使用 SDL 在 C 上创建矩形

Question

我正在尝试使用 SDL 创建一个矩形，但它无法编译。我之前创建了一个窗口屏幕，它在 SDL 编译器上运行良好。您能否检查我的代码是否有任何错误。一个例子会有帮助，谢谢。

#include <SDL.h>
#include <stdio.h>

int main()
{
    SDL_Window *p;
    SDL_Renderer *w;

    p = SDL_CreateWindow("Game",SDL_WINDOWPOS_UNDEFINED,
        SDL_WINDOWPOS_UNDEFINED,800,640,SDL_WINDOW_SHOWN);

    SDL_SetRenderDrawColor(w,255,0,0,255);
    SDL_Rect Rect = {220,140,200,200};
    SDL_RenderFillRect(w,&Rect);

    SDL_Delay(3000);
    SDL_DestroyWindow(p);
    SDL_Quit();
    return 0;
}

编译输出:

1> c: \ c lib \ sdl2-2.0.4 \ sdl2 tutorials \ sdl2 tutorials \ project 2.c (13): error C2275: 'SDL_Rect': this format was used in the wrong way.
1> c: \ c_lib \ sdl2-2.0.4 \ include \ sdl_rect.h (68): Refer to the 'SDL_Rect' declarations.
1> c: \ c_lib \ sdl2-2.0.4 \ sdl2_tutorials \ sdl2_tutorials \ project_2.c (13): error C2146: syntax error: ';' (s) 'Rect' not in front of the identifier.
1> c: \ c_lib \ sdl2-2.0.4 \ sdl2_tutorials \ sdl2_tutorials \ project_2.c (13): error C2065: 'Rect': undeclared identifier is.
1> c: \ c_lib \ sdl2-2.0.4 \ sdl2_tutorials \ sdl2_tutorials \ project_2.c (13): error C2059: syntax error: '{'
1> c: \ c_lib \ sdl2-2.0.4 \ sdl2_tutorials \ sdl2_tutorials \ project_2.c (14): error C2065: 'Rect': undeclared identifier is.
1> c: \ c_lib \ sdl2-2.0.4 \ sdl2_tutorials \ sdl2_tutorials \ project_2.c (14): warning C4133: 'function': 'int *' (on) 'const SDL_Rect *' This format is not compatible between not.
========== Build: 0 succeeded, 1 failed, the latest 0, 0 skipped ==========

Answer 1

SDL_Renderer 已声明，但未在程序中初始化和调用。我修改了您的代码来初始化并调用渲染器，它在我的机器上运行良好。代码；

#include <SDL.h>
#include <stdio.h>

int main()
{
    SDL_Window *p;
    SDL_Renderer *w;

    p = SDL_CreateWindow("Game",SDL_WINDOWPOS_UNDEFINED,
        SDL_WINDOWPOS_UNDEFINED,800,640,SDL_WINDOW_SHOWN);

    // initialize the renderer
    w = SDL_CreateRenderer(p, -1, 0);
    // clear the renderer
    SDL_RenderClear(w);

    SDL_SetRenderDrawColor(w,255,0,0,255);
    SDL_Rect Rect = {220,140,200,200};
    SDL_RenderFillRect(w,&Rect);

    // call the renderer   
    SDL_RenderPresent(w);

    SDL_Delay(3000);

    // destroy the renderer
    SDL_DestroyRenderer(w);
    SDL_DestroyWindow(p);
    SDL_Quit();
    return 0;
}

希望有帮助。