Search code examples
c++linuxx11sdl-2wayland

SDL_DrawRect() does not draw a proper rect

When I try to draw a rectangle, the bottom line always is one pixel up on the right side:

A "rect"

The problem also persists when I change the size and position.

Below I have a minimal working solution that should reproduce the problem, if it's not my computer going crazy:

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

int main(int args, char **argv) {
    if (SDL_Init(SDL_INIT_EVERYTHING) != 0) {
        printf("error initializing SDL: %s\n", SDL_GetError());
    }
    SDL_Window *window = SDL_CreateWindow("Testing", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, 0);
    Uint32 renderFlags = SDL_RENDERER_ACCELERATED;
    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, renderFlags);
    if (renderer == nullptr) {
        std::cout << "Error initializing _renderer: " << SDL_GetError() << std::endl;
    }
    int close = 0;
    SDL_Event event;

    while (!close) {
        while (SDL_PollEvent(&event)) {
            switch (event.type) {
                case SDL_QUIT:
                    close = 1;
                    break;
            }
        }

        SDL_RenderClear(renderer);

        SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255);
        SDL_Rect rect = {100, 100, 100, 100};
        SDL_RenderDrawRect(renderer, &rect);
        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);

        SDL_RenderPresent(renderer);

        SDL_Delay(1000 / 240);
    }
    SDL_Quit();
    return 0;
}

I am using Fedora 36 Linux and the Gnome 42 desktop.

I also tried starting it with x11 instead of wayland with SDL_VIDEODRIVER=x11, but that doesn't change anything.

What could be the problem here?

Solution

  • It seems like I solved the problem by changing from the Flatpak version of CLion to the native one installed from the JetBrains toolbox.

    The problem only occurs when I run the compiled executable from inside CLion, so I think it's a CLion problem. I reported the problem to JetBrains here.