/***************************************************************************
 *   Copyright (C) 2009 by Stefan Bühler                                   *
 *   stbuehler@web.de                                                      *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include "field3d.h"

#include <QPainter>
#include <QMouseEvent>
#include <QWheelEvent>

#include <GL/gl.h>

#include <QGLPixelBuffer>

#include <math.h>

template<typename T>
static T clip(T min, T max, T val) {
	if (val < min) return min;
	if (val > max) return max;
	return val;
}

template<typename T>
static T rotate(T angle, T bound = 360) {
	while (angle < 0) angle += bound;
	while (angle > bound) angle -= bound;
	return angle;
}

namespace toruschess {

	Field3D::Field3D(Game *game, QWidget *parent)
	: QGLWidget(QGLFormat(QGL::DoubleBuffer | QGL::DepthBuffer | QGL::Rgba), parent), m_game(game), m_lib(new PieceLibrary(this)),
	  m_boardMode(PLANE), m_figureMode(FIG3D),
	  m_textureBuffer(0), m_textureID(0),
	  m_camDist(5) ,m_camRotX(45), m_camRotY(0), m_camRotZ(0),
	  m_originX(0), m_originY(0), m_mouseLastX(0), m_mouseLastY(0),
	  m_skySphere(0), m_skyTextureID(0), m_skyTimerID(0), m_skyOffset(0),
	  m_pickTextureID(0) {
		for (int x = 0; x < 8; x++) for (int y = 0; y < 8; y++) m_marked[x][y] = false;
		m_lib->setSize(m_textureSize / 8, m_textureSize / 8);
	}
	
	Field3D::~Field3D() {
		freeTexture();
		
		if (m_skySphere) gluDeleteQuadric(m_skySphere);
	}
	
	void Field3D::markMoves(const QList<Move> &moves) {
		foreach(Move m, m_markedMoves) m_marked[m.to().x()][m.to().y()] = false;
		m_markedMoves = moves;
		foreach(Move m, m_markedMoves) m_marked[m.to().x()][m.to().y()] = true;
		
		updateTexture();
		updateGL();
	}
	
	QSize Field3D::sizeHint() const {
		return QSize(640, 480);
	}
	
	void Field3D::initializeGL() {
		glClearColor(0.0, 0.0, 0.0, 0.0);
		glEnable(GL_DEPTH_TEST);
		glEnable(GL_BLEND);
		glBlendFunc(GL_ONE,GL_ONE_MINUS_SRC_ALPHA);
		
		glEnable(GL_LIGHTING);
		glEnable(GL_LIGHT0);
		glDisable(GL_LIGHT1);
		glEnable(GL_COLOR_MATERIAL);
		{
			const GLfloat white[] = { 1.0, 1.0, 1.0, 1.0 },
			              inv[] = { 0.0, 0.0, 0.0, 0.0 };
			glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, white);
			glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, white);
			glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, inv);
			glLightfv(GL_LIGHT0, GL_AMBIENT, white);
			glLightfv(GL_LIGHT0, GL_DIFFUSE, inv);
			glLightfv(GL_LIGHT1, GL_AMBIENT, inv);
			glLightfv(GL_LIGHT1, GL_DIFFUSE, white);
		}
		
		glFogi(GL_FOG_MODE, GL_EXP2);
		glFogf(GL_FOG_DENSITY, 1/50.0);
		
		m_skySphere = gluNewQuadric();
		gluQuadricTexture(m_skySphere, GL_TRUE);
		
		createTexture();
		connect(m_game, SIGNAL(updated()), this, SLOT(fieldUpdated()));
		
		m_pickBuffer = new QGLPixelBuffer(QSize(1024, 1024));
		
		m_skyTimerID = startTimer(20);
	}
	
	void Field3D::resizeGL(int w, int h) {
		glViewport(0, 0, (GLint)w, (GLint)h);
		
		glMatrixMode(GL_PROJECTION);
		glLoadIdentity();
		gluPerspective(90.0, double(w)/h, 0.01, 1000);
		
