Merge pull request #1506 from rksm/non-uniform-border-radius-for-quads

non uniform border radius for quads

examples/custom_quad/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "custom_quad"
+version = "0.1.0"
+authors = ["Robert Krahn"]
+edition = "2021"
+publish = false
+
+[dependencies]
+iced = { path = "../.." }
+iced_native = { path = "../../native" }

examples/custom_quad/src/main.rs

@@ -0,0 +1,160 @@
+//! This example showcases a drawing a quad.
+mod quad {
+    use iced_native::layout::{self, Layout};
+    use iced_native::renderer;
+    use iced_native::widget::{self, Widget};
+    use iced_native::{Color, Element, Length, Point, Rectangle, Size};
+
+    pub struct CustomQuad {
+        size: f32,
+        radius: [f32; 4],
+        border_width: f32,
+    }
+
+    impl CustomQuad {
+        pub fn new(size: f32, radius: [f32; 4], border_width: f32) -> Self {
+            Self {
+                size,
+                radius,
+                border_width,
+            }
+        }
+    }
+
+    impl<Message, Renderer> Widget<Message, Renderer> for CustomQuad
+    where
+        Renderer: renderer::Renderer,
+    {
+        fn width(&self) -> Length {
+            Length::Shrink
+        }
+
+        fn height(&self) -> Length {
+            Length::Shrink
+        }
+
+        fn layout(
+            &self,
+            _renderer: &Renderer,
+            _limits: &layout::Limits,
+        ) -> layout::Node {
+            layout::Node::new(Size::new(self.size, self.size))
+        }
+
+        fn draw(
+            &self,
+            _state: &widget::Tree,
+            renderer: &mut Renderer,
+            _theme: &Renderer::Theme,
+            _style: &renderer::Style,
+            layout: Layout<'_>,
+            _cursor_position: Point,
+            _viewport: &Rectangle,
+        ) {
+            renderer.fill_quad(
+                renderer::Quad {
+                    bounds: layout.bounds(),
+                    border_radius: self.radius.into(),
+                    border_width: self.border_width,
+                    border_color: Color::from_rgb(1.0, 0.0, 0.0),
+                },
+                Color::BLACK,
+            );
+        }
+    }
+
+    impl<'a, Message, Renderer> From<CustomQuad> for Element<'a, Message, Renderer>
+    where
+        Renderer: renderer::Renderer,
+    {
+        fn from(circle: CustomQuad) -> Self {
+            Self::new(circle)
+        }
+    }
+}
+
+use iced::widget::{column, container, slider, text};
+use iced::{Alignment, Element, Length, Sandbox, Settings};
+
+pub fn main() -> iced::Result {
+    Example::run(Settings::default())
+}
+
+struct Example {
+    radius: [f32; 4],
+    border_width: f32,
+}
+
+#[derive(Debug, Clone, Copy)]
+#[allow(clippy::enum_variant_names)]
+enum Message {
+    RadiusTopLeftChanged(f32),
+    RadiusTopRightChanged(f32),
+    RadiusBottomRightChanged(f32),
+    RadiusBottomLeftChanged(f32),
+    BorderWidthChanged(f32),
+}
+
+impl Sandbox for Example {
+    type Message = Message;
+
+    fn new() -> Self {
+        Self {
+            radius: [50.0; 4],
+            border_width: 0.0,
+        }
+    }
+
+    fn title(&self) -> String {
+        String::from("Custom widget - Iced")
+    }
+
+    fn update(&mut self, message: Message) {
+        let [tl, tr, br, bl] = self.radius;
+        match message {
+            Message::RadiusTopLeftChanged(radius) => {
+                self.radius = [radius, tr, br, bl];
+            }
+            Message::RadiusTopRightChanged(radius) => {
+                self.radius = [tl, radius, br, bl];
+            }
+            Message::RadiusBottomRightChanged(radius) => {
+                self.radius = [tl, tr, radius, bl];
+            }
+            Message::RadiusBottomLeftChanged(radius) => {
+                self.radius = [tl, tr, br, radius];
+            }
+            Message::BorderWidthChanged(width) => {
+                self.border_width = width;
+            }
+        }
+    }
+
+    fn view(&self) -> Element<Message> {
+        let [tl, tr, br, bl] = self.radius;
+
+        let content = column![
+            quad::CustomQuad::new(200.0, self.radius, self.border_width),
+            text(format!("Radius: {tl:.2}/{tr:.2}/{br:.2}/{bl:.2}")),
+            slider(1.0..=100.0, tl, Message::RadiusTopLeftChanged).step(0.01),
+            slider(1.0..=100.0, tr, Message::RadiusTopRightChanged).step(0.01),
+            slider(1.0..=100.0, br, Message::RadiusBottomRightChanged)
+                .step(0.01),
+            slider(1.0..=100.0, bl, Message::RadiusBottomLeftChanged)
+                .step(0.01),
+            slider(1.0..=10.0, self.border_width, Message::BorderWidthChanged)
+                .step(0.01),
+        ]
+        .padding(20)
+        .spacing(20)
+        .max_width(500)
+        .align_items(Alignment::Center);
+
+        container(content)
+            .width(Length::Fill)
+            .height(Length::Fill)
+            .center_x()
+            .center_y()
+            .into()
+    }
+}

