/*From version of May 16 2010
	PictureFlow - animated image show widget
	http://pictureflow.googlecode.com

	Copyright (C) 2008 Ariya Hidayat (ariya@kde.org)
	Copyright (C) 2007 Ariya Hidayat (ariya@kde.org)

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in
	all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	THE SOFTWARE.
*/
/** WARNING: Don't let this file in trunk, use a directory,
 *  else Qt Designer add / in header location
 * If you want add this on QtDesigner, add this in .ui file:
 * <customwidgets>
 *  <customwidget>
 *   <class>PictureFlow</class>
 *   <extends>QWidget</extends>
 *   <header location="global">gui/pictureflow.h</header>
 *   <container>1</container>
 *  </customwidget>
 * </customwidgets>
 * And use <widget class="PictureFlow" ...
 */
#include "gui/common/PictureFlow.h"

// detect Qt version
#if QT_VERSION >= 0x040000
#define PICTUREFLOW_QT4
#elif QT_VERSION >= 0x030000
#define PICTUREFLOW_QT3
#elif QT_VERSION >= 235
#define PICTUREFLOW_QT2
#else
#error PictureFlow widgets need Qt 2, Qt 3 or Qt 4
#endif

#ifdef PICTUREFLOW_QT4
#include <QApplication>
#include <QCache>
#include <QHash>
#include <QImage>
#include <QKeyEvent>
#include <QPainter>
#include <QPixmap>
#include <QTimer>
#include <QVector>
#include <QWidget>
#endif

#ifdef PICTUREFLOW_QT3
#include <qapplication.h>
#include <qcache.h>
#include <qimage.h>
#include <qpainter.h>
#include <qpixmap.h>
#include <qdatetime.h>
#include <qtimer.h>
#include <qvaluevector.h>
#include <qwidget.h>

#define qMax(x,y) ((x) > (y)) ? (x) : (y)
#define qMin(x,y) ((x) < (y)) ? (x) : (y)

#define QVector QValueVector

#define toImage convertToImage
#define contains find
#define modifiers state
#define ControlModifier ControlButton
#endif

#ifdef PICTUREFLOW_QT2
#include <qapplication.h>
#include <qarray.h>
#include <qcache.h>
#include <qimage.h>
#include <qintdict.h>
#include <qpainter.h>
#include <qpixmap.h>
#include <qdatetime.h>
#include <qtimer.h>
#include <qwidget.h>

#define qMax(x,y) ((x) > (y)) ? (x) : (y)
#define qMin(x,y) ((x) < (y)) ? (x) : (y)

#define QVector QArray

#define toImage convertToImage
#define contains find
#define modifiers state
#define ControlModifier ControlButton
#define flush flushX
#endif

// for fixed-point arithmetic, we need minimum 32-bit long
// long long (64-bit) might be useful for multiplication and division
typedef long PFreal;
#define PFREAL_SHIFT 10
#define PFREAL_ONE (1 << PFREAL_SHIFT)

#define IANGLE_MAX 1024
#define IANGLE_MASK 1023

inline PFreal fmul(PFreal a, PFreal b)
{
	return ((long long)(a))*((long long)(b)) >> PFREAL_SHIFT;
}

inline PFreal fdiv(PFreal num, PFreal den)
{
	long long p = (long long)(num) << (PFREAL_SHIFT*2);
	long long q = p / (long long)den;
	long long r = q >> PFREAL_SHIFT;

	return r;
}

inline PFreal fsin(int iangle)
{
	// warning: regenerate the table if IANGLE_MAX and PFREAL_SHIFT are changed!
	static const PFreal tab[] = {
	      3,   103,    202,    300,    394,    485,    571,    652,
	    726,   793,    853,    904,    947,    980,   1004,   1019,
	   1023,  1018,   1003,    978,    944,    901,    849,    789,
	    721,   647,    566,    479,    388,    294,    196,     97,
	     -4,  -104,   -203,   -301,   -395,   -486,   -572,   -653,
	   -727,  -794,   -854,   -905,   -948,   -981,  -1005,  -1020,
	  -1024, -1019,  -1004,   -979,   -945,   -902,   -850,   -790,
	   -722,  -648,   -567,   -480,   -389,   -295,   -197,    -98,
	      3
	};

	while(iangle < 0)
		iangle += IANGLE_MAX;
	iangle &= IANGLE_MASK;

	int i = (iangle >> 4);
	PFreal p = tab[i];
	PFreal q = tab[(i+1)];
	PFreal g = (q - p);
	return p + g * (iangle-i*16)/16;
}

inline PFreal fcos(int iangle)
{
	return fsin(iangle + (IANGLE_MAX >> 2));
}

/* ----------------------------------------------------------

PictureFlowState stores the state of all slides, i.e. all the necessary
information to be able to render them.

PictureFlowAnimator is responsible to move the slides during the
transition between slides, to achieve the effect similar to Cover Flow,
by changing the state.

PictureFlowSoftwareRenderer (or PictureFlowOpenGLRenderer) is
the actual 3-d renderer. It should render all slides given the state
(an instance of PictureFlowState).

