#include <stdio.h>
#include <stdlib.h>
#include <GL/glut.h>
#include "Renderer.hpp"
#include "trimodel.hpp"

// MOUSE INTERFACE STUFF
int LeftButtonDown=0;        
int RightButtonDown=0;
int OldX,OldY,NewX,NewY;
float Elevation=0;
float Azimuth=0;
float Dist=3;

// Renderer GLOBALS
int WW=640, WH=480;
int numRenderStates = 1; 
Renderer NPR;

TriModel *TM=NULL;
int UseNPR = 1;
int BackfaceCullingOn=0;
int UseSmoothInterpolation=0;
int TestPlaneOn=0;
int ModelOn=1;

void myDisplay_NPR()
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(30,(float)WW/WH,0.5f,10);
  glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0,0,Dist, 0,0,0, 0,1,0);
    glRotatef(Elevation,1,0,0);
    glRotatef(Azimuth,0,1,0);

  if (TM && ModelOn)
  {
    NPR.Begin();
      for (int i=0; i<TM->NumTris; i++)
      {
        NPR.RenderTriangle(TM->Tris[i]);
      }
    NPR.End();
  }

  if (TestPlaneOn)
  {
    glNormal3f(0,0,1);
    glBegin(GL_POLYGON);
      glColor3f(1,0,0);  glVertex3f(1,1,0);
      glColor3f(0,1,0);  glVertex3f(-1,1,0);
      glColor3f(0,0,1);  glVertex3f(-1,-1,0);
      glColor3f(1,1,1);  glVertex3f(1,-1,0);
    glEnd();
  }
  
  glutSwapBuffers();
}

void myDisplay_OpenGL()
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(30,(float)WW/WH,0.5f,10);
  glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0,0,Dist, 0,0,0, 0,1,0);
    glRotatef(Elevation,1,0,0);
    glRotatef(Azimuth,0,1,0);

  if (TM && ModelOn)
  {
    glBegin(GL_TRIANGLES);
      for (int i=0; i<TM->NumTris; i++)
      {
        glColor3ubv(TM->Tris[i].Color);
        glNormal3fv(TM->Tris[i].N);
        glVertex3fv(TM->Tris[i].A);
        glVertex3fv(TM->Tris[i].B);
        glVertex3fv(TM->Tris[i].C);
      }
    glEnd();
  }

  if (TestPlaneOn)
  {
    glNormal3f(0,0,1);
    glBegin(GL_POLYGON);
      glColor3f(1,0,0);  glVertex3f(1,1,0);
      glColor3f(0,1,0);  glVertex3f(-1,1,0);
      glColor3f(0,0,1);  glVertex3f(-1,-1,0);
      glColor3f(1,1,1);  glVertex3f(1,-1,0);
    glEnd();
  }
  
  glutSwapBuffers();
}

void myReshape(int w, int h)
{
  glutReshapeWindow(WW,WH);
}

void myIdle()
{
  glutPostRedisplay();
}

void myMouseFunc(int button, int state, int x, int y)
{
  NewX=x; NewY=y;
  if (button==GLUT_LEFT_BUTTON)
    LeftButtonDown=!LeftButtonDown;
}

void myMotionFunc(int x, int y)
{
  OldX=NewX; OldY=NewY;
  NewX=x;    NewY=y;
  float RelX = (NewX-OldX) / (float)glutGet((GLenum)GLUT_WINDOW_WIDTH);
  float RelY = (NewY-OldY) / (float)glutGet((GLenum)GLUT_WINDOW_HEIGHT);
  if (LeftButtonDown) 
  { 
    Azimuth += (RelX*180);
    Elevation += (RelY*180);
  }
}

void myKeyboard(unsigned char Key, int x, int y)
{
  switch(Key)
  {
    case 27: exit(0);
    case ' ': UseNPR=!UseNPR;
      if (UseNPR) 
        { glutDisplayFunc(myDisplay_NPR);
          printf("Non-Photorealistic\n"); }
      else 
        { glutDisplayFunc(myDisplay_OpenGL); 
          printf("OpenGL\n"); }
      break;
    case ',': Dist-=0.1f; break;
    case '.': Dist+=0.1f; break;
    case 'b': BackfaceCullingOn=!BackfaceCullingOn;
      if (BackfaceCullingOn) 
        { glEnable(GL_CULL_FACE);}
      else
        { glDisable(GL_CULL_FACE);}
      break;
    case 's': UseSmoothInterpolation=!UseSmoothInterpolation;
      if (UseSmoothInterpolation)
        { glShadeModel(GL_SMOOTH);}
      else 
        { glShadeModel(GL_FLAT);}
      break;
    case 'p': TestPlaneOn=!TestPlaneOn; break;
    case 'm': ModelOn=!ModelOn; break;
  };
}

void main(void)
{
//   TM = new TriModel("teapot.tri",255,128,128);
     TM = new TriModel("tie.tri");
//   TM = new TriModel("onetri.tri");

  if (TM) TM->Normalize();

  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutInitWindowSize(WW,WH);
  glutInitWindowPosition(180,100);
  glutCreateWindow("SoftGL");

  NPR.Initialize("grey.npr");

  if (UseSmoothInterpolation)
    { glShadeModel(GL_SMOOTH); }
  else 
    { glShadeModel(GL_FLAT);}

  glutDisplayFunc(myDisplay_NPR);
  glutReshapeFunc(myReshape);
  glutIdleFunc(myIdle);

  glutMouseFunc(myMouseFunc);
  glutMotionFunc(myMotionFunc);
  glutKeyboardFunc(myKeyboard);

  glViewport(0,0,WW,WH);
  glEnable(GL_DEPTH_TEST);

  glutMainLoop();
}