examples/custom_widget/src/main.rs

@@ -61,7 +61,7 @@ mod circle {
             renderer.fill_quad(
                 renderer::Quad {
                     bounds: layout.bounds(),
-                    border_radius: self.radius,
+                    border_radius: self.radius.into(),
                     border_width: 0.0,
                     border_color: Color::TRANSPARENT,
                 },

examples/modal/src/main.rs

@@ -412,7 +412,7 @@ mod modal {
             renderer.fill_quad(
                 renderer::Quad {
                     bounds: layout.bounds(),
-                    border_radius: 0.0,
+                    border_radius: renderer::BorderRadius::from(0.0),
                     border_width: 0.0,
                     border_color: Color::TRANSPARENT,
                 },

glow/src/quad/compatibility.rs

@@ -254,7 +254,7 @@ unsafe fn create_buffers(
     gl.enable_vertex_attrib_array(4);
     gl.vertex_attrib_pointer_f32(
         4,
-        1,
+        4,
         glow::FLOAT,
         false,
         stride,
@@ -268,7 +268,7 @@ unsafe fn create_buffers(
         glow::FLOAT,
         false,
         stride,
-        4 * (2 + 2 + 4 + 4 + 1),
+        4 * (2 + 2 + 4 + 4 + 4),
     );
 
     gl.enable_vertex_attrib_array(6);
@@ -278,7 +278,7 @@ unsafe fn create_buffers(
         glow::FLOAT,
         false,
         stride,
-        4 * (2 + 2 + 4 + 4 + 1 + 1),
+        4 * (2 + 2 + 4 + 4 + 4 + 1),
     );
 
     gl.bind_vertex_array(None);
@@ -307,7 +307,7 @@ pub struct Vertex {
     pub border_color: [f32; 4],
 
     /// The border radius of the [`Vertex`].
-    pub border_radius: f32,
+    pub border_radius: [f32; 4],
 
     /// The border width of the [`Vertex`].
     pub border_width: f32,

glow/src/quad/core.rs

@@ -218,7 +218,7 @@ unsafe fn create_instance_buffer(
     gl.enable_vertex_attrib_array(4);
     gl.vertex_attrib_pointer_f32(
         4,
-        1,
+        4,
         glow::FLOAT,
         false,
         stride,
@@ -233,7 +233,7 @@ unsafe fn create_instance_buffer(
         glow::FLOAT,
         false,
         stride,
-        4 * (2 + 2 + 4 + 4 + 1),
+        4 * (2 + 2 + 4 + 4 + 4),
     );
     gl.vertex_attrib_divisor(5, 1);
 

glow/src/shader/compatibility/quad.frag

@@ -12,7 +12,7 @@ varying vec4 v_Color;
 varying vec4 v_BorderColor;
 varying vec2 v_Pos;
 varying vec2 v_Scale;
-varying float v_BorderRadius;
+varying vec4 v_BorderRadius;
 varying float v_BorderWidth;
 
 float _distance(vec2 frag_coord, vec2 position, vec2 size, float radius)
@@ -33,10 +33,26 @@ float _distance(vec2 frag_coord, vec2 position, vec2 size, float radius)
     return sqrt(distance.x * distance.x + distance.y * distance.y);
 }
 
