src/third_party/skia/samplecode/SampleTiling.cpp

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "SampleCode.h"
#include "SkView.h"
#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkPictureRecorder.h"
#include "SkRegion.h"
#include "SkShader.h"
#include "SkUtils.h"
#include "SkColorPriv.h"
#include "SkColorFilter.h"
#include "SkPicture.h"
#include "SkTypeface.h"

// effects
#include "SkGradientShader.h"
#include "SkBlurMask.h"
#include "SkBlurDrawLooper.h"

static void makebm(SkBitmap* bm, SkColorType ct, int w, int h) {
    bm->allocPixels(SkImageInfo::Make(w, h, ct, kPremul_SkAlphaType));
    bm->eraseColor(SK_ColorTRANSPARENT);

    SkCanvas    canvas(*bm);
    SkPoint     pts[] = { { 0, 0 }, { SkIntToScalar(w), SkIntToScalar(h) } };
    SkColor     colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
    SkScalar    pos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
    SkPaint     paint;

    paint.setDither(true);
    paint.setShader(SkGradientShader::MakeLinear(pts, colors, pos,
                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode));
    canvas.drawPaint(paint);
}

static void setup(SkPaint* paint, const SkBitmap& bm, bool filter,
                  SkShader::TileMode tmx, SkShader::TileMode tmy) {
    paint->setShader(SkShader::MakeBitmapShader(bm, tmx, tmy));
    paint->setFilterQuality(filter ? kLow_SkFilterQuality : kNone_SkFilterQuality);
}

static const SkColorType gColorTypes[] = {
    kN32_SkColorType,
    kRGB_565_SkColorType,
};
static const int gWidth = 32;
static const int gHeight = 32;

class TilingView : public SampleView {
    sk_sp<SkPicture>     fTextPicture;
    sk_sp<SkDrawLooper>  fLooper;
public:
    TilingView()
        : fLooper(SkBlurDrawLooper::Make(0x88000000,
                                         SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(1)),
                                         SkIntToScalar(2), SkIntToScalar(2))) {
        for (size_t i = 0; i < SK_ARRAY_COUNT(gColorTypes); i++) {
            makebm(&fTexture[i], gColorTypes[i], gWidth, gHeight);
        }
    }

    virtual ~TilingView() {
    }

    SkBitmap    fTexture[SK_ARRAY_COUNT(gColorTypes)];

protected:
    // overrides from SkEventSink
    virtual bool onQuery(SkEvent* evt) {
        if (SampleCode::TitleQ(*evt)) {
            SampleCode::TitleR(evt, "Tiling");
            return true;
        }
        return this->INHERITED::onQuery(evt);
    }

    virtual void onDrawContent(SkCanvas* canvas) {
        SkRect r = { 0, 0, SkIntToScalar(gWidth*2), SkIntToScalar(gHeight*2) };

        static const char* gConfigNames[] = { "8888", "565", "4444" };

        static const bool           gFilters[] = { false, true };
        static const char*          gFilterNames[] = {     "point",                     "bilinear" };

        static const SkShader::TileMode gModes[] = { SkShader::kClamp_TileMode, SkShader::kRepeat_TileMode, SkShader::kMirror_TileMode };
        static const char*          gModeNames[] = {    "C",                    "R",                   "M" };

        SkScalar y = SkIntToScalar(24);
        SkScalar x = SkIntToScalar(10);

        SkPictureRecorder recorder;
        SkCanvas* textCanvas = nullptr;
        if (nullptr == fTextPicture) {
            textCanvas = recorder.beginRecording(1000, 1000, nullptr, 0);
        }

        if (textCanvas) {
            for (size_t kx = 0; kx < SK_ARRAY_COUNT(gModes); kx++) {
                for (size_t ky = 0; ky < SK_ARRAY_COUNT(gModes); ky++) {
                    SkPaint p;
                    SkString str;
                    p.setAntiAlias(true);
                    p.setDither(true);
                    p.setLooper(fLooper);
                    str.printf("[%s,%s]", gModeNames[kx], gModeNames[ky]);

                    p.setTextAlign(SkPaint::kCenter_Align);
                    textCanvas->drawString(str, x + r.width()/2, y, p);

                    x += r.width() * 4 / 3;
                }
            }
        }

        y += SkIntToScalar(16);

        for (size_t i = 0; i < SK_ARRAY_COUNT(gColorTypes); i++) {
            for (size_t j = 0; j < SK_ARRAY_COUNT(gFilters); j++) {
                x = SkIntToScalar(10);
                for (size_t kx = 0; kx < SK_ARRAY_COUNT(gModes); kx++) {
                    for (size_t ky = 0; ky < SK_ARRAY_COUNT(gModes); ky++) {
                        SkPaint paint;
                        setup(&paint, fTexture[i], gFilters[j], gModes[kx], gModes[ky]);
                        paint.setDither(true);

                        canvas->save();
                        canvas->translate(x, y);
                        canvas->drawRect(r, paint);
                        canvas->restore();

                        x += r.width() * 4 / 3;
                    }
                }
                if (textCanvas) {
                    SkPaint p;
                    SkString str;
                    p.setAntiAlias(true);
                    p.setLooper(fLooper);
                    str.printf("%s, %s", gConfigNames[i], gFilterNames[j]);
                    textCanvas->drawString(str, x, y + r.height() * 2 / 3, p);
                }

                y += r.height() * 4 / 3;
            }
        }

        if (textCanvas) {
            SkASSERT(nullptr == fTextPicture);
            fTextPicture = recorder.finishRecordingAsPicture();
        }

        SkASSERT(fTextPicture);
        canvas->drawPicture(fTextPicture.get());
    }

private:
    typedef SampleView INHERITED;
};

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

static SkView* MyFactory() { return new TilingView; }
static SkViewRegister reg(MyFactory);