Instances of all the above three classes are stored in
PictureFlowPrivate.

------------------------------------------------------- */

struct SlideInfo
{
	int slideIndex;
	int angle;
	PFreal cx;
	PFreal cy;
	int left;
	int right;
	int blend;
};

class PictureFlowState
{
public:
	PictureFlowState();
	~PictureFlowState();

	void reposition();
	void reset();

	QRgb backgroundColor;
	int slideWidth;
	int slideHeight;
	float slideRatio;
	PictureFlow::ReflectionEffect reflectionEffect;
	QVector<QImage*> slideImages;

	int angle;
	int spacing;
	PFreal offsetX;
	PFreal offsetY;

	SlideInfo centerSlide;
	QVector<SlideInfo> leftSlides;
	QVector<SlideInfo> rightSlides;
	int centerIndex;
};

class PictureFlowAnimator
{
public:
	PictureFlowAnimator();
	PictureFlowState* state;

	void start(int slide);
	void stop(int slide);
	void update();

	int target;
	int step;
	int frame;
	QTimer animateTimer;
};

class PictureFlowAbstractRenderer
{
public:
	PictureFlowAbstractRenderer(): state(0), dirty(false), widget(0) {}
	virtual ~PictureFlowAbstractRenderer() {}

	PictureFlowState* state;
	bool dirty;
	QWidget* widget;

	virtual void init() = 0;
	virtual void paint() = 0;
};

class PictureFlowSoftwareRenderer: public PictureFlowAbstractRenderer
{
public:
	PictureFlowSoftwareRenderer();
	~PictureFlowSoftwareRenderer();

	virtual void init();
	virtual void paint();

private:
	QSize size;
	QRgb bgcolor;
	int effect;
	QImage buffer;
	QVector<PFreal> rays;
	QImage* blankSurface;
#ifdef PICTUREFLOW_QT4
	QCache<int,QImage> surfaceCache;
	QHash<int,QImage*> imageHash;
#endif
#ifdef PICTUREFLOW_QT3
	QCache<QImage> surfaceCache;
	QMap<int,QImage*> imageHash;
#endif
#ifdef PICTUREFLOW_QT2
	QCache<QImage> surfaceCache;
	QIntDict<QImage> imageHash;
#endif

	void render();
	void renderSlides();
	QRect renderSlide(const SlideInfo &slide, int col1 = -1, int col2 = -1);
	QImage* surface(int slideIndex);
};

// ------------- PictureFlowState ---------------------------------------

PictureFlowState::PictureFlowState():
  backgroundColor(0), slideWidth(150), slideHeight(200), slideRatio(1/ 3 * 2),
  reflectionEffect(PictureFlow::BlurredReflection), spacing(40), centerIndex(0)
{
}

PictureFlowState::~PictureFlowState()
{
    for(int i=0;i<slideImages.size();++i)
        delete slideImages[i] ;
    slideImages.clear() ;
}

// readjust the settings, call this when slide dimension is changed
void PictureFlowState::reposition()
{
	angle = 70 * IANGLE_MAX / 360;  // approx. 70 degrees tilted

	offsetX = slideWidth/2 * (PFREAL_ONE-fcos(angle));
	offsetY = slideWidth/2 * fsin(angle);
	offsetX += slideWidth * PFREAL_ONE;
	offsetY += slideWidth * PFREAL_ONE / 4;
}

// adjust slides so that they are in "steady state" position
void PictureFlowState::reset()
{
	centerSlide.angle = 0;
	centerSlide.cx = 0;
	centerSlide.cy = 0;
	centerSlide.slideIndex = centerIndex;
	centerSlide.blend = 256;

	for(int i = 0; i < (int)leftSlides.count(); ++i) {
		SlideInfo& si = leftSlides[i];
		si.angle = angle;
		si.cx = -(offsetX + spacing*i*PFREAL_ONE);
		si.cy = offsetY;
		si.slideIndex = centerIndex-1-i;
		si.blend = 256 * (((int)leftSlides.count()-i)/(float)leftSlides.count());
	}//for(int i = 0; i < (int)leftSlides.count(); i++)

	for(int i = 0; i < (int)rightSlides.count(); ++i) {
		SlideInfo& si = rightSlides[i];
		si.angle = -angle;
		si.cx = offsetX + spacing*i*PFREAL_ONE;
		si.cy = offsetY;
		si.slideIndex = centerIndex+1+i;
		si.blend = 256 * (((int)rightSlides.count()-i)/(float)rightSlides.count());
	}//for(int i = 0; i < (int)rightSlides.count(); ++i
}

// ------------- PictureFlowAnimator  ---------------------------------------

PictureFlowAnimator::PictureFlowAnimator():
  state(0), target(0), step(0), frame(0)
{
}

void PictureFlowAnimator::start(int slide)
{
	target = slide;
	if(!animateTimer.isActive() && state) {
		step = (target < state->centerSlide.slideIndex) ? -1 : 1;
		animateTimer.start(30);
	}//if(!animateTimer.isActive() && state)
}

void PictureFlowAnimator::stop(int slide)
{
	step = 0;
	target = slide;
	frame = slide << 16;
	animateTimer.stop();
}

void PictureFlowAnimator::update()
{
	//if(!animateTimer.isActive())
	//  return;
	//if(step == 0)
	//  return;
	if(!state)
		return;

	int speed = 16384/4;