+float selectBorderRadius(vec4 radi, vec2 position, vec2 center)
+{
+    float rx = radi.x;
+    float ry = radi.y;
+    rx = position.x > center.x ? radi.y : radi.x;
+    ry = position.x > center.x ? radi.z : radi.w;
+    rx = position.y > center.y ? ry : rx;
+    return rx;
+}
+
 void main() {
     vec2 fragCoord = vec2(gl_FragCoord.x, u_ScreenHeight - gl_FragCoord.y);
 
-    float internal_border = max(v_BorderRadius - v_BorderWidth, 0.0);
+    float border_radius = selectBorderRadius(
+        v_BorderRadius,
+        fragCoord,
+        (v_Pos + v_Scale * 0.5).xy
+    );
+
+    float internal_border = max(border_radius - v_BorderWidth, 0.0);
 
     float internal_distance = _distance(
         fragCoord,
@@ -57,11 +73,11 @@ void main() {
         fragCoord,
         v_Pos,
         v_Scale,
-        v_BorderRadius
+        border_radius
     );
 
     float radius_alpha =
-        1.0 - smoothstep(max(v_BorderRadius - 0.5, 0.0), v_BorderRadius + 0.5, d);
+        1.0 - smoothstep(max(border_radius - 0.5, 0.0), border_radius + 0.5, d);
 
     gl_FragColor = vec4(mixed_color.xyz, mixed_color.w * radius_alpha);
 }

glow/src/shader/compatibility/quad.vert

@@ -5,7 +5,7 @@ attribute vec2 i_Pos;
 attribute vec2 i_Scale;
 attribute vec4 i_Color;
 attribute vec4 i_BorderColor;
-attribute float i_BorderRadius;
+attribute vec4 i_BorderRadius;
 attribute float i_BorderWidth;
 attribute vec2 q_Pos;
 
@@ -13,7 +13,7 @@ varying vec4 v_Color;
 varying vec4 v_BorderColor;
 varying vec2 v_Pos;
 varying vec2 v_Scale;
-varying float v_BorderRadius;
+varying vec4 v_BorderRadius;
 varying float v_BorderWidth;
 
 
@@ -21,9 +21,11 @@ void main() {
     vec2 p_Pos = i_Pos * u_Scale;
     vec2 p_Scale = i_Scale  * u_Scale;
 
-    float i_BorderRadius = min(
+    vec4 i_BorderRadius = vec4(
-        i_BorderRadius,
+        min(i_BorderRadius.x, min(i_Scale.x, i_Scale.y) / 2.0),
-        min(i_Scale.x, i_Scale.y) / 2.0
+        min(i_BorderRadius.y, min(i_Scale.x, i_Scale.y) / 2.0),
+        min(i_BorderRadius.z, min(i_Scale.x, i_Scale.y) / 2.0),
+        min(i_BorderRadius.w, min(i_Scale.x, i_Scale.y) / 2.0)
     );
 
     mat4 i_Transform = mat4(

glow/src/shader/core/quad.frag

@@ -17,7 +17,7 @@ in vec4 v_Color;
 in vec4 v_BorderColor;
 in vec2 v_Pos;
 in vec2 v_Scale;
-in float v_BorderRadius;
+in vec4 v_BorderRadius;
 in float v_BorderWidth;
 
 float fDistance(vec2 frag_coord, vec2 position, vec2 size, float radius)
@@ -38,14 +38,30 @@ float fDistance(vec2 frag_coord, vec2 position, vec2 size, float radius)
     return sqrt(distance.x * distance.x + distance.y * distance.y);
 }
 
+float selectBorderRadius(vec4 radi, vec2 position, vec2 center)
+{
+    float rx = radi.x;
+    float ry = radi.y;
+    rx = position.x > center.x ? radi.y : radi.x;
+    ry = position.x > center.x ? radi.z : radi.w;
+    rx = position.y > center.y ? ry : rx;
+    return rx;
+}
+
 void main() {
     vec4 mixed_color;
 
     vec2 fragCoord = vec2(gl_FragCoord.x, u_ScreenHeight - gl_FragCoord.y);
 
