#include "Renderer.h"
#include "PlayerStart.h"
#include <GL/gl.h>


void Renderer::drawGrid(const Rectangle &rect, float scale) {
  float depth = log10f(scale)-0.75f;
  float depth2 = floorf(depth);
  float step = powf(0.1f, depth2);
  float f;
  int i;
  float x1 = rect.getVertex1().getX(), y1 = rect.getVertex1().getY();
  float x2 = rect.getVertex2().getX(), y2 = rect.getVertex2().getY();
  
  
  glBegin(GL_LINES);
  
  for(i = 0; 0.4f*(depth-depth2+i-1) < 0.5f; i++) {
    f = fminf(0.4f*(depth-depth2+i), 0.5f);
    glColor3f(f, f, f);
    
    for(f = x1 - fmodf(x1, step) - step; f <= x2; f+=step) {
      glVertex2f(f, y1);
      glVertex2f(f, y2);
    }
    
    for(f = y1 - fmodf(y1, step) - step; f <= y2; f+=step) {
      glVertex2f(x1, f);
      glVertex2f(x2, f);
    }
    
    step *= 10;
  }
  
  glEnd();
}

void Renderer::fillPolygon(const Polygon &polygon) {
  std::vector<Triangle> triangles;
  
  polygon.triangulate(triangles);
  
  glBegin(GL_TRIANGLES);
  
  for(std::vector<Triangle>::iterator t = triangles.begin(); t != triangles.end(); t++) {
    glVertex2f(t->getVertexA().getX(), t->getVertexA().getY());
    glVertex2f(t->getVertexB().getX(), t->getVertexB().getY());
    glVertex2f(t->getVertexC().getX(), t->getVertexC().getY());
  }
  
  glEnd();
}

void Renderer::drawPolygon(const Polygon &polygon, bool close) {
  glBegin(close ? GL_LINE_LOOP : GL_LINE_STRIP);
  
  for(Polygon::const_iterator vertex = polygon.begin(); vertex != polygon.end(); vertex++)
    glVertex2f(vertex->getX(), vertex->getY());
  
  glEnd();
}

void Renderer::drawCircle(const Vertex &m, float r, int n) {
  glBegin(GL_LINE_LOOP);
  
  for(int i = 0; i < n; i++)
    glVertex2f(m.getX()+r*cosf(2*M_PI*i/n), m.getY()+r*sinf(2*M_PI*i/n));
  
  glEnd();
}

void Renderer::drawCross(const Vertex &m, float r) {
  glBegin(GL_LINES);
  
  glVertex2f(m.getX()-r*M_SQRT1_2, m.getY()-r*M_SQRT1_2);
  glVertex2f(m.getX()+r*M_SQRT1_2, m.getY()+r*M_SQRT1_2);
  
  glVertex2f(m.getX()+r*M_SQRT1_2, m.getY()-r*M_SQRT1_2);
  glVertex2f(m.getX()-r*M_SQRT1_2, m.getY()+r*M_SQRT1_2);
  
  glEnd();
}

void Renderer::renderObject(const LevelObject &object, bool selected, bool highlighted, float scale) {
  if(object.isOfType("Room"))
    renderRoom(*(Room*)&object, selected, highlighted, scale);
  else if(object.isOfType("PlayerStart"))
    renderPlayerStart(*(PlayerStart*)&object, selected, highlighted, scale);
}

void Renderer::renderRoom(const Room &room, bool selected, bool highlighted, float scale) {
  if(selected)
    glColor4f(0.0f, 0.7f, 1.0f, 0.2f);
  else
    glColor4f(0.0f, 0.7f, 1.0f, 0.3f);
  
  fillPolygon(room);
  
  if(selected) {
    glColor4f(1.0f, 1.0f, 1.0f, 0.9f);
    glLineWidth(2.0f);
  }
  else if(highlighted) {
    glColor4f(0.0f, 0.7f, 1.0f, 0.7f);
    glLineWidth(2.0f);
  }
  else {
    glColor4f(0.0f, 0.7f, 1.0f, 0.7f);
    glLineWidth(1.0f);
  }
  
  drawPolygon(room);
}

void Renderer::renderPlayerStart(const PlayerStart &start, bool selected, bool highlighted, float scale) {
  if(selected) {
    glColor4f(1.0f, 1.0f, 1.0f, 0.9f);
    glLineWidth(2.0f);
  }
  else if(highlighted) {
    glColor4f(0.0f, 0.7f, 0.7f, 0.7f);
    glLineWidth(2.0f);
  }
  else {
    glColor4f(0.0f, 0.7f, 0.7f, 0.7f);
    glLineWidth(1.0f);
  }
  drawCircle(Vertex(start.getX(), start.getZ()), 0.3f, 128);
  
  glLineWidth(2.0f);
  glColor4f(1.0f, 1.0f, 1.0f, 0.7f);
  drawCross(Vertex(start.getX(), start.getZ()), 0.5f/sqrtf(scale));
}

void Renderer::render(const Level &level, const Rectangle &rect, float scale) {
  glClear(GL_COLOR_BUFFER_BIT);
  
  glLineWidth(1.0f);
  glPointSize(10.0f);
  
  drawGrid(rect, scale);
  
  for(Level::const_iterator object = level.begin(); object != level.end(); object++) {
    renderObject(**object, (&**object == editManager->getSelectedObject()),
        (&**object == editManager->getHighlightedObject()), scale);
  }
}