/* Definitions of new tw objects */

/* Vertex array for a unit twBarn (dimensions 1*1*1) */

// Should the following be a parameter of twDrawBarn, instead?
const GLfloat BarnShoulderHeight = 0.7;

twTriple twBarn[10] = 
{
  {0,0,0},     // 0, left, bottom, front 
  {1,0,0},     // 1, right, bottom, front 
  {1,BarnShoulderHeight,0},   // 2, right front shoulder
  {0.5,1,0},   // 3, ridge, front 
  {0,BarnShoulderHeight,0},   // 4, left front shoulder
  {0,0,-1},    // 5, echo of 0
  {1,0,-1},    // 6, echo of 1
  {1,BarnShoulderHeight,-1},   // 7, echo of 2
  {0.5,1,-1},  // 8, echo of 3
  {0,BarnShoulderHeight,-1},   // 9, echo of 4
};

void twSolidBarn(twTriple endColor, twTriple sideColor, twTriple roofColor, GLfloat specular, GLfloat shininess) {
    
    twColor(endColor,specular,shininess);
    glNormal3f(0,0,1);
    glBegin(GL_POLYGON);         // front 
    {
        glVertex3fv(twBarn[0]);
	glVertex3fv(twBarn[1]);
	glVertex3fv(twBarn[2]);
	glVertex3fv(twBarn[3]);
	glVertex3fv(twBarn[4]);
    }
    glEnd();
    glNormal3f(0,0,-1);
    glBegin(GL_POLYGON);        // back 
    {
	glVertex3fv(twBarn[5]);
	glVertex3fv(twBarn[9]);
	glVertex3fv(twBarn[8]);
	glVertex3fv(twBarn[7]);
	glVertex3fv(twBarn[6]);
    }
    glEnd();
    twColor(sideColor,specular,shininess);
    glNormal3f(-1,0,0);
    glBegin(GL_POLYGON);        // left side 
    {
      glVertex3fv(twBarn[0]);
      glVertex3fv(twBarn[4]);
      glVertex3fv(twBarn[9]);
      glVertex3fv(twBarn[5]);
    }
    glEnd();
    glNormal3f(1,0,0);
    glBegin(GL_POLYGON);        // right side 
    {
      glVertex3fv(twBarn[1]);
      glVertex3fv(twBarn[6]);
      glVertex3fv(twBarn[7]);
      glVertex3fv(twBarn[2]);
    }
    glEnd();
    twColor(roofColor,specular,shininess);
    // These perpendicular vectors aren't normalized.
    // I'm using the perp idea as found in Hill's graphics book
    glNormal3f(BarnShoulderHeight-1,0.5,0);
    glBegin(GL_POLYGON);         // left side roof 
    {
      glVertex3fv(twBarn[4]);
      glVertex3fv(twBarn[3]);
      glVertex3fv(twBarn[8]);
      glVertex3fv(twBarn[9]);
    }
    glEnd();
    glNormal3f(1-BarnShoulderHeight,0.5,0);
    glBegin(GL_POLYGON);        // right side roof 
    {
      glVertex3fv(twBarn[2]);
      glVertex3fv(twBarn[7]);
      glVertex3fv(twBarn[8]);
      glVertex3fv(twBarn[3]);
    }
    glEnd();
}

void twWireBarn(twTriple xColor, twTriple yColor, twTriple zColor) {
    twColor(xColor,0,0);
    glBegin(GL_LINES);
    {
	// front horizontals
        glVertex3fv(twBarn[0]);
	glVertex3fv(twBarn[1]);
	glVertex3fv(twBarn[2]);
	glVertex3fv(twBarn[3]);
	glVertex3fv(twBarn[2]);
	glVertex3fv(twBarn[4]);
	glVertex3fv(twBarn[3]);
	glVertex3fv(twBarn[4]);
	// back horizonals
        glVertex3fv(twBarn[0+5]);
	glVertex3fv(twBarn[1+5]);
	glVertex3fv(twBarn[2+5]);
	glVertex3fv(twBarn[3+5]);
	glVertex3fv(twBarn[2+5]);
	glVertex3fv(twBarn[4+5]);
	glVertex3fv(twBarn[3+5]);
	glVertex3fv(twBarn[4+5]);
    }
    glEnd();
    twColor(yColor,0,0);
    glBegin(GL_LINES);
    {
	// front
	glVertex3fv(twBarn[0]);
	glVertex3fv(twBarn[4]);
	glVertex3fv(twBarn[1]);
	glVertex3fv(twBarn[2]);
	// back
	glVertex3fv(twBarn[0+5]);
	glVertex3fv(twBarn[4+5]);
	glVertex3fv(twBarn[1+5]);
	glVertex3fv(twBarn[2+5]);
    }
    glEnd();
    twColor(zColor,0,0);
    glBegin(GL_LINES);
    {
      glVertex3fv(twBarn[0]);
      glVertex3fv(twBarn[0+5]);
      glVertex3fv(twBarn[1]);
      glVertex3fv(twBarn[1+5]);
      glVertex3fv(twBarn[2]);
      glVertex3fv(twBarn[2+5]);
      glVertex3fv(twBarn[3]);
      glVertex3fv(twBarn[3+5]);
      glVertex3fv(twBarn[4]);
      glVertex3fv(twBarn[4+5]);
    }
    glEnd();
}