+    float border_radius = selectBorderRadius(
+        v_BorderRadius,
+        fragCoord,
+        (v_Pos + v_Scale * 0.5).xy
+    );
+
     // TODO: Remove branching (?)
     if(v_BorderWidth > 0.0) {
-        float internal_border = max(v_BorderRadius - v_BorderWidth, 0.0);
+        float internal_border = max(border_radius - v_BorderWidth, 0.0);
 
         float internal_distance = fDistance(
             fragCoord,
@@ -69,11 +85,11 @@ void main() {
         fragCoord,
         v_Pos,
         v_Scale,
-        v_BorderRadius
+        border_radius
     );
 
     float radius_alpha =
-        1.0 - smoothstep(max(v_BorderRadius - 0.5, 0.0), v_BorderRadius + 0.5, d);
+        1.0 - smoothstep(max(border_radius - 0.5, 0.0), border_radius + 0.5, d);
 
     gl_FragColor = vec4(mixed_color.xyz, mixed_color.w * radius_alpha);
 }

glow/src/shader/core/quad.vert

@@ -5,14 +5,14 @@ in vec2 i_Pos;
 in vec2 i_Scale;
 in vec4 i_Color;
 in vec4 i_BorderColor;
-in float i_BorderRadius;
+in vec4 i_BorderRadius;
 in float i_BorderWidth;
 
 out vec4 v_Color;
 out vec4 v_BorderColor;
 out vec2 v_Pos;
 out vec2 v_Scale;
-out float v_BorderRadius;
+out vec4 v_BorderRadius;
 out float v_BorderWidth;
 
 vec2 positions[4] = vec2[](
@@ -27,9 +27,11 @@ void main() {
     vec2 p_Pos = i_Pos * u_Scale;
     vec2 p_Scale = i_Scale  * u_Scale;
 
-    float i_BorderRadius = min(
+    vec4 i_BorderRadius = vec4(
-        i_BorderRadius,
+        min(i_BorderRadius.x, min(i_Scale.x, i_Scale.y) / 2.0),
-        min(i_Scale.x, i_Scale.y) / 2.0
+        min(i_BorderRadius.y, min(i_Scale.x, i_Scale.y) / 2.0),
+        min(i_BorderRadius.z, min(i_Scale.x, i_Scale.y) / 2.0),
+        min(i_BorderRadius.w, min(i_Scale.x, i_Scale.y) / 2.0)
     );
 
     mat4 i_Transform = mat4(

graphics/src/layer/quad.rs

@@ -17,7 +17,7 @@ pub struct Quad {
     pub border_color: [f32; 4],
 
     /// The border radius of the [`Quad`].
-    pub border_radius: f32,
+    pub border_radius: [f32; 4],
 
     /// The border width of the [`Quad`].
     pub border_width: f32,

graphics/src/primitive.rs

@@ -42,7 +42,7 @@ pub enum Primitive {
         /// The background of the quad
         background: Background,
         /// The border radius of the quad
-        border_radius: f32,
+        border_radius: [f32; 4],
         /// The border width of the quad
         border_width: f32,
         /// The border color of the quad

graphics/src/renderer.rs

@@ -109,7 +109,7 @@ where
         self.primitives.push(Primitive::Quad {
             bounds: quad.bounds,
             background: background.into(),
-            border_radius: quad.border_radius,
+            border_radius: quad.border_radius.into(),
             border_width: quad.border_width,
             border_color: quad.border_color,
         });

native/src/element.rs

@@ -519,7 +519,7 @@ where
                     bounds: layout.bounds(),
                     border_color: color,
                     border_width: 1.0,
-                    border_radius: 0.0,
+                    border_radius: 0.0.into(),
                 },
                 Color::TRANSPARENT,
             );

native/src/overlay/menu.rs

@@ -287,7 +287,7 @@ where
                 },
                 border_color: appearance.border_color,
                 border_width: appearance.border_width,
-                border_radius: appearance.border_radius,
+                border_radius: appearance.border_radius.into(),
             },
             appearance.background,
         );
@@ -479,7 +479,7 @@ where
                         bounds,
                         border_color: Color::TRANSPARENT,
                         border_width: 0.0,
-                        border_radius: appearance.border_radius,
+                        border_radius: appearance.border_radius.into(),
                     },
                     appearance.selected_background,
                 );

native/src/renderer.rs

@@ -50,7 +50,7 @@ pub struct Quad {
     pub bounds: Rectangle,
 
     /// The border radius of the [`Quad`].
-    pub border_radius: f32,
+    pub border_radius: BorderRadius,
 
