Files
42_INT_10_cube3d/srcs/draw/ray_intersect.c
2022-04-28 08:52:21 +02:00

135 lines
3.1 KiB
C

#include "cube3d.h"
static void init_raycast(t_rcast *rcast, t_vec *ray)
{
rcast->is_x = 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 / rcast->cell;
rcast->cell_y = ray->start.y / rcast->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 = 0;
if (rcast->slope_x)
{
rcast->ray_step_x = ft_abs(rcast->cell);
if (rcast->slope_y)
rcast->ray_step_x *= ft_abs(rcast->slope_y);
}
rcast->ray_step_y = 0;
if (rcast->slope_y)
{
rcast->ray_step_y = ft_abs(rcast->cell);
if (rcast->slope_x)
rcast->ray_step_y *= ft_abs(rcast->slope_x);
}
// tmp
if (rcast->tmp)
printf(" [slope_x:%i, slope_y:%i]", rcast->slope_x, rcast->slope_y);
//tmp
}
static void init_first_step(t_rcast *rcast, t_vec *ray)
{
rcast->first_next_x = 0;
if (rcast->slope_x)
rcast->first_next_x = ray->start.x % rcast->cell;
if (rcast->ray_sign_x < 0)
rcast->first_next_x -= rcast->cell;
rcast->first_next_y = 0;
if (rcast->slope_y)
rcast->first_next_y = ray->start.y % rcast->cell;
if (rcast->ray_sign_y < 0)
rcast->first_next_y -= rcast->cell;
rcast->next_x = ft_abs(rcast->first_next_x);
if (rcast->slope_y != 0)
rcast->next_x *= ft_abs(rcast->slope_y);
rcast->next_y = ft_abs(rcast->first_next_y);
if (rcast->slope_x != 0)
rcast->next_y *= ft_abs(rcast->slope_x);
// tmp
if (rcast->tmp)
printf(" [next_x:%i, next_y:%i]", rcast->next_x, rcast->next_y);
//tmp
}
static void next_cell(t_rcast *rcast)
{
// tmp
if (rcast->tmp)
printf("\n [next_x(%i) > next_y(%i) ?]", rcast->next_x, rcast->next_y);
//tmp
if (!rcast->slope_x || (rcast->next_x > rcast->next_y && rcast->slope_y))
{
rcast->cell_y += rcast->next_cell_y;
rcast->next_y += rcast->ray_step_y;
rcast->is_x = 0;
// tmp
if (rcast->tmp)
printf(" [yes] (increase y by %i)", rcast->ray_step_y);
//tmp
}
else
{
rcast->cell_x += rcast->next_cell_x;
rcast->next_x += rcast->ray_step_x;
rcast->is_x = 1;
// tmp
if (rcast->tmp)
printf(" [no] (increase x by %i)", rcast->ray_step_x);
//tmp
}
}
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;
ray->end.y = rcast->ray.end.y + game->plr.pos.y;
rotate(&(game->plr), &(ray->end));
// tmp
rcast->tmp = 0;
if (ray->end.x - ray->start.x == 0)
rcast->tmp = 1;
if (ray->end.y - ray->start.y == 0)
rcast->tmp = 1;
if (rcast->tmp)
printf("[ray nb : %3i]", rcast->ray_nb);
//tmp end
init_raycast(rcast, ray);
init_first_step(rcast, ray);
while (!is_wall(game, rcast->cell_x, rcast->cell_y))
next_cell(rcast);
// tmp
if (rcast->tmp)
printf("\n");
//tmp end
}