		updateCam();
	}
	
	void Field3D::paintGL() {
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		glEnable(GL_TEXTURE_2D);
		glEnable(GL_LIGHT0);
		glDisable(GL_LIGHT1);
		
		if (m_boardMode == TORUS) {
			glDisable(GL_FOG);
			glDisable(GL_LIGHTING);
			glBindTexture(GL_TEXTURE_2D, m_skyTextureID);
			glMatrixMode(GL_TEXTURE);
			glPushMatrix();
			glTranslatef(m_skyOffset, 0, 0);
			gluSphere(m_skySphere, 256, 64, 64);
			glMatrixMode(GL_TEXTURE);
			glPopMatrix();
			glEnable(GL_LIGHTING);
			
			double ox = 2.0*(m_originX/(double)m_textureSize), oy = 2.0*(m_originY/(double)m_textureSize);
			glBindTexture(GL_TEXTURE_2D, m_textureID);
			{
				const int numc = 64, numt = 64;
				const double rad1 = 4.0, rad2 = 2.0;
				int i, j, k;
				double s, t, x, y, z, twopi;
				
				twopi = 2 * M_PI;
				for (i = 0; i < numc; i++) {
					glBegin(GL_QUAD_STRIP);
					for (j = 0; j <= numt; j++) {
						for (k = 1; k >= 0; k--) {
							s = (i + k) % numc + 0.5;
							t = j % numt;
				
							x = (rad1+rad2*cos(s*twopi/numc))*cos(t*twopi/numt);
							y = (rad1+rad2*cos(s*twopi/numc))*sin(t*twopi/numt);
							z = rad2 * sin(s * twopi / numc);
							glTexCoord2f(oy+double(i+k)/numc, ox+double(j)/numt);
							glVertex3f(x, z, y);
						}
					}
					glEnd();
				}
			}
		} else {
			const int repeat = 10;
			double ox = -2.0*(m_originX/(double)m_textureSize), oy = 2.0*(m_originY/(double)m_textureSize);
			glEnable(GL_FOG);
			glEnable(GL_LIGHTING);
			glBindTexture(GL_TEXTURE_2D, m_textureID);
			glBegin(GL_QUADS);
				glTexCoord2f(-repeat+ox,  repeat+oy); glVertex3f(-10*repeat, 0, -10*repeat);
				glTexCoord2f(-repeat+ox, -repeat+oy); glVertex3f(-10*repeat, 0,  10*repeat);
				glTexCoord2f( repeat+ox, -repeat+oy); glVertex3f( 10*repeat, 0,  10*repeat);
				glTexCoord2f( repeat+ox,  repeat+oy); glVertex3f( 10*repeat, 0, -10*repeat);
			glEnd();
			
#if 0
			glDisable(GL_TEXTURE_2D);
			glEnable(GL_LIGHT1);
			glDisable(GL_LIGHT0);
			glMatrixMode(GL_MODELVIEW);
			ox *= -10.0; oy *= 10.0;
			ox += 10.0/16; oy += 10.0/16;
			for (int i = 0; i < 8; i++) for (int j = 0; j < 8; j++) {
				if (m_game->field()->piece(Pos(i, j)) == PAWN) {
					if (m_game->field()->player(Pos(i, j)) == WHITE) {
						glColor3f(1.0, 1.0, 1.0);
					} else {
						glColor3f(.1, .1, .1);
					}
					for (int x = -10; x <= 10; x++) for (int y = -10; y <= 10; y++) {
						glPushMatrix();
						glTranslatef(ox + 10.0/8.0*i + 10*x, 0, oy + 10.0/8.0*j + 10*y);
						glRotatef(-90, 1, 0, 0);
						m_lib->paint_pawn();
						glPopMatrix();
					}
				}
			}
#endif
		}
		glDisable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D, 0);
	}
	
	bool Field3D::findPos(int mx, int my, Pos &p) {
		glDisable(GL_FOG);
		glDisable(GL_LIGHTING);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		glEnable(GL_TEXTURE_2D);
		
