/*
* 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 "SkBlurMask.h"
#include "SkBlurMaskFilter.h"
#include "SkCanvas.h"
#include "SkDevice.h"
#include "SkReadBuffer.h"
#include "SkWriteBuffer.h"
#include "SkGradientShader.h"
#include "SkLayerRasterizer.h"
#include "SkPaint.h"
#include "SkView.h"
#define BG_COLOR 0xFFDDDDDD
typedef void (*SlideProc)(SkCanvas*);
///////////////////////////////////////////////////////////////////////////////
#include "Sk1DPathEffect.h"
#include "Sk2DPathEffect.h"
#include "SkCornerPathEffect.h"
#include "SkDashPathEffect.h"
#include "SkDiscretePathEffect.h"
static void compose_pe(SkPaint* paint) {
SkPathEffect* pe = paint->getPathEffect();
SkPathEffect* corner = SkCornerPathEffect::Create(25);
SkPathEffect* compose;
if (pe) {
compose = SkComposePathEffect::Create(pe, corner);
corner->unref();
} else {
compose = corner;
}
paint->setPathEffect(compose)->unref();
}
static void hair_pe(SkPaint* paint) {
paint->setStrokeWidth(0);
}
static void hair2_pe(SkPaint* paint) {
paint->setStrokeWidth(0);
compose_pe(paint);
}
static void stroke_pe(SkPaint* paint) {
paint->setStrokeWidth(12);
compose_pe(paint);
}
static void dash_pe(SkPaint* paint) {
SkScalar inter[] = { 20, 10, 10, 10 };
paint->setStrokeWidth(12);
paint->setPathEffect(SkDashPathEffect::Create(inter, SK_ARRAY_COUNT(inter),
0))->unref();
compose_pe(paint);
}
static const int gXY[] = {
4, 0, 0, -4, 8, -4, 12, 0, 8, 4, 0, 4
};
static void scale(SkPath* path, SkScalar scale) {
SkMatrix m;
m.setScale(scale, scale);
path->transform(m);
}
static void one_d_pe(SkPaint* paint) {
SkPath path;
path.moveTo(SkIntToScalar(gXY[0]), SkIntToScalar(gXY[1]));
for (unsigned i = 2; i < SK_ARRAY_COUNT(gXY); i += 2)
path.lineTo(SkIntToScalar(gXY[i]), SkIntToScalar(gXY[i+1]));
path.close();
path.offset(SkIntToScalar(-6), 0);
scale(&path, 1.5f);
paint->setPathEffect(SkPath1DPathEffect::Create(path, SkIntToScalar(21), 0,
SkPath1DPathEffect::kRotate_Style))->unref();
compose_pe(paint);
}
typedef void (*PE_Proc)(SkPaint*);
static const PE_Proc gPE[] = { hair_pe, hair2_pe, stroke_pe, dash_pe, one_d_pe };
static void fill_pe(SkPaint* paint) {
paint->setStyle(SkPaint::kFill_Style);
paint->setPathEffect(nullptr);
}
static void discrete_pe(SkPaint* paint) {
paint->setPathEffect(SkDiscretePathEffect::Create(10, 4))->unref();
}
static SkPathEffect* MakeTileEffect() {
SkMatrix m;
m.setScale(SkIntToScalar(12), SkIntToScalar(12));
SkPath path;
path.addCircle(0, 0, SkIntToScalar(5));
return SkPath2DPathEffect::Create(m, path);
}
static void tile_pe(SkPaint* paint) {
paint->setPathEffect(MakeTileEffect())->unref();
}
static const PE_Proc gPE2[] = { fill_pe, discrete_pe, tile_pe };
static void patheffect_slide(SkCanvas* canvas) {
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
SkPath path;
path.moveTo(20, 20);
path.lineTo(70, 120);
path.lineTo(120, 30);
path.lineTo(170, 80);
path.lineTo(240, 50);
size_t i;
canvas->save();
for (i = 0; i < SK_ARRAY_COUNT(gPE); i++) {
gPE[i](&paint);
canvas->drawPath(path, paint);
canvas->translate(0, 75);
}
canvas->restore();
path.reset();
SkRect r = { 0, 0, 250, 120 };
path.addOval(r, SkPath::kCW_Direction);
r.inset(50, 50);
path.addRect(r, SkPath::kCCW_Direction);
canvas->translate(320, 20);
for (i = 0; i < SK_ARRAY_COUNT(gPE2); i++) {
gPE2[i](&paint);
canvas->drawPath(path, paint);
canvas->translate(0, 160);
}
}
