100 lines
2.2 KiB
C
100 lines
2.2 KiB
C
#include "snake.h"
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#include <stdlib.h>
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struct snake* add_snake(struct snake* snake, int x, int y) {
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struct snake* head = calloc(1, sizeof(struct snake));
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if (head == NULL) {
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return NULL; // Handle memory allocation failure
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}
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head->x = x;
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head->y = y;
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head->next = snake;
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return head;
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}
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struct snake* remove_snake(struct snake* snake) {
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if (snake == NULL) {
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return NULL;
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}
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if (snake->next == NULL) {
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free(snake);
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return NULL;
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}
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struct snake* this = snake;
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struct snake* prev = NULL;
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while (this->next != NULL) {
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prev = this;
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this = this->next;
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}
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free(this);
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prev->next = NULL;
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return snake;
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}
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void free_snake(struct snake* sn) {
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if (sn == NULL) {
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return;
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}
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free_snake(sn->next);
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free(sn);
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}
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int is_snake(struct snake* snake, int x, int y) {
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for (struct snake* this = snake; this != NULL; this = this->next) {
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if (this->x == x && this->y == y) {
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return 1;
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}
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}
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return 0;
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}
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int step_state(struct state* st) {
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// Calculate new head position
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int nx = st->snake->x + st->sx;
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int ny = st->snake->y + st->sy;
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// Check wall collision
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if (nx < 0 || nx >= st->width || ny < 0 || ny >= st->height) {
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return END_WALL;
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}
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// Check self collision
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if (is_snake(st->snake, nx, ny)) {
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return END_SNAKE;
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}
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// Check if food is eaten
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int ate_food = 0;
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int food_left = 0;
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for (int i = 0; i < FOOD_COUNT; i++) {
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if (st->foodx[i] >= 0 && st->foody[i] >= 0) {
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food_left++;
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if (st->foodx[i] == nx && st->foody[i] == ny) {
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// Eat food
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st->foodx[i] = -1;
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st->foody[i] = -1;
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ate_food = 1;
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food_left--; // This food is now eaten
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}
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}
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}
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// Add new head
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st->snake = add_snake(st->snake, nx, ny);
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if (ate_food) {
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// If all food eaten, end game
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if (food_left == 0) {
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return END_FOOD;
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}
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// Do not remove tail (snake grows)
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} else {
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// Remove tail (snake moves)
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st->snake = remove_snake(st->snake);
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}
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return END_CONTINUE;
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}
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