		if (m_boardMode == TORUS) {
			double ox = 2.0*(m_originX/(double)m_textureSize), oy = 2.0*(m_originY/(double)m_textureSize);
			glBindTexture(GL_TEXTURE_2D, m_pickTextureID);
			{
				const int numc = 64, numt = 64;
				const double rad1 = 4.0, rad2 = 2.0;
				int i, j, k;
				double s, t, x, y, z, twopi;
				
				twopi = 2 * M_PI;
				for (i = 0; i < numc; i++) {
					glBegin(GL_QUAD_STRIP);
					for (j = 0; j <= numt; j++) {
						for (k = 1; k >= 0; k--) {
							s = (i + k) % numc + 0.5;
							t = j % numt;
				
							x = (rad1+rad2*cos(s*twopi/numc))*cos(t*twopi/numt);
							y = (rad1+rad2*cos(s*twopi/numc))*sin(t*twopi/numt);
							z = rad2 * sin(s * twopi / numc);
							glTexCoord2f(oy+double(i+k)/numc, ox+double(j)/numt);
							glVertex3f(x, z, y);
						}
					}
					glEnd();
				}
			}
		} else {
			const int repeat = 10;
			double ox = -2.0*(m_originX/(double)m_textureSize), oy = 2.0*(m_originY/(double)m_textureSize);
			glBindTexture(GL_TEXTURE_2D, m_pickTextureID);
			glBegin(GL_QUADS);
				glTexCoord2f(-repeat+ox,  repeat+oy); glVertex3f(-10*repeat, 0, -10*repeat);
				glTexCoord2f(-repeat+ox, -repeat+oy); glVertex3f(-10*repeat, 0,  10*repeat);
				glTexCoord2f( repeat+ox, -repeat+oy); glVertex3f( 10*repeat, 0,  10*repeat);
				glTexCoord2f( repeat+ox,  repeat+oy); glVertex3f( 10*repeat, 0, -10*repeat);
			glEnd();
		}
		glDisable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D, 0);
		
		unsigned char pxbuf[3];
		glReadPixels(mx, height() - 1 - my, 1, 1, GL_RGB, GL_UNSIGNED_BYTE, &pxbuf);
		paintGL();
		p = Pos(pxbuf[0] - 50, pxbuf[1] - 50);
		return pxbuf[0] >= 50;
	}
	
	
	void Field3D::updateCam() {
		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();
		
		glTranslatef(0, 0, -m_camDist);
		glRotatef(m_camRotX,1,0,0);
		glRotatef(m_camRotY,0,1,0);
		glRotatef(m_camRotZ,0,0,1);
		
		updateGL();
	}
	
	
	void Field3D::createTexture() {
		freeTexture();
		m_textureBuffer = new QImage(QSize(m_textureSize, m_textureSize), QImage::Format_ARGB32_Premultiplied);
		
		updateTexture();
		
		{
			QImage *pickimage = new QImage(QSize(m_textureSize, m_textureSize), QImage::Format_ARGB32_Premultiplied);
			pickimage->fill(Qt::black);
			QPainter pt(pickimage);
			int pieceSize = m_textureSize / 8;
			for (int x = 0; x < 8; x++)
			for (int y = 0; y < 8; y++) {
				QRect prect(x * pieceSize, y * pieceSize, pieceSize - 1, pieceSize - 1);
				pt.fillRect(prect, QBrush(QColor(x+50,y+50,50)));
			}
			m_pickTextureID = bindTexture(*pickimage);
// 			delete pickimage;
		}
		
/*		glBindTexture(GL_TEXTURE_2D, m_textureID);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);*/
		
		QImage *skyimg = new QImage(":/media/skybox.jpg");
		m_skyTextureID = bindTexture(*skyimg);
		delete skyimg;
		