#if 1
	// deaccelerate when approaching the target
	const int max = 2 * 65536;

	int fi = frame;
	fi -= (target << 16);
	if(fi < 0)
		fi = -fi;
	fi = qMin(fi, max);

	int ia = IANGLE_MAX * (fi-max/2) / (max*2);
	speed = 512 + 16384 * (PFREAL_ONE+fsin(ia))/PFREAL_ONE;
#endif

	frame += speed*step;

	int index = frame >> 16;
	int pos = frame & 0xffff;
	int neg = 65536 - pos;
	int tick = (step < 0) ? neg : pos;
	PFreal ftick = (tick * PFREAL_ONE) >> 16;

	if(step < 0)
		++index;

	if(state->centerIndex != index) {
		state->centerIndex = index;
		frame = index << 16;
		state->centerSlide.slideIndex = state->centerIndex;
		for(int i = 0; i < (int)state->leftSlides.count(); ++i)
			state->leftSlides[i].slideIndex = state->centerIndex-1-i;
		for(int i = 0; i < (int)state->rightSlides.count(); ++i)
			state->rightSlides[i].slideIndex = state->centerIndex+1+i;
	}//if(state->centerIndex != index)

	state->centerSlide.angle = (step * tick * state->angle) >> 16;
	state->centerSlide.cx = -step * fmul(state->offsetX, ftick);
	state->centerSlide.cy = fmul(state->offsetY, ftick);

	if(state->centerIndex == target) {
		stop(target);
		state->reset();
		return;
	}//if(state->centerIndex == target)

	for(int i = 0; i < (int)state->leftSlides.count(); ++i) {
		SlideInfo& si = state->leftSlides[i];
		si.angle = state->angle;
		si.cx = -(state->offsetX + state->spacing*i*PFREAL_ONE + step*state->spacing*ftick);
		si.cy = state->offsetY;
	}//for(int i = 0; i < (int)state->leftSlides.count(); ++i)

	for(int i = 0; i < (int)state->rightSlides.count(); ++i) {
		SlideInfo& si = state->rightSlides[i];
		si.angle = -state->angle;
		si.cx = state->offsetX + state->spacing*i*PFREAL_ONE - step*state->spacing*ftick;
		si.cy = state->offsetY;
	}//for(int i = 0; i < (int)state->rightSlides.count(); ++i)

	if(step > 0) {
		PFreal ftick = (neg * PFREAL_ONE) >> 16;
		state->rightSlides[0].angle = -(neg * state->angle) >> 16;
		state->rightSlides[0].cx = fmul(state->offsetX, ftick);
		state->rightSlides[0].cy = fmul(state->offsetY, ftick);
	} else {
		PFreal ftick = (pos * PFREAL_ONE) >> 16;
		state->leftSlides[0].angle = (pos * state->angle) >> 16;
		state->leftSlides[0].cx = -fmul(state->offsetX, ftick);
		state->leftSlides[0].cy = fmul(state->offsetY, ftick);
	}//if(step > 0)

	// must change direction ?
	if(target < index) if(step > 0)
		step = -1;
	if(target > index) if(step < 0)
		step = 1;

	// the first and last slide must fade in/fade out
	int nleft = state->leftSlides.count();
	int nright = state->rightSlides.count();

	for(int index = 0; index < nleft; ++index) {
		int startBlend = 256 * ((nleft-index)/(float)nleft);
		int stopBlend = 256 * ((nleft-index-step)/(float)nleft);
		int blend = startBlend + ((stopBlend-startBlend) * (tick/65535.0)) ;
		if ((index==0) && (step<0)) blend = 256;//Is center
		state->leftSlides[index].blend = blend;
	}//for(int index = 0; index < nleft; ++index)
	for(int index = 0; index < nright; ++index) {
		int startBlend = 256 * ((nright-index)/(float)nright);
		int stopBlend = 256 * ((nright-index+step)/(float)nright);
		int blend = startBlend + ((stopBlend-startBlend) * (tick/65535.0)) ;
		if ((index==0) && (step>0)) blend = 256;//Is center
		state->rightSlides[index].blend = blend;
	}//for(int index = 0; index < nright; ++index)
}

// ------------- PictureFlowSoftwareRenderer ---------------------------------------

PictureFlowSoftwareRenderer::PictureFlowSoftwareRenderer():
  PictureFlowAbstractRenderer(), size(0,0), bgcolor(0), effect(-1), blankSurface(0)
{
#ifdef PICTUREFLOW_QT3
	surfaceCache.setAutoDelete(true);
#endif
}

