Modularize iced_wgpu

wgpu/src/renderer.rs

@@ -0,0 +1,167 @@
+use crate::Primitive;
+use iced_native::{renderer::Debugger, Color, Layout, Point, Widget};
+
+use raw_window_handle::HasRawWindowHandle;
+use wgpu::{
+    Adapter, CommandEncoderDescriptor, Device, DeviceDescriptor, Extensions,
+    Instance, Limits, PowerPreference, RequestAdapterOptions, Surface,
+    SwapChain, SwapChainDescriptor, TextureFormat, TextureUsage,
+};
+use wgpu_glyph::{GlyphBrush, GlyphBrushBuilder, Section};
+
+use std::{cell::RefCell, rc::Rc};
+
+mod button;
+mod checkbox;
+mod column;
+mod image;
+mod radio;
+mod row;
+mod slider;
+mod text;
+
+pub struct Renderer {
+    instance: Instance,
+    surface: Surface,
+    adapter: Adapter,
+    device: Device,
+    glyph_brush: Rc<RefCell<GlyphBrush<'static, ()>>>,
+}
+
+pub struct Target {
+    width: u16,
+    height: u16,
+    swap_chain: SwapChain,
+}
+
+impl Renderer {
+    pub fn new<W: HasRawWindowHandle>(window: &W) -> Self {
+        let instance = Instance::new();
+
+        let adapter = instance.request_adapter(&RequestAdapterOptions {
+            power_preference: PowerPreference::LowPower,
+        });
+
+        let mut device = adapter.request_device(&DeviceDescriptor {
+            extensions: Extensions {
+                anisotropic_filtering: false,
+            },
+            limits: Limits { max_bind_groups: 1 },
+        });
+
+        let surface = instance.create_surface(window.raw_window_handle());
+
+        // TODO: Think about font loading strategy
+        // Loading system fonts with fallback may be a good idea
+        let font: &[u8] =
+            include_bytes!("../../examples/tour/resources/Roboto-Regular.ttf");
+
+        let glyph_brush = GlyphBrushBuilder::using_font_bytes(font)
+            .build(&mut device, TextureFormat::Bgra8UnormSrgb);
+
+        Self {
+            instance,
+            surface,
+            adapter,
+            device,
+            glyph_brush: Rc::new(RefCell::new(glyph_brush)),
+        }
+    }
+
+    pub fn target(&self, width: u16, height: u16) -> Target {
+        Target {
+            width,
+            height,
+            swap_chain: self.device.create_swap_chain(
+                &self.surface,
+                &SwapChainDescriptor {
+                    usage: TextureUsage::OUTPUT_ATTACHMENT,
+                    format: TextureFormat::Bgra8UnormSrgb,
+                    width: u32::from(width),
+                    height: u32::from(height),
+                    present_mode: wgpu::PresentMode::Vsync,
+                },
+            ),
+        }
+    }
+
+    pub fn draw(&mut self, target: &mut Target, primitive: &Primitive) {
+        let frame = target.swap_chain.get_next_texture();
+
+        let mut encoder = self
+            .device
+            .create_command_encoder(&CommandEncoderDescriptor { todo: 0 });
+
+        let _ = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+            color_attachments: &[wgpu::RenderPassColorAttachmentDescriptor {
+                attachment: &frame.view,
+                resolve_target: None,
+                load_op: wgpu::LoadOp::Clear,
+                store_op: wgpu::StoreOp::Store,
+                clear_color: wgpu::Color {
+                    r: 1.0,
+                    g: 1.0,
+                    b: 1.0,
+                    a: 1.0,
+                },
+            }],
+            depth_stencil_attachment: None,
+        });
+
+        self.draw_primitive(primitive);
+
+        self.glyph_brush
+            .borrow_mut()
+            .draw_queued(
+                &mut self.device,
+                &mut encoder,
+                &frame.view,
+                u32::from(target.width),
+                u32::from(target.height),
+            )
+            .expect("Draw text");
+
+        self.device.get_queue().submit(&[encoder.finish()]);
+    }
+
+    fn draw_primitive(&mut self, primitive: &Primitive) {
+        match primitive {
+            Primitive::None => {}
+            Primitive::Group { primitives } => {
+                // TODO: Inspect a bit and regroup (?)
+                for primitive in primitives {
+                    self.draw_primitive(primitive)
+                }
+            }
+            Primitive::Text {
+                content,
+                bounds,
+                size,
+            } => self.glyph_brush.borrow_mut().queue(Section {
+                text: &content,
+                screen_position: (bounds.x, bounds.y),
+                bounds: (bounds.width, bounds.height),
+                scale: wgpu_glyph::Scale { x: *size, y: *size },
+                ..Default::default()
+            }),
+        }
+    }
+}
+
+impl iced_native::Renderer for Renderer {
+    // TODO: Add `MouseCursor` here (?)
+    type Primitive = Primitive;
+}
+
+impl Debugger for Renderer {
+    fn explain<Message>(
+        &mut self,
+        widget: &dyn Widget<Message, Self>,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        _color: Color,
+    ) -> Self::Primitive {
+        // TODO: Include a bordered box to display layout bounds
+        widget.draw(self, layout, cursor_position)
+    }
+}