gm/imagefiltersgraph.cpp

/*
 * 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 "gm.h"

#include "SkArithmeticMode.h"
#include "SkBlurImageFilter.h"
#include "SkColorFilter.h"
#include "SkColorFilterImageFilter.h"
#include "SkColorMatrixFilter.h"
#include "SkImage.h"
#include "SkImageSource.h"
#include "SkMatrixConvolutionImageFilter.h"
#include "SkReadBuffer.h"
#include "SkSpecialImage.h"
#include "SkSpecialSurface.h"
#include "SkWriteBuffer.h"
#include "SkMergeImageFilter.h"
#include "SkMorphologyImageFilter.h"
#include "SkTestImageFilters.h"
#include "SkXfermodeImageFilter.h"

// More closely models how Blink's OffsetFilter works as of 10/23/13. SkOffsetImageFilter doesn't
// perform a draw and this one does.
class SimpleOffsetFilter : public SkImageFilter {
public:
    class Registrar {
    public:
        Registrar() {
            SkFlattenable::Register("SimpleOffsetFilter",
                                    SimpleOffsetFilter::CreateProc,
                                    SimpleOffsetFilter::GetFlattenableType());
        }
    };
    static sk_sp<SkImageFilter> Make(SkScalar dx, SkScalar dy, sk_sp<SkImageFilter> input) {
        return sk_sp<SkImageFilter>(new SimpleOffsetFilter(dx, dy, std::move(input)));
    }

    SK_TO_STRING_OVERRIDE()
    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SimpleOffsetFilter);

protected:
    sk_sp<SkSpecialImage> onFilterImage(SkSpecialImage* source, const Context& ctx,
                                        SkIPoint* offset) const override {
        SkIPoint inputOffset = SkIPoint::Make(0, 0);
        sk_sp<SkSpecialImage> input(this->filterInput(0, source, ctx, &inputOffset));
        if (!input) {
            return nullptr;
        }

        SkIRect bounds;
        input = this->applyCropRect(ctx, input.get(), &inputOffset, &bounds);
        if (!input) {
            return nullptr;
        }

        SkImageInfo info = SkImageInfo::MakeN32Premul(bounds.width(), bounds.height());

        sk_sp<SkSpecialSurface> surf(source->makeSurface(info));
        if (!surf) {
            return nullptr;
        }

        SkCanvas* canvas = surf->getCanvas();
        SkASSERT(canvas);

        SkPaint paint;
        paint.setXfermodeMode(SkXfermode::kSrc_Mode);

        input->draw(canvas, fDX - bounds.left(), fDY - bounds.top(), &paint);

        offset->fX += bounds.left();
        offset->fY += bounds.top();
        return surf->makeImageSnapshot();
    }

    void flatten(SkWriteBuffer& buffer) const override {
        this->INHERITED::flatten(buffer);
        buffer.writeScalar(fDX);
        buffer.writeScalar(fDY);
    }

private:
    SimpleOffsetFilter(SkScalar dx, SkScalar dy, sk_sp<SkImageFilter> input)
        : SkImageFilter(&input, 1, nullptr)
        , fDX(dx)
        , fDY(dy) {
    }

    SkScalar fDX, fDY;

    typedef SkImageFilter INHERITED;
};

static SimpleOffsetFilter::Registrar gReg;

sk_sp<SkFlattenable> SimpleOffsetFilter::CreateProc(SkReadBuffer& buffer) {
    SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
    SkScalar dx = buffer.readScalar();
    SkScalar dy = buffer.readScalar();
    return Make(dx, dy, common.getInput(0));
}

#ifndef SK_IGNORE_TO_STRING
void SimpleOffsetFilter::toString(SkString* str) const {
    str->appendf("SimpleOffsetFilter: (");
    str->append(")");
}
#endif

class ImageFiltersGraphGM : public skiagm::GM {
public:
    ImageFiltersGraphGM() {}

protected:

    SkString onShortName() override {
        return SkString("imagefiltersgraph");
    }

    SkISize onISize() override { return SkISize::Make(600, 150); }

    void onOnceBeforeDraw() override {
        fImage = SkImage::MakeFromBitmap(
            sk_tool_utils::create_string_bitmap(100, 100, SK_ColorWHITE, 20, 70, 96, "e"));
    }

    void onDraw(SkCanvas* canvas) override {
        canvas->clear(SK_ColorBLACK);
        {
            sk_sp<SkImageFilter> bitmapSource(SkImageSource::Make(fImage));
            sk_sp<SkColorFilter> cf(SkColorFilter::MakeModeFilter(SK_ColorRED,
                                                                  SkXfermode::kSrcIn_Mode));
            sk_sp<SkImageFilter> blur(SkBlurImageFilter::Make(4.0f, 4.0f, std::move(bitmapSource)));
            sk_sp<SkImageFilter> erode(SkErodeImageFilter::Make(4, 4, blur));
            sk_sp<SkImageFilter> color(SkColorFilterImageFilter::Make(std::move(cf),
                                                                      std::move(erode)));
            sk_sp<SkImageFilter> merge(SkMergeImageFilter::Make(blur, color));

            SkPaint paint;
            paint.setImageFilter(std::move(merge));
            canvas->drawPaint(paint);
            canvas->translate(SkIntToScalar(100), 0);
        }
        {
            sk_sp<SkImageFilter> morph(SkDilateImageFilter::Make(5, 5, nullptr));

