gm/bigtileimagefilter.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 "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkImage.h"
#include "include/core/SkImageFilter.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkSurface.h"
#include "include/effects/SkImageFilters.h"

#include <utility>

static sk_sp<SkImage> create_circle_texture(int size, SkColor color) {
    auto surface(SkSurfaces::Raster(SkImageInfo::MakeN32Premul(size, size)));
    SkCanvas* canvas = surface->getCanvas();
    canvas->clear(0xFF000000);

    SkPaint paint;
    paint.setColor(color);
    paint.setStrokeWidth(3);
    paint.setStyle(SkPaint::kStroke_Style);

    canvas->drawCircle(size / 2.f, size / 2.f, size / 2.f, paint);

    return surface->makeImageSnapshot();
}

namespace skiagm {

class BigTileImageFilterGM : public GM {
public:
    BigTileImageFilterGM() {
        this->setBGColor(0xFF000000);
    }

protected:
    SkString getName() const override { return SkString("bigtileimagefilter"); }

    SkISize getISize() override { return SkISize::Make(kWidth, kHeight); }

    void onOnceBeforeDraw() override {
        fRedImage = create_circle_texture(kBitmapSize, SK_ColorRED);
        fGreenImage = create_circle_texture(kBitmapSize, SK_ColorGREEN);
    }

    void onDraw(SkCanvas* canvas) override {
        canvas->clear(SK_ColorBLACK);

        {
            SkPaint p;

            const SkRect bound = SkRect::MakeIWH(kWidth, kHeight);
            sk_sp<SkImageFilter> imageSource(SkImageFilters::Image(fRedImage,
                                                                   SkFilterMode::kLinear));

            sk_sp<SkImageFilter> tif(SkImageFilters::Tile(
                    SkRect::MakeIWH(kBitmapSize, kBitmapSize), SkRect::MakeIWH(kWidth, kHeight),
                    std::move(imageSource)));

            p.setImageFilter(std::move(tif));

            canvas->saveLayer(&bound, &p);
            canvas->restore();
        }

        {
            SkPaint p2;

            const SkRect bound2 = SkRect::MakeIWH(kBitmapSize, kBitmapSize);

            sk_sp<SkImageFilter> tif(SkImageFilters::Tile(
                    SkRect::MakeIWH(kBitmapSize, kBitmapSize),
                    SkRect::MakeIWH(kBitmapSize, kBitmapSize),
                    nullptr));

            p2.setImageFilter(std::move(tif));

            canvas->translate(320, 320);
            canvas->saveLayer(&bound2, &p2);
            canvas->setMatrix(SkMatrix::I());

            SkRect bound3 = SkRect::MakeXYWH(320, 320,
                                             SkIntToScalar(kBitmapSize),
                                             SkIntToScalar(kBitmapSize));
            canvas->drawImageRect(fGreenImage.get(), bound2, bound3, SkSamplingOptions(), nullptr,
                                  SkCanvas::kStrict_SrcRectConstraint);
            canvas->restore();
        }
    }

private:
    inline static constexpr int kWidth = 512;
    inline static constexpr int kHeight = 512;
    inline static constexpr int kBitmapSize = 64;

    sk_sp<SkImage> fRedImage;
    sk_sp<SkImage> fGreenImage;

    using INHERITED = GM;
};

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

DEF_GM(return new BigTileImageFilterGM;)
}  // namespace skiagm