     /// The border width of the [`Quad`].
     pub border_width: f32,
@@ -59,6 +59,29 @@ pub struct Quad {
     pub border_color: Color,
 }
 
+/// The border radi for the corners of a graphics primitive in the order:
+/// top-left, top-right, bottom-right, bottom-left.
+#[derive(Debug, Clone, Copy, PartialEq, Default)]
+pub struct BorderRadius([f32; 4]);
+
+impl From<f32> for BorderRadius {
+    fn from(w: f32) -> Self {
+        Self([w; 4])
+    }
+}
+
+impl From<[f32; 4]> for BorderRadius {
+    fn from(radi: [f32; 4]) -> Self {
+        Self(radi)
+    }
+}
+
+impl From<BorderRadius> for [f32; 4] {
+    fn from(radi: BorderRadius) -> Self {
+        radi.0
+    }
+}
+
 /// The styling attributes of a [`Renderer`].
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct Style {

native/src/widget/button.rs

@@ -393,7 +393,7 @@ where
                         y: bounds.y + styling.shadow_offset.y,
                         ..bounds
                     },
-                    border_radius: styling.border_radius,
+                    border_radius: styling.border_radius.into(),
                     border_width: 0.0,
                     border_color: Color::TRANSPARENT,
                 },
@@ -404,7 +404,7 @@ where
         renderer.fill_quad(
             renderer::Quad {
                 bounds,
-                border_radius: styling.border_radius,
+                border_radius: styling.border_radius.into(),
                 border_width: styling.border_width,
                 border_color: styling.border_color,
             },

native/src/widget/checkbox.rs

@@ -236,7 +236,7 @@ where
             renderer.fill_quad(
                 renderer::Quad {
                     bounds,
-                    border_radius: custom_style.border_radius,
+                    border_radius: custom_style.border_radius.into(),
                     border_width: custom_style.border_width,
                     border_color: custom_style.border_color,
                 },

native/src/widget/container.rs

@@ -321,7 +321,7 @@ pub fn draw_background<Renderer>(
         renderer.fill_quad(
             renderer::Quad {
                 bounds,
-                border_radius: appearance.border_radius,
+                border_radius: appearance.border_radius.into(),
                 border_width: appearance.border_width,
                 border_color: appearance.border_color,
             },

native/src/widget/pane_grid.rs

@@ -877,7 +877,7 @@ pub fn draw<Renderer, T>(
                             height: split_region.height,
                         },
                     },
-                    border_radius: 0.0,
+                    border_radius: 0.0.into(),
                     border_width: 0.0,
                     border_color: Color::TRANSPARENT,
                 },

native/src/widget/pick_list.rs

@@ -536,7 +536,7 @@ pub fn draw<T, Renderer>(
             bounds,
             border_color: style.border_color,
             border_width: style.border_width,
-            border_radius: style.border_radius,
+            border_radius: style.border_radius.into(),
         },
         style.background,
     );

native/src/widget/progress_bar.rs

@@ -129,7 +129,7 @@ where
         renderer.fill_quad(
             renderer::Quad {
                 bounds: Rectangle { ..bounds },
-                border_radius: style.border_radius,
+                border_radius: style.border_radius.into(),
                 border_width: 0.0,
                 border_color: Color::TRANSPARENT,
             },
@@ -143,7 +143,7 @@ where
                         width: active_progress_width,
                         ..bounds
                     },
-                    border_radius: style.border_radius,
+                    border_radius: style.border_radius.into(),
                     border_width: 0.0,
                     border_color: Color::TRANSPARENT,
                 },

