[oden] Oh boy here we go

src/lib.rs

@@ -8,8 +8,7 @@ use winit::{
 };
 
 mod script;
-// use script::ScriptContext;
+use script::graphics::{ClearCommand, GraphicsCommand, PrintCommand};
-
 mod texture;
 
 #[repr(C)]
@@ -298,7 +297,7 @@ impl State {
 
     fn update(&mut self) {}
 
-    fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
+    fn render(&mut self, commands: Vec<GraphicsCommand>) -> Result<(), wgpu::SurfaceError> {
         let output = self.surface.get_current_texture()?;
         let view = output
             .texture
@@ -309,37 +308,95 @@ impl State {
                 label: Some("Render Encoder"),
             });
 
-        {
+        // Group the commands into passes.
-            // BEGIN GARBAGE
+        struct Pass {
-            let r: f64 = (self.mouse_x / f64::from(self.size.width)).clamp(0.0, 1.0) * 0.1;
+            color: Option<[f64; 4]>,
-            let g: f64 = (self.mouse_y / f64::from(self.size.height)).clamp(0.0, 1.0) * 0.2;
+            commands: Vec<GraphicsCommand>,
-            // END GARBAGE
+        }
+        let mut passes = Vec::new();
+        for command in commands {
+            match command {
+                GraphicsCommand::Clear(ClearCommand { color }) => passes.push(Pass {
+                    color: Some(color),
+                    commands: Vec::new(),
+                }),
+                GraphicsCommand::EndFrame => (),
+                other => match passes.last_mut() {
+                    Some(pass) => pass.commands.push(other),
+                    None => passes.push(Pass {
+                        color: None,
+                        commands: vec![other],
+                    }),
+                },
+            }
+        }
 
+        for pass in passes {
             let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                 label: Some("Render Pass"),
                 color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                     view: &view,
                     resolve_target: None,
                     ops: wgpu::Operations {
-                        load: wgpu::LoadOp::Clear(wgpu::Color {
+                        load: if let Some([r, g, b, a]) = pass.color {
+                            wgpu::LoadOp::Clear(wgpu::Color {
                                 r, //0.1,
                                 g, //0.2,
-                            b: 0.3,
+                                b,
-                            a: 1.0,
+                                a,
-                        }),
+                            })
+                        } else {
+                            wgpu::LoadOp::Load
+                        },
                         store: true,
                     },
                 })],
                 depth_stencil_attachment: None,
             });
 
-            render_pass.set_pipeline(&self.render_pipeline);
+            for command in pass.commands {
-            render_pass.set_bind_group(0, &self.diffuse_bind_group, &[]);
+                match command {
-            render_pass.set_vertex_buffer(0, self.vertex_buffer.slice(..));
+                    GraphicsCommand::Print(PrintCommand { text }) => {
-            render_pass.set_index_buffer(self.index_buffer.slice(..), wgpu::IndexFormat::Uint16);
+                        println!("{}", text);
-            render_pass.draw_indexed(0..self.num_indices, 0, 0..1);
                     }
 
+                    GraphicsCommand::Clear(_) => (), // Already handled
+                    GraphicsCommand::EndFrame => (), // Should never appear
+                }
+            }
+        }
+
+        // {
+        //     // BEGIN GARBAGE
+        //     let r: f64 = (self.mouse_x / f64::from(self.size.width)).clamp(0.0, 1.0) * 0.1;
+        //     let g: f64 = (self.mouse_y / f64::from(self.size.height)).clamp(0.0, 1.0) * 0.2;
+        //     // END GARBAGE
+
+        //     let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+        //         label: Some("Render Pass"),
+        //         color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+        //             view: &view,
+        //             resolve_target: None,
+        //             ops: wgpu::Operations {
+        //                 load: wgpu::LoadOp::Clear(wgpu::Color {
+        //                     r, //0.1,
+        //                     g, //0.2,
+        //                     b: 0.3,
+        //                     a: 1.0,
+        //                 }),
+        //                 store: true,
+        //             },
+        //         })],
+        //         depth_stencil_attachment: None,
+        //     });
+
+        //     render_pass.set_pipeline(&self.render_pipeline);
+        //     render_pass.set_bind_group(0, &self.diffuse_bind_group, &[]);
+        //     render_pass.set_vertex_buffer(0, self.vertex_buffer.slice(..));
+        //     render_pass.set_index_buffer(self.index_buffer.slice(..), wgpu::IndexFormat::Uint16);
+        //     render_pass.draw_indexed(0..self.num_indices, 0, 0..1);
+        // }
+
         // Submit will accept anything that implements IntoIter
         self.queue.submit(std::iter::once(encoder.finish()));
         output.present();
@@ -403,8 +460,7 @@ pub async fn run() {
                 context.update();
                 state.update();
 
-                context.render();
+                match state.render(context.render()) {
-                match state.render() {
                     Ok(_) => {}
                     // Reconfigure the surface if lost
                     Err(wgpu::SurfaceError::Lost) => state.resize(state.size),

src/main.js

@@ -1,11 +1,11 @@
-import * as graphics from 'graphics';
+import { cls, print } from "graphics";
 
-function init() {
+export function init() {
-  graphics.print("Hello world!");
+  print("Hello world!");
 }
 