/* It isn't particularly efficient to allocate some memory just to use it
   and discard it.  It would be cleaner to allocate the memory once for
   each disk at the beginning of the program, and use the quadrics during
   the display function, but that's more awkward to code. The following
   function trades efficiency for convenience. */

void twDisk(GLfloat radius, GLint slices) {
    GLUquadric* tmpquad;
    tmpquad = gluNewQuadric();
    if( tmpquad == 0 ) {
	printf("Can't allocate another quadric\n");
    } else {
	gluQuadricDrawStyle(tmpquad,GL_POLYGON);
	gluDisk(tmpquad,0,radius,slices,1);
	gluDeleteQuadric(tmpquad);
    }
}

/* Similar efficiency comments as for twDisk. */

void twCylinder(GLfloat base, GLfloat top, GLfloat height,
		GLint slices, GLint stacks) {
  GLUquadric* myCylinder;
  myCylinder = gluNewQuadric();
  if( myCylinder == 0 ) {
	printf("Can't allocate another quadric\n");
    } else {
	gluQuadricDrawStyle(myCylinder,GL_POLYGON);
	gluQuadricNormals(myCylinder,GL_SMOOTH);
	gluCylinder(myCylinder,base,top,height,slices,stacks);
	gluDeleteQuadric(myCylinder);
    }
}

void twTube(GLfloat base, GLfloat top, GLfloat height,
	    GLint slices,GLint stacks) {
    glPushMatrix();
    // must flip sides so we see the correct side for shading
    glRotatef(180,1,0,0); 
    twDisk(base,slices);
    glPopMatrix();
    twCylinder(base,top,height,slices,stacks);
    // translate length of cylinder to draw bottom
    glPushMatrix();
    glTranslatef(0,0,height); 
    twDisk(top,slices);
    glPopMatrix();
}


void twSolidCylinder(GLfloat top,GLfloat base,GLfloat height,
		     GLint slices,GLint stacks) {
    glPushMatrix();
    glRotatef(90,1,0,0);
    glPushMatrix();
    // must flip sides so we see the correct side for shading
    glRotatef(180,1,0,0); 
    twDisk(top,slices);
    glPopMatrix();
    twCylinder(top,base,height,slices,stacks);
    // translate length of cylinder to draw bottom
    glTranslatef(0,0,height); 
    twDisk(base,slices);
    glPopMatrix();
}

/* Draws a bear within a 1*1*1 box, with the y axis running through the
   center. */
void twTeddyBear() {
    twTriple lightBrown = {0.8,0.5,0.3};
    twTriple darkBrown  = {0.7,0.4,0.2};
    twTriple black      = {0.0,0.0,0.0};

    glPushMatrix();
    twColor(lightBrown,0,0);
    glScalef(0.1,0.1,0.1);
    glTranslated(0,3,0);
    glPushMatrix();
    glTranslated(-0.6,0.7,0.2);
    glScaled(1,1,0.5);
    glutSolidSphere(0.4,20,20);  // left ear
    glPopMatrix();
    glPushMatrix();
    glTranslated(0.6,0.7,0.2);
    glScaled(1,1,0.5);
    glutSolidSphere(0.4,20,20);  // right ear
    glPopMatrix();

