[oden] Oh boy here we go

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);
+    }
+}