#ifndef M_PI
#define M_PI 3.141592654
#endif
void normalize(float* a){
	float l = sqrt(a[1]*a[1] + a[2]*a[2] + a[0]*a[0]);
	if (l<0.00000001) l = 1;
	for (int i=0;i<3;i++) a[i] = a[i]/l*currentScale;
}

void cross(float *a, float *b, float *c, float *d){
	d[0] = (b[1]-a[1]) * (c[2]-a[2]) - (b[2]-a[2]) * (c[1]-a[1]);
	d[1] = (b[2]-a[2]) * (c[0]-a[0]) - (b[0]-a[0]) * (c[2]-a[2]);
	d[2] = (b[0]-a[0]) * (c[1]-a[1]) - (b[1]-a[1]) * (c[0]-a[0]);
	normalize(d);
}

void averageNormals(float* a, float* b, float* c, float* d, float* e){
	e[0] = (a[0]+b[0]+c[0]+d[0])/4.0f;
	e[1] = (a[1]+b[1]+c[1]+d[1])/4.0f;
	e[2] = (a[2]+b[2]+c[2]+d[2])/4.0f;
	normalize(e);
}
#define layers 28
#define n 20

void drawMyCreation()
{
	//glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
	
	glEnable(GL_CULL_FACE);
	glCullFace(GL_BACK);
	glPolygonMode(GL_FRONT, GL_FILL);
	
	
	glClearColor(1,1,1,1);
	GLfloat mat_color1[] = {0.3,0.3,0.5,1};
	GLfloat mat_color2[] = {0.5, 0.5, 0.7,1};
	GLfloat mat_color3[] = {1, 1, 1 ,1};
	glMaterialfv(GL_FRONT, GL_AMBIENT, mat_color1);	
	glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_color2);	
	glMaterialfv(GL_FRONT, GL_SPECULAR, mat_color3);	
	glMaterialf(GL_FRONT, GL_SHININESS, 100);
	
	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	xCurrent %= 360;
	yCurrent %= 360;
	glRotated(yCurrent , 1, 0, 0);
	glRotated(xCurrent , 0, 0, 1);
	glRotated(180, 0, 1, 0);
	
	glTranslated(0, -130, 0);
	
	// your composite obejct here
//layers = 26;
	float x[layers] = {0,9.72,16.84,18.42,18.42,18.42,18.42,18.27,17.8,16.03,12.81,11.03,10.06,9.04,8.46,7.84,7.84,7.84,7.84,7.84,7.84,11.22,11.61,11.15,11,7.77,4.66,0};
	float y[layers] = {259.1,259.08,257.05,253.49,250.39,234.33,165.5,156.2,148.23,123.23,107.11,100.35,95.68,89.72,83.93,70.71,64.96,42.21,24.83,10,9.94,9.72,7.3,5.74,3.55,1.07,0.23,0};
//	int n = 20;
	float vertices[n*layers*2*3];
	int count = 0;
	for (int i=0;i<layers;i++){
		for (int j=0;j<2*n;j++){
			float thex  = x[i]*sin(j*M_PI/n);
			float thez  = x[i]*cos(j*M_PI/n);
			float they  = y[i];
			vertices[count++] = thex;
			vertices[count++] = they;
			vertices[count++] = thez;
		}
	}
	
	float faceNormals[layers][2*n][3];
	count = 0;
	for (int i=0;i<layers-1;i++){
		for (int j=0;j<2*n-1;j++){
			float a[] = {vertices[(i*n*2+j)*3],vertices[(i*n*2+j)*3+1],vertices[(i*n*2+j)*3+2]};
			float b[] = {vertices[(i*n*2+j+1)*3],vertices[(i*n*2+j+1)*3+1],vertices[(i*n*2+j+1)*3+2]};
			float c[] = {vertices[((i+1)*n*2+j)*3],vertices[((i+1)*n*2+j)*3+1],vertices[((i+1)*n*2+j)*3+2]};			
			cross(a,c,b,faceNormals[i][j]);
		}
		float a[] = {vertices[(i*n*2+2*n-1)*3],vertices[(i*n*2+2*n-1)*3+1],vertices[(i*n*2+2*n-1)*3+2]};
		float b[] = {vertices[(i*n*2+0)*3],vertices[(i*n*2+0)*3+1],vertices[(i*n*2+0)*3+2]};
		float c[] = {vertices[((i+1)*n*2+0)*3],vertices[((i+1)*n*2+0)*3+1],vertices[((i+1)*n*2+0)*3+2]};			
		cross(a,c,b,faceNormals[i][2*n-1]);
	}
	float normals[layers*2*n*3];
	for (int i=0;i<2*n;i++){
		float nor[3];
		averageNormals(faceNormals[0][(i+2*n-1)%(2*n)],faceNormals[0][i],faceNormals[0][(i+2*n-1)%(2*n)],faceNormals[0][i],nor);
		normals[count++] = 0;//nor[0];
		normals[count++] = 1;//nor[1];
		normals[count++] = 0;//nor[2];
	}
	for (int i=1;i<layers-1;i++){
		for (int j=0;j<2*n;j++){
			float nor[3];
			averageNormals(faceNormals[i-1][(j+2*n-1)%(2*n)],faceNormals[i-1][j],faceNormals[i][(j+2*n-1)%(2*n)],faceNormals[i][j],nor);
			normals[count++] = nor[0];
			normals[count++] = nor[1];
			normals[count++] = nor[2];			
		}
	}
	for (int i=0;i<2*n;i++){
		float nor[3];
		averageNormals(faceNormals[layers-2][(i+2*n-1)%(2*n)],faceNormals[layers-2][i],faceNormals[layers-2][(i+2*n-1)%(2*n)],faceNormals[layers-2][i],nor);
		normals[count++] = nor[0];
		normals[count++] = nor[1];
		normals[count++] = nor[2];
	}
	
	unsigned int indices[(n*20)*(layers-1)*4];
	count = 0;
	for (int i=0;i<layers-1;i++){
		for (int j=0;j<2*n;j++){
			indices[count++] = i*n*2+j;
			indices[count++] = (i+1)*n*2+j;
			indices[count++] = (i+1)*n*2+(j+1)%(2*n);
			indices[count++] = i*n*2+(j+1)%(2*n);
		}
	}
			   
	
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_NORMAL_ARRAY);
	glVertexPointer(3, GL_FLOAT, 0, vertices);
	glNormalPointer(GL_FLOAT, 0, normals);
	
	glDrawElements(GL_QUADS, (layers-1)*2*n*4, GL_UNSIGNED_INT, indices);
	
	glDisableClientState(GL_VERTEX_ARRAY);
	glDisableClientState(GL_NORMAL_ARRAY);
	
	glFlush();
	glutSwapBuffers();
}