Cube3d/srcs/exec/raycast.c

99 lines
2.5 KiB
C

/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* raycast.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: jle-neze <marvin@42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2025/10/29 18:15:00 by jle-neze #+# #+# */
/* Updated: 2025/10/29 18:15:00 by jle-neze ### ########.fr */
/* */
/* ************************************************************************** */
#include "cub.h"
static void init_ray_vars(t_game *g, int x, t_ray *r)
{
double cam;
cam = 2.0 * x / (double)g->gfx.w - 1.0;
r->ray_dir_x = g->cam.dir_x + g->cam.plane_x * cam;
r->ray_dir_y = g->cam.dir_y + g->cam.plane_y * cam;
r->map_x = (int)g->cam.pos_x;
r->map_y = (int)g->cam.pos_y;
if (r->ray_dir_x == 0)
r->delta_dist_x = 1e30;
else
r->delta_dist_x = fabs(1.0 / r->ray_dir_x);
if (r->ray_dir_y == 0)
r->delta_dist_y = 1e30;
else
r->delta_dist_y = fabs(1.0 / r->ray_dir_y);
}
static void calc_step_side(t_game *g, t_ray *r)
{
if (r->ray_dir_x < 0)
{
r->step_x = -1;
r->side_dist_x = (g->cam.pos_x - r->map_x) * r->delta_dist_x;
}
else
{
r->step_x = 1;
r->side_dist_x = (r->map_x + 1.0 - g->cam.pos_x) * r->delta_dist_x;
}
if (r->ray_dir_y < 0)
{
r->step_y = -1;
r->side_dist_y = (g->cam.pos_y - r->map_y) * r->delta_dist_y;
}
else
{
r->step_y = 1;
r->side_dist_y = (r->map_y + 1.0 - g->cam.pos_y) * r->delta_dist_y;
}
}
static void perform_dda(t_game *g, t_ray *r)
{
int hit;
hit = 0;
while (!hit)
{
if (r->side_dist_x < r->side_dist_y)
{
r->side_dist_x += r->delta_dist_x;
r->map_x += r->step_x;
r->side = 0;
}
else
{
r->side_dist_y += r->delta_dist_y;
r->map_y += r->step_y;
r->side = 1;
}
if (r->map_x < 0 || r->map_y < 0 || r->map_x >= g->world.w
|| r->map_y >= g->world.h
|| g->world.grid[r->map_y][r->map_x] == '1')
hit = 1;
}
}
void raycast_frame(t_game *g)
{
int x;
t_ray r;
x = 0;
while (x < g->gfx.w)
{
init_ray_vars(g, x, &r);
calc_step_side(g, &r);
perform_dda(g, &r);
draw_column(g, x, &r);
x++;
}
}