AnimBlurSlide.cpp

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/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
#include "include/core/SkBlurTypes.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColorPriv.h"
#include "include/core/SkMaskFilter.h"
#include "src/base/SkRandom.h"
#include "tools/viewer/Slide.h"
 
#include <iterator>
 
SkScalar get_anim_sin(double secs, SkScalar amplitude, SkScalar periodInSec, SkScalar phaseInSec) {
    if (!periodInSec) {
        return 0;
    }
    double t = secs + phaseInSec;
    t *= (2 * SK_ScalarPI) / periodInSec;
    amplitude = SK_ScalarHalf * amplitude;
    return amplitude * SkDoubleToScalar(sin(t)) + amplitude;
}
 
class AnimBlurSlide : public Slide {
    SkScalar fBlurSigma = 0;
    SkScalar fCircleRadius = 100;
 
public:
    AnimBlurSlide() { fName ="AnimBlur"; }
 
    void draw(SkCanvas* canvas) override {
        static const SkBlurStyle gStyles[] = {
            kNormal_SkBlurStyle,
            kInner_SkBlurStyle,
            kSolid_SkBlurStyle,
            kOuter_SkBlurStyle,
        };
        SkRandom random;
 
        for (size_t i = 0; i < std::size(gStyles); ++i) {
            SkPaint paint;
            paint.setMaskFilter(SkMaskFilter::MakeBlur(gStyles[i],
                                                       fBlurSigma));
            paint.setColor(random.nextU() | 0xff000000);
            canvas->drawCircle(200 * SK_Scalar1 + 400 * (i % 2) * SK_Scalar1,
                               200 * SK_Scalar1 + i / 2 * 400 * SK_Scalar1,
                               fCircleRadius, paint);
        }
    }
 
    bool animate(double nanos) override {
        fBlurSigma = get_anim_sin(1e-9 * nanos, 100, 4, 5);
        fCircleRadius = 3 + get_anim_sin(1e-9 * nanos, 150, 25, 3);
        return true;
    }
};
 
DEF_SLIDE( return new AnimBlurSlide(); )