///////////////////////////////////////////////////////////////////////////////
#include "SkGradientShader.h"
struct GradData {
int fCount;
const SkColor* fColors;
const SkScalar* fPos;
};
static const SkColor gColors[] = {
SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
};
static const SkScalar gPos0[] = { 0, SK_Scalar1 };
static const SkScalar gPos1[] = { SK_Scalar1/4, SK_Scalar1*3/4 };
static const SkScalar gPos2[] = {
0, SK_Scalar1/8, SK_Scalar1/2, SK_Scalar1*7/8, SK_Scalar1
};
static const GradData gGradData[] = {
{ 2, gColors, nullptr },
{ 2, gColors, gPos0 },
{ 2, gColors, gPos1 },
{ 5, gColors, nullptr },
{ 5, gColors, gPos2 }
};
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 tm) {
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);
}
static SkShader* Make2Conical(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
SkPoint center0, center1;
center0.set(SkScalarAve(pts[0].fX, pts[1].fX),
SkScalarAve(pts[0].fY, pts[1].fY));
center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5),
SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4));
return SkGradientShader::CreateTwoPointConical(
center1, (pts[1].fX - pts[0].fX) / 7,
center0, (pts[1].fX - pts[0].fX) / 2,
data.fColors, data.fPos, data.fCount, tm);
}
typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm);
static const GradMaker gGradMakers[] = {
MakeLinear, MakeRadial, MakeSweep, Make2Conical
};
static void gradient_slide(SkCanvas* canvas) {
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);
paint.setDither(true);
canvas->translate(SkIntToScalar(20), SkIntToScalar(10));
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);
canvas->drawRect(r, paint);
shader->unref();
canvas->translate(0, SkIntToScalar(120));
}
canvas->restore();
canvas->translate(SkIntToScalar(120), 0);
}
}
///////////////////////////////////////////////////////////////////////////////
#include "SkPathMeasure.h"
static SkScalar getpathlen(const SkPath& path) {
SkPathMeasure meas(path, false);
return meas.getLength();
}
static void textonpath_slide(SkCanvas* canvas) {
const char* text = "Displacement";
size_t len =strlen(text);
SkPath path;
path.moveTo(100, 300);
path.quadTo(300, 100, 500, 300);
path.offset(0, -100);
SkPaint paint;
paint.setAntiAlias(true);
paint.setTextSize(40);
paint.setStyle(SkPaint::kStroke_Style);
canvas->drawPath(path, paint);
paint.setStyle(SkPaint::kFill_Style);
SkScalar x = 50;
paint.setColor(0xFF008800);
canvas->drawTextOnPathHV(text, len, path,
x, paint.getTextSize()*2/3, paint);
paint.setColor(SK_ColorRED);
canvas->drawTextOnPathHV(text, len, path,
x + 60, 0, paint);
paint.setColor(SK_ColorBLUE);
canvas->drawTextOnPathHV(text, len, path,
x + 120, -paint.getTextSize()*2/3, paint);
path.offset(0, 200);
paint.setTextAlign(SkPaint::kRight_Align);
text = "Matrices";
len = strlen(text);
SkScalar pathLen = getpathlen(path);
SkMatrix matrix;
paint.setColor(SK_ColorBLACK);
paint.setStyle(SkPaint::kStroke_Style);
canvas->drawPath(path, paint);
paint.setStyle(SkPaint::kFill_Style);
paint.setTextSize(50);
canvas->drawTextOnPath(text, len, path, nullptr, paint);
paint.setColor(SK_ColorRED);
matrix.setScale(-SK_Scalar1, SK_Scalar1);
matrix.postTranslate(pathLen, 0);
canvas->drawTextOnPath(text, len, path, &matrix, paint);
paint.setColor(SK_ColorBLUE);
matrix.setScale(SK_Scalar1, -SK_Scalar1);
canvas->drawTextOnPath(text, len, path, &matrix, paint);
paint.setColor(0xFF008800);
