From f19d0c87ed0cfa828f8f1909e311e47c1ae8f9a5 Mon Sep 17 00:00:00 2001
From: Evan Martin <evan.martin@gmail.com>
Date: Thu, 27 Feb 2025 09:43:09 -0800
Subject: [PATCH] ddraw: show canvas inline in debugger

---
 web/debugger/ddraw.tsx    | 20 +++++++++++---
 web/debugger/debugger.tsx |  2 +-
 web/glue/src/debugger.rs  | 58 +++++++++++++++++++++++----------------
 web/glue/src/emulator.rs  |  4 +--
 web/glue/src/host.rs      |  4 +--
 5 files changed, 55 insertions(+), 33 deletions(-)

diff --git a/web/debugger/ddraw.tsx b/web/debugger/ddraw.tsx
index 55ed1122..c7dd0905 100644
--- a/web/debugger/ddraw.tsx
+++ b/web/debugger/ddraw.tsx
@@ -4,14 +4,25 @@ import { MemoryView, Number } from './memory';
 
 namespace DirectDraw {
   export interface Props extends MemoryView {
-    state: wasm.DirectDrawState;
+    surfaces: wasm.SurfaceDebug[];
+  }
+  export interface State {
+    hover?: wasm.SurfaceDebug;
   }
 }
-export class DirectDraw extends preact.Component<DirectDraw.Props> {
+export class DirectDraw extends preact.Component<DirectDraw.Props, DirectDraw.State> {
+  canvasContainer = (parent: HTMLElement | null) => {
+    if (!parent) return;
+    parent.appendChild(this.state.hover!.canvas);
+  };
+
   render() {
-    const rows = this.props.state.surfaces.map((surface) => {
+    const rows = this.props.surfaces.map((surface) => {
       return (
-        <tr>
+        <tr
+          onMouseEnter={() => this.setState({ hover: surface })}
+          onMouseLeave={() => this.setState({ hover: undefined })}
+        >
           <td style={{ textAlign: 'right' }}>
             <Number digits={8} {...this.props}>{surface.ptr}</Number>
           </td>
@@ -34,6 +45,7 @@ export class DirectDraw extends preact.Component<DirectDraw.Props> {
           </tr>
           {rows}
         </table>
+        {this.state.hover && <div ref={this.canvasContainer} />}
       </div>
     );
   }
diff --git a/web/debugger/debugger.tsx b/web/debugger/debugger.tsx
index 61b0e4ec..f567308b 100644
--- a/web/debugger/debugger.tsx
+++ b/web/debugger/debugger.tsx
@@ -285,7 +285,7 @@ export class Debugger extends preact.Component<Debugger.Props, Debugger.State> {
                 />
               ),
 
-              directdraw: () => <DirectDraw state={emulator.emu.directdraw_state()} {...this.memoryView} />,
+              directdraw: () => <DirectDraw surfaces={emulator.emu.direct_draw_surfaces()} {...this.memoryView} />,
             }}
             selected={this.state.selectedTab}
             switchTab={(selectedTab) => this.setState({ selectedTab })}
diff --git a/web/glue/src/debugger.rs b/web/glue/src/debugger.rs
index 1db8016a..44a6a22d 100644
--- a/web/glue/src/debugger.rs
+++ b/web/glue/src/debugger.rs
@@ -1,6 +1,9 @@
 //! API used specifically for debugging the emulator.
 
-use tsify::Tsify;
+use tsify::{JsValueSerdeExt, Tsify};
+use wasm_bindgen::prelude::*;
+
+use crate::host::WebSurface;
 
 /// Registers are serialized as a JSON blob.
 #[derive(Tsify, serde::Serialize)]
@@ -51,8 +54,13 @@ impl Registers {
     }
 }
 
+#[wasm_bindgen(typescript_custom_section)]
+const SURFACE_META_TS: &'static str = r#"
+export type SurfaceDebug = DirectDrawSurfaceMeta & { canvas: HTMLCanvasElement };
+"#;
+
 #[derive(Tsify, serde::Serialize)]
-pub struct DirectDrawSurface {
+pub struct DirectDrawSurfaceMeta {
     pub ptr: u32,
     pub width: u32,
     pub height: u32,
@@ -64,27 +72,29 @@ pub struct DirectDrawSurface {
     // pub attached: u32,
 }
 
-#[derive(Tsify, serde::Serialize)]
-#[tsify(into_wasm_abi)]
-pub struct DirectDrawState {
-    surfaces: Vec<DirectDrawSurface>,
-}
+pub fn surfaces_from_machine(machine: &win32::Machine) -> Vec<JsValue> {
+    machine
+        .state
+        .ddraw
+        .surfaces
+        .iter()
+        .map(|(&ptr, s)| {
+            let meta = DirectDrawSurfaceMeta {
+                ptr,
+                width: s.width,
+                height: s.height,
+                bytes_per_pixel: s.bytes_per_pixel,
+                primary: s.primary,
+            };
 
-impl DirectDrawState {
-    pub fn from_machine(machine: &win32::Machine) -> DirectDrawState {
-        let ddraw = &machine.state.ddraw;
-        DirectDrawState {
-            surfaces: ddraw
-                .surfaces
-                .iter()
-                .map(|(&ptr, s)| DirectDrawSurface {
-                    ptr,
-                    width: s.width,
-                    height: s.height,
-                    bytes_per_pixel: s.bytes_per_pixel,
-                    primary: s.primary,
-                })
-                .collect(),
-        }
-    }
+            // Attach canvas property to JS object we create from meta.
+            let val = JsValue::from_serde(&meta).unwrap();
+            let web_surface =
+                unsafe { &*(s.host.as_ref() as *const dyn win32::Surface as *const WebSurface) };
+            js_sys::Reflect::set(&val, &"canvas".into(), &web_surface.canvas.clone().into())
+                .unwrap();
+
+            val
+        })
+        .collect()
 }
diff --git a/web/glue/src/emulator.rs b/web/glue/src/emulator.rs
index 80316384..e8db275c 100644
--- a/web/glue/src/emulator.rs
+++ b/web/glue/src/emulator.rs
@@ -124,8 +124,8 @@ impl Emulator {
         win32::winapi::trace::set_scheme(scheme);
     }
 
-    pub fn directdraw_state(&self) -> debugger::DirectDrawState {
-        debugger::DirectDrawState::from_machine(&self.machine)
+    pub fn direct_draw_surfaces(&self) -> Vec<JsValue> {
+        debugger::surfaces_from_machine(&self.machine)
     }
 }
 
diff --git a/web/glue/src/host.rs b/web/glue/src/host.rs
index d23e4c4a..9b6f5749 100644
--- a/web/glue/src/host.rs
+++ b/web/glue/src/host.rs
@@ -16,9 +16,9 @@ use win32::{Stat, StatKind, WindowsPath};
 ///
 /// https://developer.chrome.com/blog/taking-advantage-of-gpu-acceleration-in-the-2d-canvas
 /// https://web.dev/articles/canvas-performance
-struct WebSurface {
+pub struct WebSurface {
     _hwnd: u32,
-    canvas: web_sys::HtmlCanvasElement,
+    pub canvas: web_sys::HtmlCanvasElement,
     width: u32,
     ctx: web_sys::CanvasRenderingContext2d,
     screen: web_sys::CanvasRenderingContext2d,