gm/gradientDirtyLaundry.cpp

/*
 * Copyright 2013 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 "SkGradientShader.h"

using namespace skiagm;

struct GradData {
    int             fCount;
    const SkColor*  fColors;
    const SkScalar* fPos;
};

static const SkColor gColors[] = {
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK,
};

//static const SkScalar gPos[] = { SK_Scalar1*999/2000, SK_Scalar1*1001/2000 };

static const GradData gGradData[] = {
    { 40, gColors, NULL },
    //  { 2, gColors, gPos },
    //  { 2, gCol2, NULL },
};

static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
    return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos, data.fCount, tm);
}

static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
    SkPoint center;
    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
               SkScalarAve(pts[0].fY, pts[1].fY));
    return SkGradientShader::CreateRadial(center, center.fX, data.fColors,
                                          data.fPos, data.fCount, tm);
}

static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data, SkShader::TileMode) {
    SkPoint center;
    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
               SkScalarAve(pts[0].fY, pts[1].fY));
    return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount);
}


typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm);

static const GradMaker gGradMakers[] = {
    MakeLinear, MakeRadial, MakeSweep,
};

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

class GradientsGM : public GM {
public:
    GradientsGM() {
        this->setBGColor(0xFFDDDDDD);
    }

protected:
    SkString onShortName() override { return SkString("gradient_dirty_laundry"); }
    SkISize onISize() override { return SkISize::Make(640, 615); }

    void onDraw(SkCanvas* canvas) override {
        SkPoint pts[2] = { { 0, 0 },
                           { SkIntToScalar(100), SkIntToScalar(100) }
        };
        SkShader::TileMode tm = SkShader::kClamp_TileMode;
        SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
        SkPaint paint;
        paint.setAntiAlias(true);

        canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
        for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
            canvas->save();
            for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) {
                SkShader* shader = gGradMakers[j](pts, gGradData[i], tm);
                paint.setShader(shader)->unref();
                canvas->drawRect(r, paint);
                canvas->translate(0, SkIntToScalar(120));
            }
            canvas->restore();
            canvas->translate(SkIntToScalar(120), 0);
        }
    }

private:
    typedef GM INHERITED;
};

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

static GM* MyFactory(void*) { return new GradientsGM; }
static GMRegistry reg(MyFactory);