RogueLife/src/map.c

#include "map.h"
#include <stdlib.h>

frect_t tile_shape(struct tile const *tile)
{
    if(!tile->solid) return (frect_t){ 0 };

    return (frect_t){
        .l = -fix(1)/2,
        .r =  fix(1)/2,
        .t = -fix(1)/2,
        .b =  fix(1)/2,
    };
}

struct tile *map_tile(map_t const *m, int x, int y)
{
    if((unsigned)x >= (unsigned)m->width || (unsigned)y >= (unsigned)m->height)
        return NULL;

    return &m->tiles[y * m->width + x];
}

bool map_collides(map_t const *m, frect_t hitbox)
{
    int y_min = ffloor(hitbox.t);
    int y_max = fceil(hitbox.b);
    int x_min = ffloor(hitbox.l);
    int x_max = fceil(hitbox.r);

    /* Collisions against walls and static objects */
    for(int y = y_min; y < y_max; y++)
    for(int x = x_min; x < x_max; x++) {
        struct tile *t = map_tile(m, x, y);
        if(!t || !t->solid) continue;

        fpoint_t center = { fix(x) + fix(1)/2, fix(y) + fix(1)/2 };
        frect_t tile_hitbox = rect_translate(tile_shape(t), center);

        if(rect_collide(hitbox, tile_hitbox))
            return true;
    }

    return false;
}