PictureFlowSoftwareRenderer::~PictureFlowSoftwareRenderer()
{
	surfaceCache.clear();
	buffer = QImage();
	if (blankSurface) delete blankSurface;
}

void PictureFlowSoftwareRenderer::paint()
{
	if(!widget)
		return;

	if(widget->size() != size)
		init();

	if(state->backgroundColor != bgcolor) {
		bgcolor = state->backgroundColor;
		surfaceCache.clear();
	}//if(state->backgroundColor != bgcolor)

	if((int)(state->reflectionEffect) != effect) {
		effect = (int)state->reflectionEffect;
		surfaceCache.clear();
	}//if((int)(state->reflectionEffect) != effect)

	if(dirty)
		render();

	QPainter painter(widget);
	painter.drawImage(QPoint(0,0), buffer);
}

void PictureFlowSoftwareRenderer::init()
{
	if(!widget)
		return;

	surfaceCache.clear();
	if (blankSurface) delete blankSurface;
	blankSurface = 0;

	size = widget->size();
	int ww = size.width();
	int wh = size.height();
	int w = (ww+1)/2;
	int h = (wh+1)/2;

#ifdef PICTUREFLOW_QT4
	buffer = QImage(ww, wh, QImage::Format_RGB32);
#endif
#if defined(PICTUREFLOW_QT3) || defined(PICTUREFLOW_QT2)
	buffer.create(ww, wh, 32);
#endif
	buffer.fill(bgcolor);

	rays.resize(w*2);
	for(int i = 0; i < w; ++i) {
		PFreal gg = ((PFREAL_ONE >> 1) + i * PFREAL_ONE) / (2*h);
		rays[w-i-1] = -gg;
		rays[w+i] = gg;
	}//for(int i = 0; i < w; ++i)

	dirty = true;
}

// TODO: optimize this with lookup tables
static QRgb blendColor(QRgb c1, QRgb c2, int blend)
{
	int r = qRed(c1) * blend/256 + qRed(c2)*(256-blend)/256;
	int g = qGreen(c1) * blend/256 + qGreen(c2)*(256-blend)/256;
	int b = qBlue(c1) * blend/256 + qBlue(c2)*(256-blend)/256;
	return qRgb(r, g, b);
}


static QImage* prepareSurface(const QImage* slideImage, int w, int h, QRgb bgcolor,
                              PictureFlow::ReflectionEffect reflectionEffect)
{
#ifdef PICTUREFLOW_QT4
	Qt::TransformationMode mode = Qt::SmoothTransformation;
	QImage img = slideImage->scaled(w, h, Qt::IgnoreAspectRatio, mode);
#endif
#if defined(PICTUREFLOW_QT3) || defined(PICTUREFLOW_QT2)
	QImage img = slideImage->smoothScale(w, h);
#endif

	// slightly larger, to accomodate for the reflection
	int hs = h * 2;
	int hofs = h / 3;

	// offscreen buffer: black is sweet
#ifdef PICTUREFLOW_QT4
	QImage* result = new QImage(hs, w, QImage::Format_RGB32);
#endif
#if defined(PICTUREFLOW_QT3) || defined(PICTUREFLOW_QT2)
	QImage* result = new QImage;
	result->create(hs, w, 32);
#endif
	result->fill(bgcolor);

	// transpose the image, this is to speed-up the rendering
	// because we process one column at a time
	// (and much better and faster to work row-wise, i.e in one scanline)
	for(int x = 0; x < w; ++x)
		for(int y = 0; y < h; ++y)
			result->setPixel(hofs + y, x, img.pixel(x, y));

	if(reflectionEffect != PictureFlow::NoReflection) {
		// create the reflection
		int ht = hs - h - hofs;
		int hte = ht;
		for(int x = 0; x < w; ++x)
			for(int y = 0; y < ht; ++y) {
				QRgb color = img.pixel(x, img.height()-y-1);
				result->setPixel(h+hofs+y, x, blendColor(color,bgcolor,128*(hte-y)/hte));
			}//for(int y = 0; y < ht; ++y)

		if(reflectionEffect == PictureFlow::BlurredReflection) {
			// blur the reflection everything first
			// Based on exponential blur algorithm by Jani Huhtanen
			QRect rect(hs/2, 0, hs/2, w);
			rect &= result->rect();

			int r1 = rect.top();
			int r2 = rect.bottom();
			int c1 = rect.left();
			int c2 = rect.right();

			int bpl = result->bytesPerLine();
			int rgba[4];
			unsigned char* p;

			// how many times blur is applied?
			// for low-end system, limit this to only 1 loop
			for(int loop = 0; loop < 2; ++loop) {
				for(int col = c1; col <= c2; ++col) {
					p = result->scanLine(r1) + col*4;
					for(int i = 0; i < 3; ++i)
						rgba[i] = p[i] << 4;

					p += bpl;
					for(int j = r1; j < r2; ++j, p += bpl)
						for(int i = 0; i < 3; ++i)
							p[i] = (rgba[i] += (((p[i]<<4)-rgba[i])) >> 1) >> 4;
				}//for(int col = c1; col <= c2; ++col)

				for(int row = r1; row <= r2; ++row) {
					p = result->scanLine(row) + c1*4;
					for(int i = 0; i < 3; ++i)
						rgba[i] = p[i] << 4;

