141 lines
3.6 KiB
C
141 lines
3.6 KiB
C
#include "cube3d.h"
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static void init_raycast(t_rcast *rcast, t_vec *ray)
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{
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rcast->is_x = 0;
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rcast->wall_height = 0;
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// ray sign
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rcast->ray_sign_x = 1;
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if (ray->start.x < ray->end.x)
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rcast->ray_sign_x = -1;
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rcast->ray_sign_y = 1;
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if (ray->start.y < ray->end.y)
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rcast->ray_sign_y = -1;
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// cell position of ray
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rcast->cell_x = ray->start.x / rcast->cell;
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rcast->cell_y = ray->start.y / rcast->cell;
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// slope of ray
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rcast->slope_x = ray->end.x - ray->start.x;
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rcast->slope_y = ray->end.y - ray->start.y;
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// direction of next cell
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rcast->next_cell_x = -rcast->ray_sign_x;
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rcast->next_cell_y = -rcast->ray_sign_y;
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// ray steps in both axis
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rcast->ray_step_x = ft_abs(rcast->cell * rcast->slope_y);
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rcast->ray_step_y = ft_abs(rcast->cell * rcast->slope_x);
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}
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static void init_first_step(t_rcast *rcast, t_vec *ray)
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{
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// first next time ray cross grid
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rcast->first_next_x = ray->start.x % rcast->cell;
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if (rcast->first_next_x && rcast->ray_sign_x < 0)
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rcast->first_next_x = rcast->cell - rcast->first_next_x;
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if (!rcast->first_next_x && rcast->ray_sign_x < 0)
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rcast->first_next_x = rcast->cell;
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rcast->first_next_y = ray->start.y % rcast->cell;
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if (rcast->first_next_y && rcast->ray_sign_y < 0)
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rcast->first_next_y = rcast->cell - rcast->first_next_y;
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if (!rcast->first_next_y && rcast->ray_sign_y < 0)
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rcast->first_next_y = rcast->cell;
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rcast->next_x = ft_abs(rcast->first_next_x * rcast->slope_y);
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rcast->next_y = ft_abs(rcast->first_next_y * rcast->slope_x);
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}
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static void next_cell(t_rcast *rcast)
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{
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if (rcast->next_x > rcast->next_y)
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{
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rcast->cell_y += rcast->next_cell_y;
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rcast->next_y += rcast->ray_step_y;
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rcast->is_x = 0;
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}
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else
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{
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rcast->cell_x += rcast->next_cell_x;
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rcast->next_x += rcast->ray_step_x;
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rcast->is_x = 1;
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}
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}
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static void calcul_ray_end(t_rcast *rcast, t_vec *ray)
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{
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/*
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if (rcast->is_x)
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{
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ray->end.x = rcast->cell_x * rcast->cell;
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if (rcast->ray_sign_x == 1)
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ray->end.x += rcast->cell;
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if (rcast->slope_x)
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{
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rcast->ratio = (double)(ray->end.x - ray->start.x) / (double)rcast->slope_x;
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ray->end.y = ray->start.y + (double)rcast->slope_y * rcast->ratio;
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}
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}
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else
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{
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ray->end.y = rcast->cell_y * rcast->cell;
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if (rcast->ray_sign_y == 1)
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ray->end.y += rcast->cell;
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if (rcast->slope_y)
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{
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rcast->ratio = (double)(ray->end.y - ray->start.y) / (double)rcast->slope_y;
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ray->end.x = ray->start.x + (double)rcast->slope_x * rcast->ratio;
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}
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}
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*/
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int *nd1;
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int *cell1;
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int *sign1;
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int *st1;
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int *slp1;
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int *nd2;
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int *st2;
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int *slp2;
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if (rcast->is_x)
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{
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nd1 = &(ray->end.x);
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cell1 = &(rcast->cell_x);
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sign1 = &(rcast->ray_sign_x);
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st1 = &(ray->start.x);
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slp1 = &(rcast->slope_x);
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nd2 = &(ray->end.y);
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st2 = &(ray->start.y);
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slp2 = &(rcast->slope_y);
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}
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else
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{
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nd1 = &(ray->end.y);
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cell1 = &(rcast->cell_y);
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sign1 = &(rcast->ray_sign_y);
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st1 = &(ray->start.y);
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slp1 = &(rcast->slope_y);
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nd2 = &(ray->end.x);
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st2 = &(ray->start.x);
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slp2 = &(rcast->slope_x);
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}
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*nd1 = *cell1 * rcast->cell;
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if (*sign1 == 1)
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*nd1 += rcast->cell;
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if (*slp1)
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*nd2 = *st2 + (double)(*slp2) * (double)(*nd1 - *st1) / (double)(*slp1);
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}
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void ray_intersect(t_game *game, t_rcast *rcast, t_vec *ray)
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{
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ray->start.x = rcast->ray.start.x + game->plr.pos.x;
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ray->start.y = rcast->ray.start.y + game->plr.pos.y;
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ray->end.x = rcast->ray.end.x + game->plr.pos.x;
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ray->end.x += rcast->ray_nb;
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ray->end.y = rcast->ray.end.y + game->plr.pos.y;
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rotate(&(game->plr), &(ray->end));
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init_raycast(rcast, ray);
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init_first_step(rcast, ray);
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// loop through grid
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while (!is_wall(game, rcast->cell_x, rcast->cell_y))
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next_cell(rcast);
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// end ray position
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calcul_ray_end(rcast, ray);
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}
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