Struct Context

Source

pub struct Context {
    pub time: Time,
    pub input: InputState,
    pub graphics: GraphicsContext,
    pub audio: AudioManager,
    pub ui_state: UiState,
    pub ui_theme: UiTheme,
    pub particles: Vec<ParticleEmitter>,
    pub tweens: TweenManager,
    pub window: WindowConfig,
    /* private fields */
}

Expand description

The main context object passed to all game state methods.

Contains all engine subsystems: time, input, graphics, audio, etc. This is the single point of access for everything the game needs each frame.

Fields§

§time: Time

Time and delta tracking.

§input: InputState

Input state (keyboard, mouse, actions).

§graphics: GraphicsContext

Graphics context (drawing commands).

§audio: AudioManager

Audio manager (feature-gated).

§ui_state: UiState

UI state and theme (feature-gated).

§ui_theme: UiTheme§particles: Vec<ParticleEmitter>

Active particle emitters (feature-gated).

§tweens: TweenManager

Active tweens (feature-gated).

§window: WindowConfig

Window configuration.

Implementations§

Source §

impl Context

Source

pub fn quit(&mut self)

Request the game to exit (will close after the current frame).

Examples found in repository ?

examples/particles.rs (line 68)

49    fn update(&mut self, ctx: &mut Context) {
50        let dt = ctx.time.delta() as f32;
51
52        // Move fire emitter to mouse X
53        self.emitters[0].position.x = ctx.input.mouse.position.x;
54        self.emitters[0].position.y = ctx.screen_height() - 50.0;
55
56        // Burst on click
57        if ctx.input.mouse.is_pressed(MouseButton::Left) {
58            self.emitters[1].position = ctx.input.mouse.position;
59            self.emitters[1].burst_now(50);
60        }
61
62        // Update all emitters
63        for emitter in &mut self.emitters {
64            emitter.update(dt);
65        }
66
67        if ctx.input.keyboard.is_pressed(KeyCode::Escape) {
68            ctx.quit();
69        }
70    }

More examples

Hide additional examples

examples/scene_demo.rs (line 52)

34    fn update(&mut self, ctx: &mut Context) {
35        if ctx.input.keyboard.is_pressed(KeyCode::Up) || ctx.input.keyboard.is_pressed(KeyCode::W) {
36            self.selected = self.selected.saturating_sub(1);
37        }
38        if ctx.input.keyboard.is_pressed(KeyCode::Down) || ctx.input.keyboard.is_pressed(KeyCode::S) {
39            self.selected = (self.selected + 1).min(self.options.len() - 1);
40        }
41        if ctx.input.keyboard.is_pressed(KeyCode::Enter) {
42            match self.selected {
43                0 => {
44                    // Transition to game scene
45                    let _transition = Transition::Fade {
46                        duration: 0.5,
47                        color: [0.0, 0.0, 0.0, 1.0],
48                    };
49                    // ctx.scene.push_with_transition(GameScene::new(), transition);
50                }
51                2 => {
52                    ctx.quit();
53                }
54                _ => {}
55            }
56        }
57    }

examples/basics.rs (line 103)

