/*
 * TopView.cpp
 * 
 * Copyright (C) 2008 Matthias Schiffer <matthias@gamezock.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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "TopView.h"
#include <Data/Level.h>
#include <Data/Room.h>
#include <Data/Triangle.h>
#include <Gui/RenderArea.h>
#include <GL/gl.h>
#include <cmath>
#include <set>

namespace ZoomEdit {
namespace View {

bool TopView::Edge::operator<(const Edge &e) const {
  if(v1->getX() < e.v1->getX())
    return true;
  if(v1->getX() > e.v1->getX())
    return false;
  if(v1->getY() < e.v1->getY())
    return true;
  if(v1->getY() > e.v1->getY())
    return false;
  if(v1->getZ() < e.v1->getZ())
    return true;
  if(v1->getZ() > e.v1->getZ())
    return false;
  if(v2->getX() < e.v2->getX())
    return true;
  if(v2->getX() > e.v2->getX())
    return false;
  if(v2->getY() < e.v2->getY())
    return true;
  if(v2->getY() > e.v2->getY())
    return false;
  if(v2->getZ() < e.v2->getZ())
    return true;
  if(v2->getZ() > e.v2->getZ())
    return false;
  
  return false;
}

void TopView::drawGrid(Gui::RenderArea *renderArea) {
  float depth = std::log10(renderArea->getScale())-0.75f;
  float depth2 = std::floor(depth);
  float step = std::pow(0.1f, depth2);
  float x1, x2;
  float y1, y2;
  float width = renderArea->getViewWidth();
  float height = renderArea->getViewHeight();
  
  x1 = x2 = renderArea->getXCenter();
  y1 = y2 = renderArea->getYCenter();
  x1 -= width/2; x2 += width/2;
  y1 -= height/2; y2 += height/2;
  
  glLineWidth(1.0f);
  
  glBegin(GL_LINES);
  
  for(int i = 0; 0.4f*(depth-depth2+i-1) < 0.5f; i++) {
    float f = std::min(0.4f*(depth-depth2+i), 0.5f);
    glColor3f(f, f, f);
    
    for(f = x1 - std::fmod(x1, step); f <= x2; f+=step) {
      glVertex2f(f, y1);
      glVertex2f(f, y2);
    }
    
    for(f = y1 - std::fmod(y1, step); f <= y2; f+=step) {
      glVertex2f(x1, f);
      glVertex2f(x2, f);
    }
    
    step *= 10;
  }
  
  glEnd();
}

void TopView::renderRoom(Data::Room *room) {
  const std::list<Data::Triangle*> &floor = room->getFloorTriangles();
  std::multiset<Edge> edges;
  
  glColor4f(0.0f, 0.7f, 1.0f, 0.3f);
  
  glBegin(GL_TRIANGLES);
  
  for(std::list<Data::Triangle*>::const_iterator t = floor.begin(); t != floor.end(); ++t) {
    for(int i = 0; i < 3; ++i) {
      const Data::Vertex &v = (*t)->getVertex(i);
      const Data::Vertex &v2 = (*t)->getVertex((i+1)%3);
      
      glVertex2f(v.getX(), v.getZ());
      
      edges.insert(Edge(&v, &v2));
    }
  }
  
  glEnd();
  
  for(std::multiset<Edge>::iterator next = edges.begin(); next != edges.end();) {
    std::multiset<Edge>::iterator edge = next++;
    std::multiset<Edge>::iterator edge2 = edges.find(Edge(edge->v2, edge->v1));
    
    if(edge2 != edges.end()) {
      edges.erase(edge2);
      next = edge;
      ++next;
      edges.erase(edge);
    }
  }
  
  glColor4f(0.0f, 0.7f, 1.0f, 0.7f);
  glLineWidth(1.0f);
  
  glBegin(GL_LINES);
  
  for(std::multiset<Edge>::iterator edge = edges.begin(); edge != edges.end(); ++edge) {
    glVertex2f(edge->v1->getX(), edge->v1->getZ());
    glVertex2f(edge->v2->getX(), edge->v2->getZ());
  }
  
  glEnd();
}

void TopView::render(Gui::RenderArea *renderArea) {
  drawGrid(renderArea);
  
  if(!level)
    return;
  
  const std::list<Data::Room*> &rooms = level->getRooms();
  
  for(std::list<Data::Room*>::const_iterator room = rooms.begin(); room != rooms.end(); ++room)
    renderRoom(*room);
}

void TopView::getBounds(float *minX, float *maxX, float *minY, float *maxY) {
  if(!level)
    return;
  
  if(minX)
    *minX = 0;
  if(maxX)
    *maxX = 0;
  if(minY)
    *minY = 0;
  if(maxY)
    *maxY = 0;
  
  const std::list<Data::Room*> &rooms = level->getRooms();
  
  for(std::list<Data::Room*>::const_iterator room = rooms.begin(); room != rooms.end(); ++room) {
    const std::list<Data::Triangle*> &triangles = (*room)->getFloorTriangles();
    
    for(std::list<Data::Triangle*>::const_iterator t = triangles.begin(); t != triangles.end(); ++t) {
      const Data::Vertex &v1 = (*t)->getVertex(0), &v2 = (*t)->getVertex(1), &v3 = (*t)->getVertex(2);
      
      if(minX)
        *minX = std::min(std::min(*minX, v1.getX()), std::min(v2.getX(), v3.getX()));
      if(maxX)
        *maxX = std::max(std::max(*maxX, v1.getX()), std::max(v2.getX(), v3.getX()));
      if(minY)
        *minY = std::min(std::min(*minY, v1.getZ()), std::min(v2.getZ(), v3.getZ()));
      if(maxY)
        *maxY = std::max(std::max(*maxY, v1.getZ()), std::max(v2.getZ(), v3.getZ()));
    }
  }
  
  if(minX)
    *minX -= 5;
  if(maxX)
    *maxX += 5;
  if(minY)
    *minY -= 5;
  if(maxY)
    *maxY += 5;
}

}
}