Redesign iced_wgpu layering architecture

wgpu/src/engine.rs

@@ -0,0 +1,79 @@
+use crate::buffer;
+use crate::graphics::Antialiasing;
+use crate::primitive::pipeline;
+use crate::quad;
+use crate::text;
+use crate::triangle;
+
+#[allow(missing_debug_implementations)]
+pub struct Engine {
+    pub(crate) quad_pipeline: quad::Pipeline,
+    pub(crate) text_pipeline: text::Pipeline,
+    pub(crate) triangle_pipeline: triangle::Pipeline,
+    pub(crate) _pipeline_storage: pipeline::Storage,
+    #[cfg(any(feature = "image", feature = "svg"))]
+    pub(crate) image_pipeline: crate::image::Pipeline,
+    pub(crate) staging_belt: wgpu::util::StagingBelt,
+}
+
+impl Engine {
+    pub fn new(
+        _adapter: &wgpu::Adapter,
+        device: &wgpu::Device,
+        queue: &wgpu::Queue,
+        format: wgpu::TextureFormat,
+        antialiasing: Option<Antialiasing>, // TODO: Initialize AA pipelines lazily
+    ) -> Self {
+        let text_pipeline = text::Pipeline::new(device, queue, format);
+        let quad_pipeline = quad::Pipeline::new(device, format);
+        let triangle_pipeline =
+            triangle::Pipeline::new(device, format, antialiasing);
+
+        #[cfg(any(feature = "image", feature = "svg"))]
+        let image_pipeline = {
+            let backend = _adapter.get_info().backend;
+
+            crate::image::Pipeline::new(device, format, backend)
+        };
+
+        Self {
+            // TODO: Resize belt smartly (?)
+            // It would be great if the `StagingBelt` API exposed methods
+            // for introspection to detect when a resize may be worth it.
+            staging_belt: wgpu::util::StagingBelt::new(
+                buffer::MAX_WRITE_SIZE as u64,
+            ),
+            quad_pipeline,
+            text_pipeline,
+            triangle_pipeline,
+            _pipeline_storage: pipeline::Storage::default(),
+
+            #[cfg(any(feature = "image", feature = "svg"))]
+            image_pipeline,
+        }
+    }
+
+    #[cfg(any(feature = "image", feature = "svg"))]
+    pub fn image_cache(&self) -> &crate::image::cache::Shared {
+        self.image_pipeline.cache()
+    }
+
+    pub fn submit(
+        &mut self,
+        queue: &wgpu::Queue,
+        encoder: wgpu::CommandEncoder,
+    ) -> wgpu::SubmissionIndex {
+        self.staging_belt.finish();
+        let index = queue.submit(Some(encoder.finish()));
+        self.staging_belt.recall();
+
+        self.quad_pipeline.end_frame();
+        self.text_pipeline.end_frame();
+        self.triangle_pipeline.end_frame();
+
+        #[cfg(any(feature = "image", feature = "svg"))]
+        self.image_pipeline.end_frame();
+
+        index
+    }
+}