    // draw head, slightly darker brown
    twColor(darkBrown,0,0); // dark brown
    glPushMatrix();
    glutSolidSphere(1,30,30);
    glTranslated(-0.25,0.1,0.9);
    twColor(black,1,64);	// shiny black
    glutSolidSphere(0.12,20,20);  // left eye
    glTranslated(0.5,0,0);
    glutSolidSphere(0.12,20,20);  // right eye
    glTranslated(-0.25,-0.4,0);
    glutSolidSphere(0.2,10,10);   // nose
    glPopMatrix();
  
    // draw body
    twColor(lightBrown,0,0); // light brown again
    glTranslated(0,-3.8,0);
    glPushMatrix();
    glScaled(1.3,2,1);
    glutSolidSphere(1.5,30,30); // body
    glPopMatrix();
  
    // legs and arms are in darker brown
    twColor(darkBrown,0,0); // dark brown
    // draw right leg
    glTranslated(0.9,-1.9,0);
    glPushMatrix();
    glRotated(35,-1,0,1);
    twSolidCylinder(0.7,0.6,2,20,1);
    glPopMatrix();
  
    // draw left leg
    glTranslated(-1.8,0,0);
    glPushMatrix();
    glRotated(-35,1,0,1);
    twSolidCylinder(0.7,0.6,2,20,1); 
    glPopMatrix();
  
    // draw left arm
    glTranslated(0,3.8,0);
    glPushMatrix();
    glRotated(-90,0,0,1);
    twSolidCylinder(0.5,0.4,2,20,1); 
    glPopMatrix();

    // draw right arm
    glTranslated(2,0,0);
    glPushMatrix();
    glRotated(90,0,0,1);
    twSolidCylinder(0.5,0.4,2,20,1); 
    glPopMatrix();
    glPopMatrix();
}


void twGround(){
    glPushAttrib(GL_POLYGON_BIT);
    glEnable(GL_CULL_FACE);
    glBegin(GL_QUADS);
    // y=BBMin[1].  The other coordinates change in the usual way.  The
    // order is important, because we want the polygon to be facing the
    // center, so that it's culled when we look up at it, but not when we
    // look down on it.
    glVertex3f(BBMin[0],BBMin[1],BBMax[2]);
    glVertex3f(BBMax[0],BBMin[1],BBMax[2]);
    glVertex3f(BBMax[0],BBMin[1],BBMin[2]);
    glVertex3f(BBMin[0],BBMin[1],BBMin[2]);
    glEnd();
    glPopAttrib();
}

void twSky() {
    glPushAttrib(GL_POLYGON_BIT);
    glEnable(GL_CULL_FACE);
    glBegin(GL_QUADS);
    // y=BBMax[1]
    glVertex3f(BBMin[0],BBMax[1],BBMax[2]);
    glVertex3f(BBMin[0],BBMax[1],BBMin[2]);
    glVertex3f(BBMax[0],BBMax[1],BBMin[2]);
    glVertex3f(BBMax[0],BBMax[1],BBMax[2]);
    // x=BBMin[0]
    glVertex3f(BBMin[0],BBMin[1],BBMin[2]);
    glVertex3f(BBMin[0],BBMax[1],BBMin[2]);
    glVertex3f(BBMin[0],BBMax[1],BBMax[2]);
    glVertex3f(BBMin[0],BBMin[1],BBMax[2]);
    // x=BBMax[0]
    glVertex3f(BBMax[0],BBMin[1],BBMin[2]);
    glVertex3f(BBMax[0],BBMin[1],BBMax[2]);
    glVertex3f(BBMax[0],BBMax[1],BBMax[2]);
    glVertex3f(BBMax[0],BBMax[1],BBMin[2]);
    // z=BBMax[2]
    glVertex3f(BBMin[0],BBMin[1],BBMax[2]);
    glVertex3f(BBMin[0],BBMax[1],BBMax[2]);
    glVertex3f(BBMax[0],BBMax[1],BBMax[2]);
    glVertex3f(BBMax[0],BBMin[1],BBMax[2]);
    // z=BBMin[2]
    glVertex3f(BBMin[0],BBMin[1],BBMin[2]);
    glVertex3f(BBMax[0],BBMin[1],BBMin[2]);
    glVertex3f(BBMax[0],BBMax[1],BBMin[2]);
    glVertex3f(BBMin[0],BBMax[1],BBMin[2]);
    glEnd();
    glPopAttrib();
}