            SkScalar matrix[20] = { SK_Scalar1, 0, 0, 0, 0,
                                    0, SK_Scalar1, 0, 0, 0,
                                    0, 0, SK_Scalar1, 0, 0,
                                    0, 0, 0, 0.5f, 0 };

            sk_sp<SkColorFilter> matrixFilter(SkColorFilter::MakeMatrixFilterRowMajor255(matrix));
            sk_sp<SkImageFilter> colorMorph(SkColorFilterImageFilter::Make(std::move(matrixFilter),
                                                                           std::move(morph)));
            SkPaint paint;
            paint.setImageFilter(SkXfermodeImageFilter::Make(
                                        SkXfermode::Make(SkXfermode::kSrcOver_Mode),
                                        std::move(colorMorph)));

            DrawClippedImage(canvas, fImage.get(), paint);
            canvas->translate(SkIntToScalar(100), 0);
        }
        {
            SkScalar matrix[20] = { SK_Scalar1, 0, 0, 0, 0,
                                    0, SK_Scalar1, 0, 0, 0,
                                    0, 0, SK_Scalar1, 0, 0,
                                    0, 0, 0, 0.5f, 0 };
            sk_sp<SkColorFilter> matrixCF(SkColorFilter::MakeMatrixFilterRowMajor255(matrix));
            sk_sp<SkImageFilter> matrixFilter(SkColorFilterImageFilter::Make(std::move(matrixCF),
                                                                             nullptr));
            sk_sp<SkImageFilter> offsetFilter(SimpleOffsetFilter::Make(10.0f, 10.f, matrixFilter));

            SkPaint paint;
            paint.setImageFilter(
                SkXfermodeImageFilter::Make(SkArithmeticMode::Make(0, SK_Scalar1, SK_Scalar1, 0),
                                            std::move(matrixFilter),
                                            std::move(offsetFilter),
                                            nullptr));

            DrawClippedImage(canvas, fImage.get(), paint);
            canvas->translate(SkIntToScalar(100), 0);
        }
        {
            sk_sp<SkImageFilter> blur(SkBlurImageFilter::Make(SkIntToScalar(10),
                                                              SkIntToScalar(10),
                                                              nullptr));

            SkImageFilter::CropRect cropRect(SkRect::MakeWH(SkIntToScalar(95), SkIntToScalar(100)));
            SkPaint paint;
            paint.setImageFilter(
                SkXfermodeImageFilter::Make(SkXfermode::Make(SkXfermode::kSrcIn_Mode),
                                            std::move(blur),
                                            nullptr, &cropRect));
            DrawClippedImage(canvas, fImage.get(), paint);
            canvas->translate(SkIntToScalar(100), 0);
        }
        {
            // Dilate -> matrix convolution.
            // This tests that a filter using asFragmentProcessor (matrix
            // convolution) correctly handles a non-zero source offset
            // (supplied by the dilate).
            sk_sp<SkImageFilter> dilate(SkDilateImageFilter::Make(5, 5, nullptr));

            SkScalar kernel[9] = {
                SkIntToScalar(-1), SkIntToScalar( -1 ), SkIntToScalar(-1),
                SkIntToScalar(-1), SkIntToScalar(  7 ), SkIntToScalar(-1),
                SkIntToScalar(-1), SkIntToScalar( -1 ), SkIntToScalar(-1),
            };
            SkISize kernelSize = SkISize::Make(3, 3);
            SkScalar gain = 1.0f, bias = SkIntToScalar(0);
            SkIPoint kernelOffset = SkIPoint::Make(1, 1);
            auto tileMode = SkMatrixConvolutionImageFilter::kClamp_TileMode;
            bool convolveAlpha = false;
            sk_sp<SkImageFilter> convolve(
                SkMatrixConvolutionImageFilter::Create(kernelSize,
                                                       kernel,
                                                       gain,
                                                       bias,
                                                       kernelOffset,
                                                       tileMode,
                                                       convolveAlpha,
                                                       dilate.get()));

            SkPaint paint;
            paint.setImageFilter(std::move(convolve));
            DrawClippedImage(canvas, fImage.get(), paint);
            canvas->translate(SkIntToScalar(100), 0);
        }
        {
            // Test that crop offsets are absolute, not relative to the parent's crop rect.
            sk_sp<SkColorFilter> cf1(SkColorFilter::MakeModeFilter(SK_ColorBLUE,
                                                                   SkXfermode::kSrcIn_Mode));
            sk_sp<SkColorFilter> cf2(SkColorFilter::MakeModeFilter(SK_ColorGREEN,
                                                                   SkXfermode::kSrcIn_Mode));
            SkImageFilter::CropRect outerRect(SkRect::MakeXYWH(SkIntToScalar(10), SkIntToScalar(10),
                                                               SkIntToScalar(80), SkIntToScalar(80)));
            SkImageFilter::CropRect innerRect(SkRect::MakeXYWH(SkIntToScalar(20), SkIntToScalar(20),
                                                               SkIntToScalar(60), SkIntToScalar(60)));
            sk_sp<SkImageFilter> color1(SkColorFilterImageFilter::Make(std::move(cf1),
                                                                       nullptr,
                                                                       &outerRect));
            sk_sp<SkImageFilter> color2(SkColorFilterImageFilter::Make(std::move(cf2),
                                                                       std::move(color1),
                                                                       &innerRect));

            SkPaint paint;
            paint.setImageFilter(std::move(color2));
            paint.setColor(SK_ColorRED);
            canvas->drawRect(SkRect::MakeXYWH(0, 0, 100, 100), paint);
            canvas->translate(SkIntToScalar(100), 0);
        }
    }

private:
    static void DrawClippedImage(SkCanvas* canvas, const SkImage* image, const SkPaint& paint) {
        canvas->save();
        canvas->clipRect(SkRect::MakeIWH(image->width(), image->height()));
        canvas->drawImage(image, 0, 0, &paint);
        canvas->restore();
    }

    sk_sp<SkImage> fImage;

    typedef GM INHERITED;
};

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

DEF_GM(return new ImageFiltersGraphGM;)