BUG: Hard limit on rendering more than 999 characters

[alexlnkp]

I was trying to make a "pseudo-terminal" SDL2 window, when I encountered this. I thought I was going insane at first, but there ACTUALLY seems to be some kind of a weird limit on number of characters that can be rendered in a single draw call, which is equal to 999. Code that reproduces the issue:

#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>
#include <stdio.h>

#include "lib/SDL_FontCache.h"

#define GRID_X_RES 41
#define GRID_Y_RES 41

void render_grid(char* grid) {
    Uint32 x = 0, y = 0, idx = 0;
    for (y = 0; y < GRID_Y_RES; ++y) {
        for (x = 0; x < GRID_X_RES; ++x) {
            idx = x + y * GRID_X_RES;
            grid[idx] = '.' - ('$' * ((idx+1) % GRID_X_RES == 0));
        }
    }
    grid[GRID_X_RES * GRID_Y_RES + GRID_Y_RES] = '\0';
}

int main(int argc, char* argv[]) {
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError());
    }

    SDL_Window* window = SDL_CreateWindow(
        "SDL2 Pseudo-Terminal",
        SDL_WINDOWPOS_UNDEFINED,
        SDL_WINDOWPOS_UNDEFINED,
        800, 600,
        SDL_WINDOW_SHOWN
    );

    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);

    FC_Font* font = FC_CreateFont();
    FC_LoadFont(font, renderer, "res/PressStart2P-Regular.ttf", 20, FC_MakeColor(255, 255, 255, 255), TTF_STYLE_NORMAL);  

    int running = 1;

    /* malloc gives same results as simple `char grid[((GRID_X_RES * GRID_Y_RES + GRID_Y_RES) + 1)]` */
    char* grid = malloc(((GRID_X_RES * GRID_Y_RES + GRID_Y_RES) + 1) * sizeof(char));

    SDL_Event event;
    while (running) {
        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_QUIT) {
                running = 0;
            }
        }

        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
        SDL_RenderClear(renderer);

        render_grid(grid);
        FC_Draw(font, renderer, 0, 0, "%s", grid); 

        SDL_RenderPresent(renderer);
    }

    FC_FreeFont(font);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}

Screenshot

Changing GRID_Y_RES to any number higher than what is currently set doesn't change a thing in rendering, however printing the constructed grid to regular terminal does what is expected.

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I'm not exactly sure if this is an SDL2 quirk or this library's issue, just thought I'd report this nonetheless