Color animation + changing RectButton colors

src/anim.rs

@@ -1,19 +1,24 @@
 use keyframe::EasingFunction;
+use crate::Color;
+
+pub trait AnimationLerp<T> {
+    fn lerp(&self, x: f32) -> T;
+}
 
 #[derive(Clone)]
-pub struct Animation<F> {
+pub struct Animation<F, T = f32> {
     time: f32,
     duration: f32,
     in_delay: f32,
     out_delay: f32,
-    from: f32,
-    to: f32,
+    from: T,
+    to: T,
     function: F,
     direction: bool,
 }
 
-impl<F: EasingFunction> Animation<F> {
-    pub fn new(function: F, duration: f32, from: f32, to: f32) -> Self {
+impl<F: EasingFunction, T: Copy> Animation<F, T> {
+    pub fn new(function: F, duration: f32, from: T, to: T) -> Self {
         Self {
             time: duration,
             duration,
@@ -34,34 +39,6 @@ impl<F: EasingFunction> Animation<F> {
         self.time < self.duration
     }
 
-    pub fn get(&self) -> f32 {
-        if self.is_active() {
-            if self.time <= 0.0 {
-                if self.direction {
-                    self.from
-                } else {
-                    self.to
-                }
-            } else {
-                let x = self.time / self.duration;
-                let x = if self.direction { x } else { 1.0 - x };
-                let lerp = self.function.y(x as f64) as f32;
-                (1.0 - lerp) * self.from + lerp * self.to
-            }
-        } else if self.direction {
-            self.to
-        } else {
-            self.from
-        }
-    }
-
-    pub fn ease_to(&mut self, to: f32) {
-        self.from = self.get();
-        self.to = to;
-        self.time = 0.0;
-        self.direction = true;
-    }
-
     pub fn ease_in(&mut self) {
         if !self.direction {
             self.ease_toggle();
@@ -93,4 +70,62 @@ impl<F: EasingFunction> Animation<F> {
     pub fn set_out_delay(&mut self, delay: f32) {
         self.out_delay = delay;
     }
+
+    pub fn clamped(&self) -> Option<T> {
+        if self.is_active() {
+            if self.time <= 0.0 {
+                if self.direction {
+                    Some(self.from)
+                } else {
+                    Some(self.to)
+                }
+            } else {
+                None
+            }
+        } else if self.direction {
+            Some(self.to)
+        } else {
+            Some(self.from)
+        }
+    }
+}
+
+impl<F: EasingFunction> AnimationLerp<f32> for Animation<F, f32> {
+    fn lerp(&self, x: f32) -> f32 {
+        (1.0 - x) * self.from + x * self.to
+    }
+}
+
+impl<F: EasingFunction> AnimationLerp<Color> for Animation<F, Color> {
+    fn lerp(&self, x: f32) -> Color {
+        let from: glam::Vec4 = self.from.into();
+        let to: glam::Vec4 = self.to.into();
+        let lerp = (1.0 - x) * from + x * to;
+        lerp.into()
+    }
+}
+
+impl<F, T> Animation<F, T>
+where
+    F: EasingFunction,
+    T: Copy,
+    Animation<F, T>: AnimationLerp<T>,
+{
+    pub fn get(&self) -> T {
+        if let Some(clamped) = self.clamped() {
+            clamped
+        } else {
+            let x = self.time / self.duration;
+            let x = if self.direction { x } else { 1.0 - x };
+            let lerp = self.function.y(x as f64) as f32;
+            self.lerp(lerp)
+        }
+    }
+
+    pub fn ease_to(&mut self, to: T) {
+        self.from = self.get();
+        self.to = to;
+        self.time = 0.0;
+        self.direction = true;
+    }
 }

src/lib.rs

@@ -48,6 +48,30 @@ pub struct Color {
     pub a: f32,
 }
 
+impl Color {
+    pub const WHITE: Self = Self::new(1., 1., 1., 1.);
+    pub const BLACK: Self = Self::new(0., 0., 0., 1.);
+    pub const TRANSPARENT: Self = Self::new(0., 0., 0., 0.);
+
+    pub const fn new(r: f32, g: f32, b: f32, a: f32) -> Self {
+        Self { r, g, b, a }
+    }
+}
+
+impl From<glam::Vec4> for Color {
+    fn from(other: glam::Vec4) -> Self {
+        let glam::Vec4 { x, y, z, w } = other;
+        Self::new(x, y, z, w)
+    }
+}
+
+impl From<Color> for glam::Vec4 {
+    fn from(other: Color) -> Self {
+        let Color { r, g, b, a } = other;
+        Self::new(r, g, b, a)
+    }
+}
+
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum CursorEventKind {
     Hover,

src/widgets.rs

@@ -94,7 +94,9 @@ pub struct RectButton {
     pub pos: Vec2,
     pub size: Vec2,
     pub was_clicked: bool,
-    pub color: Color,
+    pub is_selected: bool,
+    pub is_hovering: bool,
+    pub color_anim: Animation<EaseInQuad, Color>,
 }
 
 impl Button for RectButton {
@@ -104,17 +106,23 @@ impl Button for RectButton {
 }
 
