Group all solid triangles independently of color

9 files changed, 294 insertions, 100 deletions

diff --git a/graphics/src/layer.rs b/graphics/src/layer.rs
index e95934b0..fd670f48 100644
--- a/graphics/src/layer.rs
+++ b/graphics/src/layer.rs
@@ -166,10 +166,27 @@ impl<'a> Layer<'a> {
                     border_color: border_color.into_linear(),
                 });
             }
-            Primitive::Mesh2D {
+            Primitive::SolidMesh { buffers, size } => {
+                let layer = &mut layers[current_layer];
+
+                let bounds = Rectangle::new(
+                    Point::new(translation.x, translation.y),
+                    *size,
+                );
+
+                // Only draw visible content
+                if let Some(clip_bounds) = layer.bounds.intersection(&bounds) {
+                    layer.meshes.push(Mesh::Solid {
+                        origin: Point::new(translation.x, translation.y),
+                        buffers,
+                        clip_bounds,
+                    });
+                }
+            }
+            Primitive::GradientMesh {
                 buffers,
                 size,
-                style,
+                gradient,
             } => {
                 let layer = &mut layers[current_layer];
 
@@ -180,11 +197,11 @@ impl<'a> Layer<'a> {
 
                 // Only draw visible content
                 if let Some(clip_bounds) = layer.bounds.intersection(&bounds) {
-                    layer.meshes.push(Mesh {
+                    layer.meshes.push(Mesh::Gradient {
                         origin: Point::new(translation.x, translation.y),
                         buffers,
                         clip_bounds,
-                        style,
+                        gradient,
                     });
                 }
             }
diff --git a/graphics/src/layer/mesh.rs b/graphics/src/layer/mesh.rs
index 979081f1..7661c5c9 100644
--- a/graphics/src/layer/mesh.rs
+++ b/graphics/src/layer/mesh.rs
@@ -1,31 +1,93 @@
 //! A collection of triangle primitives.
 use crate::triangle;
-use crate::{Point, Rectangle};
+use crate::{Gradient, Point, Rectangle};
 
 /// A mesh of triangles.
 #[derive(Debug, Clone, Copy)]
-pub struct Mesh<'a> {
-    /// The origin of the vertices of the [`Mesh`].
-    pub origin: Point,
+pub enum Mesh<'a> {
+    /// A mesh of triangles with a solid color.
+    Solid {
+        /// The origin of the vertices of the [`Mesh`].
+        origin: Point,
 
-    /// The vertex and index buffers of the [`Mesh`].
-    pub buffers: &'a triangle::Mesh2D,
+        /// The vertex and index buffers of the [`Mesh`].
+        buffers: &'a triangle::Mesh2D<triangle::ColoredVertex2D>,
 
-    /// The clipping bounds of the [`Mesh`].
-    pub clip_bounds: Rectangle<f32>,
+        /// The clipping bounds of the [`Mesh`].
+        clip_bounds: Rectangle<f32>,
+    },
+    /// A mesh of triangles with a gradient color.
+    Gradient {
+        /// The origin of the vertices of the [`Mesh`].
+        origin: Point,
 
-    /// The shader of the [`Mesh`].
-    pub style: &'a triangle::Style,
+        /// The vertex and index buffers of the [`Mesh`].
+        buffers: &'a triangle::Mesh2D<triangle::Vertex2D>,
+
+        /// The clipping bounds of the [`Mesh`].
+        clip_bounds: Rectangle<f32>,
+
+        /// The gradient to apply to the [`Mesh`].
+        gradient: &'a Gradient,
+    },
+}
+
+impl Mesh<'_> {
+    /// Returns the origin of the [`Mesh`].
+    pub fn origin(&self) -> Point {
+        match self {
+            Self::Solid { origin, .. } | Self::Gradient { origin, .. } => {
+                *origin
+            }
+        }
+    }
+
+    /// Returns the indices of the [`Mesh`].
+    pub fn indices(&self) -> &[u32] {
+        match self {
+            Self::Solid { buffers, .. } => &buffers.indices,
+            Self::Gradient { buffers, .. } => &buffers.indices,
+        }
+    }
+
+    /// Returns the clip bounds of the [`Mesh`].
+    pub fn clip_bounds(&self) -> Rectangle<f32> {
+        match self {
+            Self::Solid { clip_bounds, .. }
+            | Self::Gradient { clip_bounds, .. } => *clip_bounds,
+        }
+    }
+}
+
+/// The result of counting the attributes of a set of meshes.
+#[derive(Debug, Clone, Copy, Default)]
+pub struct AttributeCount {
+    /// The total amount of solid vertices.
+    pub solid_vertices: usize,
+
+    /// The total amount of gradient vertices.
+    pub gradient_vertices: usize,
+
+    /// The total amount of indices.
+    pub indices: usize,
 }
 
