Update project structure, update README, add input handler

src/render.rs

@@ -0,0 +1,90 @@
+use amethyst::{
+    ecs::prelude::{ReadExpect, Resources, SystemData},
+    renderer::{
+        pass::DrawFlat2DDesc,
+        rendy::{
+            factory::Factory,
+            graph::{
+                render::{RenderGroupDesc, SubpassBuilder},
+                GraphBuilder,
+            },
+            hal::format::Format,
+        },
+        types::DefaultBackend,
+        GraphCreator, Kind,
+    },
+    window::{ScreenDimensions, Window},
+};
+
+// Window background color
+static CLEAR_COLOR: [f32; 4] = [0.34, 0.36, 0.52, 1.0];
+
+#[derive(Default)]
+pub struct RenderGraph {
+    dimensions: Option<ScreenDimensions>,
+    dirty: bool,
+}
+
+impl GraphCreator<DefaultBackend> for RenderGraph {
+    fn rebuild(&mut self, res: &Resources) -> bool {
+        use std::ops::Deref;
+
+        // Only rebuild when dimensions have changed
+        let new_dimensions = res.try_fetch::<ScreenDimensions>();
+        let new_dimensions = new_dimensions.as_ref().map(|d| d.deref());
+
+        if self.dimensions.as_ref() != new_dimensions {
+            self.dirty = true;
+            self.dimensions = new_dimensions.map(|d| d.clone());
+            return false;
+        }
+
+        self.dirty
+    }
+
+    fn builder(
+        &mut self,
+        factory: &mut Factory<DefaultBackend>,
+        res: &Resources,
+    ) -> GraphBuilder<DefaultBackend, Resources> {
+        use amethyst::renderer::rendy::{
+            graph::present::PresentNode,
+            hal::command::{ClearDepthStencil, ClearValue},
+        };
+
+        // Since we're freshly building the graph, it will never
+        // be dirty after this function is called.
+        self.dirty = false;
+
+        let window = <ReadExpect<'_, Window>>::fetch(res);
+
+        let surface = factory.create_surface(&window);
+        let surface_format = factory.get_surface_format(&surface);
+
+        let dimensions = self.dimensions.as_ref().unwrap();
+        let window_kind = Kind::D2(dimensions.width() as u32, dimensions.height() as u32, 1, 1);
+
+        let clear_color = ClearValue::Color(CLEAR_COLOR.into());
+        let clear_depth = ClearValue::DepthStencil(ClearDepthStencil(1.0, 0));
+
+        // Build the RenderGraph
+        let mut builder = GraphBuilder::new();
+        let color = builder.create_image(window_kind, 1, surface_format, Some(clear_color));
+        let depth = builder.create_image(window_kind, 1, Format::D32Sfloat, Some(clear_depth));
+
+        // Add additional draw groups here for things like UI
+        let pass = builder.add_node(
+            SubpassBuilder::new()
+                .with_group(DrawFlat2DDesc::new().builder()) // Draw sprites
+                .with_color(color)
+                .with_depth_stencil(depth)
+                .into_pass(),
+        );
+
+        // Render the result to the surface
+        let present = PresentNode::builder(factory, surface, color).with_dependency(pass);
+        builder.add_node(present);
+
+        builder
+    }
+}