/*		glBindTexture(GL_TEXTURE_2D, m_skyTextureID);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);*/
	}
	
	void Field3D::freeTexture() {
		if (m_textureID != 0) {
			deleteTexture(m_textureID);
			m_textureID = 0;
		}
		if (m_skyTextureID != 0) {
			deleteTexture(m_skyTextureID);
			m_skyTextureID = 0;
		}
		if (m_pickTextureID != 0) {
			deleteTexture(m_pickTextureID);
			m_textureID = 0;
		}
		if (m_textureBuffer) {
			delete m_textureBuffer;
			m_textureBuffer = 0;
		}
	}
	
	void Field3D::updateTexture() {
		QPainter pt(m_textureBuffer);
		pt.fillRect(QRect(0, 0, m_textureSize, m_textureSize), Qt::black);
		
		int pieceSize = m_textureSize / 8;
		for (int x = 0; x < 8; x++)
		for (int y = 0; y < 8; y++) {
			bool marked = m_marked[x][y];
			int place = m_game->field()->place(Pos(x, y));

			QRect prect(x * pieceSize, y * pieceSize, pieceSize - 1, pieceSize - 1);
			m_lib->paint_board(pt, (x+y) % 2 == 1, prect);
			m_lib->paint(pt, place, prect);
			if (marked) {
				int r = qMax(1, (pieceSize + pieceSize) / 36);
				pt.setBrush(place != 0 ? Qt::green : Qt::white);
				pt.setPen(Qt::red);
				pt.drawEllipse(QPoint(prect.x() + pieceSize / 2, prect.y() + pieceSize / 2), r, r);
			}
		}
		pt.setCompositionMode(QPainter::CompositionMode_Plus);
		pt.fillRect(0, 0, m_textureSize, m_textureSize, Qt::black);
		pt.setCompositionMode(QPainter::CompositionMode_SourceOver);
		if (m_textureID) deleteTexture(m_textureID);
		m_textureID = bindTexture(*m_textureBuffer);
	}
	
	void Field3D::mousePressEvent(QMouseEvent *event) {
		if (event->button() == Qt::LeftButton) {
			QList<Move> moves;
			Pos p;
			if (findPos(event->x(), event->y(), p))
				moves = m_game->field()->validMoves(p);
			markMoves(moves);
			updateTexture();
			updateGL();
		}
		m_mouseLastX = event->x();
		m_mouseLastY = event->y();
	}
	
	void Field3D::mouseMoveEvent(QMouseEvent *event) {
		if (event->buttons() & Qt::RightButton) {
			m_originX = rotate<int>(m_originX + event->x() - m_mouseLastX, m_textureSize);
			m_originY = rotate<int>(m_originY + event->y() - m_mouseLastY, m_textureSize);
			updateCam();
		} else if (event->buttons() & Qt::MidButton) {
			m_camRotY = rotate(m_camRotY + 0.5*(event->x() - m_mouseLastX));
// 			m_camRotX = clip<double>(10, 170, m_camRotX + 0.5*(event->y() - m_mouseLastY));
			m_camRotX = rotate(m_camRotX + 0.5*(event->y() - m_mouseLastY));
			updateCam();
		}
		m_mouseLastX = event->x();
		m_mouseLastY = event->y();
	}
	
	void Field3D::mouseReleaseEvent(QMouseEvent *event) {
		m_mouseLastX = event->x();
		m_mouseLastY = event->y();
		if (event->button() == Qt::LeftButton) {
			if (m_markedMoves.size() == 0) return;
			Pos from = m_markedMoves[0].from();
			QList<Move> moves;
			markMoves(QList<Move>());
			Pos p;
			if (findPos(event->x(), event->y(), p)) {
				Move m(m_game->field(), from, p);
				m_game->move(m);
			}
		}
	}
	
	void Field3D::wheelEvent(QWheelEvent *event) {
		double zoom = pow(1.2, - event->delta() / 120);
		m_camDist = clip<double>(1.0, 40.0, m_camDist * zoom);
		updateCam();
	}
	
	void Field3D::fieldUpdated() {
		updateTexture();
		updateGL();
	}
	
	void Field3D::setFigureMode(FigureMode m) {
		m_figureMode = m;
		updateTexture();
		updateGL();
	}
	
	void Field3D::timerEvent(QTimerEvent *) {
		m_skyOffset = rotate<double>(m_skyOffset + 0.001, 1);
		if (m_boardMode == TORUS)
			updateGL();
	}
	
}