 /// Returns the number of total vertices & total indices of all [`Mesh`]es.
-pub fn attribute_count_of<'a>(meshes: &'a [Mesh<'a>]) -> (usize, usize) {
+pub fn attribute_count_of<'a>(meshes: &'a [Mesh<'a>]) -> AttributeCount {
     meshes
         .iter()
-        .map(|Mesh { buffers, .. }| {
-            (buffers.vertices.len(), buffers.indices.len())
-        })
-        .fold((0, 0), |(total_v, total_i), (v, i)| {
-            (total_v + v, total_i + i)
+        .fold(AttributeCount::default(), |mut count, mesh| {
+            match mesh {
+                Mesh::Solid { buffers, .. } => {
+                    count.solid_vertices += buffers.vertices.len();
+                    count.indices += buffers.indices.len();
+                }
+                Mesh::Gradient { buffers, .. } => {
+                    count.gradient_vertices += buffers.vertices.len();
+                    count.indices += buffers.indices.len();
+                }
+            }
+
+            count
         })
 }
diff --git a/graphics/src/primitive.rs b/graphics/src/primitive.rs
index b481ac0b..9759d97a 100644
--- a/graphics/src/primitive.rs
+++ b/graphics/src/primitive.rs
@@ -3,6 +3,7 @@ use iced_native::svg;
 use iced_native::{Background, Color, Font, Rectangle, Size, Vector};
 
 use crate::alignment;
+use crate::gradient::Gradient;
 use crate::triangle;
 
 use std::sync::Arc;
@@ -77,20 +78,32 @@ pub enum Primitive {
         /// The primitive to translate
         content: Box<Primitive>,
     },
-    /// A low-level primitive to render a mesh of triangles.
+    /// A low-level primitive to render a mesh of triangles with a solid color.
     ///
     /// It can be used to render many kinds of geometry freely.
-    Mesh2D {
-        /// The vertex and index buffers of the mesh
-        buffers: triangle::Mesh2D,
+    SolidMesh {
+        /// The vertices and indices of the mesh.
+        buffers: triangle::Mesh2D<triangle::ColoredVertex2D>,
+
+        /// The size of the drawable region of the mesh.
+        ///
+        /// Any geometry that falls out of this region will be clipped.
+        size: Size,
+    },
+    /// A low-level primitive to render a mesh of triangles with a gradient.
+    ///
+    /// It can be used to render many kinds of geometry freely.
+    GradientMesh {
+        /// The vertices and indices of the mesh.
+        buffers: triangle::Mesh2D<triangle::Vertex2D>,
 
         /// The size of the drawable region of the mesh.
         ///
         /// Any geometry that falls out of this region will be clipped.
         size: Size,
 
-        /// The shader of the mesh
-        style: triangle::Style,
+        /// The [`Gradient`] to apply to the mesh.
+        gradient: Gradient,
     },
     /// A cached primitive.
     ///
diff --git a/graphics/src/triangle.rs b/graphics/src/triangle.rs
index 8b41bfc4..f52b2339 100644
--- a/graphics/src/triangle.rs
+++ b/graphics/src/triangle.rs
@@ -1,15 +1,12 @@
 //! Draw geometry using meshes of triangles.
-use crate::Color;
-#[cfg(not(target_arch = "wasm32"))]
-use crate::Gradient;
-
 use bytemuck::{Pod, Zeroable};
 
 /// A set of [`Vertex2D`] and indices representing a list of triangles.
 #[derive(Clone, Debug)]
-pub struct Mesh2D {
+pub struct Mesh2D<T> {
     /// The vertices of the mesh
-    pub vertices: Vec<Vertex2D>,
+    pub vertices: Vec<T>,
+
     /// The list of vertex indices that defines the triangles of the mesh.
     ///
     /// Therefore, this list should always have a length that is a multiple of 3.
@@ -24,25 +21,13 @@ pub struct Vertex2D {
     pub position: [f32; 2],
 }
 
-#[derive(Debug, Clone, PartialEq)]
-/// Supported shaders for triangle primitives.
-pub enum Style {
-    /// Fill a primitive with a solid color.
-    Solid(Color),
-    #[cfg(not(target_arch = "wasm32"))]
-    /// Fill a primitive with an interpolated color.
-    Gradient(Gradient),
-}
-
-impl From<Color> for Style {
-    fn from(color: Color) -> Self {
-        Self::Solid(color)
-    }
-}
+/// A two-dimensional vertex with a color.
+#[derive(Copy, Clone, Debug, Zeroable, Pod)]
+#[repr(C)]
+pub struct ColoredVertex2D {
+    /// The vertex position in 2D space.
+    pub position: [f32; 2],
 
