skia2/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/gm.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkBlendMode.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkImage.h"
#include "include/core/SkImageFilter.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPoint.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/effects/SkImageFilters.h"
#include "tools/ToolUtils.h"

#include <utility>

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(
                ToolUtils::create_string_bitmap(100, 100, SK_ColorWHITE, 20, 70, 96, "e"));
    }

    void onDraw(SkCanvas* canvas) override {
        canvas->clear(SK_ColorBLACK);
        {
            sk_sp<SkImageFilter> bitmapSource(SkImageFilters::Image(fImage));
            sk_sp<SkColorFilter> cf(SkColorFilters::Blend(SK_ColorRED,
                                                                  SkBlendMode::kSrcIn));
            sk_sp<SkImageFilter> blur(SkImageFilters::Blur(4.0f, 4.0f, std::move(bitmapSource)));
            sk_sp<SkImageFilter> erode(SkImageFilters::Erode(4, 4, blur));
            sk_sp<SkImageFilter> color(SkImageFilters::ColorFilter(std::move(cf),
                                                                      std::move(erode)));
            sk_sp<SkImageFilter> merge(SkImageFilters::Merge(blur, color));

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

            float matrix[20] = { 1, 0, 0, 0, 0,
                                 0, 1, 0, 0, 0,
                                 0, 0, 1, 0, 0,
                                 0, 0, 0, 0.5f, 0 };

            sk_sp<SkColorFilter> matrixFilter(SkColorFilters::Matrix(matrix));
            sk_sp<SkImageFilter> colorMorph(SkImageFilters::ColorFilter(std::move(matrixFilter),
                                                                           std::move(morph)));
            SkPaint paint;
            paint.setImageFilter(SkImageFilters::Blend(SkBlendMode::kSrcOver,
                                                       std::move(colorMorph)));

            DrawClippedImage(canvas, fImage.get(), paint);
            canvas->translate(SkIntToScalar(100), 0);
        }
        {
            float matrix[20] = { 1, 0, 0, 0, 0,
                                 0, 1, 0, 0, 0,
                                 0, 0, 1, 0, 0,
                                 0, 0, 0, 0.5f, 0 };
            sk_sp<SkColorFilter> matrixCF(SkColorFilters::Matrix(matrix));
            sk_sp<SkImageFilter> matrixFilter(SkImageFilters::ColorFilter(std::move(matrixCF),
                                                                             nullptr));
            sk_sp<SkImageFilter> offsetFilter(SkImageFilters::Offset(10.0f, 10.f, matrixFilter));

            SkPaint paint;
            paint.setImageFilter(SkImageFilters::Arithmetic(
                    0, 1, 1, 0, true, std::move(matrixFilter), std::move(offsetFilter), nullptr));

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

            SkIRect cropRect = SkIRect::MakeWH(95, 100);
            SkPaint paint;
            paint.setImageFilter(
                SkImageFilters::Blend(SkBlendMode::kSrcIn, 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(SkImageFilters::Dilate(5, 5, nullptr));

            SkScalar kernel[9] = { -1, -1, -1,
                                   -1,  7, -1,
                                   -1, -1, -1 };
            SkISize kernelSize = SkISize::Make(3, 3);
            SkScalar gain = 1.0f, bias = 0;
            SkIPoint kernelOffset = SkIPoint::Make(1, 1);
            bool convolveAlpha = false;
            sk_sp<SkImageFilter> convolve(SkImageFilters::MatrixConvolution(
                    kernelSize, kernel, gain, bias, kernelOffset, SkTileMode::kClamp, convolveAlpha,
                    std::move(dilate)));

            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(SkColorFilters::Blend(SK_ColorBLUE, SkBlendMode::kSrcIn));
            sk_sp<SkColorFilter> cf2(SkColorFilters::Blend(SK_ColorGREEN, SkBlendMode::kSrcIn));
            SkIRect outerRect = SkIRect::MakeXYWH(10, 10, 80, 80);
            SkIRect innerRect= SkIRect::MakeXYWH(20, 20, 60, 60);
            sk_sp<SkImageFilter> color1(SkImageFilters::ColorFilter(
                    std::move(cf1), nullptr, &outerRect));
            sk_sp<SkImageFilter> color2(SkImageFilters::ColorFilter(
                    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;

    using INHERITED = GM;
};

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

DEF_GM(return new ImageFiltersGraphGM;)