Re-organize `custom` module as `pipeline` module

... and move `Shader` widget to `iced_widget` crate

6 files changed, 154 insertions, 118 deletions

diff --git a/wgpu/src/backend.rs b/wgpu/src/backend.rs
index 27ef0b3c..f89bcee1 100644
--- a/wgpu/src/backend.rs
+++ b/wgpu/src/backend.rs
@@ -2,8 +2,11 @@ use crate::core::{Color, Size};
 use crate::graphics::backend;
 use crate::graphics::color;
 use crate::graphics::{Transformation, Viewport};
+use crate::primitive::pipeline;
 use crate::primitive::{self, Primitive};
-use crate::{custom, quad, text, triangle};
+use crate::quad;
+use crate::text;
+use crate::triangle;
 use crate::{Layer, Settings};
 
 #[cfg(feature = "tracing")]
@@ -23,7 +26,7 @@ pub struct Backend {
     quad_pipeline: quad::Pipeline,
     text_pipeline: text::Pipeline,
     triangle_pipeline: triangle::Pipeline,
-    pipeline_storage: custom::Storage,
+    pipeline_storage: pipeline::Storage,
 
     #[cfg(any(feature = "image", feature = "svg"))]
     image_pipeline: image::Pipeline,
@@ -49,7 +52,7 @@ impl Backend {
             quad_pipeline,
             text_pipeline,
             triangle_pipeline,
-            pipeline_storage: custom::Storage::default(),
+            pipeline_storage: pipeline::Storage::default(),
 
             #[cfg(any(feature = "image", feature = "svg"))]
             image_pipeline,
@@ -183,9 +186,9 @@ impl Backend {
                 );
             }
 
-            if !layer.shaders.is_empty() {
-                for shader in &layer.shaders {
-                    shader.primitive.prepare(
+            if !layer.pipelines.is_empty() {
+                for pipeline in &layer.pipelines {
+                    pipeline.primitive.prepare(
                         format,
                         device,
                         queue,
@@ -323,19 +326,17 @@ impl Backend {
             // kill render pass to let custom shaders get mut access to encoder
             let _ = ManuallyDrop::into_inner(render_pass);
 
-            if !layer.shaders.is_empty() {
-                for shader in &layer.shaders {
-                    //This extra check is needed since each custom pipeline must set it's own
-                    //scissor rect, which will panic if bounds.w/h < 1
-                    let bounds = shader.bounds * scale_factor;
+            if !layer.pipelines.is_empty() {
+                for pipeline in &layer.pipelines {
+                    let bounds = (pipeline.bounds * scale_factor).snap();
 
-                    if bounds.width < 1.0 || bounds.height < 1.0 {
+                    if bounds.width < 1 || bounds.height < 1 {
                         continue;
                     }
 
-                    shader.primitive.render(
+                    pipeline.primitive.render(
                         &self.pipeline_storage,
-                        bounds.snap(),
+                        bounds,
                         target,
                         target_size,
                         encoder,
diff --git a/wgpu/src/custom.rs b/wgpu/src/custom.rs
index 65a6f133..98e2b396 100644
--- a/wgpu/src/custom.rs
+++ b/wgpu/src/custom.rs
@@ -1,67 +1,8 @@
 //! Draw custom primitives.
 use crate::core::{Rectangle, Size};
 use crate::graphics::Transformation;
+use crate::primitive;
+
 use std::any::{Any, TypeId};
 use std::collections::HashMap;
 use std::fmt::Debug;
-
-/// Stores custom, user-provided pipelines.
-#[derive(Default, Debug)]
-pub struct Storage {
-    pipelines: HashMap<TypeId, Box<dyn Any>>,
-}
-
-impl Storage {
-    /// Returns `true` if `Storage` contains a pipeline with type `T`.
-    pub fn has<T: 'static>(&self) -> bool {
-        self.pipelines.get(&TypeId::of::<T>()).is_some()
-    }
-
-    /// Inserts the pipeline `T` in to [`Storage`].
-    pub fn store<T: 'static>(&mut self, pipeline: T) {
-        let _ = self.pipelines.insert(TypeId::of::<T>(), Box::new(pipeline));
-    }
-
-    /// Returns a reference to pipeline with type `T` if it exists in [`Storage`].
-    pub fn get<T: 'static>(&self) -> Option<&T> {
-        self.pipelines.get(&TypeId::of::<T>()).map(|pipeline| {
-            pipeline
-                .downcast_ref::<T>()
-                .expect("Pipeline with this type does not exist in Storage.")
-        })
-    }
-
-    /// Returns a mutable reference to pipeline `T` if it exists in [`Storage`].
-    pub fn get_mut<T: 'static>(&mut self) -> Option<&mut T> {
-        self.pipelines.get_mut(&TypeId::of::<T>()).map(|pipeline| {
-            pipeline
-                .downcast_mut::<T>()
-                .expect("Pipeline with this type does not exist in Storage.")
-        })
-    }
-}
-
-/// A set of methods which allows a [`Primitive`] to be rendered.
-pub trait Primitive: Debug + Send + Sync + 'static {
-    /// Processes the [`Primitive`], allowing for GPU buffer allocation.
-    fn prepare(
-        &self,
-        format: wgpu::TextureFormat,
-        device: &wgpu::Device,
-        queue: &wgpu::Queue,
-        target_size: Size<u32>,
-        scale_factor: f32,
-        transform: Transformation,
-        storage: &mut Storage,
-    );
-
-    /// Renders the [`Primitive`].
-    fn render(
-        &self,
-        storage: &Storage,
-        bounds: Rectangle<u32>,
-        target: &wgpu::TextureView,
-        target_size: Size<u32>,
-        encoder: &mut wgpu::CommandEncoder,
-    );
-}
diff --git a/wgpu/src/layer.rs b/wgpu/src/layer.rs
index d451cbfd..33aaf670 100644
--- a/wgpu/src/layer.rs
+++ b/wgpu/src/layer.rs
@@ -35,8 +35,8 @@ pub struct Layer<'a> {
     /// The images of the [`Layer`].
     pub images: Vec<Image>,
 
