c语言代码怎么显示图片

C 语言中显示图片

在 C 语言中，可以使用 SDL2 库（Simple DirectMedia Layer）来显示图片。以下步骤介绍如何使用 SDL2 在 C 语言中显示图片：

1. 初始化 SDL2 库

<code class="c">#include <stdio.h>
#include <SDL2/SDL.h>
int main() {
  if (SDL_Init(SDL_INIT_VIDEO) != 0) {
    fprintf(stderr, "SDL_Init Error: %s\n", SDL_GetError());
    return 1;
  }</code>

2. 创建一个窗口

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<code class="c">  SDL_Window *window = SDL_CreateWindow("Image Viewer", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 800, 600, SDL_WINDOW_SHOWN);
  if (window == NULL) {
    fprintf(stderr, "SDL_CreateWindow Error: %s\n", SDL_GetError());
    SDL_Quit();
    return 1;
  }</code>

3. 创建一个渲染器

<code class="c">  SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
  if (renderer == NULL) {
    fprintf(stderr, "SDL_CreateRenderer Error: %s\n", SDL_GetError());
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 1;
  }</code>

4. 加载图片

<code class="c">  SDL_Surface *image = SDL_LoadBMP("image.bmp");
  if (image == NULL) {
    fprintf(stderr, "SDL_LoadBMP Error: %s\n", SDL_GetError());
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 1;
  }</code>

5. 创建图片纹理

<code class="c">  SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, image);
  SDL_FreeSurface(image);
  if (texture == NULL) {
    fprintf(stderr, "SDL_CreateTextureFromSurface Error: %s\n", SDL_GetError());
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 1;
  }</code>

6. 清除渲染器

<code class="c">  SDL_RenderClear(renderer);</code>

7. 渲染图片

<code class="c">  int w, h;
  SDL_QueryTexture(texture, NULL, NULL, &w, &h);
  SDL_Rect dstrect = { 0, 0, w, h };
  SDL_RenderCopy(renderer, texture, NULL, &dstrect);</code>

8. 更新显示

<code class="c">  SDL_RenderPresent(renderer);</code>

9. 主循环

<code class="c">  SDL_Event event;
  while (SDL_PollEvent(&event)) {
    if (event.type == SDL_QUIT) {
      break;
    }
  }</code>

10. 销毁资源

<code class="c">  SDL_DestroyTexture(texture);
  SDL_DestroyRenderer(renderer);
  SDL_DestroyWindow(window);
  SDL_Quit();
  return 0;
}</code>