matrix.setScale(-SK_Scalar1, -SK_Scalar1);
matrix.postTranslate(pathLen, 0);
canvas->drawTextOnPath(text, len, path, &matrix, paint);
}
///////////////////////////////////////////////////////////////////////////////
#include "SkImageDecoder.h"
#include "SkOSFile.h"
#include "SkRandom.h"
#include "SkStream.h"
static SkShader* make_shader0(SkIPoint* size) {
SkBitmap bm;
SkImageDecoder::DecodeFile("/skimages/logo.gif", &bm);
size->set(bm.width(), bm.height());
return SkShader::CreateBitmapShader(bm, SkShader::kClamp_TileMode,
SkShader::kClamp_TileMode);
}
static SkShader* make_shader1(const SkIPoint& size) {
SkPoint pts[] = { { 0, 0 },
{ SkIntToScalar(size.fX), SkIntToScalar(size.fY) } };
SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorRED };
return SkGradientShader::CreateLinear(pts, colors, nullptr,
SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode);
}
class Rec {
public:
SkCanvas::VertexMode fMode;
int fCount;
SkPoint* fVerts;
SkPoint* fTexs;
Rec() : fCount(0), fVerts(nullptr), fTexs(nullptr) {}
~Rec() { delete[] fVerts; delete[] fTexs; }
};
static void make_tris(Rec* rec) {
int n = 10;
SkRandom rand;
rec->fMode = SkCanvas::kTriangles_VertexMode;
rec->fCount = n * 3;
rec->fVerts = new SkPoint[rec->fCount];
for (int i = 0; i < n; i++) {
SkPoint* v = &rec->fVerts[i*3];
for (int j = 0; j < 3; j++) {
v[j].set(rand.nextUScalar1() * 250, rand.nextUScalar1() * 250);
}
}
}
static void make_fan(Rec* rec, int texWidth, int texHeight) {
const SkScalar tx = SkIntToScalar(texWidth);
const SkScalar ty = SkIntToScalar(texHeight);
const int n = 24;
rec->fMode = SkCanvas::kTriangleFan_VertexMode;
rec->fCount = n + 2;
rec->fVerts = new SkPoint[rec->fCount];
rec->fTexs = new SkPoint[rec->fCount];
SkPoint* v = rec->fVerts;
SkPoint* t = rec->fTexs;
v[0].set(0, 0);
t[0].set(0, 0);
for (int i = 0; i < n; i++) {
SkScalar cos;
SkScalar sin = SkScalarSinCos(SK_ScalarPI * 2 * i / n, &cos);
v[i+1].set(cos, sin);
t[i+1].set(i*tx/n, ty);
}
v[n+1] = v[1];
t[n+1].set(tx, ty);
SkMatrix m;
m.setScale(SkIntToScalar(100), SkIntToScalar(100));
m.postTranslate(SkIntToScalar(110), SkIntToScalar(110));
m.mapPoints(v, rec->fCount);
}
static void make_strip(Rec* rec, int texWidth, int texHeight) {
const SkScalar tx = SkIntToScalar(texWidth);
const SkScalar ty = SkIntToScalar(texHeight);
const int n = 24;
rec->fMode = SkCanvas::kTriangleStrip_VertexMode;
rec->fCount = 2 * (n + 1);
rec->fVerts = new SkPoint[rec->fCount];
rec->fTexs = new SkPoint[rec->fCount];
SkPoint* v = rec->fVerts;
SkPoint* t = rec->fTexs;
for (int i = 0; i < n; i++) {
SkScalar cos;
SkScalar sin = SkScalarSinCos(SK_ScalarPI * 2 * i / n, &cos);
v[i*2 + 0].set(cos/2, sin/2);
v[i*2 + 1].set(cos, sin);
t[i*2 + 0].set(tx * i / n, ty);
t[i*2 + 1].set(tx * i / n, 0);
}
v[2*n + 0] = v[0];
v[2*n + 1] = v[1];
t[2*n + 0].set(tx, ty);
t[2*n + 1].set(tx, 0);
SkMatrix m;
m.setScale(SkIntToScalar(100), SkIntToScalar(100));
m.postTranslate(SkIntToScalar(110), SkIntToScalar(110));
m.mapPoints(v, rec->fCount);
}
static void mesh_slide(SkCanvas* canvas) {
Rec fRecs[3];
SkIPoint size;
SkShader* fShader0 = make_shader0(&size);
SkShader* fShader1 = make_shader1(size);
SkAutoUnref aur0(fShader0);
SkAutoUnref aur1(fShader1);
make_strip(&fRecs[0], size.fX, size.fY);
make_fan(&fRecs[1], size.fX, size.fY);
make_tris(&fRecs[2]);
SkPaint paint;
paint.setDither(true);
paint.setFilterQuality(kLow_SkFilterQuality);
