---
url: /examples.md
---
# 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.

## Running the examples

```sh
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:

```sh
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()`](./modules/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](./modules/input#simulated-input) to play itself, saves `autorun.png` with [`screenshot`](./modules/display#screenshot), and quits. With the dummy video driver, no window opens:

```sh
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](./modules/lighting). 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](https://github.com/adsgames/asw/tree/main/examples/advanced_lighting) · [Lighting](./modules/lighting) · [Geometry](./modules/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](https://github.com/adsgames/asw/tree/main/examples/lighting) · [Draw](./modules/draw) · [Assets](./modules/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](https://github.com/adsgames/asw/tree/main/examples/particles) · [Particles](./modules/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](https://github.com/adsgames/asw/tree/main/examples/primitives) · [Draw](./modules/draw) · [Color](./modules/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](https://github.com/adsgames/asw/tree/main/examples/text) · [Draw](./modules/draw) · [Assets](./modules/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](https://github.com/adsgames/asw/tree/main/examples/easing) · [Easing](./modules/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](https://github.com/adsgames/asw/tree/main/examples/scenes) · [Scene](./modules/scene) · [Game Objects](./modules/game)

### 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](https://github.com/adsgames/asw/tree/main/examples/camera) · [Camera](./modules/camera) · [Sprite Sheet](./modules/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](https://github.com/adsgames/asw/tree/main/examples/ui) · [UI Widgets](./modules/ui) · [Dialog](./modules/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](https://github.com/adsgames/asw/tree/main/examples/overlays) · [UI Widgets](./modules/ui#modal) · [Assets](./modules/assets#read-save-write-save)

## 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](https://github.com/adsgames/asw/tree/main/examples/sound) · [Sound](./modules/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](https://github.com/adsgames/asw/tree/main/examples/keyboard) · [Input](./modules/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](https://github.com/adsgames/asw/tree/main/examples/mouse) · [Input](./modules/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](https://github.com/adsgames/asw/tree/main/examples/actions) · [Actions](./modules/action)

### 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](https://github.com/adsgames/asw/tree/main/examples/controller) · [Input](./modules/input#game-controller)