-#[cfg(not(target_arch = "wasm32"))]
-impl From<Gradient> for Style {
-    fn from(gradient: Gradient) -> Self {
-        Self::Gradient(gradient)
-    }
+    /// The color of the vertex in __linear__ RGBA.
+    pub color: [f32; 4],
 }
diff --git a/graphics/src/widget/canvas.rs b/graphics/src/widget/canvas.rs
index a14940d9..b070d0a6 100644
--- a/graphics/src/widget/canvas.rs
+++ b/graphics/src/widget/canvas.rs
@@ -13,6 +13,7 @@ mod cursor;
 mod frame;
 mod geometry;
 mod program;
+mod style;
 mod text;
 
 pub use crate::gradient::{self, Gradient};
@@ -25,6 +26,7 @@ pub use geometry::Geometry;
 pub use path::Path;
 pub use program::Program;
 pub use stroke::{LineCap, LineDash, LineJoin, Stroke};
+pub use style::Style;
 pub use text::Text;
 
 use crate::{Backend, Primitive, Renderer};
diff --git a/graphics/src/widget/canvas/fill.rs b/graphics/src/widget/canvas/fill.rs
index e2fc1cfe..e954ebb5 100644
--- a/graphics/src/widget/canvas/fill.rs
+++ b/graphics/src/widget/canvas/fill.rs
@@ -1,7 +1,7 @@
 //! Fill [crate::widget::canvas::Geometry] with a certain style.
 use crate::{Color, Gradient};
 
-pub use crate::triangle::Style;
+pub use crate::widget::canvas::Style;
 
 /// The style used to fill geometry.
 #[derive(Debug, Clone)]
diff --git a/graphics/src/widget/canvas/frame.rs b/graphics/src/widget/canvas/frame.rs
index a7b88502..d68548ae 100644
--- a/graphics/src/widget/canvas/frame.rs
+++ b/graphics/src/widget/canvas/frame.rs
@@ -1,7 +1,6 @@
 use crate::gradient::Gradient;
 use crate::triangle;
-use crate::triangle::Vertex2D;
-use crate::widget::canvas::{path, Fill, Geometry, Path, Stroke, Text};
+use crate::widget::canvas::{path, Fill, Geometry, Path, Stroke, Style, Text};
 use crate::Primitive;
 
 use iced_native::{Point, Rectangle, Size, Vector};
@@ -23,8 +22,16 @@ pub struct Frame {
     stroke_tessellator: tessellation::StrokeTessellator,
 }
 
+enum Buffer {
+    Solid(tessellation::VertexBuffers<triangle::ColoredVertex2D, u32>),
+    Gradient(
+        tessellation::VertexBuffers<triangle::Vertex2D, u32>,
+        Gradient,
+    ),
+}
+
 struct BufferStack {
-    stack: Vec<(tessellation::VertexBuffers<Vertex2D, u32>, triangle::Style)>,
+    stack: Vec<Buffer>,
 }
 
 impl BufferStack {
@@ -32,22 +39,64 @@ impl BufferStack {
         Self { stack: Vec::new() }
     }
 
-    fn get(
-        &mut self,
-        mesh_style: triangle::Style,
-    ) -> tessellation::BuffersBuilder<'_, Vertex2D, u32, Vertex2DBuilder> {
-        match self.stack.last_mut() {
-            Some((_, current_style)) if current_style == &mesh_style => {}
-            _ => {
-                self.stack
-                    .push((tessellation::VertexBuffers::new(), mesh_style));
+    fn get_mut(&mut self, style: &Style) -> &mut Buffer {
+        match style {
+            Style::Solid(_) => match self.stack.last() {
+                Some(Buffer::Solid(_)) => {}
+                _ => {
+                    self.stack.push(Buffer::Solid(
+                        tessellation::VertexBuffers::new(),
+                    ));
+                }
+            },
+            Style::Gradient(gradient) => match self.stack.last() {
+                Some(Buffer::Gradient(_, last)) if gradient == last => {}
+                _ => {
+                    self.stack.push(Buffer::Gradient(
+                        tessellation::VertexBuffers::new(),
+                        gradient.clone(),
+                    ));
+                }
+            },
+        }
+
+        self.stack.last_mut().unwrap()
+    }
+
+    fn get_fill<'a>(
+        &'a mut self,
+        style: &Style,
+    ) -> Box<dyn tessellation::FillGeometryBuilder + 'a> {
+        match (style, self.get_mut(style)) {
+            (Style::Solid(color), Buffer::Solid(buffer)) => {
+                Box::new(tessellation::BuffersBuilder::new(
+                    buffer,
+                    TriangleVertex2DBuilder(color.into_linear()),
+                ))
             }
-        };
+            (Style::Gradient(_), Buffer::Gradient(buffer, _)) => Box::new(
+                tessellation::BuffersBuilder::new(buffer, Vertex2DBuilder),
+            ),
+            _ => unreachable!(),
+        }
+    }
 
