/*
* Copyright 2017 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 "SkAnimTimer.h"
#include "SkCanvas.h"
#include "SkGlyphCache.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkRandom.h"
#include "SkTaskGroup.h"
////////////////////////////////////////////////////////////////////////////////////////////////////
// Static text from paths.
class PathText : public SampleView {
public:
constexpr static int kNumPaths = 1500;
virtual const char* getName() const { return "PathText"; }
PathText() : fRand(25) {
SkPaint defaultPaint;
SkAutoGlyphCache agc(defaultPaint, nullptr, &SkMatrix::I());
SkGlyphCache* cache = agc.getCache();
SkPath glyphPaths[52];
for (int i = 0; i < 52; ++i) {
// I and l are rects on OS X ...
char c = "aQCDEFGH7JKLMNOPBRZTUVWXYSAbcdefghijk1mnopqrstuvwxyz"[i];
SkGlyphID id = cache->unicharToGlyph(c);
cache->getScalerContext()->getPath(SkPackedGlyphID(id), &glyphPaths[i]);
}
for (int i = 0; i < kNumPaths; ++i) {
const SkPath& p = glyphPaths[i % 52];
fGlyphs[i].init(fRand, p);
}
}
virtual void reset() {
for (Glyph& glyph : fGlyphs) {
glyph.reset(fRand, this->width(), this->height());
}
}
void onOnceBeforeDraw() final { this->INHERITED::onOnceBeforeDraw(); this->reset(); }
void onSizeChange() final { this->INHERITED::onSizeChange(); this->reset(); }
bool onQuery(SkEvent* evt) final {
if (SampleCode::TitleQ(*evt)) {
SampleCode::TitleR(evt, this->getName());
return true;
}
return this->INHERITED::onQuery(evt);
}
void onDrawContent(SkCanvas* canvas) override {
for (Glyph& glyph : fGlyphs) {
SkAutoCanvasRestore acr(canvas, true);
canvas->translate(glyph.fPosition.x(), glyph.fPosition.y());
canvas->scale(glyph.fZoom, glyph.fZoom);
canvas->rotate(glyph.fSpin);
canvas->translate(-glyph.fMidpt.x(), -glyph.fMidpt.y());
canvas->drawPath(glyph.fPath, glyph.fPaint);
}
}
protected:
struct Glyph {
void init(SkRandom& rand, const SkPath& path);
void reset(SkRandom& rand, int w, int h);
SkPath fPath;
SkPaint fPaint;
SkPoint fPosition;
SkScalar fZoom;
SkScalar fSpin;
SkPoint fMidpt;
};
Glyph fGlyphs[kNumPaths];
SkRandom fRand;
typedef SampleView INHERITED;
};
void PathText::Glyph::init(SkRandom& rand, const SkPath& path) {
fPath = path;
fPaint.setAntiAlias(true);
fPaint.setColor(rand.nextU() | 0x80808080);
}
void PathText::Glyph::reset(SkRandom& rand, int w, int h) {
int screensize = SkTMax(w, h);
const SkRect& bounds = fPath.getBounds();
SkScalar t;
fPosition = {rand.nextF() * w, rand.nextF() * h};
t = pow(rand.nextF(), 100);
fZoom = ((1 - t) * screensize / 50 + t * screensize / 3) /
SkTMax(bounds.width(), bounds.height());
fSpin = rand.nextF() * 360;
fMidpt = {bounds.centerX(), bounds.centerY()};
}
////////////////////////////////////////////////////////////////////////////////////////////////////
// Text from paths with animated transformation matrices.
class MovingPathText : public PathText {
public:
const char* getName() const override { return "MovingPathText"; }
MovingPathText()
: fFrontMatrices(kNumPaths)
, fBackMatrices(kNumPaths) {
}
~MovingPathText() override {
fBackgroundAnimationTask.wait();
}
void reset() override {
const SkScalar screensize = static_cast<SkScalar>(SkTMax(this->width(), this->height()));
this->INHERITED::reset();
for (auto& v : fVelocities) {
for (SkScalar* d : {&v.fDx, &v.fDy}) {
SkScalar t = pow(fRand.nextF(), 3);
*d = ((1 - t) / 60 + t / 10) * (fRand.nextBool() ? screensize : -screensize);
}
SkScalar t = pow(fRand.nextF(), 25);
v.fDSpin = ((1 - t) * 360 / 7.5 + t * 360 / 1.5) * (fRand.nextBool() ? 1 : -1);
}
// Get valid front data.
fBackgroundAnimationTask.wait();
this->runAnimationTask(0, 0, this->width(), this->height());
memcpy(fFrontMatrices, fBackMatrices, kNumPaths * sizeof(SkMatrix));
fLastTick = 0;
}
bool onAnimate(const SkAnimTimer& timer) final {
fBackgroundAnimationTask.wait();
this->swapAnimationBuffers();
const double tsec = timer.secs();
const double dt = fLastTick ? (timer.secs() - fLastTick) : 0;
fBackgroundAnimationTask.add(std::bind(&MovingPathText::runAnimationTask, this, tsec,
dt, this->width(), this->height()));
fLastTick = timer.secs();
return true;
}
/**
* Called on a background thread. Here we can only modify fBackMatrices.