					p += 4;
					for(int j = c1; j < c2; ++j, p+=4)
						for(int i = 0; i < 3; ++i)
							p[i] = (rgba[i] += (((p[i]<<4)-rgba[i])) >> 1) >> 4;
				}//for(int row = r1; row <= r2; ++row)

				for(int col = c1; col <= c2; ++col) {
					p = result->scanLine(r2) + col*4;
					for(int i = 0; i < 3; ++i)
						rgba[i] = p[i] << 4;

					p -= bpl;
					for(int j = r1; j < r2; ++j, p -= bpl)
						for(int i = 0; i < 3; ++i)
							p[i] = (rgba[i] += (((p[i]<<4)-rgba[i])) >> 1) >> 4;
				}//for(int col = c1; col <= c2; ++col)

				for(int row = r1; row <= r2; ++row) {
					p = result->scanLine(row) + c2*4;
					for(int i = 0; i < 3; ++i)
						rgba[i] = p[i] << 4;

					p -= 4;
					for(int j = c1; j < c2; ++j, p-=4)
						for(int i = 0; i < 3; ++i)
							p[i] = (rgba[i] += (((p[i]<<4)-rgba[i])) >> 1) >> 4;
				}//for(int row = r1; row <= r2; ++row)
			}//for(int loop = 0; loop < 2; ++loop)

			// overdraw to leave only the reflection blurred (but not the actual image)
			for(int x = 0; x < w; ++x)
				for(int y = 0; y < h; ++y)
					result->setPixel(hofs + y, x, img.pixel(x, y));
		}//if(reflectionEffect == PictureFlow::BlurredReflection)
	}//if(reflectionEffect != PictureFlow::NoReflection)

	return result;
}

QImage* PictureFlowSoftwareRenderer::surface(int slideIndex)
{
	if(!state)
		return 0;
	if(slideIndex < 0)
		return 0;
	if(slideIndex >= (int)state->slideImages.count())
		return 0;

#ifdef PICTUREFLOW_QT4
	int key = slideIndex;
#endif
#if defined(PICTUREFLOW_QT3) || defined(PICTUREFLOW_QT2)
	QString key = QString::number(slideIndex);
#endif

	QImage* img = state->slideImages.at(slideIndex);
	bool empty = img ? img->isNull() : true;
	if(empty) {
		surfaceCache.remove(key);
		delete imageHash.take(slideIndex);
		if(!blankSurface) {
			int sw = state->slideWidth;
			int sh = state->slideHeight;

#ifdef PICTUREFLOW_QT4
			QImage img = QImage(sw, sh, QImage::Format_RGB32);

			QPainter painter(&img);
			QPoint p1(sw*4/10, 0);
			QPoint p2(sw*6/10, sh);
			QLinearGradient linearGrad(p1, p2);
			linearGrad.setColorAt(0, Qt::black);
			linearGrad.setColorAt(1, Qt::white);
			painter.setBrush(linearGrad);
			painter.fillRect(0, 0, sw, sh, QBrush(linearGrad));

			painter.setPen(QPen(QColor(64,64,64), 4));
			painter.setBrush(QBrush());
			painter.drawRect(2, 2, sw-3, sh-3);
			painter.end();
#endif
#if defined(PICTUREFLOW_QT3) || defined(PICTUREFLOW_QT2)
			QPixmap pixmap(sw, sh, 32);
			QPainter painter(&pixmap);
			painter.fillRect(pixmap.rect(), QColor(192,192,192));
			painter.fillRect(5, 5, sw-10, sh-10, QColor(64,64,64));
			painter.end();
			QImage img = pixmap.convertToImage();
#endif

			blankSurface = prepareSurface(&img, sw, sh, bgcolor, state->reflectionEffect);
		}//if(!blankSurface)
		return blankSurface;
	}//if(empty)

#ifdef PICTUREFLOW_QT2
	if(img == imageHash[slideIndex])
#endif
#ifdef PICTUREFLOW_QT3
	bool exist = imageHash.find(slideIndex) != imageHash.end();
	if(exist)
		if(img == imageHash.find(slideIndex).data())
#endif
#ifdef PICTUREFLOW_QT4
	bool exist = imageHash.contains(slideIndex);
	if(exist)
		if(img == imageHash.find(slideIndex).value())
#endif
			if(surfaceCache.contains(key))
				return surfaceCache[key];

	QImage* sr = prepareSurface(img, state->slideWidth, state->slideHeight, bgcolor, state->reflectionEffect);

	surfaceCache.insert(key, sr); // QCache takes ownership on sr. And delete it when removed.
	imageHash.insert(slideIndex, img);

	return sr;
}

// Renders a slide to offscreen buffer. Returns a rect of the rendered area.
// col1 and col2 limit the column for rendering.
QRect PictureFlowSoftwareRenderer::renderSlide(const SlideInfo &slide, int col1, int col2)
{
	int blend = slide.blend;
	if(!blend)
		return QRect();

	QImage* src = surface(slide.slideIndex); // src is owned by surfaceCache(QCache) don't delete it.
	if(!src)
		return QRect();

