RRV - Radiosity Renderer and Visualizer (C++, OpenGL)

/*
 * Copyright (C) 2007 TODO
 *
 * This file is part of rrv (Radiosity Renderer and Visualizer).
 *
 * rrv is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * rrv is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with rrv.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "Entity.h"
#include "BarrelEntity.h"
#include <math.h>
#ifndef M_PI
	#define M_PI		3.14159265358979323846
#endif
 
using namespace XML;
 
void BarrelEntity::impl_deserialize( XMLNode *from ) {
	setName(from, "barrel");
	this->polygonize();
}
 
void BarrelEntity::polygonize ( ) {
	const int PLANE_COUNT = 20;
	const float RADIUS = 0.5;
 
	Vertex v[4];
	for(int i=0; i<PLANE_COUNT+1; i++)
	{
		v[3] = v[2];
		v[0] = v[1];
		// compute coords (http://en.wikipedia.org/wiki/Sphere)
		float angle = 2 * M_PI / PLANE_COUNT * i;
		float x = RADIUS * cos(angle);
		float z = RADIUS * sin(angle);
		v[2].x = v[1].x = x;
		v[2].z = v[1].z = z;
		v[2].y = -0.5;
		v[1].y = +0.5;
		if(0 != i)
		{
			// face
			this->addQuad(v);
			// upper and lower base
			this->addBaseTriangles(v);
		}
	}
}
 
void BarrelEntity::addBaseTriangles(Vertex vertex[4])
{
	// Triangle initialization
	Triangle t;
	setTriangleProperties( t );
 
	Vertex v;
	for(int j=0; j<4; j+=2)
	{
		for (int i=j+0; i<j+2; i++)
		{
			t.vertex[i-j] = vertex[2*j+1-i];
			v.x=v.z=0;
			v.y=vertex[i].y;
			t.vertex[i+1-j]=v;
		}
		this->addTriangle(&t);
	}
}
 
void BarrelEntity::addQuad(Vertex vertex[4])
{
	// Triangle initialization
	Triangle t;
	setTriangleProperties( t );
 
	// Add triangle #1
	for (int i=0; i<3; i++)
		t.vertex[i] = vertex[i];
	this->addTriangle(&t);
 
	// Add triangle #2
	t.vertex[1] = vertex[2];
	t.vertex[2] = vertex[3];
	this->addTriangle(&t);
}