*/
virtual void runAnimationTask(double t, double dt, int w, int h) {
for (int idx = 0; idx < kNumPaths; ++idx) {
Velocity* v = &fVelocities[idx];
Glyph* glyph = &fGlyphs[idx];
SkMatrix* backMatrix = &fBackMatrices[idx];
glyph->fPosition.fX += v->fDx * dt;
if (glyph->fPosition.x() < 0) {
glyph->fPosition.fX -= 2 * glyph->fPosition.x();
v->fDx = -v->fDx;
} else if (glyph->fPosition.x() > w) {
glyph->fPosition.fX -= 2 * (glyph->fPosition.x() - w);
v->fDx = -v->fDx;
}
glyph->fPosition.fY += v->fDy * dt;
if (glyph->fPosition.y() < 0) {
glyph->fPosition.fY -= 2 * glyph->fPosition.y();
v->fDy = -v->fDy;
} else if (glyph->fPosition.y() > h) {
glyph->fPosition.fY -= 2 * (glyph->fPosition.y() - h);
v->fDy = -v->fDy;
}
glyph->fSpin += v->fDSpin * dt;
backMatrix->setTranslate(glyph->fPosition.x(), glyph->fPosition.y());
backMatrix->preScale(glyph->fZoom, glyph->fZoom);
backMatrix->preRotate(glyph->fSpin);
backMatrix->preTranslate(-glyph->fMidpt.x(), -glyph->fMidpt.y());
}
}
virtual void swapAnimationBuffers() {
std::swap(fFrontMatrices, fBackMatrices);
}
void onDrawContent(SkCanvas* canvas) override {
for (int i = 0; i < kNumPaths; ++i) {
SkAutoCanvasRestore acr(canvas, true);
canvas->concat(fFrontMatrices[i]);
canvas->drawPath(fGlyphs[i].fPath, fGlyphs[i].fPaint);
}
}
protected:
struct Velocity {
SkScalar fDx, fDy;
SkScalar fDSpin;
};
Velocity fVelocities[kNumPaths];
SkAutoTMalloc<SkMatrix> fFrontMatrices;
SkAutoTMalloc<SkMatrix> fBackMatrices;
SkTaskGroup fBackgroundAnimationTask;
double fLastTick;
typedef PathText INHERITED;
};
////////////////////////////////////////////////////////////////////////////////////////////////////
// Text from paths with animated control points.
class WavyPathText : public MovingPathText {
public:
const char* getName() const override { return "WavyPathText"; }
WavyPathText()
: fFrontPaths(kNumPaths)
, fBackPaths(kNumPaths) {}
~WavyPathText() override {
fBackgroundAnimationTask.wait();
}
void reset() override {
fWaves.reset(fRand, this->width(), this->height());
this->INHERITED::reset();
std::copy(fBackPaths.get(), fBackPaths.get() + kNumPaths, fFrontPaths.get());
}
/**
* Called on a background thread. Here we can only modify fBackPaths.
*/
void runAnimationTask(double t, double dt, int w, int h) override {
const float tsec = static_cast<float>(t);
this->INHERITED::runAnimationTask(t, 0.5 * dt, w, h);
for (int i = 0; i < kNumPaths; ++i) {
const Glyph& glyph = fGlyphs[i];
const SkMatrix& backMatrix = fBackMatrices[i];
const Sk2f matrix[3] = {
Sk2f(backMatrix.getScaleX(), backMatrix.getSkewY()),
Sk2f(backMatrix.getSkewX(), backMatrix.getScaleY()),
Sk2f(backMatrix.getTranslateX(), backMatrix.getTranslateY())
};
SkPath* backpath = &fBackPaths[i];
backpath->reset();
backpath->setFillType(SkPath::kEvenOdd_FillType);
SkPath::RawIter iter(glyph.fPath);
SkPath::Verb verb;
SkPoint pts[4];
while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
switch (verb) {
case SkPath::kMove_Verb: {
SkPoint pt = fWaves.apply(tsec, matrix, pts[0]);
backpath->moveTo(pt.x(), pt.y());
break;
}
case SkPath::kLine_Verb: {
SkPoint endpt = fWaves.apply(tsec, matrix, pts[1]);
backpath->lineTo(endpt.x(), endpt.y());
break;
}
case SkPath::kQuad_Verb: {
SkPoint controlPt = fWaves.apply(tsec, matrix, pts[1]);
SkPoint endpt = fWaves.apply(tsec, matrix, pts[2]);
backpath->quadTo(controlPt.x(), controlPt.y(), endpt.x(), endpt.y());
break;
}
case SkPath::kClose_Verb: {
backpath->close();
break;
}
case SkPath::kCubic_Verb:
case SkPath::kConic_Verb:
case SkPath::kDone_Verb:
SkFAIL("Unexpected path verb");
break;
}
}
}
}
void swapAnimationBuffers() override {
this->INHERITED::swapAnimationBuffers();
fFrontPaths.swap(fBackPaths);
}
void onDrawContent(SkCanvas* canvas) override {
for (int i = 0; i < kNumPaths; ++i) {
canvas->drawPath(fFrontPaths[i], fGlyphs[i].fPaint);
}
}
private:
/**
* Describes 4 stacked sine waves that can offset a point as a function of wall time.
