SDL2Bug

SDL2Bug.cpp

#include <SDL2/SDL.h>

int main(int argc, const char * argv[]) {
    
    SDL_SetHint(SDL_HINT_RENDER_DRIVER, "opengl");
    SDL_Init(SDL_INIT_EVERYTHING);
    
    SDL_Window* window1 = SDL_CreateWindow("Test Window 1", 0, 0, 32 * 5, 32 * 5, SDL_WINDOW_OPENGL);
    SDL_Renderer* renderer1 = SDL_CreateRenderer(window1, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE | SDL_RENDERER_PRESENTVSYNC);
    SDL_Texture* texture1 = SDL_CreateTexture(renderer1, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, 32, 32);
    
    SDL_Window* window2 = SDL_CreateWindow("Test Window 2", 32 * 5, 0, 32 * 5, 32 * 5, SDL_WINDOW_OPENGL);
    SDL_Renderer* renderer2 = SDL_CreateRenderer(window2, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE | SDL_RENDERER_PRESENTVSYNC);
    
    bool running = true;
    
    
    SDL_Event ev;
    while (running) {
        while (SDL_PollEvent(&ev)) {
            if (ev.type == SDL_QUIT) {
                running = false;
            }
            if (ev.type == SDL_KEYUP) {
                SDL_Keycode key = ev.key.keysym.sym;
                //press pace to destroy renderer2
                if (key == SDLK_SPACE) {
                    SDL_DestroyRenderer(renderer2);
                }
            }
        }
        
        //draw to texture
        SDL_SetRenderTarget(renderer1, texture1);
        SDL_SetRenderDrawColor(renderer1, 255, 0, 0, 255); // red color
        SDL_RenderClear(renderer1);
        SDL_SetRenderDrawColor(renderer1, 0, 255, 0, 255); // green color
        SDL_Rect rect = {0, 0, 32, 32};
        SDL_RenderFillRect(renderer1, &rect);
        
        //draw texture to ours screen
        SDL_SetRenderTarget(renderer1, NULL);
        SDL_SetRenderDrawColor(renderer1, 0, 0, 255, 255); // blue color
        SDL_RenderClear(renderer1);
        SDL_RenderCopy(renderer1, texture1, NULL, NULL);
        SDL_RenderPresent(renderer1);
        
        //theoretically we should see green color, and we see it, but..
        //but untill we destroy renderer2
        //and interesting fact, if we do anything to renderer2, like clear it or present, then renderer1 will works as expected
    }
    SDL_DestroyTexture(texture1);
    SDL_DestroyRenderer(renderer1);
    SDL_DestroyWindow(window1);
    
    SDL_DestroyRenderer(renderer2);
    SDL_DestroyWindow(window2);
    
    SDL_Quit();
    
    return 0;
}