 impl RectButton {
+    pub const INACTIVE_COLOR: Color = Color::new(1., 1., 1., 0.2);
+    pub const HOVER_COLOR: Color = Color::new(1., 1., 1., 0.8);
+    pub const SELECTED_COLOR: Color = Color::new(1., 1., 0., 1.);
+
     pub fn new(pos: Vec2, size: Vec2) -> Self {
         Self {
             pos,
             size,
-            was_clicked: true,
-            color: Color {
-                r: 1.0,
-                g: 1.0,
-                b: 1.0,
-                a: 0.2,
-            },
+            was_clicked: false,
+            is_selected: false,
+            is_hovering: false,
+            color_anim: Animation::new(
+                EaseInQuad,
+                0.05,
+                Self::INACTIVE_COLOR,
+                Self::INACTIVE_COLOR,
+            ),
         }
     }
 }
@@ -122,21 +130,46 @@ impl RectButton {
 impl Widget for RectButton {
     fn update(&mut self, dt: f32) {
         self.was_clicked = false;
+        self.color_anim.update(dt);
     }
 
     fn draw(&mut self, ctx: &DrawContext) {
-        ctx.draw_rect(self.pos, self.size, self.color);
+        ctx.draw_rect(self.pos, self.size, self.color_anim.get());
     }
 
     fn on_cursor_event(&mut self, kind: CursorEventKind, at: Vec2) {
         let local = at - self.pos;
-        if kind == CursorEventKind::Deselect
-            && local.x > 0.0
-            && local.y > 0.0
-            && local.x < self.size.x
-            && local.y < self.size.y
-        {
-            self.was_clicked = true;
+        let is_on = local.x > 0. && local.y > 0. && local.x < self.size.x && local.y < self.size.y;
+
+        match kind {
+            CursorEventKind::Hover | CursorEventKind::Drag => {
+                if is_on {
+                    if !self.is_hovering && !self.is_selected {
+                        self.color_anim.ease_to(Self::HOVER_COLOR);
+                    }
+
+                    self.is_hovering = true;
+                } else {
+                    if self.is_hovering && !self.is_selected {
+                        self.color_anim.ease_to(Self::INACTIVE_COLOR);
+                    }
+
+                    self.is_hovering = false;
+                }
+            }
+            CursorEventKind::Select => {
+                if is_on {
+                    self.is_selected = true;
+                    self.color_anim.ease_to(Self::SELECTED_COLOR);
+                }
+            }
+            CursorEventKind::Deselect => {
+                if self.is_selected {
+                    self.was_clicked = true;
+                    self.is_selected = false;
+                    self.color_anim.ease_to(Self::HOVER_COLOR);
+                }
+            }
         }
     }
 }
@@ -346,6 +379,33 @@ impl<T: Widget + Button> Widget for ScrollMenu<T> {
     }
 }
 
+pub struct Offset<T> {
+    inner: T,
+    offset: Vec2,
+}
+
+impl<T: Widget> Offset<T> {
+    pub fn new(inner: T, offset: Vec2) -> Self {
+        Self { inner, offset }
+    }
+}
+
+impl<T: Widget> Widget for Offset<T> {
+    fn update(&mut self, dt: f32) {
+        self.inner.update(dt);
+    }
+
+    fn draw(&mut self, ctx: &DrawContext) {
+        let ctx = ctx.with_offset(self.offset);
+        self.inner.draw(&ctx);
+    }
+
+    fn on_cursor_event(&mut self, kind: CursorEventKind, at: Vec2) {
+        let at = at - self.offset;
+        self.inner.on_cursor_event(kind, at);
+    }
+}
+
 pub struct Reveal<T> {
     inner: T,
     slide_anim: Animation<EaseIn>,
@@ -412,7 +472,11 @@ impl<T: Widget> Widget for Reveal<T> {
 
 pub struct MainMenu {
     pub menu: ScrollMenu<RoundButton>,
-    pub inventory: Reveal<Inventory>,
+    pub inventory: Reveal<Offset<Inventory>>,
+}
+
+impl MainMenu {
+    pub const SUBMENU_SPACING: f32 = 0.05;
 }
 
 impl Default for MainMenu {
@@ -424,6 +488,7 @@ impl Default for MainMenu {
         }
 
         let inventory = Inventory::new();
+        let inventory = Offset::new(inventory, Vec2::new(Self::SUBMENU_SPACING, 0.0));
         let inventory = Reveal::new(inventory, -0.02, 0.1);
 
         Self {
@@ -453,13 +518,12 @@ impl Widget for MainMenu {
 
     fn draw(&mut self, ctx: &DrawContext) {
         self.menu.draw(&ctx);
-
-        let inventory_ctx = ctx.with_offset(Vec2::new(0.05, 0.0));
-        self.inventory.draw(&inventory_ctx);
+        self.inventory.draw(&ctx);
     }
 
     fn on_cursor_event(&mut self, kind: CursorEventKind, at: Vec2) {
         self.menu.on_cursor_event(kind, at);
+        self.inventory.on_cursor_event(kind, at);
     }
 }