103 lines
2.9 KiB
C
103 lines
2.9 KiB
C
#include "cube3d.h"
|
|
|
|
static void init_raycast(t_rcast *rcast, t_vec *ray)
|
|
{
|
|
rcast->is_x = 0;
|
|
rcast->wall_height = 0;
|
|
// ray sign
|
|
rcast->ray_sign_x = 1;
|
|
if (ray->start.x < ray->end.x)
|
|
rcast->ray_sign_x = -1;
|
|
rcast->ray_sign_y = 1;
|
|
if (ray->start.y < ray->end.y)
|
|
rcast->ray_sign_y = -1;
|
|
// cell position of ray
|
|
rcast->cell_x = ray->start.x / CELL;
|
|
rcast->cell_y = ray->start.y / CELL;
|
|
// slope of ray
|
|
rcast->slope_x = ray->end.x - ray->start.x;
|
|
rcast->slope_y = ray->end.y - ray->start.y;
|
|
// direction of next cell
|
|
rcast->next_cell_x = -rcast->ray_sign_x;
|
|
rcast->next_cell_y = -rcast->ray_sign_y;
|
|
// ray steps in both axis
|
|
rcast->ray_step_x = ft_abs(CELL * rcast->slope_y);
|
|
rcast->ray_step_y = ft_abs(CELL * rcast->slope_x);
|
|
}
|
|
|
|
static void init_first_step(t_rcast *rcast, t_vec *ray)
|
|
{
|
|
// first next time ray cross grid
|
|
rcast->first_next_x = ray->start.x % CELL;
|
|
if (rcast->first_next_x && rcast->ray_sign_x < 0)
|
|
rcast->first_next_x = CELL - rcast->first_next_x;
|
|
if (!rcast->first_next_x && rcast->ray_sign_x < 0)
|
|
rcast->first_next_x = CELL;
|
|
rcast->first_next_y = ray->start.y % CELL;
|
|
if (rcast->first_next_y && rcast->ray_sign_y < 0)
|
|
rcast->first_next_y = CELL - rcast->first_next_y;
|
|
if (!rcast->first_next_y && rcast->ray_sign_y < 0)
|
|
rcast->first_next_y = CELL;
|
|
rcast->next_x = ft_abs(rcast->first_next_x * rcast->slope_y);
|
|
rcast->next_y = ft_abs(rcast->first_next_y * rcast->slope_x);
|
|
}
|
|
|
|
static void next_cell(t_rcast *rcast)
|
|
{
|
|
if (rcast->next_x > rcast->next_y)
|
|
{
|
|
rcast->cell_y += rcast->next_cell_y;
|
|
rcast->next_y += rcast->ray_step_y;
|
|
rcast->is_x = 0;
|
|
}
|
|
else
|
|
{
|
|
rcast->cell_x += rcast->next_cell_x;
|
|
rcast->next_x += rcast->ray_step_x;
|
|
rcast->is_x = 1;
|
|
}
|
|
}
|
|
|
|
static void calcul_ray_end(t_rcast *rcast, t_vec *ray)
|
|
{
|
|
if (rcast->is_x)
|
|
{
|
|
ray->end.x = rcast->cell_x * CELL;
|
|
if (rcast->ray_sign_x == 1)
|
|
ray->end.x += CELL;
|
|
if (rcast->slope_x)
|
|
{
|
|
rcast->ratio = (double)(ray->end.x - ray->start.x) / (double)rcast->slope_x;
|
|
ray->end.y = ray->start.y + (double)rcast->slope_y * rcast->ratio;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
ray->end.y = rcast->cell_y * CELL;
|
|
if (rcast->ray_sign_y == 1)
|
|
ray->end.y += CELL;
|
|
if (rcast->slope_y)
|
|
{
|
|
rcast->ratio = (double)(ray->end.y - ray->start.y) / (double)rcast->slope_y;
|
|
ray->end.x = ray->start.x + (double)rcast->slope_x * rcast->ratio;
|
|
}
|
|
}
|
|
}
|
|
|
|
void ray_intersect(t_game *game, t_rcast *rcast, t_vec *ray)
|
|
{
|
|
ray->start.x = rcast->ray.start.x + game->plr.pos.x;
|
|
ray->start.y = rcast->ray.start.y + game->plr.pos.y;
|
|
ray->end.x = rcast->ray.end.x + game->plr.pos.x;
|
|
ray->end.x += rcast->ray_nb * SCREEN_SIZE / SCREEN_DEF;
|
|
ray->end.y = rcast->ray.end.y + game->plr.pos.y;
|
|
rotate(&(game->plr), &(ray->end));
|
|
init_raycast(rcast, ray);
|
|
init_first_step(rcast, ray);
|
|
// loop through grid
|
|
while (!is_wall(game, rcast->cell_x, rcast->cell_y))
|
|
next_cell(rcast);
|
|
// end ray position
|
|
calcul_ray_end(rcast, ray);
|
|
}
|