*/
class Waves {
public:
void reset(SkRandom& rand, int w, int h);
SkPoint apply(float tsec, const Sk2f matrix[3], const SkPoint& pt) const;
private:
constexpr static double kAverageAngle = SK_ScalarPI / 8.0;
constexpr static double kMaxOffsetAngle = SK_ScalarPI / 3.0;
float fAmplitudes[4];
float fFrequencies[4];
float fDirsX[4];
float fDirsY[4];
float fSpeeds[4];
float fOffsets[4];
};
SkAutoTArray<SkPath> fFrontPaths;
SkAutoTArray<SkPath> fBackPaths;
Waves fWaves;
typedef MovingPathText INHERITED;
};
void WavyPathText::Waves::reset(SkRandom& rand, int w, int h) {
const double pixelsPerMeter = 0.06 * SkTMax(w, h);
const double medianWavelength = 8 * pixelsPerMeter;
const double medianWaveAmplitude = 0.05 * 4 * pixelsPerMeter;
const double gravity = 9.8 * pixelsPerMeter;
for (int i = 0; i < 4; ++i) {
const double offsetAngle = (rand.nextF() * 2 - 1) * kMaxOffsetAngle;
const double intensity = pow(2, rand.nextF() * 2 - 1);
const double wavelength = intensity * medianWavelength;
fAmplitudes[i] = intensity * medianWaveAmplitude;
fFrequencies[i] = 2 * SK_ScalarPI / wavelength;
fDirsX[i] = cosf(kAverageAngle + offsetAngle);
fDirsY[i] = sinf(kAverageAngle + offsetAngle);
fSpeeds[i] = -sqrt(gravity * 2 * SK_ScalarPI / wavelength);
fOffsets[i] = rand.nextF() * 2 * SK_ScalarPI;
}
}
SkPoint WavyPathText::Waves::apply(float tsec, const Sk2f matrix[3], const SkPoint& pt) const {
constexpr static int kTableSize = 4096;
static float sin2table[kTableSize];
static SkOnce initTable;
initTable([]() {
for (int i = 0; i <= kTableSize; ++i) {
const double sintheta = sin(i * (SK_ScalarPI / kTableSize));
sin2table[i] = static_cast<float>(sintheta * sintheta - 0.5);
}
});
const Sk4f amplitudes = Sk4f::Load(fAmplitudes);
const Sk4f frequencies = Sk4f::Load(fFrequencies);
const Sk4f dirsX = Sk4f::Load(fDirsX);
const Sk4f dirsY = Sk4f::Load(fDirsY);
const Sk4f speeds = Sk4f::Load(fSpeeds);
const Sk4f offsets = Sk4f::Load(fOffsets);
float devicePt[2];
(matrix[0] * pt.x() + matrix[1] * pt.y() + matrix[2]).store(devicePt);
const Sk4f t = (frequencies * (dirsX * devicePt[0] + dirsY * devicePt[1]) +
speeds * tsec +
offsets).abs() * (float(kTableSize) / float(SK_ScalarPI));
const Sk4i ipart = SkNx_cast<int>(t);
const Sk4f fpart = t - SkNx_cast<float>(ipart);
int32_t indices[4];
(ipart & (kTableSize-1)).store(indices);
const Sk4f left(sin2table[indices[0]], sin2table[indices[1]],
sin2table[indices[2]], sin2table[indices[3]]);
const Sk4f right(sin2table[indices[0] + 1], sin2table[indices[1] + 1],
sin2table[indices[2] + 1], sin2table[indices[3] + 1]);
const Sk4f height = amplitudes * (left * (1.f - fpart) + right * fpart);
Sk4f dy = height * dirsY;
Sk4f dx = height * dirsX;
float offsetY[4], offsetX[4];
(dy + SkNx_shuffle<2,3,0,1>(dy)).store(offsetY); // accumulate.
(dx + SkNx_shuffle<2,3,0,1>(dx)).store(offsetX);;
return {devicePt[0] + offsetY[0] + offsetY[1], devicePt[1] - offsetX[0] - offsetX[1]};
}
////////////////////////////////////////////////////////////////////////////////////////////////////
DEF_SAMPLE( return new WavyPathText; )
DEF_SAMPLE( return new MovingPathText; )
DEF_SAMPLE( return new PathText; )