44    fn update(&mut self, ctx: &mut Context) {
45        let dt = ctx.time.delta() as f32;
46
47        // --- Ball physics ---
48        self.ball.velocity.y += 600.0 * dt; // Gravity
49        self.ball.position += self.ball.velocity * dt;
50
51        // Bounce off walls
52        let w = ctx.screen_width();
53        let h = ctx.screen_height();
54
55        if self.ball.position.x - self.ball.radius < 0.0 {
56            self.ball.position.x = self.ball.radius;
57            self.ball.velocity.x = self.ball.velocity.x.abs();
58        }
59        if self.ball.position.x + self.ball.radius > w {
60            self.ball.position.x = w - self.ball.radius;
61            self.ball.velocity.x = -self.ball.velocity.x.abs();
62        }
63        if self.ball.position.y - self.ball.radius < 0.0 {
64            self.ball.position.y = self.ball.radius;
65            self.ball.velocity.y = self.ball.velocity.y.abs();
66        }
67        if self.ball.position.y + self.ball.radius > h {
68            self.ball.position.y = h - self.ball.radius;
69            self.ball.velocity.y = -self.ball.velocity.y.abs() * 0.95; // Damping
70        }
71
72        // Update trail
73        self.ball.trail.push((self.ball.position, 1.0));
74        if self.ball.trail.len() > 60 {
75            self.ball.trail.remove(0);
76        }
77        for (_, alpha) in &mut self.ball.trail {
78            *alpha -= dt * 2.0;
79        }
80        self.ball.trail.retain(|(_, a)| *a > 0.0);
81
82        // --- Input ---
83        if ctx.input.is_action_pressed("shake") {
84            ctx.graphics.camera.shake(10.0, 0.3);
85        }
86
87        if ctx.input.mouse.is_pressed(MouseButton::Left) {
88            self.click_count += 1;
89            // Change ball color
90            self.hue = (self.hue + 30.0) % 360.0;
91            self.ball.color = Color::from_hsla(self.hue, 0.8, 0.6, 1.0);
92            // Boost ball toward click
93            let dir = ctx.input.mouse.position - self.ball.position;
94            self.ball.velocity += dir.normalize_or_zero() * 200.0;
95        }
96
97        // Zoom with scroll
98        let zoom = ctx.graphics.camera.zoom + ctx.input.mouse.scroll.y * 0.1;
99        ctx.graphics.camera.set_zoom(zoom);
100
101        // Escape to quit
102        if ctx.input.keyboard.is_pressed(KeyCode::Escape) {
103            ctx.quit();
104        }
105
106        // Update camera follow target
107        ctx.graphics.camera.follow(self.ball.position, 0.05);
108    }

Source

pub fn is_quitting(&self) -> bool

Check if the game is about to exit.

Source

pub fn pause(&mut self)

Pause the game (skips update but still renders).

Source

pub fn resume(&mut self)

Resume from pause.

Source

pub fn is_paused(&self) -> bool

Check if the game is paused.

Source

pub fn toggle_pause(&mut self)

Toggle pause.

Source

pub fn screen_width(&self) -> f32

Current screen width.

Examples found in repository ?

examples/basics.rs (line 52)

44    fn update(&mut self, ctx: &mut Context) {
45        let dt = ctx.time.delta() as f32;
46
47        // --- Ball physics ---
48        self.ball.velocity.y += 600.0 * dt; // Gravity
49        self.ball.position += self.ball.velocity * dt;
50
51        // Bounce off walls
52        let w = ctx.screen_width();
53        let h = ctx.screen_height();
54
55        if self.ball.position.x - self.ball.radius < 0.0 {
56            self.ball.position.x = self.ball.radius;
57            self.ball.velocity.x = self.ball.velocity.x.abs();
58        }
59        if self.ball.position.x + self.ball.radius > w {
60            self.ball.position.x = w - self.ball.radius;
61            self.ball.velocity.x = -self.ball.velocity.x.abs();
62        }
63        if self.ball.position.y - self.ball.radius < 0.0 {
64            self.ball.position.y = self.ball.radius;
65            self.ball.velocity.y = self.ball.velocity.y.abs();
66        }
67        if self.ball.position.y + self.ball.radius > h {
68            self.ball.position.y = h - self.ball.radius;
69            self.ball.velocity.y = -self.ball.velocity.y.abs() * 0.95; // Damping
70        }
71
72        // Update trail
73        self.ball.trail.push((self.ball.position, 1.0));
74        if self.ball.trail.len() > 60 {
75            self.ball.trail.remove(0);
76        }
77        for (_, alpha) in &mut self.ball.trail {
78            *alpha -= dt * 2.0;
79        }
80        self.ball.trail.retain(|(_, a)| *a > 0.0);
81
82        // --- Input ---
83        if ctx.input.is_action_pressed("shake") {
84            ctx.graphics.camera.shake(10.0, 0.3);
85        }
86
87        if ctx.input.mouse.is_pressed(MouseButton::Left) {
88            self.click_count += 1;
89            // Change ball color
90            self.hue = (self.hue + 30.0) % 360.0;
91            self.ball.color = Color::from_hsla(self.hue, 0.8, 0.6, 1.0);
92            // Boost ball toward click
93            let dir = ctx.input.mouse.position - self.ball.position;
94            self.ball.velocity += dir.normalize_or_zero() * 200.0;
95        }
96
97        // Zoom with scroll
98        let zoom = ctx.graphics.camera.zoom + ctx.input.mouse.scroll.y * 0.1;
99        ctx.graphics.camera.set_zoom(zoom);
100
101        // Escape to quit
102        if ctx.input.keyboard.is_pressed(KeyCode::Escape) {
103            ctx.quit();
104        }
105
106        // Update camera follow target
107        ctx.graphics.camera.follow(self.ball.position, 0.05);
108    }

Source

pub fn screen_height(&self) -> f32

Current screen height.

