写一个可以在arm6818开发板上运行的2048小游戏

好的，以下是基于 SDL 库实现的 ARM6818 开发板上运行的 2048 小游戏的代码。注意，此代码仅供参考，可能需要根据您的具体情况进行适当的修改。

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <SDL2/SDL.h>

#define SCREEN_WIDTH 480
#define SCREEN_HEIGHT 800
#define BLOCK_SIZE 100
#define BLOCK_PADDING 10
#define BOARD_PADDING 20
#define BOARD_SIZE (BLOCK_SIZE*4+BLOCK_PADDING*3+BOARD_PADDING*2)

SDL_Window* window = NULL;
SDL_Renderer* renderer = NULL;
SDL_Texture* block_texture = NULL;
SDL_Texture* bg_texture = NULL;
SDL_Texture* gameover_texture = NULL;
SDL_Rect block_rect;

int board[4][4] = {0};
bool is_gameover = false;

void init() {
    SDL_Init(SDL_INIT_VIDEO);
    window = SDL_CreateWindow("2048", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    SDL_Surface* surface = SDL_LoadBMP("block.bmp");
    block_texture = SDL_CreateTextureFromSurface(renderer, surface);
    SDL_FreeSurface(surface);
    surface = SDL_LoadBMP("bg.bmp");
    bg_texture = SDL_CreateTextureFromSurface(renderer, surface);
    SDL_FreeSurface(surface);
    surface = SDL_LoadBMP("gameover.bmp");
    gameover_texture = SDL_CreateTextureFromSurface(renderer, surface);
    SDL_FreeSurface(surface);
}

void quit() {
    SDL_DestroyTexture(block_texture);
    SDL_DestroyTexture(bg_texture);
    SDL_DestroyTexture(gameover_texture);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
}

void draw_block(int row, int col, int value) {
    block_rect.x = BOARD_PADDING + (BLOCK_SIZE + BLOCK_PADDING) * col;
    block_rect.y = BOARD_PADDING + (BLOCK_SIZE + BLOCK_PADDING) * row;
    block_rect.w = BLOCK_SIZE;
    block_rect.h = BLOCK_SIZE;
    SDL_RenderCopy(renderer, block_texture, NULL, &block_rect);

    char str[16];
    sprintf(str, "%d", value);
    SDL_Surface* surface = TTF_RenderText_Solid(font, str, (SDL_Color){255, 255, 255, 255});
    SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer, surface);
    SDL_Rect rect;
    rect.x = block_rect.x + BLOCK_SIZE / 2 - surface->w / 2;
    rect.y = block_rect.y + BLOCK_SIZE / 2 - surface->h / 2;
    rect.w = surface->w;
    rect.h = surface->h;
    SDL_RenderCopy(renderer, texture, NULL, &rect);
    SDL_FreeSurface(surface);
    SDL_DestroyTexture(texture);
}

void draw_board() {
    SDL_RenderCopy(renderer, bg_texture, NULL, NULL);
    for (int row = 0; row < 4; row++) {
        for (int col = 0; col < 4; col++) {
            if (board[row][col] > 0) {
                draw_block(row, col, board[row][col]);
            }
        }
    }
}

bool is_full() {
    for (int row = 0; row < 4; row++) {
        for (int col = 0; col < 4; col++) {
            if (board[row][col] == 0) {
                return false;
            }
        }
    }
    return true;
}

bool is_gameover() {
    if (!is_full()) {
        return false;
    }
    for (int row = 0; row < 4; row++) {
        for (int col = 0; col < 4; col++) {
            if (row > 0 && board[row][col] == board[row - 1][col]) {
                return false;
            }
            if (row < 3 && board[row][col] == board[row + 1][col]) {
                return false;
            }
            if (col > 0 && board[row][col] == board[row][col - 1]) {
                return false;
            }
            if (col < 3 && board[row][col] == board[row][col + 1]) {
                return false;
            }
        }
    }
    return true;
}

void add_random_block() {
    int row, col;
    do {
        row = rand() % 4;
        col = rand() % 4;
    } while (board[row][col] != 0);
    board[row][col] = (rand() % 2 + 1) * 2;
}

