Examples

The ASW repository has an example program for each part of the library. You can play each one here in your browser: press Play, then click the game to give it the keyboard. The examples are the same C++ programs as on desktop, built to WebAssembly with Emscripten.

Advanced lighting

Running the examples

git clone https://github.com/adsgames/asw.git
cd asw
cmake --preset debug -DASW_BUILD_EXAMPLES=ON
cmake --build --preset debug
./build/debug/bin/example_lighting

Each example is in build/debug/bin/ as example_<name>. If an example uses assets, the build copies them next to the executable.

To build the examples for the browser, use the Emscripten toolchain, then serve the output folder:

emcmake cmake -S . -B build/web -DCMAKE_BUILD_TYPE=Release -DASW_BUILD_EXAMPLES=ON
cmake --build build/web
cd build/web/bin && python3 -m http.server

Then open http://localhost:8000/example_particles.html. The examples use asw::core::run() for their main loop, so the same code runs on desktop and in the browser.

Each example also has a scripted run. It uses simulated input to play itself, saves autorun.png with screenshot, and quits. With the dummy video driver, no window opens:

ASW_EXAMPLE_AUTORUN=1 SDL_VIDEO_DRIVER=dummy ./build/debug/bin/example_particles

In the browser, add ?autorun to the address of an example. The screenshots on this page come from these scripted runs in the browser, taken for each ASW release.

Graphics

Advanced lighting

A dark level lit with the lighting module. The camera scrolls, and the lights stay in place in the world.

asw::lighting::LightMap with a camera
Point lights and spot lights, with Linear, Smooth and Quadratic falloff
Flicker and pulse on lights
Occluders with Cast and Visibility shadows
add_glow() for sprites that give off light, such as lava
asw::lighting::AmbientCycle for day and night
asw::lighting::TileLight for light that spreads across a tile grid
asw::geometry::visibility() as a field of view
asw::draw::polygon_fill(), polygon() and triangle_fill()

Controls: WASD / arrows move. The mouse aims the flashlight. Left click drops a colored light. F toggles the flashlight. 1 / 2 / 3 select no shadows, cast shadows and visibility shadows. 4 selects the next falloff. Q toggles flicker and pulse. E toggles glows. N toggles the day and night cycle. T toggles tile lighting. V shows the field of view. L toggles lighting.

View source · Lighting · Geometry

Lighting

Render targets, blend modes and sprite drawing, without the lighting module. A light map is made from radial gradients drawn with BlendMode::Add into a texture. The light map is then drawn over the scene with BlendMode::Modulate.

asw::assets::create_texture() and asw::display::set_render_target() to draw textures at runtime
asw::draw::set_scale_mode(): Nearest and Linear on the same art
asw::draw::rotate_sprite(), sprite_flip() and stretch_sprite()
asw::draw::stretch_sprite_rotate() to scale, rotate and flip in one call
asw::draw::set_tint() and set_alpha()

Controls: Mouse moves the torch. Left click drops a colored light. L toggles lighting. 1 / 2 / 3 select dusk, night and pitch black.

View source · Draw · Assets

Particles

Fire, fountain, smoke, snow and a glowing trail that follows the mouse.

asw::ParticleConfig: lifetime, speed, angle, color, size and gravity
asw::ParticleEmitter: continuous emission (set_emission_rate, start, stop) and bursts (emit)
Textured particles from asw::assets::create_radial_gradient()
Additive blending with asw::draw::set_blend_mode() and set_tint()

Controls: 1–4 toggle the emitters. Left click makes a firework burst at the cursor.

View source · Particles

Primitives

asw::draw::point(), line(), rect(), rect_fill(), circle() and circle_fill()
asw::draw::rect() with a thickness, and rect_fill_rotate()
asw::draw::triangle_fill(), polygon() and polygon_fill() with a concave shape
asw::draw::text() and text_shadow()
asw::color constants and Color helpers (lighten, darken, with_alpha)
Alpha blending of shapes that overlap

Controls: Space pauses the animation.

View source · Draw · Color

Text

asw::assets::load_font() with FontStyle::Pixel and FontStyle::Smooth
Font caching with load_font(..., key) and get_font(key)
asw::draw::text() with Left, Center and Right justification, and text_shadow()
Text that fades through the alpha of its color
asw::util::get_text_size() to fit boxes around text, and get_font_height() for line spacing

Controls: Space restarts the typewriter.

View source · Draw · Assets

Easing

Each cell plots one asw::easing function as a curve, with smoothstep last, with a dot that moves along it. The bar under each curve moves by the eased value, so you can easily see overshoot and bounce.

Controls: Space pauses. Up / Down change the speed.

