# HG changeset patch
# User sl
# Date 1401392527 -7200
# Node ID be04ffbb561cdefe87a2f222ca92df5b4d32cae3
# Parent  79801cc3bc947f04705a594970aefc780d26a2cd
Trying to optimize our swap buffer implementation by sending only the pixel
block which ave changed. No joy so far.

diff -r 79801cc3bc94 -r be04ffbb561c MiniDisplay/FutabaVfd.cpp
--- a/MiniDisplay/FutabaVfd.cpp	Thu May 29 19:46:57 2014 +0200
+++ b/MiniDisplay/FutabaVfd.cpp	Thu May 29 21:42:07 2014 +0200
@@ -73,7 +73,13 @@
 
 GP1212A01A::GP1212A01A():
 	iDisplayPositionX(0),iDisplayPositionY(0),
-    iOffScreenMode(true),iFrameBuffer(NULL),iRequest(ERequestNone),iPowerOn(false)
+    iOffScreenMode(true),
+    iFrameAlpha(NULL),
+    iFrameBeta(NULL),
+    iCurrentFrame(NULL),
+    iNextFrame(NULL),
+    iNeedFullFrameUpdate(true),
+    iRequest(ERequestNone),iPowerOn(false)
 	{
 	//ResetBuffers();
 	}
@@ -82,8 +88,16 @@
 */
 GP1212A01A::~GP1212A01A()
 	{
-	delete iFrameBuffer;
-	iFrameBuffer=NULL;
+    delete iFrameAlpha;
+    iFrameAlpha=NULL;
+    //
+    delete iFrameBeta;
+    iFrameBeta=NULL;
+    //
+    iNextFrame=NULL;
+    iCurrentFrame=NULL;
+    //
+    iNeedFullFrameUpdate=true;
 	}
 
 /**
@@ -93,9 +107,20 @@
 	int success = HidDevice::Open(KFutabaVendorId,KFutabaProductIdGP1212A01A,NULL);
 	if (success)
 		{
-		delete iFrameBuffer;
-		iFrameBuffer = NULL;
-		iFrameBuffer=new BitArray(KGP12xFrameBufferPixelCount);
+        //Allocate both frames
+        delete iFrameAlpha;
+        iFrameAlpha=NULL;
+        iFrameAlpha=new BitArray(KGP12xFrameBufferPixelCount);
+        //
+        delete iFrameBeta;
+        iFrameBeta=NULL;
+        iFrameBeta=new BitArray(KGP12xFrameBufferPixelCount);
+        //
+        iCurrentFrame=iFrameAlpha;
+        iNextFrame=iFrameBeta;
+        //To make sure it is synced properly
+        iNeedFullFrameUpdate=true;
+        //
 		SetNonBlocking(1);
         //Since we can't get our display position we force it to our default
 		//This makes sure frames are in sync from the start
@@ -112,17 +137,17 @@
 	//
 	//int byteOffset=(aX*HeightInPixels()+aY)/8;
 	//int bitOffset=(aX*HeightInPixels()+aY)%8;
-	//iFrameBuffer[byteOffset] |= ( (aOn?0x01:0x00) << bitOffset );
+    //iNextFrame[byteOffset] |= ( (aOn?0x01:0x00) << bitOffset );
 
     if (iOffScreenMode)
         {
         if (aOn)
             {
-            iFrameBuffer->SetBit(aX*HeightInPixels()+aY);
+            iNextFrame->SetBit(aX*HeightInPixels()+aY);
             }
         else
             {
-            iFrameBuffer->ClearBit(aX*HeightInPixels()+aY);
+            iNextFrame->ClearBit(aX*HeightInPixels()+aY);
             }
         }
     else
@@ -141,7 +166,7 @@
 		{
 		for (int j=0;j<aSrcHeight;j++)
 			{
-			iFrameBuffer->SetBitValue((aTargetX+i)*HeightInPixels()+aTargetY+j,aBitmap[+i*aSrcHeight+j]);
+            iNextFrame->SetBitValue((aTargetX+i)*HeightInPixels()+aTargetY+j,aBitmap[+i*aSrcHeight+j]);
 			}
 		}
 	}
@@ -161,7 +186,7 @@
 
