load/saveControlsState() support in recorder

doc/notes.txt

@@ -54,6 +54,7 @@ TODO:
 - make sure we don't store files in local storage unnecc.
 - state buffer/replay
 - intro/help text for each platform
+- make sure controls work with replay feature (we'll have to save control state every frame)
 
 FYI: Image links for the books on http://8bitworkshop.com/ are broken
 On the website the additional grey spacing next to the program line numbers is not dynamically resized when the web browser window size is changed.  Intentional?

src/baseplatform.ts

@@ -19,8 +19,16 @@ export interface CpuState {
   A:number, X:number, Y:number, SP:number, R:boolean, 
   N,V,D,Z,C:boolean*/
 };
-export interface EmuState {c:CpuState, b?:number[]};
+export interface EmuState {
-export type DisasmLine = {line:string, nbytes:number};
+  c:CpuState,	 // CPU state
+  b?:number[]	 // RAM
+};
+export interface EmuControlsState {
+}
+export type DisasmLine = {
+  line:string,
+  nbytes:number
+};
 
 export interface Platform {
   start() : void;
@@ -60,6 +68,8 @@ export interface Platform {
   
   setRecorder?(recorder : EmuRecorder) : void;
   advance?(novideo? : boolean) : void;
+  loadControlsState?(state : EmuControlsState) : void;
+  saveControlsState?() : EmuControlsState;
 }
 
 export interface Preset {
@@ -80,7 +90,7 @@ type BreakpointCallback = (EmuState) => void;
 
 export interface EmuRecorder {
   frameRequested() : boolean;
-  recordFrame(platform : Platform, state : EmuState);
+  recordFrame(state : EmuState);
 }
 
 /////
@@ -132,7 +142,7 @@ abstract class BaseDebugPlatform {
   updateRecorder() {
     // are we recording and do we need to save a frame?
     if (this.recorder && (<Platform><any>this).isRunning() && this.recorder.frameRequested()) {
-      this.recorder.recordFrame(<Platform><any>this, this.saveState());
+      this.recorder.recordFrame(this.saveState());
     }
   }
 }

src/platform/apple2.ts

@@ -335,6 +335,14 @@ var Apple2Platform = function(mainElement) {
       lc:{s:auxRAMselected,b:auxRAMbank,w:writeinhibit},
     };
   }
+  this.loadControlsState = function(state) {
+    kbdlatch = state.kbd;
+  }
+  this.saveControlsState = function() {
+    return {
+      kbd:kbdlatch,
+    };
+  }
   this.getCPUState = function() {
     return cpu.saveState();
   }

src/recorder.ts

@@ -0,0 +1,83 @@
+
+import { Platform, EmuState, EmuControlsState, EmuRecorder } from "./baseplatform";
+
+export class StateRecorderImpl implements EmuRecorder {
+    checkpointInterval : number = 60;
+    callbackStateChanged : () => void;
+    maxCheckpoints : number = 120;
+    
+    platform : Platform;
+    buffer : EmuState[];
+    controls : EmuControlsState[];
+    frameCount : number;
+    lastSeekFrame : number = -1;
+    
+    constructor(platform : Platform) {
+        this.reset();
+        this.platform = platform;
+    }
+
+    reset() {
+        this.buffer = [];
+        this.controls = [];
+        this.frameCount = 0;
+        this.lastSeekFrame = -1;
+    }
+
+    frameRequested() : boolean {
+        // buffer full?
+        if (this.buffer.length >= this.maxCheckpoints) {
+            return false;
+        }
+        // record the control state, if available
+        if (this.platform.saveControlsState) {
+            this.controls.push(this.platform.saveControlsState());
+        }
+        // pick up where we left off, if we used the seek function
+        if (this.lastSeekFrame >= 0) {
+            this.frameCount = this.lastSeekFrame;
+            this.lastSeekFrame = -1;
+            // truncate buffers
+            this.buffer = this.buffer.slice(0, Math.floor((this.frameCount + this.checkpointInterval - 1) / this.checkpointInterval));
+            this.controls = this.controls.slice(0, this.frameCount);
+        }
+        // time to save next frame?
+        this.frameCount++;
+        if (this.callbackStateChanged) {
+            this.callbackStateChanged();
+        }
+        return (this.frameCount % this.checkpointInterval) == 0;
+    }
+    
+    numFrames() : number {
+        return this.frameCount;
+    }
+    
+    recordFrame(state : EmuState) {
+        this.buffer.push(state);
+    }
+
+    getStateAtOrBefore(frame : number) : {frame : number, state : EmuState} {
+        var bufidx = Math.floor(frame / this.checkpointInterval);
+        var foundidx = bufidx < this.buffer.length ? bufidx : this.buffer.length-1;
+        var foundframe = foundidx * this.checkpointInterval;
+        return {frame:foundframe, state:this.buffer[foundidx]};
+    }
+
+    loadFrame(seekframe : number) {
+        let {frame,state} = this.getStateAtOrBefore(seekframe);
+        if (state) {
+            this.platform.pause();
+            this.platform.loadState(state);
+            while (frame < seekframe) {
+                if (frame < this.controls.length) {
+                    this.platform.loadControlsState(this.controls[frame]);
+                }
+                this.platform.advance(true); // TODO: infinite loop?
+                frame++;
+            }
+            this.platform.advance();
+            this.lastSeekFrame = seekframe;
+        }
+    }
+}

src/ui.ts

@@ -30,7 +30,7 @@ var current_project : CodeProject;	// current CodeProject object
 
 var projectWindows : ProjectWindows;	// window manager
 
-var stateRecorder : StateRecorderImpl = new StateRecorderImpl();
+var stateRecorder : StateRecorderImpl;
 
 // TODO: codemirror multiplex support?
 var TOOL_TO_SOURCE_STYLE = {
@@ -771,7 +771,7 @@ function setupDebugControls(){
     };
     replayslider.on('input', function(e) {
       _pause();
-      stateRecorder.loadFrame(platform, (<any>e.target).value);
+      stateRecorder.loadFrame((<any>e.target).value);
     });
     $("#replay_bar").show();
   }
@@ -908,6 +908,7 @@ function addPageFocusHandlers() {
 function startPlatform() {
   if (!PLATFORMS[platform_id]) throw Error("Invalid platform '" + platform_id + "'.");
   platform = new PLATFORMS[platform_id]($("#emulator")[0]);
+  stateRecorder = new StateRecorderImpl(platform);
   PRESETS = platform.getPresets();
   if (qs['file']) {
     // start platform and load file