/* *****************************************************************************
 * dynamic.c -- dynamic thingies.
 * Copyright (C) 2017 Olivier "Ninestars" Lanneau
 * Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
 *
 * This file is part of libwindmill.
 * libwindmill is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3.0 of the License,
 * or (at your option) any later version.
 *
 * libwindmill 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libwindmill; if not, see <http://www.gnu.org/licenses/>.
 * ************************************************************************** */
#include <libwindmill/internals.h>

void wml_dynamic(wml_vertex_t *vertex, int axe, int x, int y, int z,
	float cosinus, float sinus)
{
	int vertex_x = vertex->x,
		vertex_y = vertex->y,
		vertex_z = vertex->z;
	if (axe == N) {
		vertex->x = vertex_x + x;
		vertex->y = vertex_y + y;
		vertex->z = vertex_z + z;
	} else if (axe == X) {
		vertex->x = vertex_x + x;
		vertex->y = vertex_y * cosinus - vertex_z * sinus + y;
		vertex->z = vertex_z * sinus + vertex_z * cosinus + z;
	} else if (axe == Y) {
		vertex->x = vertex_x * cosinus - vertex_z * sinus + x;
		vertex->y = vertex_y + y;
		vertex->z = vertex_x * sinus + vertex_z * cosinus + z;
	} else if (axe == Z) {
		vertex->x = vertex_x * cosinus - vertex_y * sinus + x;
		vertex->y = vertex_x * sinus + vertex_y * cosinus + y;
		vertex->z = vertex_z + z;
	}
}

void wml_transform(wml_scene_t *scene, wml_vertex_t *vertex)
{
	int vertex_x = vertex->x - (int)scene->camera_x,
		vertex_y = vertex->y - (int)scene->camera_y,
		vertex_z = vertex->z - (int)scene->camera_z;

	/* produit matriciel */
	int x = scene->a1 * vertex_x + scene->a2 * vertex_y;
	int y = scene->a4 * vertex_x + scene->a5 * vertex_y + scene->a6 * vertex_z;
	int z = scene->a7 * vertex_x + scene->a8 * vertex_y + scene->a9 * vertex_z;

	/* perspective */
	if (z < 0) { /* z < near * 128 * 128 */
		vertex->x = -(x * scene->scale_coef + 8192) / z + shift_x;
		vertex->y = -(y * scene->scale_coef + 8192) / z + shift_y;
		vertex->z = 8192 / z;

		/* calcul de z normalise entre les deux plans de clipping */
		vertex->z_normalized = -(0xFFFF *
			(scene->near_coef * z + scene->far_coef) + 32767) / z;
	} else
		vertex->z = 1;
}