-    /// The custom shader primitives of this [`Layer`].
-    pub shaders: Vec<primitive::Shader>,
+    /// The custom pipelines of this [`Layer`].
+    pub pipelines: Vec<primitive::Pipeline>,
 }
 
 impl<'a> Layer<'a> {
@@ -48,7 +48,7 @@ impl<'a> Layer<'a> {
             meshes: Vec::new(),
             text: Vec::new(),
             images: Vec::new(),
-            shaders: Vec::new(),
+            pipelines: Vec::new(),
         }
     }
 
@@ -312,16 +312,21 @@ impl<'a> Layer<'a> {
                         }
                     }
                 },
-                primitive::Custom::Shader(shader) => {
+                primitive::Custom::Pipeline(pipeline) => {
                     let layer = &mut layers[current_layer];
 
                     let bounds = Rectangle::new(
                         Point::new(translation.x, translation.y),
-                        shader.bounds.size(),
+                        pipeline.bounds.size(),
                     );
 
-                    if layer.bounds.intersection(&bounds).is_some() {
-                        layer.shaders.push(shader.clone());
+                    if let Some(clip_bounds) =
+                        layer.bounds.intersection(&bounds)
+                    {
+                        layer.pipelines.push(primitive::Pipeline {
+                            bounds: clip_bounds,
+                            primitive: pipeline.primitive.clone(),
+                        });
                     }
                 }
             },
diff --git a/wgpu/src/lib.rs b/wgpu/src/lib.rs
index 13d8e886..424dfeb3 100644
--- a/wgpu/src/lib.rs
+++ b/wgpu/src/lib.rs
@@ -29,7 +29,6 @@
     rustdoc::broken_intra_doc_links
 )]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
-pub mod custom;
 pub mod layer;
 pub mod primitive;
 pub mod settings;
diff --git a/wgpu/src/primitive.rs b/wgpu/src/primitive.rs
index 4347dcda..fff927ea 100644
--- a/wgpu/src/primitive.rs
+++ b/wgpu/src/primitive.rs
@@ -1,10 +1,12 @@
 //! Draw using different graphical primitives.
+pub mod pipeline;
+
+pub use pipeline::Pipeline;
+
 use crate::core::Rectangle;
-use crate::custom;
 use crate::graphics::{Damage, Mesh};
-use std::any::Any;
+
 use std::fmt::Debug;
-use std::sync::Arc;
 
 /// The graphical primitives supported by `iced_wgpu`.
 pub type Primitive = crate::graphics::Primitive<Custom>;
@@ -14,44 +16,15 @@ pub type Primitive = crate::graphics::Primitive<Custom>;
 pub enum Custom {
     /// A mesh primitive.
     Mesh(Mesh),
-    /// A custom shader primitive
-    Shader(Shader),
-}
-
-impl Custom {
-    /// Create a custom [`Shader`] primitive.
-    pub fn shader<P: custom::Primitive>(
-        bounds: Rectangle,
-        primitive: P,
-    ) -> Self {
-        Self::Shader(Shader {
-            bounds,
-            primitive: Arc::new(primitive),
-        })
-    }
+    /// A custom pipeline primitive.
+    Pipeline(Pipeline),
 }
 
