/* Demo of the classic barn object.

Implemented Fall 2003
Scott D. Anderson
*/

#include <stdio.h>
#include <math.h> // for sqrt

#ifdef MAC
#include <GLUT/glut.h>
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#else
#include <GL/glut.h>
#endif

#include <tw.h>

const int barnWidth =30;
const int barnHeight=40;
const int barnLength=50;

GLfloat barn[10][3] = 
{
  {0,0,0},                                 //left, bottom, front 
  {barnWidth,0,0},                         // right, bottom, front 
  {barnWidth,barnHeight,0},                 // right, top, front 
  {0,barnHeight,0},                         // left, top, front 
  {barnWidth/2.0,barnHeight+barnWidth/2.0,0}, // ridge, front 
  {0,0,-barnLength},                     // left, bottom, back 
  {barnWidth,0,-barnLength},             // right, bottom, back 
  {barnWidth,barnHeight,-barnLength},    //right, top, back 
  {0,barnHeight,-barnLength},            // left, top, back 
  {barnWidth/2.0,barnHeight+barnWidth/2.0,-barnLength},// ridge, back 
};

// Almost every facet is a different color so that we can see them.

void drawBarn() {
    int i;

    glColor3f(1,0,0);		// set color to red
    glBegin(GL_POLYGON);        // front 
    {
        glVertex3fv(barn[0]);
        glVertex3fv(barn[1]);
        glVertex3fv(barn[2]);
        glVertex3fv(barn[3]);
    }
    glEnd();
    //glColor3f(0,1,1);
    glBegin(GL_POLYGON);        // front ridge 
    {
        glVertex3fv(barn[3]);
        glVertex3fv(barn[2]);
        glVertex3fv(barn[4]);
    }
    glEnd();
    glColor3f(0,1,0);
    glBegin(GL_POLYGON);        // back 
    {
        glVertex3fv(barn[5]);
        glVertex3fv(barn[6]);
        glVertex3fv(barn[7]);
        glVertex3fv(barn[8]);
    }
    glEnd();
    glBegin(GL_POLYGON);         // back ridge 
    {
        glVertex3fv(barn[7]);
        glVertex3fv(barn[8]);
        glVertex3fv(barn[9]);
    }
    glEnd();
    glColor3f(0.5,0,0.5);
    glBegin(GL_POLYGON);        // left side 
    {
      glVertex3fv(barn[0]);
      glVertex3fv(barn[3]);
      glVertex3fv(barn[8]);
      glVertex3fv(barn[5]);
    }
    glEnd();
    glColor3f(0.5,0,0);
    glBegin(GL_POLYGON);        // right side 
    {
      glVertex3fv(barn[1]);
      glVertex3fv(barn[2]);
      glVertex3fv(barn[7]);
      glVertex3fv(barn[6]);
    }
    glEnd();
    glColor3f(0.5,0.5,0);
    glBegin(GL_POLYGON);        // left side roof 
    {
      glVertex3fv(barn[3]);
      glVertex3fv(barn[4]);
      glVertex3fv(barn[9]);
      glVertex3fv(barn[8]);
    }
    glEnd();
    glBegin(GL_POLYGON);        /* right side roof */
    {
      glVertex3fv(barn[2]);
      glVertex3fv(barn[4]);
      glVertex3fv(barn[9]);
      glVertex3fv(barn[7]);
    }
    glEnd();
}

void display(void) {
  glClearColor(0.75,0.75,0.75,1);
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  twCamera();
  
  drawBarn();

  glFlush();
  glutSwapBuffers();
}

int main(int argc, char** argv) {
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutInitWindowSize(400,300);
  glutCreateWindow(argv[0]);
  twMainInit();
  glutDisplayFunc(display);
  twBoundingBox(0,30,0,55,-50,0);
  glutMainLoop();
  return 0;
}