/* Puts up a fence around the barn.  Demonstrates display lists and affine
   transforms.

Written by Caroline Geiersbach and Scott D. Anderson
scott.anderson@acm.org
Summer 2003
*/

#include <stdio.h>
#include <math.h>
#include <GL/glut.h>
#include <tw.h>

#define barnWidth 30
#define barnHeight 40
#define barnLength 50

twTriple barn[10] = 
{
  {0,0,0},        // left, bottom, front 
  {1,0,0},        // right, bottom, front 
  {1,1,0},        // right, top, front 
  {0,1,0},        // left, top, front 
  {0.5,1.5,0},  // ridge, front 
  {0,0,-1},     // left, bottom, back 
  {1,0,-1},     // right, bottom, back 
  {1,1,-1},     // right, top, back 
  {0,1,-1},     // left, top, back 
  {0.5,1.5,-1}, // ridge, back 
};

void drawBarn(int frontBack, int sides, int roof) {
    int i;
    twColorName(frontBack);        // set color for front and back of barn
    glBegin(GL_POLYGON);        // front 
    {
        glVertex3fv(barn[0]);
        glVertex3fv(barn[1]);
        glVertex3fv(barn[2]);
        glVertex3fv(barn[3]);
    }
    glEnd();
    glBegin(GL_POLYGON);        // front ridge 
    {
        glVertex3fv(barn[3]);
        glVertex3fv(barn[2]);
        glVertex3fv(barn[4]);
    }
    glEnd();
    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();
    twColorName(sides);          // set color for sides
    glBegin(GL_POLYGON);        // left side 
    {
      glVertex3fv(barn[0]);
      glVertex3fv(barn[3]);
      glVertex3fv(barn[8]);
      glVertex3fv(barn[5]);
    }
    glEnd();
    glBegin(GL_POLYGON);        // right side 
    {
      glVertex3fv(barn[1]);
      glVertex3fv(barn[2]);
      glVertex3fv(barn[7]);
      glVertex3fv(barn[6]);
    }
    glEnd();
    twColorName(roof);         // set color for roof
    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();
}

twTriple rail [] =
{
  {0,0,0},
  {5,0,0},
  {5,3,0},
  {0,3,0}
};


void drawRail () {
    glBegin(GL_POLYGON);
    {
        glVertex3fv(rail[0]);
        glVertex3fv(rail[1]);
        glVertex3fv(rail[2]);
        glVertex3fv(rail[3]);
    }
    glEnd();
}

// Arbitrary numeric identifier for this call list.
#define PICKET 100

void drawInit() {
    /* Create a call list for one picket of the fence */
    glNewList(PICKET, GL_COMPILE);
    glPushMatrix();
    glScalef(4,10,2); // must scale to create 4*10*2 barn
    drawBarn(TW_MAROON, TW_BLACK, TW_ORANGE);
    glPopMatrix();
    glPushMatrix();
    twColorName(TW_OLIVE);
    glTranslatef(-0.5,2,-1);
    drawRail();
    glTranslatef(0,5,0);
    drawRail();
    glPopMatrix();
    glEndList();
}

void display(void) {
    int i;
    twDisplayInit();
    twCamera();

    // draw ground
    twGround(TW_GREEN);

    // draw front fence
    glPushMatrix();
    glTranslatef(-40,0,0);
    for(i=0;i<20;i++) {
        glCallList(PICKET);
        glTranslatef(5,0,0);
    }
    glPopMatrix();
  
    // draw right side fence
    glPushMatrix();
    glTranslatef(60,0,0);
    glRotatef(90,0,1,0); 
    for(i=0;i<25;i++) {
        glCallList(PICKET);
        glTranslatef(5,0,0);
    }
    glPopMatrix();
  
    // draw left side fence
    glPushMatrix();
    glTranslatef(-40,0,0);
    glRotatef(90,0,1,0);
    for(i=0;i<25;i++) {
        glCallList(PICKET);
        glTranslatef(5,0,0);
    }
  
    // draw barn
    glPopMatrix();
    glPushMatrix();
    glTranslatef(0,0,-40);
    glScalef(35,40,50);
    drawBarn(TW_TEAL,TW_DARK_BLUE,TW_CYAN);
    glPopMatrix();

    glFlush();
    glutSwapBuffers();       // necessary for animation
}

int main(int argc, char** argv) {
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  twInitWindowSize(500,500);
  glutCreateWindow(argv[0]);
  drawInit();
  glutDisplayFunc(display);
  twBoundingBox(-40,60,0,60,-125,0);
  twMainInit(); 
  glutMainLoop();
  return 0;
}