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 "SkBenchmark.h"
#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkDashPathEffect.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkRandom.h"
#include "SkString.h"
#include "SkTDArray.h"


/*
 *  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 void path_hline(SkPath* path) {
    path->moveTo(SkIntToScalar(10), SkIntToScalar(10));
    path->lineTo(SkIntToScalar(600), SkIntToScalar(10));
}

class DashBench : public SkBenchmark {
protected:
    SkString            fName;
    SkTDArray<SkScalar> fIntervals;
    int                 fWidth;

    enum {
        N = SkBENCHLOOP(100)
    };
public:
    DashBench(void* param, const SkScalar intervals[], int count, int width) : INHERITED(param) {
        fIntervals.append(count, intervals);
        for (int i = 0; i < count; ++i) {
            fIntervals[i] *= width;
        }
        fWidth = width;
        fName.printf("dash_%d", width);
    }

    virtual void makePath(SkPath* path) {
        path_hline(path);
    }

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

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

        SkPath path;
        this->makePath(&path);

        paint.setPathEffect(new SkDashPathEffect(fIntervals.begin(),
                                                 fIntervals.count(), 0))->unref();
        this->handlePath(canvas, path, paint, N);
    }

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

private:
    typedef SkBenchmark INHERITED;
};

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

protected:
    virtual void handlePath(SkCanvas* canvas, const SkPath& path,
                            const SkPaint& paint, int N) SK_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(NULL);

            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:
    typedef DashBench INHERITED;
};

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

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

#define PARAM(array)    array, SK_ARRAY_COUNT(array)

static SkBenchmark* gF0(void* p) { return new DashBench(p, PARAM(gDots), 0); }
static SkBenchmark* gF1(void* p) { return new DashBench(p, PARAM(gDots), 1); }
static SkBenchmark* gF2(void* p) { return new DashBench(p, PARAM(gDots), 4); }
static SkBenchmark* gF3(void* p) { return new RectDashBench(p, PARAM(gDots), 4); }

static BenchRegistry gR0(gF0);
static BenchRegistry gR1(gF1);
static BenchRegistry gR2(gF2);
static BenchRegistry gR3(gF3);