Sdl3 Example Info

// Render SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255); // black background SDL_RenderClear(renderer); // Draw a filled circle (using SDL_RenderFillRect would be simpler, but we approximate) // For a real circle, we'd use a texture, but SDL3's renderer still lacks native circle. // Let's draw a simple rectangle to keep the example focused. SDL_FRect ball_rect = { ball_x - BALL_RADIUS, ball_y - BALL_RADIUS, BALL_RADIUS * 2, BALL_RADIUS * 2 }; SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255); // blue SDL_RenderFillRect(renderer, &ball_rect); // In SDL3, we call SDL_RenderPresent (same as SDL2) SDL_RenderPresent(renderer); // Frame rate control (optional: ~60 FPS) SDL_Delay(16); }

– Simple bounding-box collision with the window edges. Because the ball is represented by a rectangle for simplicity, we adjust the bounce condition to consider the radius. The velocity vector is inverted on collision, and the ball is repositioned to prevent sticking. sdl3 example

// 6. Cleanup SDL_DestroyRenderer(renderer); SDL_DestroyWindow(window); SDL_Quit(); return 0; } 1. Initialization – SDL_Init(SDL_INIT_VIDEO) returns a boolean (true on success). Unlike SDL2’s integer return, SDL3 uses bool consistently. Error messages are retrieved via SDL_GetError() . We only initialize the video subsystem because we don’t need audio or game controllers. // Render SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255); //

// 3. Create a renderer for accelerated 2D SDL_Renderer* renderer = SDL_CreateRenderer(window, NULL, SDL_RENDERER_ACCELERATED); if (!renderer) { SDL_Log("SDL_CreateRenderer Error: %s", SDL_GetError()); SDL_DestroyWindow(window); SDL_Quit(); return 1; } Because the ball is represented by a rectangle

ball_x += velocity_x * delta_time; ball_y += velocity_y * delta_time;

– SDL_SetRenderDrawColor sets the drawing color. SDL_RenderClear fills the whole window with black. We then draw a filled rectangle (representing the ball) in blue. Note: SDL3’s renderer still does not include a native filled circle primitive, so a rectangle suffices for demonstration. Finally, SDL_RenderPresent swaps the buffers to show the frame.