void move_left() {
    bool is_moved = false;
    for (int row = 0; row < 4; row++) {
        int i = 0;
        for (int col = 1; col < 4; col++) {
            if (board[row][col] > 0) {
                if (board[row][i] == 0) {
                    board[row][i] = board[row][col];
                    board[row][col] = 0;
                    is_moved = true;
                } else if (board[row][i] == board[row][col]) {
                    board[row][i] *= 2;
                    board[row][col] = 0;
                    is_moved = true;
                } else {
                    i++;
                    if (i != col) {
                        board[row][i] = board[row][col];
                        board[row][col] = 0;
                        is_moved = true;
                    }
                }
            }
        }
    }
    if (is_moved) {
        add_random_block();
    }
}

void move_right() {
    bool is_moved = false;
    for (int row = 0; row < 4; row++) {
        int i = 3;
        for (int col = 2; col >= 0; col--) {
            if (board[row][col] > 0) {
                if (board[row][i] == 0) {
                    board[row][i] = board[row][col];
                    board[row][col] = 0;
                    is_moved = true;
                } else if (board[row][i] == board[row][col]) {
                    board[row][i] *= 2;
                    board[row][col] = 0;
                    is_moved = true;
                } else {
                    i--;
                    if (i != col) {
                        board[row][i] = board[row][col];
                        board[row][col] = 0;
                        is_moved = true;
                    }
                }
            }
        }
    }
    if (is_moved) {
        add_random_block();
    }
}

void move_up() {
    bool is_moved = false;
    for (int col = 0; col < 4; col++) {
        int i = 0;
        for (int row = 1; row < 4; row++) {
            if (board[row][col] > 0) {
                if (board[i][col] == 0) {
                    board[i][col] = board[row][col];
                    board[row][col] = 0;
                    is_moved = true;
                } else if (board[i][col] == board[row][col]) {
                    board[i][col] *= 2;
                    board[row][col] = 0;
                    is_moved = true;
                } else {
                    i++;
                    if (i != row) {
                        board[i][col] = board[row][col];
                        board[row][col] = 0;
                        is_moved = true;
                    }
                }
            }
        }
    }
    if (is_moved) {
        add_random_block();
    }
}

void move_down() {
    bool is_moved = false;
    for (int col = 0; col < 4; col++) {
        int i = 3;
        for (int row = 2; row >= 0; row--) {
            if (board[row][col] > 0) {
                if (board[i][col] == 0) {
                    board[i][col] = board[row][col];
                    board[row][col] = 0;
                    is_moved = true;
                } else if (board[i][col] == board[row][col]) {
                    board[i][col] *= 2;
                    board[row][col] = 0;
                    is_moved = true;
                } else {
                    i--;
                    if (i != row) {
                        board[i][col] = board[row][col];
                        board[row][col] = 0;
                        is_moved = true;
                    }
                }
            }
        }
    }
    if (is_moved) {
        add_random_block();
    }
}

void handle_event(SDL_Event* event) {
    switch (event->type) {
        case SDL_QUIT:
            is_gameover = true;
            break;
        case SDL_KEYDOWN:
            switch (event->key.keysym.sym) {
                case SDLK_LEFT:
                    move_left();
                    break;
                case SDLK_RIGHT:
                    move_right();
                    break;
                case SDLK_UP:
                    move_up();
                    break;
                case SDLK_DOWN:
                    move_down();
                    break;
            }
            if (is_gameover()) {
                is_gameover = true;
            }
            break;
    }
}

void game_loop() {
    while (!is_gameover) {
        SDL_Event event;
        while (SDL_PollEvent(&event)) {
            handle_event(&event);
        }
        SDL_RenderClear(renderer);
        draw_board();
        SDL_RenderPresent(renderer);
        SDL_Delay(10);
    }
    SDL_RenderCopy(renderer, gameover_texture, NULL, NULL);
    SDL_RenderPresent(renderer);
    SDL_Delay(3000);
}

int main(int argc, char* argv[]) {
    init();
    add_random_block();
    add_random_block();
    game_loop();
    quit();
    return 0;
}

注意，此代码中涉及到了一些图形界面的操作和事件处理，需要您提前安装好相应的库并进行配置。此外，此代码中使用了 SDL2 的事件循环机制来处理用户输入和游戏逻辑，您可以根据自己的需求进行修改。