-function update() {}
+export function update() {}
 
-function draw() {}
+export function draw() {
-
+  cls(0.1, 0.2, 0.3);
-export { init, update, draw }
+}

src/script.rs

@@ -1,12 +1,17 @@
 use oden_js::{Context, Runtime, Value};
+use std::sync::mpsc::{channel, Receiver};
 
-mod graphics;
+pub mod graphics;
+use graphics::GraphicsCommand;
 
 pub struct ScriptContext {
     context: Context,
     init: Value,
     update: Value,
     draw: Value,
+
+    gfx: graphics::GraphicsAPI,
+    gfx_receive: Receiver<graphics::GraphicsCommand>,
 }
 
 impl ScriptContext {
@@ -18,7 +23,10 @@ impl ScriptContext {
         context.add_intrinsic_bigdecimal();
         context.add_intrinsic_operators();
 
-        graphics::GraphicsAPI::define(&context).expect("Graphics module should load without error");
+        let (gfx_send, gfx_receive) = channel();
+
+        let gfx = graphics::GraphicsAPI::define(&context, gfx_send)
+            .expect("Graphics module should load without error");
 
         let js = include_str!("main.js");
         let module = context
@@ -37,12 +45,20 @@ impl ScriptContext {
 
         ScriptContext {
             context,
+
             init,
             update,
             draw,
+
+            gfx,
+            gfx_receive,
         }
     }
 
+    // TODO: The script could really be on a background thread you know.
+    //       We would want a bi-directional gate for frames to not let the
+    //       game thread go to fast probably? And to discard whole frames &c.
+
     pub fn init(&self) {
         self.init.call(&self.context).expect("Exception in init");
     }
@@ -53,7 +69,17 @@ impl ScriptContext {
             .expect("Exception in update");
     }
 
-    pub fn render(&self) {
+    pub fn render(&self) -> Vec<graphics::GraphicsCommand> {
         self.draw.call(&self.context).expect("Exception in draw");
+        self.gfx.end_frame();
+
+        let mut commands = Vec::new();
+        loop {
+            match self.gfx_receive.recv().unwrap() {
+                GraphicsCommand::EndFrame => break,
+                other => commands.push(other),
+            }
+        }
+        commands
     }
 }

src/script/graphics.rs

@@ -0,0 +1,93 @@
+use oden_js::{module, ContextRef, Error, Value, ValueRef, ValueResult};
+use std::sync::mpsc::Sender;
+use std::sync::Arc;
+
+pub struct PrintCommand {
+    pub text: String,
+}
+
+pub struct ClearCommand {
+    pub color: [f64; 4],
+}
+
+pub enum GraphicsCommand {
+    Clear(ClearCommand),
+    Print(PrintCommand),
+    EndFrame,
+}
+
+const MAGIC_VALUE: u64 = 0xABCDB00BABCDBEEB;
+
+struct GraphicsImpl {
+    magic: u64,
+    sender: Sender<GraphicsCommand>,
+}
+
+impl GraphicsImpl {
+    pub fn new(sender: Sender<GraphicsCommand>) -> Self {
+        GraphicsImpl {
+            magic: MAGIC_VALUE,
+            sender,
+        }
+    }
+
+    fn print_fn(&self, ctx: &ContextRef, args: &[&ValueRef]) -> ValueResult {
+        assert_eq!(self.magic, MAGIC_VALUE);
+        let mut text = String::with_capacity(128);
+        for arg in args {
+            let v = arg.to_string(ctx)?;
+            text.push_str(&v);
+        }
+
+        let _ = self
+            .sender
+            .send(GraphicsCommand::Print(PrintCommand { text }));
+
+        Ok(Value::undefined(ctx))
+    }
+
+    fn cls_fn(&self, ctx: &ContextRef, args: &[&ValueRef]) -> ValueResult {
+        assert_eq!(self.magic, MAGIC_VALUE);
+        if args.len() != 3 {
+            return Err(Error::ArgumentCountMismatch {
+                expected: 3,
+                received: args.len(),
+            });
+        }
+        let r = args[0].to_float64(&ctx)?;
+        let g = args[1].to_float64(&ctx)?;
+        let b = args[1].to_float64(&ctx)?;
+
+        let _ = self.sender.send(GraphicsCommand::Clear(ClearCommand {
+            color: [r, g, b, 1.0],
+        }));
+        Ok(Value::undefined(ctx))
+    }
+}
+
+pub struct GraphicsAPI {
+    gfx: Arc<GraphicsImpl>,
+}
+
+impl GraphicsAPI {
+    pub fn define(ctx: &ContextRef, sender: Sender<GraphicsCommand>) -> oden_js::Result<Self> {
+        let gfx = Arc::new(GraphicsImpl::new(sender));
+        let gfx_a = gfx.clone();
+        let gfx_b = gfx.clone();
+        module::NativeModuleBuilder::new(ctx)
+            .export(
+                "print",
+                ctx.new_dynamic_fn(move |ctx, _, args| gfx_a.print_fn(ctx, args))?,
+            )?
+            .export(
+                "cls",
+                ctx.new_dynamic_fn(move |ctx, _, args| gfx_b.cls_fn(ctx, args))?,
+            )?
+            .build("graphics")?;
+        Ok(GraphicsAPI { gfx })
+    }
+
+    pub fn end_frame(&self) {
+        let _ = self.gfx.sender.send(GraphicsCommand::EndFrame);
+    }
+}