pvjc24/a2/snake.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "snake.h"

// Global variables to store the direction of the snake
int sx = 0; // Horizontal speed
int sy = 0; // Vertical speed

// Function to move the snake based on the direction
void move_snake(struct snake* head) {
    // Update the position of the head based on the current speed
    head->x += sx;
    head->y += sy;
}

// Function to update the direction of the snake based on user input
void update_direction(int direction) {
    switch(direction) {
        case KEY_UP:
            sx = 0;
            sy = -1;
            break;
        case KEY_DOWN:
            sx = 0;
            sy = 1;
            break;
        case KEY_LEFT:
            sx = -1;
            sy = 0;
            break;
        case KEY_RIGHT:
            sx = 1;
            sy = 0;
            break;
        default:
            break;
    }
}

// Function to handle collision detection and game logic
int handle_collision(struct state* state) {
    // Check if the new head position is within the bounds of the game area
    if (state->snake->x < 0 || state->snake->x >= state->width || state->snake->y < 0 || state->snake->y >= state->height) {
        return END_WALL; // End game if the head hits the wall
    }
    
    // Check if the new head position overlaps with the snake's body
    if (is_snake(state->snake, state->snake->x, state->snake->y)) {
        return END_SNAKE; // End game if the head collides with the snake's body
    }
    
    // Check if the new head position overlaps with any food item
    for (int i = 0; i < FOOD_COUNT; i++) {
        if (state->foodx[i] == state->snake->x && state->foody[i] == state->snake->y) {
            // Mark the food item as eaten
            state->foodx[i] = -1;
            state->foody[i] = -1;
            return END_CONTINUE; // Continue game if the snake eats food
        }
    }
    
    // If none of the above conditions are met, continue the game
    return END_CONTINUE;
}

// Function to initialize the game world
void initialize_world(struct state* state) {
    // Initialize random seed
    srand(time(NULL));
    
    // Place the snake in the center of the game area
    state->snake = malloc(sizeof(struct snake));
    state->snake->x = state->width / 2;
    state->snake->y = state->height / 2;
    state->snake->next = NULL;
    
    // Place 20 food items randomly in the game area
    for (int i = 0; i < FOOD_COUNT; i++) {
        state->foodx[i] = rand() % state->width;
        state->foody[i] = rand() % state->height;
    }
}