BENCH( return new DashLineBench(0, false); )
DEF_BENCH( return new DashLineBench(SK_Scalar1, false); )
DEF_BENCH( return new DashLineBench(2 * SK_Scalar1, false); )
DEF_BENCH( return new DashLineBench(0, true); )
DEF_BENCH( return new DashLineBench(SK_Scalar1, true); )
DEF_BENCH( return new DashLineBench(2 * SK_Scalar1, true); )

DEF_BENCH( return new DrawPointsDashingBench(1, 1, false); )
DEF_BENCH( return new DrawPointsDashingBench(1, 1, true); )
DEF_BENCH( return new DrawPointsDashingBench(3, 1, false); )
DEF_BENCH( return new DrawPointsDashingBench(3, 1, true); )
DEF_BENCH( return new DrawPointsDashingBench(5, 5, false); )
DEF_BENCH( return new DrawPointsDashingBench(5, 5, true); )

/* Disable the GiantDashBench for Android devices until we can better control
 * the memory usage. (https://code.google.com/p/skia/issues/detail?id=1430)
 */
#ifndef SK_BUILD_FOR_ANDROID
DEF_BENCH( return new GiantDashBench(GiantDashBench::kHori_LineType, 0); )
DEF_BENCH( return new GiantDashBench(GiantDashBench::kVert_LineType, 0); )
DEF_BENCH( return new GiantDashBench(GiantDashBench::kDiag_LineType, 0); )

// pass 2 to explicitly avoid any 1-is-the-same-as-hairline special casing

// hori_2 is just too slow to enable at the moment
DEF_BENCH( return new GiantDashBench(GiantDashBench::kHori_LineType, 2); )
DEF_BENCH( return new GiantDashBench(GiantDashBench::kVert_LineType, 2); )
DEF_BENCH( return new GiantDashBench(GiantDashBench::kDiag_LineType, 2); )

DEF_BENCH( return new DashGridBench(1, 1, true); )
DEF_BENCH( return new DashGridBench(1, 1, false); )
DEF_BENCH( return new DashGridBench(3, 1, true); )
DEF_BENCH( return new DashGridBench(3, 1, false); )
#endif