SDL_ttf text rendering issue

Question

I have a simple program that tries to render a text on a window with SDL_ttf:

#include <stdio.h>
#include <SDL.h>
#include <SDL_ttf.h>
#include <stdbool.h>

SDL_Renderer* renderer;
TTF_Font* font = NULL;

int main()
{
    SDL_Init(SDL_INIT_VIDEO);

    SDL_Window* win = SDL_CreateWindow("Title", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_SHOWN);
    renderer = SDL_CreateRenderer(win, -1, SDL_RENDERER_PRESENTVSYNC);
    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0);

    // Font
    if (TTF_Init() < 0)
    {
        printf("Failed to initialize TTF!\n");
    }
    font = TTF_OpenFont("arial.ttf", 12);
    if (!font)
    {
        printf("Failed to load font!\n");
    }

    bool quit = false;
    SDL_Event e;
    while (!quit)
    {
        while (SDL_PollEvent(&e) != 0)
        {
            if (e.type == SDL_KEYDOWN && e.key.keysym.sym == SDLK_q)
            {
                quit = true;
            }
        }
        SDL_RenderClear(renderer);

        SDL_SetRenderDrawColor(renderer, 255, 0, 0, 0);
        SDL_Rect rect = { 200, 40, 400, 400 };
        SDL_RenderDrawRect(renderer, &rect);

        SDL_Color textColor = { 0, 0, 0 };
        SDL_Surface* textSurface = TTF_RenderText_Solid(font, "HELLO", textColor);
        if (textSurface == NULL)
        {
            printf("Error %s\n", SDL_GetError());
        }
        else
        {
            SDL_Texture* mTexture = SDL_CreateTextureFromSurface(renderer, textSurface);
            if (mTexture == NULL) 
            {
                printf("Error %s\n", SDL_GetError());
            }
            else
            {
                SDL_Rect rectSrc = { 0, 0, textSurface->w, textSurface->h };
                SDL_Rect rectDes = { 25, 25, textSurface->w, textSurface->h };
                SDL_RenderCopy(renderer, mTexture, &rectSrc, &rectDes);

                SDL_DestroyTexture(mTexture);
            }
            SDL_FreeSurface(textSurface);
        }

        SDL_SetRenderDrawColor(renderer, 255, 255, 255, 0);
        SDL_RenderPresent(renderer);
    }

    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(win);
    TTF_Quit();
    SDL_Quit();

    return 0;
}

However I’m getting the following error on line SDL_FreeSurface(textSurface);:

Exception thrown at 0x000000005FA48159 (SDL2.dll) in TestSDL.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.

This is the textSurface output at the time of error:

By removing line SDL_FreeSurface(textSurface); the program works as intended, but then I have a memory leak.

What seems to be causing this error?

I’m using Visual studio 2022 with SDL2 2.0.22 and SDL2_ttf 2.20.0.

I can't reproduce the segfault. I had to replace `int main()` with `int main(int, char *[])` though, otherwise it doesn't compile. — Nelfeal, Nov 26 '22 at 14:34
That's strange, since SDL pretty much [*requires* this signature](https://stackoverflow.com/questions/11976084/why-sdl-defines-main-macro). — Nelfeal, Nov 26 '22 at 16:19
OK, adding `int argc, char* args[]` to main() works fine. But the error persists. And it only happens with text rendering (I have a larger SDL program that works just fine without the text rendering). I'll have to test this out on another environment. — Kazgaa, Nov 26 '22 at 16:38
Could you get a stacktrace and/or disassembly at that crash? What happens if you do `TTF_RenderText_Blended` instead? Are you sure you use `SDL2_ttf` and not `SDL_ttf` (check what dlls are loaded at runtime)? — keltar, Nov 27 '22 at 08:13
@keltar I checked runtime dlls and indeed it loaded the ttf dll from a different directory than the one I specified in my project's settings (I guess that dll was an earlier version of SDL2_ttf.dll). So I just moved the dll to the same folder as .exe. It works fine now. Thanks! — Kazgaa, Nov 27 '22 at 11:13

SDL_ttf text rendering issue

0 Answers0