	QRect rect(0, 0, 0, 0);

	int sw = src->height();
	int sh = src->width();
	int h = buffer.height();
	int w = buffer.width();

	if(col1 > col2) {
		int c = col2;
		col2 = col1;
		col1 = c;
	}//if(col1 > col2)

	col1 = (col1 >= 0) ? col1 : 0;
	col2 = (col2 >= 0) ? col2 : w-1;
	col1 = qMin(col1, w-1);
	col2 = qMin(col2, w-1);

	int zoom = 100;
	int distance = h * 100 / zoom;
	PFreal sdx = fcos(slide.angle);
	PFreal sdy = fsin(slide.angle);
	PFreal xs = slide.cx - state->slideWidth * sdx/2;
	PFreal ys = slide.cy - state->slideWidth * sdy/2;
	PFreal dist = distance * PFREAL_ONE;

	int xi = qMax((PFreal)0, ((w*PFREAL_ONE/2) + fdiv(xs*h, dist+ys)) >> PFREAL_SHIFT);
	if(xi >= w)
		return rect;

	bool flag = false;
	rect.setLeft(xi);
	for(int x = qMax(xi, col1); x <= col2; ++x) {
		PFreal hity = 0;
		PFreal fk = rays[x];
		if(sdy) {
			fk = fk - fdiv(sdx,sdy);
			hity = -fdiv((rays[x]*distance - slide.cx + slide.cy*sdx/sdy), fk);
		}//if(sdy)

		dist = distance*PFREAL_ONE + hity;
		if(dist < 0)
			continue;

		PFreal hitx = fmul(dist, rays[x]);
		PFreal hitdist = fdiv(hitx - slide.cx, sdx);

		int column = sw/2 + (hitdist >> PFREAL_SHIFT);
		if(column >= sw)
			break;
		if(column < 0)
			continue;

		rect.setRight(x);
		if(!flag)
			rect.setLeft(x);
		flag = true;

		int y1 = h/2;
		int y2 = y1+ 1;
		QRgb* pixel1 = (QRgb*)(buffer.scanLine(y1)) + x;
		QRgb* pixel2 = (QRgb*)(buffer.scanLine(y2)) + x;
		QRgb pixelstep = pixel2 - pixel1;

		int center = (sh/2);
		int dy = dist / h;
		int p1 = center*PFREAL_ONE - dy/2;
		int p2 = center*PFREAL_ONE + dy/2;

		const QRgb *ptr = (const QRgb*)(src->scanLine(column));
		if(blend == 256)
			while((y1 >= 0) && (y2 < h) && (p1 >= 0)) {
				*pixel1 = ptr[p1 >> PFREAL_SHIFT];
				*pixel2 = ptr[p2 >> PFREAL_SHIFT];
				p1 -= dy;
				p2 += dy;
				--y1;
				++y2;
				pixel1 -= pixelstep;
				pixel2 += pixelstep;
			}//while((y1 >= 0) && (y2 < h) && (p1 >= 0))
		else
			while((y1 >= 0) && (y2 < h) && (p1 >= 0)) {
				QRgb c1 = ptr[p1 >> PFREAL_SHIFT];
				QRgb c2 = ptr[p2 >> PFREAL_SHIFT];
				*pixel1 = blendColor(c1, bgcolor, blend);
				*pixel2 = blendColor(c2, bgcolor, blend);
				p1 -= dy;
				p2 += dy;
				--y1;
				++y2;
				pixel1 -= pixelstep;
				pixel2 += pixelstep;
			}//while((y1 >= 0) && (y2 < h) && (p1 >= 0))
	}//for(int x = qMax(xi, col1); x <= col2; ++x)

	rect.setTop(0);
	rect.setBottom(h-1);

	return rect;
}

void PictureFlowSoftwareRenderer::renderSlides()
{
	int nleft = state->leftSlides.count();
	int nright = state->rightSlides.count();

	QRect r = renderSlide(state->centerSlide);
	int c1 = r.left();
	int c2 = r.right();
	state->centerSlide.left=c1;
	state->centerSlide.right=c2;

	for(int index = 0; index < nleft; ++index) {
		QRect rs = renderSlide(state->leftSlides[index], 0, c1-1);
		if(!rs.isEmpty()) {
			state->leftSlides[index].left=rs.left();
			state->leftSlides[index].right=rs.right();
			c1 = rs.left();
		}//if(!rs.isEmpty())
	}//for(int index = 0; index < nleft; ++index)

	for(int index = 0; index < nright; ++index) {
		QRect rs = renderSlide(state->rightSlides[index], c2+1, buffer.width());
		if(!rs.isEmpty()){
			state->rightSlides[index].left=rs.left();
			state->rightSlides[index].right=rs.right();
			c2 = rs.right();
		}//if(!rs.isEmpty())
	}//for(int index = 0; index < nright; ++index)
}

// Render the slides. Updates only the offscreen buffer.
void PictureFlowSoftwareRenderer::render()
{
	buffer.fill(state->backgroundColor);
	renderSlides();
	dirty = false;
}

// -----------------------------------------

class PictureFlowPrivate
{
public:
	PictureFlowState* state;
	PictureFlowAnimator* animator;
	PictureFlowAbstractRenderer* renderer;
	QTimer triggerTimer;
};