-        tessellation::BuffersBuilder::new(
-            &mut self.stack.last_mut().unwrap().0,
-            Vertex2DBuilder,
-        )
+    fn get_stroke<'a>(
+        &'a mut self,
+        style: &Style,
+    ) -> Box<dyn tessellation::StrokeGeometryBuilder + 'a> {
+        match (style, self.get_mut(style)) {
+            (Style::Solid(color), Buffer::Solid(buffer)) => {
+                Box::new(tessellation::BuffersBuilder::new(
+                    buffer,
+                    TriangleVertex2DBuilder(color.into_linear()),
+                ))
+            }
+            (Style::Gradient(_), Buffer::Gradient(buffer, _)) => Box::new(
+                tessellation::BuffersBuilder::new(buffer, Vertex2DBuilder),
+            ),
+            _ => unreachable!(),
+        }
     }
 }
 
@@ -73,12 +122,11 @@ impl Transform {
         point.y = transformed.y;
     }
 
-    fn transform_style(&self, style: triangle::Style) -> triangle::Style {
+    fn transform_style(&self, style: Style) -> Style {
         match style {
-            triangle::Style::Solid(color) => triangle::Style::Solid(color),
-            #[cfg(not(target_arch = "wasm32"))]
-            triangle::Style::Gradient(gradient) => {
-                triangle::Style::Gradient(self.transform_gradient(gradient))
+            Style::Solid(color) => Style::Solid(color),
+            Style::Gradient(gradient) => {
+                Style::Gradient(self.transform_gradient(gradient))
             }
         }
     }
@@ -146,7 +194,7 @@ impl Frame {
 
         let mut buffer = self
             .buffers
-            .get(self.transforms.current.transform_style(style));
+            .get_fill(&self.transforms.current.transform_style(style));
 
         let options =
             tessellation::FillOptions::default().with_fill_rule(rule.into());
@@ -155,7 +203,7 @@ impl Frame {
             self.fill_tessellator.tessellate_path(
                 path.raw(),
                 &options,
-                &mut buffer,
+                buffer.as_mut(),
             )
         } else {
             let path = path.transformed(&self.transforms.current.raw);
@@ -163,7 +211,7 @@ impl Frame {
             self.fill_tessellator.tessellate_path(
                 path.raw(),
                 &options,
-                &mut buffer,
+                buffer.as_mut(),
             )
         }
         .expect("Tessellate path.");
@@ -181,7 +229,7 @@ impl Frame {
 
         let mut buffer = self
             .buffers
-            .get(self.transforms.current.transform_style(style));
+            .get_fill(&self.transforms.current.transform_style(style));
 
         let top_left =
             self.transforms.current.raw.transform_point(
@@ -200,7 +248,7 @@ impl Frame {
             .tessellate_rectangle(
                 &lyon::math::Box2D::new(top_left, top_left + size),
                 &options,
-                &mut buffer,
+                buffer.as_mut(),
             )
             .expect("Fill rectangle");
     }
@@ -212,7 +260,7 @@ impl Frame {
 
         let mut buffer = self
             .buffers
-            .get(self.transforms.current.transform_style(stroke.style));
+            .get_stroke(&self.transforms.current.transform_style(stroke.style));
 
         let mut options = tessellation::StrokeOptions::default();
         options.line_width = stroke.width;
@@ -230,7 +278,7 @@ impl Frame {
             self.stroke_tessellator.tessellate_path(
                 path.raw(),
                 &options,
-                &mut buffer,
+                buffer.as_mut(),
             )
         } else {
             let path = path.transformed(&self.transforms.current.raw);
@@ -238,7 +286,7 @@ impl Frame {
             self.stroke_tessellator.tessellate_path(
                 path.raw(),
                 &options,
-                &mut buffer,
+                buffer.as_mut(),
             )
         }
         .expect("Stroke path");
@@ -383,16 +431,31 @@ impl Frame {
     }
 