Examples found in repository ?

examples/particles.rs (line 54)

49    fn update(&mut self, ctx: &mut Context) {
50        let dt = ctx.time.delta() as f32;
51
52        // Move fire emitter to mouse X
53        self.emitters[0].position.x = ctx.input.mouse.position.x;
54        self.emitters[0].position.y = ctx.screen_height() - 50.0;
55
56        // Burst on click
57        if ctx.input.mouse.is_pressed(MouseButton::Left) {
58            self.emitters[1].position = ctx.input.mouse.position;
59            self.emitters[1].burst_now(50);
60        }
61
62        // Update all emitters
63        for emitter in &mut self.emitters {
64            emitter.update(dt);
65        }
66
67        if ctx.input.keyboard.is_pressed(KeyCode::Escape) {
68            ctx.quit();
69        }
70    }

More examples

Hide additional examples

examples/basics.rs (line 53)

44    fn update(&mut self, ctx: &mut Context) {
45        let dt = ctx.time.delta() as f32;
46
47        // --- Ball physics ---
48        self.ball.velocity.y += 600.0 * dt; // Gravity
49        self.ball.position += self.ball.velocity * dt;
50
51        // Bounce off walls
52        let w = ctx.screen_width();
53        let h = ctx.screen_height();
54
55        if self.ball.position.x - self.ball.radius < 0.0 {
56            self.ball.position.x = self.ball.radius;
57            self.ball.velocity.x = self.ball.velocity.x.abs();
58        }
59        if self.ball.position.x + self.ball.radius > w {
60            self.ball.position.x = w - self.ball.radius;
61            self.ball.velocity.x = -self.ball.velocity.x.abs();
62        }
63        if self.ball.position.y - self.ball.radius < 0.0 {
64            self.ball.position.y = self.ball.radius;
65            self.ball.velocity.y = self.ball.velocity.y.abs();
66        }
67        if self.ball.position.y + self.ball.radius > h {
68            self.ball.position.y = h - self.ball.radius;
69            self.ball.velocity.y = -self.ball.velocity.y.abs() * 0.95; // Damping
70        }
71
72        // Update trail
73        self.ball.trail.push((self.ball.position, 1.0));
74        if self.ball.trail.len() > 60 {
75            self.ball.trail.remove(0);
76        }
77        for (_, alpha) in &mut self.ball.trail {
78            *alpha -= dt * 2.0;
79        }
80        self.ball.trail.retain(|(_, a)| *a > 0.0);
81
82        // --- Input ---
83        if ctx.input.is_action_pressed("shake") {
84            ctx.graphics.camera.shake(10.0, 0.3);
85        }
86
87        if ctx.input.mouse.is_pressed(MouseButton::Left) {
88            self.click_count += 1;
89            // Change ball color
90            self.hue = (self.hue + 30.0) % 360.0;
91            self.ball.color = Color::from_hsla(self.hue, 0.8, 0.6, 1.0);
92            // Boost ball toward click
93            let dir = ctx.input.mouse.position - self.ball.position;
94            self.ball.velocity += dir.normalize_or_zero() * 200.0;
95        }
96
97        // Zoom with scroll
98        let zoom = ctx.graphics.camera.zoom + ctx.input.mouse.scroll.y * 0.1;
99        ctx.graphics.camera.set_zoom(zoom);
100
101        // Escape to quit
102        if ctx.input.keyboard.is_pressed(KeyCode::Escape) {
103            ctx.quit();
104        }
105
106        // Update camera follow target
107        ctx.graphics.camera.follow(self.ball.position, 0.05);
108    }