Rendering Text with SDL_ttf

Text Rendering Performance

What's the performance impact of rendering text every frame vs. caching text surfaces?

3D art representing computer programming

Rendering text every frame versus caching text surfaces can have a significant impact on performance, especially in applications with lots of text or limited processing power. Let's break down the two approaches:

Rendering text every frame:

  • Pros: Flexibility for dynamic text that changes frequently.
  • Cons: High CPU usage, potential frame rate drops.

Caching text surfaces:

  • Pros: Better performance, reduced CPU usage.
  • Cons: Higher memory usage, potential complexity for managing cached surfaces.

In general, caching text surfaces is more performant. Here's a simple example to illustrate the difference:

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

class Text {
public:
  Text(TTF_Font* font, const char* text,
       SDL_Color color) {
    surface = TTF_RenderText_Blended(
      font, text, color);
  }

  void render(SDL_Surface* dest, int x, int y) {
    SDL_Rect dstRect = {x, y, 0, 0};
    SDL_BlitSurface(surface, nullptr, dest,
                    &dstRect);
  }

  ~Text() { SDL_FreeSurface(surface); }

private:
  SDL_Surface* surface;
};

// Usage
Text cachedText(font, "Hello, World!",
                {255, 255, 255, 255});

// In render loop
cachedText.render(
  screenSurface, 100, 100);

This cached approach is much faster than rendering the text every frame:

// In render loop (slower)
SDL_Surface* textSurface =
  TTF_RenderText_Blended(font, "Hello, World!",
                         {255, 255, 255, 255});
SDL_BlitSurface(textSurface, nullptr,
                screenSurface, &dstRect);
SDL_FreeSurface (textSurface);

For optimal performance, cache static text and only re-render when the text content changes.

Answers to questions are automatically generated and may not have been reviewed.

3D art representing computer programming
Part of the course:

Building Minesweeper with C++ and SDL2

Apply what we learned to build an interactive, portfolio-ready capstone project using C++ and the SDL2 library

Free, unlimited access

This course includes:

  • 37 Lessons
  • 100+ Code Samples
  • 92% Positive Reviews
  • Regularly Updated
  • Help and FAQ
Free, Unlimited Access

Professional C++

Comprehensive course covering advanced concepts, and how to use them on large-scale projects.

Screenshot from Warhammer: Total War
Screenshot from Tomb Raider
Screenshot from Jedi: Fallen Order
Contact|Privacy Policy|Terms of Use
Copyright © 2024 - All Rights Reserved