SDL2笔记02_加载一批png图片和加载gif

1. 加载一批png图片显示

1. 首先用ffmpeg.exe准备一批png格式的图片

      .\ffmpeg.exe -ss 59:07.000 -t 7 -r 24 -i G:\Xubuntu_Work_Space\From_Xubuntu\下载\[迅雷下载www.2tu.cc]穿越时空的少女.BD1280高清日语中字.rmvb -y -f image2  C:\Users\majiao\Desktop\heyzo1031\2m%04d.png
   

2. cmakelists.txt里需要链接SDL2和SDL_Image，如下

        cmake_minimum_required(VERSION 3.19)
        project(main)
        set(SDL2_DIR G:/Xubuntu_Work_Space/From_Xubuntu/codeTest_2019_2_21/SDL2/win/SDL2-devel-2.0.14-mingw/SDL2-2.0.14/x86_64-w64-mingw32)
        set(SDL2_IMAGE_DIR G:/Xubuntu_Work_Space/From_Xubuntu/codeTest_2019_2_21/SDL2/win/SDL2_image-devel-2.0.5-mingw/SDL2_image-2.0.5/x86_64-w64-mingw32)
   
        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -lmingw32")
        set(CMAKE_EXE_LINKER_FLAGS "-static-libgcc -static-libstdc++")
   
        include_directories(
                ${SDL2_DIR}/include/SDL2
                ${SDL2_IMAGE_DIR}/include/SDL2
        )
        link_directories(
                ${SDL2_DIR}/lib
                ${SDL2_IMAGE_DIR}/lib
        )
   
        set(SOURCE_FILES main.cpp)
        add_executable(main ${SOURCE_FILES})
   
        target_link_libraries(main mingw32 SDL2main SDL2 SDL2_image)
   
   

3. 写下main.cpp

   • 使用了C++11的chrono

    //main.c
   
    #include <Windows.h>
    #include <vector>
    #include <string>
    #include <chrono>
   
    using namespace std;
    using namespace chrono;
    #include "SDL.h"
    #include "SDL_image.h"
   
    vector<SDL_Texture *> MyLoadImage(SDL_Renderer *renderer);
    template< typename... Args >
    std::string string_sprintf( const char* format, Args... args ) {
        int length = std::snprintf( nullptr, 0, format, args... );
        char* buf = new char[length + 1];
        std::snprintf( buf, length + 1, format, args... );
   
        std::string str( buf );
        delete[] buf;
        return str;
    }
   
    int main(int argc, char** argv) {
        int ret = SDL_Init(SDL_INIT_EVERYTHING);
        if (ret != 0) {
            return -1;
        }
   
        SDL_Window *pWin = SDL_CreateWindow("Game", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 800, 491, 0);
        if (pWin == NULL) {
            return -2;
        }
   
        SDL_Renderer *pRenderer = SDL_CreateRenderer(pWin, -1, SDL_RENDERER_ACCELERATED);
        if (pRenderer == NULL) {
            SDL_DestroyWindow(pWin);
            return -3;
        }
   
        int quit = 0;
        SDL_Event evt;
   
        SDL_Texture *sdlTexture = IMG_LoadTexture(pRenderer, "G:\\Xubuntu_Work_Space\\From_Windows\\img\\pixiv\\not_h\\39700353_p0.jpg");
        vector<SDL_Texture*> pngTextures = MyLoadImage(pRenderer);
        int now = -1,
            n = pngTextures.size(),
            len = 1000/23;  // 23 FPS
        while (!quit) {
            if (SDL_PollEvent(&evt)) {
                if (evt.type == SDL_QUIT) {
                    quit = 1;
                }
                /**else {
                    //清除背景
                    SDL_SetRenderDrawColor(pRenderer, 0, 0, 0, 255);
                    SDL_RenderClear(pRenderer);
                    //TODO:渲染图像
                    SDL_RenderCopy(pRenderer, pngTextures[(++now)%n], NULL, NULL);
                    //显示图像
                    SDL_RenderPresent(pRenderer);
                    SDL_Log("渲染%d\n", now%n);
                }*/
            } else {
                auto start = system_clock::now();
                //清除背景
                SDL_SetRenderDrawColor(pRenderer, 0, 0, 0, 255);
                SDL_RenderClear(pRenderer);
   
                //TODO:渲染图像
                SDL_RenderCopy(pRenderer, pngTextures[(++now)%n], NULL, NULL);
   
                //显示图像
                SDL_RenderPresent(pRenderer);
                auto end   = system_clock::now();
                auto duration = duration_cast<milliseconds>(end - start);
                SDL_Log("else 渲染%d   %lldms\n", now%n, duration.count());
                SDL_Delay(len-duration.count());
            }
        }
   
        if (pRenderer) {
            SDL_DestroyRenderer(pRenderer);
        }
   
        if (pWin) {
            SDL_DestroyWindow(pWin);
        }
   
        SDL_Quit();
   
        return 0;
    }
   
    vector<SDL_Texture *> MyLoadImage(SDL_Renderer* renderer) {
        vector<SDL_Texture *> vec;
        int lef = 0, rig = 168;
        for (int i=1; i<=rig; i++) {
            string filePath = string_sprintf("C:\\Users\\majiao\\Desktop\\heyzo1031\\2m%04d.png", i);
            SDL_Log(filePath.c_str());
            vec.push_back(IMG_LoadTexture(renderer, filePath.c_str()));
        }
        return vec;
    }
   
   

4. 运行后，600多MB的内存消耗，和2.5%的GPU消耗。。。。太拉跨了，不过毕竟是写着玩的东西，就不计较这些了
   

2. 加载GIF