     fn into_primitives(mut self) -> Vec<Primitive> {
-        for (buffer, style) in self.buffers.stack {
-            if !buffer.indices.is_empty() {
-                self.primitives.push(Primitive::Mesh2D {
-                    buffers: triangle::Mesh2D {
-                        vertices: buffer.vertices,
-                        indices: buffer.indices,
-                    },
-                    size: self.size,
-                    style,
-                })
+        for buffer in self.buffers.stack {
+            match buffer {
+                Buffer::Solid(buffer) => {
+                    if !buffer.indices.is_empty() {
+                        self.primitives.push(Primitive::SolidMesh {
+                            buffers: triangle::Mesh2D {
+                                vertices: buffer.vertices,
+                                indices: buffer.indices,
+                            },
+                            size: self.size,
+                        })
+                    }
+                }
+                Buffer::Gradient(buffer, gradient) => {
+                    if !buffer.indices.is_empty() {
+                        self.primitives.push(Primitive::GradientMesh {
+                            buffers: triangle::Mesh2D {
+                                vertices: buffer.vertices,
+                                indices: buffer.indices,
+                            },
+                            size: self.size,
+                            gradient,
+                        })
+                    }
+                }
             }
         }
 
@@ -402,25 +465,66 @@ impl Frame {
 
 struct Vertex2DBuilder;
 
-impl tessellation::FillVertexConstructor<Vertex2D> for Vertex2DBuilder {
-    fn new_vertex(&mut self, vertex: tessellation::FillVertex<'_>) -> Vertex2D {
+impl tessellation::FillVertexConstructor<triangle::Vertex2D>
+    for Vertex2DBuilder
+{
+    fn new_vertex(
+        &mut self,
+        vertex: tessellation::FillVertex<'_>,
+    ) -> triangle::Vertex2D {
+        let position = vertex.position();
+
+        triangle::Vertex2D {
+            position: [position.x, position.y],
+        }
+    }
+}
+
+impl tessellation::StrokeVertexConstructor<triangle::Vertex2D>
+    for Vertex2DBuilder
+{
+    fn new_vertex(
+        &mut self,
+        vertex: tessellation::StrokeVertex<'_, '_>,
+    ) -> triangle::Vertex2D {
+        let position = vertex.position();
+
+        triangle::Vertex2D {
+            position: [position.x, position.y],
+        }
+    }
+}
+
+struct TriangleVertex2DBuilder([f32; 4]);
+
+impl tessellation::FillVertexConstructor<triangle::ColoredVertex2D>
+    for TriangleVertex2DBuilder
+{
+    fn new_vertex(
+        &mut self,
+        vertex: tessellation::FillVertex<'_>,
+    ) -> triangle::ColoredVertex2D {
         let position = vertex.position();
 
-        Vertex2D {
+        triangle::ColoredVertex2D {
             position: [position.x, position.y],
+            color: self.0,
         }
     }
 }
 
-impl tessellation::StrokeVertexConstructor<Vertex2D> for Vertex2DBuilder {
+impl tessellation::StrokeVertexConstructor<triangle::ColoredVertex2D>
+    for TriangleVertex2DBuilder
+{
     fn new_vertex(
         &mut self,
         vertex: tessellation::StrokeVertex<'_, '_>,
-    ) -> Vertex2D {
+    ) -> triangle::ColoredVertex2D {
         let position = vertex.position();
 
-        Vertex2D {
+        triangle::ColoredVertex2D {
             position: [position.x, position.y],
+            color: self.0,
         }
     }
 }
diff --git a/graphics/src/widget/canvas/stroke.rs b/graphics/src/widget/canvas/stroke.rs
index a882531a..4c19251d 100644
--- a/graphics/src/widget/canvas/stroke.rs
+++ b/graphics/src/widget/canvas/stroke.rs
@@ -1,5 +1,5 @@
 //! Create lines from a [crate::widget::canvas::Path] and assigns them various attributes/styles.
-pub use crate::triangle::Style;
+pub use crate::widget::canvas::Style;
 
 use iced_native::Color;
 
diff --git a/graphics/src/widget/canvas/style.rs b/graphics/src/widget/canvas/style.rs
new file mode 100644
index 00000000..794109bd
--- /dev/null
+++ b/graphics/src/widget/canvas/style.rs
@@ -0,0 +1,11 @@
+use crate::{Color, Gradient};
+
+/// The coloring style of some drawing.
+#[derive(Debug, Clone, PartialEq)]
+pub enum Style {
+    /// A solid [`Color`].
+    Solid(Color),
+
+    /// A [`Gradient`] color.
+    Gradient(Gradient),
+}