From 008428800463b4fb15781b81b4f474bea67416fb Mon Sep 17 00:00:00 2001
From: Marc Trudel <mtrudel@wizcorp.jp>
Date: Thu, 25 Mar 2021 17:17:45 +0900
Subject: [PATCH] chores: MD settings, no recompile module on init

- Settings for Mega Drive were missing from the API
- Compile the module on the first initialize only; recreating a new
  binary is costly, and likely will consume a lot more memory than
  needed.
---
 higan/target-web/api.d.ts | 14 +++++++++++++
 higan/target-web/api.js   | 42 +++++++++++++++++++++++++++------------
 2 files changed, 43 insertions(+), 13 deletions(-)

diff --git a/higan/target-web/api.d.ts b/higan/target-web/api.d.ts
index 8c46c79..283f7a4 100644
--- a/higan/target-web/api.d.ts
+++ b/higan/target-web/api.d.ts
@@ -86,6 +86,20 @@ export const Settings: SettingsEntries = {
        */
       SyncOnce: 'cpu/synconce'
     }
+  },
+  [Emulator.MegaDrive]: {
+    PPU: {
+      /**
+       * Skip frame. When enabled, skip the rendering of half the frames, which
+       * may provide slighgtly better performance.
+       */
+      Skipframe: 'ppu/skipframe',
+      /**
+       * Skip DMA execution when the DMA is inactive or disabled. Off by default, as
+       * it can break a number of games.
+       */
+      OptimizeSteps: 'vdp/optimizeSteps'
+    }
   }
 }
 
diff --git a/higan/target-web/api.js b/higan/target-web/api.js
index f269617..9d0012e 100644
--- a/higan/target-web/api.js
+++ b/higan/target-web/api.js
@@ -12,7 +12,7 @@ export const EmulatorEvent = {
 }
 
 export const Settings = {
-  ['Super Famicom']: {
+  [Emulator.SuperFamicom]: {
     CPU: {
       Lockstep: 'cpu/lockstep',
       Fastmath: 'cpu/fastmath',
@@ -28,7 +28,7 @@ export const Settings = {
       Skipframe: 'ppu/skipframe'
     }
   },
-  ['Famicom']: {
+  [Emulator.Famicom]: {
     PPU: {
       Skipframe: 'ppu/skipframe',
       Overscan: 'ppu/overscan'
@@ -36,6 +36,12 @@ export const Settings = {
     CPU: {
       SyncOnce: 'cpu/synconce'
     }
+  },
+  [Emulator.MegaDrive]: {
+    PPU: {
+      Skipframe: 'ppu/skipframe',
+      OptimizeSteps: 'vdp/optimizeSteps'
+    }
   }
 }
 
@@ -132,6 +138,26 @@ byuu.initialize = async function (parent, ctxOptions) {
     throw new Error('The DOM ID attribute "canvas" is reserved by byuu for it\'s own canvas')
   }
 
+  function finalize() {
+    lib.initialize(document.title || 'byuu')
+  
+    // Set callbacks, patch into event emission
+    lib.onFrameStart(() => byuu.emit('frame.start'))
+    lib.onFrameEnd(() => byuu.emit('frame.end'))
+    lib.onResize((width, height) => {
+      byuu.displayRatio = width / height;
+      byuu.emit('resize', { width, height });
+    })
+    
+    initialized = true
+  }
+
+  // If the module was initialized at least once, do not reload;
+  // immediately complete the initialization steps, and return;
+  if (initialized) {
+    return finalize();
+  }
+
   return new Promise((resolve) => {
     // Module isn't a real promise, and unless we set
     // things as follow the code seem to tight-loop
@@ -146,17 +172,7 @@ byuu.initialize = async function (parent, ctxOptions) {
       canvas
     }).then((result) => {
       lib = result
-      lib.initialize(document.title || 'byuu')
-  
-      // Set callbacks, patch into event emission
-      lib.onFrameStart(() => byuu.emit('frame.start'))
-      lib.onFrameEnd(() => byuu.emit('frame.end'))
-      lib.onResize((width, height) => {
-        byuu.displayRatio = width / height;
-        byuu.emit('resize', { width, height });
-      })
-      
-      initialized = true
+      finalize()
       resolve()
     })
   })