 impl Damage for Custom {
     fn bounds(&self) -> Rectangle {
         match self {
             Self::Mesh(mesh) => mesh.bounds(),
-            Self::Shader(shader) => shader.bounds,
+            Self::Pipeline(pipeline) => pipeline.bounds,
         }
     }
 }
-
-#[derive(Clone, Debug)]
-/// A custom primitive which can be used to render primitives associated with a custom pipeline.
-pub struct Shader {
-    /// The bounds of the [`Shader`].
-    pub bounds: Rectangle,
-
-    /// The [`custom::Primitive`] to render.
-    pub primitive: Arc<dyn custom::Primitive>,
-}
-
-impl PartialEq for Shader {
-    fn eq(&self, other: &Self) -> bool {
-        self.primitive.type_id() == other.primitive.type_id()
-    }
-}
diff --git a/wgpu/src/primitive/pipeline.rs b/wgpu/src/primitive/pipeline.rs
new file mode 100644
index 00000000..b59aeff1
--- /dev/null
+++ b/wgpu/src/primitive/pipeline.rs
@@ -0,0 +1,117 @@
+//! Draw primitives using custom pipelines.
+use crate::core::{Rectangle, Size};
+use crate::graphics::Transformation;
+
+use std::any::{Any, TypeId};
+use std::collections::HashMap;
+use std::fmt::Debug;
+use std::sync::Arc;
+
+#[derive(Clone, Debug)]
+/// A custom primitive which can be used to render primitives associated with a custom pipeline.
+pub struct Pipeline {
+    /// The bounds of the [`Shader`].
+    pub bounds: Rectangle,
+
+    /// The [`custom::Primitive`] to render.
+    pub primitive: Arc<dyn Primitive>,
+}
+
+impl Pipeline {
+    /// Creates a new [`Pipeline`] with the given [`Primitive`].
+    pub fn new(bounds: Rectangle, primitive: impl Primitive) -> Self {
+        Pipeline {
+            bounds,
+            primitive: Arc::new(primitive),
+        }
+    }
+}
+
+impl PartialEq for Pipeline {
+    fn eq(&self, other: &Self) -> bool {
+        self.primitive.type_id() == other.primitive.type_id()
+    }
+}
+
+/// A set of methods which allows a [`Primitive`] to be rendered.
+pub trait Primitive: Debug + Send + Sync + 'static {
+    /// Processes the [`Primitive`], allowing for GPU buffer allocation.
+    fn prepare(
+        &self,
+        format: wgpu::TextureFormat,
+        device: &wgpu::Device,
+        queue: &wgpu::Queue,
+        target_size: Size<u32>,
+        scale_factor: f32,
+        transform: Transformation,
+        storage: &mut Storage,
+    );
+
+    /// Renders the [`Primitive`].
+    fn render(
+        &self,
+        storage: &Storage,
+        bounds: Rectangle<u32>,
+        target: &wgpu::TextureView,
+        target_size: Size<u32>,
+        encoder: &mut wgpu::CommandEncoder,
+    );
+}
+
+/// A renderer than can draw custom pipeline primitives.
+pub trait Renderer: crate::core::Renderer {
+    /// Draws a custom pipeline primitive.
+    fn draw_pipeline_primitive(
+        &mut self,
+        bounds: Rectangle,
+        primitive: impl Primitive,
+    );
+}
+
+impl<Theme> Renderer for crate::Renderer<Theme> {
+    fn draw_pipeline_primitive(
+        &mut self,
+        bounds: Rectangle,
+        primitive: impl Primitive,
+    ) {
+        self.draw_primitive(super::Primitive::Custom(super::Custom::Pipeline(
+            Pipeline::new(bounds, primitive),
+        )));
+    }
+}
+
+/// Stores custom, user-provided pipelines.
+#[derive(Default, Debug)]
+pub struct Storage {
+    pipelines: HashMap<TypeId, Box<dyn Any>>,
+}
+
+impl Storage {
+    /// Returns `true` if `Storage` contains a pipeline with type `T`.
+    pub fn has<T: 'static>(&self) -> bool {
+        self.pipelines.get(&TypeId::of::<T>()).is_some()
+    }
+
+    /// Inserts the pipeline `T` in to [`Storage`].
+    pub fn store<T: 'static>(&mut self, pipeline: T) {
+        let _ = self.pipelines.insert(TypeId::of::<T>(), Box::new(pipeline));
+    }
+
+    /// Returns a reference to pipeline with type `T` if it exists in [`Storage`].
+    pub fn get<T: 'static>(&self) -> Option<&T> {
+        self.pipelines.get(&TypeId::of::<T>()).map(|pipeline| {
+            pipeline
+                .downcast_ref::<T>()
+                .expect("Pipeline with this type does not exist in Storage.")
+        })
+    }
+
+    /// Returns a mutable reference to pipeline `T` if it exists in [`Storage`].
+    pub fn get_mut<T: 'static>(&mut self) -> Option<&mut T> {
+        self.pipelines.get_mut(&TypeId::of::<T>()).map(|pipeline| {
+            pipeline
+                .downcast_mut::<T>()
+                .expect("Pipeline with this type does not exist in Storage.")
+        })
+    }
+}