View source · Easing

Game Framework

Scenes

A title screen and a ball-popping game.

asw::scene::SceneManager with two scenes and scene switching
Scene::create_object() and get_object_view()
asw::game::GameObject with a Physics body, z_index, alpha and alive
asw::ParticleEmitter used as a scene object
asw::easing and asw::random for animation and spawning

Controls: Enter starts the game. Left click pops a ball, or makes a ball on empty space. Space makes ten balls.

View source · Scene · Game Objects

Camera

A scrolling world.

asw::Camera follows the player, stays inside the world and shakes
asw::Quad::get_push_out() stops the player from walking through walls
asw::SpriteSheet and asw::Animation for an animated sprite
asw::ParticleEmitter drawn in world space through the camera

Controls: WASD / arrows move. Space shakes the camera and makes a burst of particles. F12 saves a screenshot.

View source · Camera · Sprite Sheet

UI

asw::ui::Root controls input, layout and drawing
Panel, Stack, Label, Button, Choice, Slider, Checkbox and InputBox, with on_click and on_change callbacks
The theme font, so widgets do not each need a font
Keyboard and controller navigation with asw::ui::bind_default_navigation() and Root::on_back
Changes to asw::ui::Theme at runtime, and a ButtonStyle for one button
asw::assets::get_save_path() keeps the name between runs
asw::dialog::request_file() and take_file() for a native file chooser, and confirm() and warn() message boxes

View source · UI Widgets · Dialog

Overlays

Widget::anchor pins buttons to the corners of the screen
Root::toast() for short messages, with the theme toast.anchor set to TopRight
Root::open_modal() with add_text(), add_button() and on_close
asw::util::open_url() to open a web page
asw::assets::write_save() and read_save() count the runs, also in the browser

Controls: Mouse clicks buttons. Arrows / D-pad move focus, and Enter / A presses. Escape / B closes the modal.

View source · UI Widgets · Assets

Audio

Sound

You are the listener. Walk around a radio behind walls and a fast-moving source.

asw::sound::play_positional() with a listener that follows the player
SoundHandle moves a looping sound while it plays
Doppler pitch shift, and occlusion that muffles the radio behind walls
pitch_variation and volume_variation on footsteps
Buses and ducking: explosions duck the ambient bus
Priority-based voice stealing, and Stereo and Surround spatial modes

Controls: WASD / arrows move. Left click makes an explosion. F fills every voice. Tab switches the spatial mode. O toggles doppler. M mutes the ambient bus.

View source · Sound

Input

Keyboard

get_key() (held), get_key_down() and get_key_up() (this frame only)
Movement that does not change with frame rate, with asw::core::get_delta_time()
get_keyboard() for the last key pressed, and get_text_input() for typed text

View source · Input

Mouse

Mouse position and movement (get_mouse().position / .change) and the scroll wheel (.z)
get_mouse_button(), get_mouse_button_down() and get_mouse_button_up()
set_cursor() to change the system cursor, and set_cursor_visible() to hide it

View source · Input

Actions

bind_action() with each binding type: key, mouse button, controller button and controller axis
More than one binding on an action
get_action_down(), get_action() and get_action_up() to tap, charge and release a shot
get_action_strength() for analog movement from a stick
ANY_CONTROLLER, so every connected controller controls the same actions
get_last_device() to show keyboard or controller prompts

View source · Actions

Controller

Shows each connected controller and lights up the sticks, triggers and buttons that you use. Controllers can be connected and disconnected while the example runs.

get_controller_count() and get_controller_name()
get_controller_stick() for sticks, with a radial dead zone
get_controller_axis() for triggers (0 to 1)
get_controller_button() and get_controller_button_down()
ANY_CONTROLLER to read all connected controllers at once
set_controller_dead_zone()
rumble_controller() and rumble_controller_triggers(), with controller_has_rumble() and controller_has_trigger_rumble()
get_last_device() to tell keyboard players and controller players apart

Controls: A makes a short rumble. The trigger motors rumble as hard as you pull each trigger.

View source · Input

Examples ​

Running the examples ​

Graphics ​

Advanced lighting ​

Lighting ​

Particles ​

Primitives ​

Text ​

Easing ​

Game Framework ​

Scenes ​

Camera ​

UI ​

Overlays ​

Audio ​

Sound ​

Input ​

Keyboard ​

Mouse ​

Actions ​

Controller ​

Examples

Running the examples

Graphics

Advanced lighting

Lighting

Particles

Primitives

Text

Easing

Game Framework

Scenes

Camera

UI

Overlays

Audio

Sound

Input

Keyboard

Mouse

Actions

Controller