     if (iOffScreenMode)
         {
-        memset(iFrameBuffer->Ptr(),aPattern,FrameBufferSizeInBytes());
+        memset(iNextFrame->Ptr(),aPattern,FrameBufferSizeInBytes());
         }
     else
         {
@@ -259,10 +284,10 @@
 */
 void GP1212A01A::Clear()
 	{
-	//memset(iFrameBuffer->Ptr(),0x00,FrameBufferSizeInBytes());
+    //memset(iNextFrame->Ptr(),0x00,FrameBufferSizeInBytes());
     if (iOffScreenMode)
         {
-        iFrameBuffer->ClearAll();
+        iNextFrame->ClearAll();
         }
     else
         {
@@ -338,16 +363,70 @@
 	if (OffScreenMode())
 		{
 		//Send host back buffer to device back buffer
-		SetPixelBlock(0,0,63,FrameBufferSizeInBytes(),iFrameBuffer->Ptr());
+        if (iNeedFullFrameUpdate)
+            {
+            //TODO: enable this once SendModifiedPixelBlocks works
+            //iNeedFullFrameUpdate=false;
+            SetPixelBlock(0,0,63,FrameBufferSizeInBytes(),iNextFrame->Ptr());
+            }
+        else
+            {
+            SendModifiedPixelBlocks();
+            }
 		//Swap device front and back buffer
 		SetDisplayPosition(iDisplayPositionX,OffScreenY());
 		//Swap host buffers
-		//unsigned char* backBuffer=iBackBuffer;
-		//iBackBuffer = iFrontBuffer;
-		//iFrontBuffer = backBuffer;
+        BitArray* nextFrame=iCurrentFrame;
+        iCurrentFrame = iNextFrame;
+        iNextFrame = nextFrame;
 		}
 	}
 
+
+/**
+ * @brief GP1212A01A::SendModifiedPixelBlocks
+ * Compare our back and front buffer and send to the device only the modified pixels.
+ * TODO: Get this working at some point.
+ */
+void GP1212A01A::SendModifiedPixelBlocks()
+    {
+    //The largest pixel block we can sanely send with one report is 16*16
+    //const int KBlocksPerRow = WidthInPixels()/16; //16
+    //const int KBlocksPerColumn = HeightInPixels()/16; //4
+
+    int w=WidthInPixels();
+    int h=HeightInPixels();
+
+    BitArray block(16*16);
+    //TODO: optimize with memcmp and 16 inc
+    for (int i=0;i<w;i+=16)
+        {
+        for (int j=0;j<h;j+=16)
+            {
+            //aX*HeightInPixels()+aY
+            int offset=(i*w/8)+(j/8);
+            if (memcmp(iNextFrame->Ptr()+offset,iCurrentFrame->Ptr()+offset,32 /*(16*16/8)*/))
+                {
+                //We need to update that block
+
+                for (int x=i;x<i+16;x++)
+                    {
+                    for (int y=i;y<j+16;y++)
+                        {
+                        block.SetBitValue((x-i)*h+(y-j),(*iNextFrame)[x*h+y]);
+                        }
+                    }
+                SetPixelBlock(i,j,15,32,block.Ptr());
+                //SetDisplayPosition(iDisplayPositionX,OffScreenY());
+                //SetDisplayPosition(iDisplayPositionX,OffScreenY());
+
+                //SetPixelBlock(i,j,15,32,iNextFrame->Ptr()+offset);
+                }
+            }
+        }
+
+    }
+
 /**
 Translate the given pixel coordinate according to our off screen mode.
 */
@@ -365,8 +444,8 @@
 */
 void GP1212A01A::ResetBuffers()
 	{
-	//iFrameBuffer->ClearAll();
-	//memset(iFrameBuffer,0x00,sizeof(iFrameBuffer));
+    //iNextFrame->ClearAll();
+    //memset(iFrameAlpha,0x00,sizeof(iFrameAlpha));
 	//memset(iFrameBeta,0x00,sizeof(iFrameBeta));
 	}
 
diff -r 79801cc3bc94 -r be04ffbb561c MiniDisplay/FutabaVfd.h
--- a/MiniDisplay/FutabaVfd.h	Thu May 29 19:46:57 2014 +0200
+++ b/MiniDisplay/FutabaVfd.h	Thu May 29 21:42:07 2014 +0200
@@ -166,7 +166,7 @@
     Request AttemptRequestCompletion();
     FutabaVfdReport& InputReport() {return iInputReport;}
     bool PowerOn(){return iPowerOn;}
-	
+
 private:
 	enum DW
 		{
@@ -179,6 +179,7 @@
 	void SendClearCommand();
 	void OffScreenTranslation(unsigned char& aX, unsigned char& aY);
 	void ResetBuffers();
+    void SendModifiedPixelBlocks();
 
 private:
 	unsigned char iDisplayPositionX;
@@ -190,7 +191,13 @@
 	//FutabaVfdReport iReport;
 	///
 	//unsigned char iFrameBuffer[256*64];
-	BitArray* iFrameBuffer;
+    BitArray* iNextFrame;
+    BitArray* iCurrentFrame;
+    //
+    BitArray* iFrameAlpha;
+    BitArray* iFrameBeta;
+    //
+    bool iNeedFullFrameUpdate;
 	//unsigned char iFrameBeta[256*64];
 	//unsigned char *iFrontBuffer;
 	//unsigned char *iBackBuffer;