Sdl3 — Example

// Update based on delta time Uint64 current_time = SDL_GetTicks(); float delta_time = (current_time - last_time) / 1000.0f; if (delta_time > 0.05f) delta_time = 0.05f; // clamp for safety last_time = current_time;

– 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. // Update based on delta time Uint64 current_time

// 4. Ball state float ball_x = WINDOW_WIDTH / 2.0f; float ball_y = WINDOW_HEIGHT / 2.0f; float velocity_x = 250.0f; // pixels per second float velocity_y = 200.0f; Uint64 last_time = SDL_GetTicks(); bool running = true; SDL_Event event; Unlike SDL2’s integer return, SDL3 uses bool consistently

– We store position and velocity as floats for smooth sub-pixel movement. The key addition in SDL3’s API is the use of SDL_GetTicks() returning Uint64 (milliseconds), which is far less prone to overflow than SDL2’s 32-bit value. Delta time calculation ensures the ball moves at a consistent speed regardless of frame rate.

#define WINDOW_WIDTH 800 #define WINDOW_HEIGHT 600 #define BALL_RADIUS 20