PictureFlow::PictureFlow(QWidget* parent): QWidget(parent)
{
	d = new PictureFlowPrivate;

	d->state = new PictureFlowState;
	d->state->reset();
	d->state->reposition();

	d->renderer = new PictureFlowSoftwareRenderer;
	d->renderer->state = d->state;
	d->renderer->widget = this;
	d->renderer->init();

	d->animator = new PictureFlowAnimator;
	d->animator->state = d->state;
	QObject::connect(&d->animator->animateTimer, SIGNAL(timeout()), this, SLOT(updateAnimation()));

	QObject::connect(&d->triggerTimer, SIGNAL(timeout()), this, SLOT(render()));

#ifdef PICTUREFLOW_QT4
	setAttribute(Qt::WA_StaticContents, true);
	setAttribute(Qt::WA_OpaquePaintEvent, true);
	setAttribute(Qt::WA_NoSystemBackground, true);
#endif
#ifdef PICTUREFLOW_QT3
	setWFlags(getWFlags() | Qt::WStaticContents);
	setWFlags(getWFlags() | Qt::WNoAutoErase);
#endif
#ifdef PICTUREFLOW_QT2
	setWFlags(getWFlags() | Qt::WPaintClever);
	setWFlags(getWFlags() | Qt::WRepaintNoErase);
	setWFlags(getWFlags() | Qt::WResizeNoErase);
#endif
}

PictureFlow::~PictureFlow()
{
	delete d->renderer;
	delete d->animator;
	delete d->state;
	delete d;
}

int PictureFlow::slideCount() const
{
	return d->state->slideImages.count();
}

QColor PictureFlow::backgroundColor() const
{
	return QColor(d->state->backgroundColor);
}

void PictureFlow::setBackgroundColor(const QColor& c)
{
	d->state->backgroundColor = c.rgb();
	triggerRender();
}

QSize PictureFlow::slideSize() const
{
	return QSize(d->state->slideWidth, d->state->slideHeight);
}

float PictureFlow::slideSizeRatio() const
{
	return d->state->slideRatio;
}

void PictureFlow::setSlideSizeRatio(float ratio)
{
	if (ratio>0) d->state->slideRatio = ratio;

	int h = (height() * (6/10.0));
	int w = (width() * (6/10.0));
	int hh = qMin(h, w);
	int ww = hh * d->state->slideRatio;
	d->state->spacing = (ww/2);// (hh-ww);

	//int slideCount = (width()/(float)(ww+d->state->spacing));
	int widthLeft=(width()-2*ww);
	int slideCount = widthLeft<=0 ? 1 : (widthLeft/(float)(d->state->spacing));
	if (slideCount<2) slideCount=2;
	d->state->leftSlides.resize(slideCount / 2);//6);
	d->state->rightSlides.resize(slideCount / 2);//6);

	d->state->slideWidth = ww;
	d->state->slideHeight = hh;
	d->state->reposition();
	updateAnimation();
	//triggerRender();
}

PictureFlow::ReflectionEffect PictureFlow::reflectionEffect() const
{
	return d->state->reflectionEffect;
}

void PictureFlow::setReflectionEffect(ReflectionEffect effect)
{
	d->state->reflectionEffect = effect;
	triggerRender();
}

QImage PictureFlow::slide(int index) const
{
	QImage* i = 0;
	if((index >= 0) && (index < slideCount()))
		i = d->state->slideImages[index];
	return i ? QImage(*i) : QImage();
}

int PictureFlow::slideAt(QPoint point) const
{
	int center=centerIndex();
	int count=slideCount();
	int left=d->state->leftSlides[0].right;
	int right=d->state->rightSlides[0].left;
	if (center==0) left=0;
	if (center==count-1) right=width();

	if ((point.x()>=left) && (point.x()<=right))
		return d->state->centerSlide.slideIndex;

	if (point.x()<(width()/2)){
		int leftCount=d->state->leftSlides.count();
		for (int curs=0; (curs<leftCount) && ((center-curs)>0); ++curs){
			left=d->state->leftSlides[curs].left;
			right=d->state->leftSlides[curs].right;
			if ((point.x()>=left) && (point.x()<=right))
				return d->state->leftSlides[curs].slideIndex;
		}//for (int curs=0; curs<leftCount; ++curs)
		return 0;
	} else {
		int rightCount=d->state->rightSlides.count();
		for (int curs=0; (curs<rightCount) && ((center+curs+1)<count); ++curs){
			left=d->state->rightSlides[curs].left;
			right=d->state->rightSlides[curs].right;
			if ((point.x()>=left) && (point.x()<=right))
				return d->state->rightSlides[curs].slideIndex;
		}//for (int curs=0; curs<leftCount; ++curs)
		return count-1;
	}//if (point.x()<(width()/2))
	return -1;
}

void PictureFlow::addSlide(const QImage& image)
{
	int c = d->state->slideImages.count();
	d->state->slideImages.resize(c+1);
	d->state->slideImages[c] = new QImage(image);
	triggerRender();
}

