SDL2 显示图片

在上篇的项目中，设置好了SDL2的头文件和库文件，本篇使用SDL2_image 显示图片。

1. 准备库

该库的下载地址： SDL2_image-devel-2.8.2-VC.zip

下载后解压：

 2. 配置头文件、库文件

• Add the include path of SDL_image to the project
• Add the lib path of SD_image to the project
• Add the new lib entry SDL2_image.lib

 3. 复制DLL文件到目标文件夹

• SDL2_image.dll – DLL of SDL_image
• libjpeg-9.dll – DLL of libjpeg (add if you want to read JPEG images)
• libpng16-16.dll – DLL of libpng (add if you want to read PNG images)
• libtiff-5.dll – DLL of libtiff (add if you want to read TIFF images)
• libwebp-7.dll – DLL of libwebp (add if you want to read WEBP images)
• zlib1.dll – DLL of zlib (add if you want to read png images)

4. 准备图片

自己准备个png图片吧，我这里用的是girl.png，路径在下面的代码里。

5. 显示图片的代码如下

// SdlTest.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>
#include "SDL.h"
#include "SDL_image.h"

int main(int argc, char* argv[]) {
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS) < 0) {
        std::cout << "Error SDL2 Initialization : " << SDL_GetError();
        return 1;
    }

    if (IMG_Init(IMG_INIT_PNG) == 0) {
        std::cout << "Error SDL2_image Initialization";
        return 2;
    }

    SDL_Window* window = SDL_CreateWindow("First program", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 800, 600, SDL_WINDOW_OPENGL);
    if (window == NULL) {
        std::cout << "Error window creation";
        return 3;
    }

    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    if (renderer == NULL) {
        std::cout << "Error renderer creation";
        return 4;
    }

    SDL_Surface* lettuce_sur = IMG_Load("D:\\Temp\\SdlTest\\x64\\Debug\\girl.png");
    if (lettuce_sur == NULL) {
        std::cout << "Error loading image: " << IMG_GetError();
        return 5;
    }

    SDL_Texture* lettuce_tex = SDL_CreateTextureFromSurface(renderer, lettuce_sur);
    if (lettuce_tex == NULL) {
        std::cout << "Error creating texture";
        return 6;
    }

    SDL_FreeSurface(lettuce_sur);

    while (true) {
        SDL_Event e;
        if (SDL_PollEvent(&e)) {
            if (e.type == SDL_QUIT) {
                break;
            }
        }

        SDL_RenderClear(renderer);
        SDL_RenderCopy(renderer, lettuce_tex, NULL, NULL);
        SDL_RenderPresent(renderer);
    }

    SDL_DestroyTexture(lettuce_tex);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    IMG_Quit();
    SDL_Quit();

    return 0;
}
 

代码不多， 这里不再解释了，原文中有一定的解释，可以参照：

Display an image with SDL_image, free tutorial (glusoft.com)

上一篇忘记写原文出处了， 这里补上：
Install SDL on Windows, free tutorial (glusoft.com)
6. 运行效果

会打开一个窗口，里面显示我们准备的图片：