native/src/widget/radio.rs

@@ -245,7 +245,7 @@ where
             renderer.fill_quad(
                 renderer::Quad {
                     bounds,
-                    border_radius: size / 2.0,
+                    border_radius: (size / 2.0).into(),
                     border_width: custom_style.border_width,
                     border_color: custom_style.border_color,
                 },
@@ -261,7 +261,7 @@ where
                             width: bounds.width - dot_size,
                             height: bounds.height - dot_size,
                         },
-                        border_radius: dot_size / 2.0,
+                        border_radius: (dot_size / 2.0).into(),
                         border_width: 0.0,
                         border_color: Color::TRANSPARENT,
                     },

native/src/widget/rule.rs

@@ -123,7 +123,7 @@ where
         renderer.fill_quad(
             renderer::Quad {
                 bounds,
-                border_radius: style.radius,
+                border_radius: style.radius.into(),
                 border_width: 0.0,
                 border_color: Color::TRANSPARENT,
             },

native/src/widget/scrollable.rs

@@ -704,7 +704,7 @@ pub fn draw<Renderer>(
                     renderer.fill_quad(
                         renderer::Quad {
                             bounds: scrollbar.bounds,
-                            border_radius: style.border_radius,
+                            border_radius: style.border_radius.into(),
                             border_width: style.border_width,
                             border_color: style.border_color,
                         },
@@ -721,7 +721,7 @@ pub fn draw<Renderer>(
                     renderer.fill_quad(
                         renderer::Quad {
                             bounds: scrollbar.scroller.bounds,
-                            border_radius: style.scroller.border_radius,
+                            border_radius: style.scroller.border_radius.into(),
                             border_width: style.scroller.border_width,
                             border_color: style.scroller.border_color,
                         },

native/src/widget/slider.rs

@@ -380,7 +380,7 @@ pub fn draw<T, R>(
                 width: bounds.width,
                 height: 2.0,
             },
-            border_radius: 0.0,
+            border_radius: 0.0.into(),
             border_width: 0.0,
             border_color: Color::TRANSPARENT,
         },
@@ -395,7 +395,7 @@ pub fn draw<T, R>(
                 width: bounds.width,
                 height: 2.0,
             },
-            border_radius: 0.0,
+            border_radius: 0.0.into(),
             border_width: 0.0,
             border_color: Color::TRANSPARENT,
         },
@@ -435,7 +435,7 @@ pub fn draw<T, R>(
                 width: handle_width,
                 height: handle_height,
             },
-            border_radius: handle_border_radius,
+            border_radius: handle_border_radius.into(),
             border_width: style.handle.border_width,
             border_color: style.handle.border_color,
         },

native/src/widget/text_input.rs

@@ -801,7 +801,7 @@ pub fn draw<Renderer>(
     renderer.fill_quad(
         renderer::Quad {
             bounds,
-            border_radius: appearance.border_radius,
+            border_radius: appearance.border_radius.into(),
             border_width: appearance.border_width,
             border_color: appearance.border_color,
         },
@@ -833,7 +833,7 @@ pub fn draw<Renderer>(
                                 width: 1.0,
                                 height: text_bounds.height,
                             },
-                            border_radius: 0.0,
+                            border_radius: 0.0.into(),
                             border_width: 0.0,
                             border_color: Color::TRANSPARENT,
                         },
@@ -877,7 +877,7 @@ pub fn draw<Renderer>(
                                 width,
                                 height: text_bounds.height,
                             },
-                            border_radius: 0.0,
+                            border_radius: 0.0.into(),
                             border_width: 0.0,
                             border_color: Color::TRANSPARENT,
                         },

native/src/widget/toggler.rs

@@ -278,7 +278,7 @@ where
         renderer.fill_quad(
             renderer::Quad {
                 bounds: toggler_background_bounds,
-                border_radius,
+                border_radius: border_radius.into(),
                 border_width: 1.0,
                 border_color: style
                     .background_border
@@ -302,7 +302,7 @@ where
         renderer.fill_quad(
             renderer::Quad {
                 bounds: toggler_foreground_bounds,
-                border_radius,
+                border_radius: border_radius.into(),
                 border_width: 1.0,
                 border_color: style
                     .foreground_border

