Function to get a font surface pixels.

MatVGL::FontData MatVGL::VFonts::createString(MatVGL_Font font, String *text,
                                              Int16 r, Int16 g, Int16 b) {
  // Put the given colors into SDL_Color, making sure they are between 0 and
  // 255.
  if (r < 0)
    r = 0;
  if (g < 0)
    g = 0;
  if (b < 0)
    b = 0;
  if (r > 255)
    r = 255;
  if (g > 255)
    g = 255;
  if (b > 255)
    b = 255;

  SDL_Color fontColor{(unsigned char)r, (unsigned char)g, (unsigned char)b,
                      255};

  // Create the surface with the given data.
  SDL_Surface *fontSurface =
      TTF_RenderText_Solid(p_fontsMap.find(font)->second, text, fontColor);

  // Put all the data into the structure.
  FontData fontData = {(UInt32)fontSurface->w, (UInt32)fontSurface->h,
                       fontSurface->pixels};

  // We have to free the surface.
  SDL_FreeSurface(fontSurface);

  // Return the surface data.
  return fontData;
}

////////// Fonts.h ↓
typedef struct FontData {
  UInt32 w;
  UInt32 h;
  void *data;
} FontData;