void PictureFlow::addSlide(const QPixmap& pixmap)
{
	addSlide(pixmap.toImage());
}

void PictureFlow::setSlide(int index, const QImage& image)
{
	if((index >= 0) && (index < slideCount())) {
		QImage* i = image.isNull() ? 0 : new QImage(image);
		delete d->state->slideImages[index];
		d->state->slideImages[index] = i;
		triggerRender();
	}//if((index >= 0) && (index < slideCount()))
}

void PictureFlow::setSlide(int index, const QPixmap& pixmap)
{
	setSlide(index, pixmap.toImage());
}

int PictureFlow::centerIndex() const
{
	return d->state->centerIndex;
}

void PictureFlow::setCenterIndex(int index)
{
	index = qMin(index, slideCount()-1);
	index = qMax(index, 0);
	d->state->centerIndex = index;
	d->state->reset();
	d->animator->stop(index);
	triggerRender();
}

void PictureFlow::clear()
{
    for(int i=0;i<d->state->slideImages.size();++i)
        delete d->state->slideImages[i] ;
    d->state->slideImages.clear() ;
    
	d->state->reset();
	triggerRender();
}

void PictureFlow::render()
{
	d->renderer->dirty = true;
	update();
}

void PictureFlow::triggerRender()
{
#ifdef PICTUREFLOW_QT4
	d->triggerTimer.setSingleShot(true);
	d->triggerTimer.start(0);
#endif
#if defined(PICTUREFLOW_QT3) || defined(PICTUREFLOW_QT2)
	d->triggerTimer.start(0, true);
#endif
}

void PictureFlow::showPrevious()
{
	int step = d->animator->step;
	int center = d->state->centerIndex;

	if(step > 0)
		d->animator->start(center);

	if(step == 0)
		if(center > 0)
			d->animator->start(center - 1);

	if(step < 0)
		d->animator->target = qMax(0, center - 2);
}

void PictureFlow::showNext()
{
	int step = d->animator->step;
	int center = d->state->centerIndex;

	if(step < 0)
		d->animator->start(center);

	if(step == 0)
		if(center < slideCount()-1)
			d->animator->start(center + 1);

	if(step > 0)
		d->animator->target = qMin(center + 2, slideCount()-1);
}

void PictureFlow::showSlide(int index)
{
	index = qMax(index, 0);
	index = qMin(slideCount()-1, index);
	if(index == d->state->centerSlide.slideIndex)
		return;

	d->animator->start(index);
}

void PictureFlow::keyPressEvent(QKeyEvent* event)
{
	if(event->key() == Qt::Key_Left) {
		if(event->modifiers() == Qt::ControlModifier)
			showSlide(centerIndex()-10);
		else
			showPrevious();
		event->accept();
		return;
	}//if(event->key() == Qt::Key_Left)

	if(event->key() == Qt::Key_Right) {
		if(event->modifiers() == Qt::ControlModifier)
			showSlide(centerIndex()+10);
		else
			showNext();
		event->accept();
		return;
	}//if(event->key() == Qt::Key_Right)

	if (event->key() == Qt::Key_Enter || event->key() == Qt::Key_Select) {
		emit centerIndexChanged(centerIndex());
		event->accept();
		return;
  }//if (event->key() == Qt::Key_Enter || event->key() == Qt::Key_Select)

	event->ignore();
}

void PictureFlow::mousePressEvent(QMouseEvent* event)
{
	int index=slideAt(event->pos());
	if (index>=0) showSlide(index);
}

void PictureFlow::paintEvent(QPaintEvent* event)
{
	Q_UNUSED(event);
	d->renderer->paint();
}

void PictureFlow::resizeEvent(QResizeEvent* event)
{
	setSlideSizeRatio(0);
	QWidget::resizeEvent(event);
}

void PictureFlow::mouseMoveEvent(QMouseEvent* event)
{
	int index = slideAt(event->pos());
	if (index>=0)
		emit mouseMoveOverSlideEvent(event, index);
}

void PictureFlow::updateAnimation()
{
	int old_center = d->state->centerIndex;
	d->animator->update();
	triggerRender();
	if(d->state->centerIndex != old_center)
		emit centerIndexChanged(d->state->centerIndex);
}

void PictureFlow::dragEnterEvent(QDragEnterEvent *event)
{
	emit dragEnterEventOccurs(event);
}

void PictureFlow::dragMoveEvent(QDragMoveEvent *event)
{
	int index = slideAt(event->pos());
	int center = centerIndex();
	int offset = index - center;

	if (index == 0) {
		offset = -d->state->leftSlides.count();
	}//if (index = 0)
	if (index == slideCount()-1) {
		offset = d->state->rightSlides.count();
	}//if (index = slideCount()-1)

	if (index < center && event->pos().x() < dragMoveLastPos.x())
		showSlide(center + offset);
	else if (index > center && event->pos().x() > dragMoveLastPos.x())
		showSlide(center + offset);

	emit dragMoveEventOccurs(event);
	dragMoveLastPos = event->pos();
}

void PictureFlow::dropEvent(QDropEvent *event)
{
	emit dropEventOccurs(event);
}