wgpu/src/quad.rs

@@ -91,7 +91,7 @@ impl Pipeline {
                                 2 => Float32x2,
                                 3 => Float32x4,
                                 4 => Float32x4,
-                                5 => Float32,
+                                5 => Float32x4,
                                 6 => Float32,
                             ),
                         },

wgpu/src/shader/quad.wgsl

@@ -11,7 +11,7 @@ struct VertexInput {
     @location(2) scale: vec2<f32>,
     @location(3) color: vec4<f32>,
     @location(4) border_color: vec4<f32>,
-    @location(5) border_radius: f32,
+    @location(5) border_radius: vec4<f32>,
     @location(6) border_width: f32,
 }
 
@@ -21,7 +21,7 @@ struct VertexOutput {
     @location(1) border_color: vec4<f32>,
     @location(2) pos: vec2<f32>,
     @location(3) scale: vec2<f32>,
-    @location(4) border_radius: f32,
+    @location(4) border_radius: vec4<f32>,
     @location(5) border_width: f32,
 }
 
@@ -32,9 +32,12 @@ fn vs_main(input: VertexInput) -> VertexOutput {
     var pos: vec2<f32> = input.pos * globals.scale;
     var scale: vec2<f32> = input.scale * globals.scale;
 
-    var border_radius: f32 = min(
+    var min_border_radius = min(input.scale.x, input.scale.y) * 0.5;
-        input.border_radius,
+    var border_radius: vec4<f32> = vec4<f32>(
-        min(input.scale.x, input.scale.y) / 2.0
+        min(input.border_radius.x, min_border_radius),
+        min(input.border_radius.y, min_border_radius),
+        min(input.border_radius.z, min_border_radius),
+        min(input.border_radius.w, min_border_radius)
     );
 
     var transform: mat4x4<f32> = mat4x4<f32>(
@@ -76,6 +79,18 @@ fn distance_alg(
     return sqrt(dist.x * dist.x + dist.y * dist.y);
 }
 
+// Based on the fragement position and the center of the quad, select one of the 4 radi.
+// Order matches CSS border radius attribute:
+// radi.x = top-left, radi.y = top-right, radi.z = bottom-right, radi.w = bottom-left
+fn select_border_radius(radi: vec4<f32>, position: vec2<f32>, center: vec2<f32>) -> f32 {
+    var rx = radi.x;
+    var ry = radi.y;
+    rx = select(radi.x, radi.y, position.x > center.x);
+    ry = select(radi.w, radi.z, position.x > center.x);
+    rx = select(rx, ry, position.y > center.y);
+    return rx;
+}
+
 
 @fragment
 fn fs_main(
@@ -83,14 +98,17 @@ fn fs_main(
 ) -> @location(0) vec4<f32> {
     var mixed_color: vec4<f32> = input.color;
 
+    var border_radius = select_border_radius(
+        input.border_radius,
+        input.position.xy,
+        (input.pos + input.scale * 0.5).xy
+    );
+
     if (input.border_width > 0.0) {
-        var internal_border: f32 = max(
+        var internal_border: f32 = max(border_radius - input.border_width, 0.0);
-            input.border_radius - input.border_width,
-            0.0
-        );
 
         var internal_distance: f32 = distance_alg(
-            vec2<f32>(input.position.x, input.position.y),
+            input.position.xy,
             input.pos + vec2<f32>(input.border_width, input.border_width),
             input.scale - vec2<f32>(input.border_width * 2.0, input.border_width * 2.0),
             internal_border
@@ -109,13 +127,14 @@ fn fs_main(
         vec2<f32>(input.position.x, input.position.y),
         input.pos,
         input.scale,
-        input.border_radius
+        border_radius
     );
 
     var radius_alpha: f32 = 1.0 - smoothstep(
-        max(input.border_radius - 0.5, 0.0),
+        max(border_radius - 0.5, 0.0),
-        input.border_radius + 0.5,
+        border_radius + 0.5,
-        dist);
+        dist
+    );
 
     return vec4<f32>(mixed_color.x, mixed_color.y, mixed_color.z, mixed_color.w * radius_alpha);
 }