//----------------------------------------------------------------------------------------------------
// 
// WINDMILL
//
// version : 2.0
// Moteur de rendu 3D base sur la methode de rasterisation avec buffer de profondeur
//
// Cree par Olivier Lanneau, alias NineStars
// Planet-casio.fr
//
//----------------------------------------------------------------------------------------------------


#include "windmill.hpp"

void debug_pop(char const *fmt, ...);
void debug_display(char const *fmt, ...);


extern Texture tex_white;
extern Texture tex_light;
extern Texture tex_dark;
extern Texture tex_black;


//----------------------------------------------------------------------------------------------------
//                                        INITIALISATION
//----------------------------------------------------------------------------------------------------
Windmill::Windmill()
{
	camera2 = NULL;
	map = NULL;
	//object = NULL;
	z_buffer = NULL;
	set_viewport(0, 0, 128, 64);

	sun = {0, 0, 100};
}


Windmill::~Windmill()
{
	free(z_buffer);
    //free(object);
}


void Windmill::set_camera(Camera* _camera)
{
	camera2 = _camera;
}


void Windmill::set_viewport(int viewport_x1, int viewport_y1, int viewport_x2, int viewport_y2)
{	
	viewport.x1 = max(0, viewport_x1);
	viewport.y1 = max(0, viewport_y1);
	viewport.x2 = min(viewport_x2, DWIDTH);
	viewport.y2 = min(viewport_y2, DHEIGHT);
	
	//if (z_buffer != NULL) free(z_buffer);
	free(z_buffer);
	shift_x = (viewport.x1 + viewport.x2) / 2;
	shift_y = (viewport.y1 + viewport.y2) / 2;

	z_buffer_size = (viewport.x2 - viewport.x1) * (viewport.y2 - viewport.y1);
	z_buffer = (unsigned short*) calloc(z_buffer_size, 2);
	//if (z_buffer == NULL) debug_pop("ERROR ptr z_buffer NULL");
	z_buffer_width = viewport.x2 - viewport.x1;
	z_buffer_offset = - viewport.x1 - viewport.y1 * DWIDTH;
	clear_z_buffer();
}


void Windmill::set_map(Map* _map)
{
	loading = true;

	if (map != _map)
	{	
		// free les anciennes ombres
		// ...

		// attribution de la map
		map = _map;

		// enregistrement d'une liste triable
		//set_objects();

		// calcul des spheres englobantes de chaque objet
		compute_bouding_sphere();

		// calcul des ombres projetees au sol par chaque objet
		//compute_shadows();
	}

	loading = false;
}

/*void Windmill::set_objects()
{
	//objects = new Object* [map->object_length];
    objects = (Object**) malloc(map->object_length * sizeof(Object));
	if (objects == NULL) debug_pop("ERROR ptr object NULL");

	for (int i = 0; i<map->object_length; i++)
	{
		objects[i] = map->object[i];
	}
}*/


void Windmill::compute_bouding_sphere()
{
	// calcul des spheres englobantes pour chaque objet
	for (int i = 0; i<map->object_length; i++)
	{
		Object* object = map->object[i];
		int nb_point = 0;
		int barycenter_x = 0;
		int barycenter_y = 0;
		int barycenter_z = 0;

		// calcul du barycentre
		for (int v = 0; v<object->mesh->v_length; v++)
		{
			VertexPoint vp = object->mesh->v[v];
			barycenter_x += vp.x;
			barycenter_y += vp.y;
			barycenter_z += vp.z;

			nb_point++;
		}
		barycenter_x /= nb_point;
		barycenter_y /= nb_point;
		barycenter_z /= nb_point;

		// recherche du point le plus eloigne du barycentre
		int square_radius_max = 0;
		for (int v = 0; v<object->mesh->v_length; v++)
		{
			VertexPoint vp = object->mesh->v[v];
			int dx = vp.x - barycenter_x;
			int dy = vp.y - barycenter_y;
			int dz = vp.z - barycenter_z;
			int square_radius = dx*dx + dy*dy + dz*dz;
			if (square_radius > square_radius_max)
			{
				square_radius_max = square_radius;
			}
		}
		
		// enregistrement 
		object->sphere.x = barycenter_x;
		object->sphere.y = barycenter_y;
		object->sphere.z = barycenter_z;
		object->sphere.radius = sqrtf(square_radius_max) + 1;
		object->sphere.square_radius = square_radius_max + 1;
	}
}


/*WMesh Windmill::compute_shadows()
{
	// pout chaque objet
	for (int i = 0; i<map->object_length; i++)
	{
		Object* object = map->object[i];

		list_shadows_length = get_points_size(object;
		//debug_pop("sh %i", list_shadows_length);
    	shadows = (Point*) malloc(list_shadows_length * sizeof(Point));
    	int index = 0;

    	// pour chaque poly
		for (int j = 0; j<object->modele_size; j++)
		{
			const Modele* current_poly = &object->modele[j];
			for (int k = 0; k<current_poly->type; k++)
			{
				Point point = get_point(current_poly, k);
				Point shadow_point = {(sun.x * point.z - sun.z * point.x) / (point.z - sun.z), (sun.y * point.z - sun.z * point.y) / (point.z - sun.z), 0};
				
				shadows[index] = shadow_point;
				index ++;
				//debug_pop("p %i %i %i", point.x, point.y, point.z);
				//debug_pop("s %i %i %i", shadow_point.x, shadow_point.y, shadow_point.z);
			}
		}

	}


}



// Gift Wrapping algorithme
void Windmill::compute_shadows_hull(Point3D* points, int points_size)
{
	if (points_size < 3) return;

	Point3D* temp_hull = (Point3D*) malloc(list_shadows_length * sizeof(Point3D));
	int temp_hull_length = 0;

	// commencer par le point le plus a gauche
	int left = 0;
	for (int i = 1; i<points_size; i++)
	{
		if (points[i].x < points[left].x)
		{
			left = i;
		}
	}

	// calcul de la coque
	int p = left, q;
	do
	{
		// conserver point p
		temp_hull[temp_hull_length] = points[p];
		temp_hull_length ++;

		q = (p+1)%points_size;

		for (int i = 0; i < points_size; i++)
		{
			if (compute_shadows_hull_orientation(points[p], points[i], points[q]) == 2) // clockwise
			{
				q = i;
			}
			p = q;
		}

	} while (p != left);


	free(temp_hull);

	int hull_length = temp_hull_length;

	Point3D* hull = (Point3D*) malloc(hull_length * sizeof(Point3D));
	memcpy(hull, temp_hull, hull_length * sizeof(Point3D));

	for (int i = 0; i<temp_hull_length; i++)
	{
		//dprint(0, 8*i)
	}
}


int Windmill::compute_shadows_hull_orientation(Point3D a, Point3D b, Point3D c)
{
	int val = (b.y - a.y) * (c.x - b.x) - (b.x - a.x) * (c.y - b.y);
	if (val == 0) return 0; // colineaire
	return (val > 0)? 1 : 2; // clock ou counterclock wise
}*/