Core

Core routines including initialization and the main loop.

Header: #include <asw/modules/core.h>
Namespace: asw::core

Functions

init

void init(int width, int height, int scale = 1);

Initializes the core module. This must be called before using any other ASW functionality. It loads the config file named by ASW_CONFIG, if it is set, before it opens the window.

Parameter	Type	Description
width	int	The width of the window
height	int	The height of the window
scale	int	The scale of the window (default: 1)

init_opengl

void init_opengl(int width, int height, int scale = 1);

Initializes the core module with an OpenGL context instead of an SDL renderer. The parameters are the same as init. Use asw::display::swap_window() to present each frame.

update

void update();

Updates core module functionality. Called each frame to process events, update input state and update the sound module (fades, ducking and positional sounds).

run

void run(const std::function<void()>& frame);

Run a main loop until exit() is called. run calls frame once per frame. In frame, call update(), run your game logic, draw, and call asw::display::present().

• Desktop: run is a plain loop. It returns after exit() is called, so you can call shutdown() after it.
• Browser (Emscripten): the browser runs the loop with emscripten_set_main_loop. run does not return, and code after it does not run. When exit() is called, the loop stops and Module.onStop is called if the web page defines it. The page made by asw_add_web_target() uses this to show a restart message.

Use run instead of a while (!is_exiting()) loop, so that the same code works on desktop and in the browser. A while loop blocks the browser, so the page freezes. SceneManager::start() uses run in the browser too.

asw::core::run([&]() {
  asw::core::update();
  // game logic and drawing
  asw::display::present();
});

get_delta_time

float get_delta_time();

Get the time in seconds between the last two calls to update(). The value is capped at 0.25 seconds, so a breakpoint or a stalled window does not make objects jump. Returns 0 before the second call to update().

Use this in a custom loop. The managed SceneManager::start() loop passes a fixed dt to your scenes.

print_info

void print_info();

Prints information about the core module to the console.

exit

void exit();

Exit the application. Sets the exiting flag, which causes the main loop to exit on the next update.

is_exiting

bool is_exiting();

Returns true after exit() was called or the window was closed.

shutdown

void shutdown();

Release the resources that the core module uses. Call this on application exit, after the main loop.

Example

#include <asw/asw.h>

int main() {
  asw::core::init(640, 480, 2);

  asw::core::run([&]() {
    asw::core::update();
    const float dt = asw::core::get_delta_time();

    if (asw::input::get_key_down(asw::input::Key::Escape)) {
      asw::core::exit();
    }

    // game logic here, scaled by dt

    asw::display::present();
  });

  asw::core::shutdown(); // desktop only, run() does not return in the browser
  return 0;
}