for (size_t i = 0; i < SK_ARRAY_COUNT(fRecs); i++) {
canvas->save();
paint.setShader(nullptr);
canvas->drawVertices(fRecs[i].fMode, fRecs[i].fCount,
fRecs[i].fVerts, fRecs[i].fTexs,
nullptr, nullptr, nullptr, 0, paint);
canvas->translate(SkIntToScalar(210), 0);
paint.setShader(fShader0);
canvas->drawVertices(fRecs[i].fMode, fRecs[i].fCount,
fRecs[i].fVerts, fRecs[i].fTexs,
nullptr, nullptr, nullptr, 0, paint);
canvas->translate(SkIntToScalar(210), 0);
paint.setShader(fShader1);
canvas->drawVertices(fRecs[i].fMode, fRecs[i].fCount,
fRecs[i].fVerts, fRecs[i].fTexs,
nullptr, nullptr, nullptr, 0, paint);
canvas->restore();
canvas->translate(0, SkIntToScalar(250));
}
}
///////////////////////////////////////////////////////////////////////////////
static void r0(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
p.setMaskFilter(SkBlurMaskFilter::Create(kNormal_SkBlurStyle,
SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(3))))->unref();
rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));
p.setMaskFilter(nullptr);
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(SK_Scalar1);
rastBuilder->addLayer(p);
p.setAlpha(0x11);
p.setStyle(SkPaint::kFill_Style);
p.setXfermodeMode(SkXfermode::kSrc_Mode);
rastBuilder->addLayer(p);
}
static void r1(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
rastBuilder->addLayer(p);
p.setAlpha(0x40);
p.setXfermodeMode(SkXfermode::kSrc_Mode);
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(SK_Scalar1*2);
rastBuilder->addLayer(p);
}
static void r2(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
p.setStyle(SkPaint::kStrokeAndFill_Style);
p.setStrokeWidth(SK_Scalar1*4);
rastBuilder->addLayer(p);
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(SK_Scalar1*3/2);
p.setXfermodeMode(SkXfermode::kClear_Mode);
rastBuilder->addLayer(p);
}
static void r3(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(SK_Scalar1*3);
rastBuilder->addLayer(p);
p.setAlpha(0x20);
p.setStyle(SkPaint::kFill_Style);
p.setXfermodeMode(SkXfermode::kSrc_Mode);
rastBuilder->addLayer(p);
}
static void r4(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
p.setAlpha(0x60);
rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));
p.setAlpha(0xFF);
p.setXfermodeMode(SkXfermode::kClear_Mode);
rastBuilder->addLayer(p, SK_Scalar1*3/2, SK_Scalar1*3/2);
p.setXfermode(nullptr);
rastBuilder->addLayer(p);
}
#include "SkDiscretePathEffect.h"
static void r5(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
rastBuilder->addLayer(p);
p.setPathEffect(SkDiscretePathEffect::Create(SK_Scalar1*4, SK_Scalar1*3))->unref();
p.setXfermodeMode(SkXfermode::kSrcOut_Mode);
rastBuilder->addLayer(p);
}
static void r6(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
rastBuilder->addLayer(p);
p.setAntiAlias(false);
SkLayerRasterizer::Builder rastBuilder2;
r5(&rastBuilder2, p);
p.setRasterizer(rastBuilder2.detachRasterizer())->unref();
p.setXfermodeMode(SkXfermode::kClear_Mode);
rastBuilder->addLayer(p);
}
#include "Sk2DPathEffect.h"
static SkPathEffect* MakeDotEffect(SkScalar radius, const SkMatrix& matrix) {
SkPath path;
path.addCircle(0, 0, radius);
return SkPath2DPathEffect::Create(matrix, path);
}
static void r7(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
SkMatrix lattice;
lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
p.setPathEffect(MakeDotEffect(SK_Scalar1*4, lattice))->unref();
