jtmm2-old/src/collide.c

#include <gint/defs/types.h>
#include <stdbool.h>

#include "collide.h"
#include "conf.h"
#include "level.h"

uint8_t collide_point(Vec point, const Level *level, uint layer_id) {
	Vec cursor; /* the final position to test */
	vec_cpy(&cursor, point);
	vec_div(&cursor, TILE_SIZE); /* get the expected tile ID */
	if (point.x < 0 || point.y < 0 ||
		cursor.x >= level->width || cursor.y >= level->height) {
		return 0; /* the point is out of bounds */
	}
	else {
		return level->layers[layer_id][cursor.x + cursor.y * level->width];
	}
}

/* TODO: 'collide{right,left,up,down} are a bad idea, should replace all
 * of these for by an unique function i.e. 'player_collide'.
 */
bool collide_right(Player *player, Vec position, const Level *level, uint layer_id) {
	Vec pos;
	vec_cpy(&pos, position);
	vec_sub(&pos, player->origin);
	pos.x += player->hbox.x;
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	pos.y += player->hbox.y;
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	return false;
}

bool collide_left(Player *player, Vec position, const Level *level, uint layer_id) {
	Vec pos;
	vec_cpy(&pos, position);
	vec_sub(&pos, player->origin);
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	pos.y += player->hbox.y;
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	return false;
}

bool collide_down(Player *player, Vec position, const Level *level, uint layer_id) {
	Vec pos;
	vec_cpy(&pos, position);
	vec_sub(&pos, player->origin);
	pos.y += player->hbox.y;
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	pos.x += player->hbox.x;
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	return false;
}

bool collide_up(Player *player, Vec position, const Level *level, uint layer_id) {
	Vec pos;
	vec_cpy(&pos, position);
	vec_sub(&pos, player->origin);
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	pos.x += player->hbox.x;
	if (collide_point(pos, level, layer_id)) {
		return true;
	}
	return false;
}

bool collide_full(Player *player, Vec position, const Level *level, uint layer_id) {
	return collide_up(player, position, level, layer_id) ||
		collide_down(player, position, level, layer_id);
}