rastBuilder->addLayer(p);
}
static void r8(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
rastBuilder->addLayer(p);
SkMatrix lattice;
lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
p.setPathEffect(MakeDotEffect(SK_Scalar1*2, lattice))->unref();
p.setXfermodeMode(SkXfermode::kClear_Mode);
rastBuilder->addLayer(p);
p.setPathEffect(nullptr);
p.setXfermode(nullptr);
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(SK_Scalar1);
rastBuilder->addLayer(p);
}
static void r9(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p)
{
rastBuilder->addLayer(p);
SkMatrix lattice;
lattice.setScale(SK_Scalar1, SK_Scalar1*6, 0, 0);
lattice.postRotate(SkIntToScalar(30), 0, 0);
p.setPathEffect(SkLine2DPathEffect::Create(SK_Scalar1*2, lattice))->unref();
p.setXfermodeMode(SkXfermode::kClear_Mode);
rastBuilder->addLayer(p);
p.setPathEffect(nullptr);
p.setXfermode(nullptr);
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(SK_Scalar1);
rastBuilder->addLayer(p);
}
typedef void (*raster_proc)(SkLayerRasterizer::Builder*, SkPaint&);
static const raster_proc gRastProcs[] = {
r0, r1, r2, r3, r4, r5, r6, r7, r8, r9
};
static void apply_shader(SkPaint* paint, int index) {
raster_proc proc = gRastProcs[index];
SkPaint p;
SkLayerRasterizer::Builder rastBuilder;
p.setAntiAlias(true);
proc(&rastBuilder, p);
paint->setRasterizer(rastBuilder.detachRasterizer())->unref();
paint->setColor(SK_ColorBLUE);
}
#include "SkTypeface.h"
static void texteffect_slide(SkCanvas* canvas) {
const char* str = "Google";
size_t len = strlen(str);
SkScalar x = 20;
SkScalar y = 80;
SkPaint paint;
paint.setTypeface(SkTypeface::CreateFromName("Georgia", SkTypeface::kItalic));
paint.setTextSize(75);
paint.setAntiAlias(true);
paint.setColor(SK_ColorBLUE);
for (size_t i = 0; i < SK_ARRAY_COUNT(gRastProcs); i++) {
apply_shader(&paint, (int)i);
canvas->drawText(str, len, x, y, paint);
y += 80;
if (i == 4) {
x += 320;
y = 80;
}
}
}
///////////////////////////////////////////////////////////////////////////////
#include "SkImageEncoder.h"
static const SlideProc gProc[] = {
patheffect_slide,
gradient_slide,
textonpath_slide,
mesh_slide,
texteffect_slide
};
class SlideView : public SampleView {
int fIndex;
bool fOnce;
public:
SlideView() {
fOnce = false;
}
void init() {
if (fOnce) {
return;
}
fOnce = true;
fIndex = 0;
SkBitmap bm;
bm.allocN32Pixels(1024, 768);
SkCanvas canvas(bm);
SkScalar s = SkIntToScalar(1024) / 640;
canvas.scale(s, s);
for (size_t i = 0; i < SK_ARRAY_COUNT(gProc); i++) {
canvas.save();
canvas.drawColor(BG_COLOR);
gProc[i](&canvas);
canvas.restore();
SkString str;
str.printf("/skimages/slide_" SK_SIZE_T_SPECIFIER ".png", i);
SkImageEncoder::EncodeFile(str.c_str(), bm, SkImageEncoder::kPNG_Type, 100);
}
this->setBGColor(BG_COLOR);
}
protected:
// overrides from SkEventSink
bool onQuery(SkEvent* evt) override {
if (SampleCode::TitleQ(*evt)) {
SampleCode::TitleR(evt, "Slides");
return true;
}
return this->INHERITED::onQuery(evt);
}
void onDrawContent(SkCanvas* canvas) override {
this->init();
gProc[fIndex](canvas);
}
SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned) override {
this->init();
fIndex = (fIndex + 1) % SK_ARRAY_COUNT(gProc);
this->inval(nullptr);
return nullptr;
}
private:
typedef SampleView INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
static SkView* MyFactory() { return new SlideView; }
static SkViewRegister reg(MyFactory);