From a813f73557461bb1186c54fcfff47527efdfc9ac Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Fri, 11 Apr 2025 04:57:26 -0500
Subject: [PATCH] improve cmd stream hex view visual aid

definitely not vspcplay
---
 src/engine/cmdStream.cpp | 47 +++++++++++++++++++++++++++++++++++++++-
 src/engine/cmdStream.h   |  5 +++++
 src/gui/csPlayer.cpp     | 27 +++++------------------
 3 files changed, 57 insertions(+), 22 deletions(-)

diff --git a/src/engine/cmdStream.cpp b/src/engine/cmdStream.cpp
index c2821ca0b..9098e8f57 100644
--- a/src/engine/cmdStream.cpp
+++ b/src/engine/cmdStream.cpp
@@ -39,6 +39,10 @@ unsigned char* DivCSPlayer::getData() {
   return b;
 }
 
+unsigned short* DivCSPlayer::getDataAccess() {
+  return bAccessTS;
+}
+
 size_t DivCSPlayer::getDataLen() {
   return bLen;
 }
@@ -59,10 +63,19 @@ unsigned char* DivCSPlayer::getFastCmds() {
   return fastCmds;
 }
 
+unsigned int DivCSPlayer::getCurTick() {
+  return curTick;
+}
+
 void DivCSPlayer::cleanup() {
-  delete b;
+  delete[] b;
   b=NULL;
   bLen=0;
+
+  if (bAccessTS) {
+    delete[] bAccessTS;
+    bAccessTS=NULL;
+  }
 }
 
 bool DivCSPlayer::tick() {
@@ -82,6 +95,8 @@ bool DivCSPlayer::tick() {
         break;
       }
 
+      unsigned int accessTSBegin=stream.tell();
+
       chan[i].trace[chan[i].tracePos++]=chan[i].readPos;
       if (chan[i].tracePos>=DIV_MAX_CSTRACE) {
         chan[i].tracePos=0;
@@ -97,9 +112,11 @@ bool DivCSPlayer::tick() {
         chan[i].vibratoPos=0;
       } else if (next>=0xd0 && next<=0xdf) {
         command=fastCmds[next&15];
+        bAccessTS[fastCmdsOff+(next&15)]=curTick;
       } else if (next>=0xe0 && next<=0xef) { // preset delay
         chan[i].waitTicks=fastDelays[next&15];
         chan[i].lastWaitLen=chan[i].waitTicks;
+        bAccessTS[fastDelaysOff+(next&15)]=curTick;
       } else switch (next) {
         case 0xb4: // note on null
           e->dispatchCmd(DivCommand(DIV_CMD_NOTE_ON,i,DIV_NOTE_NULL));
@@ -126,6 +143,7 @@ bool DivCSPlayer::tick() {
         case 0xd8: case 0xd9: case 0xda: case 0xdb:
         case 0xdc: case 0xdd: case 0xde: case 0xdf:
           command=fastCmds[next-0xd0];
+          
           break;
         case 0xf0: // placeholder
           stream.readC();
@@ -529,6 +547,12 @@ bool DivCSPlayer::tick() {
         }
       }
 
+      for (unsigned int j=accessTSBegin; j<stream.tell(); j++) {
+        if (j<bLen) {
+          bAccessTS[j]=curTick;
+        }
+      }
+
       if (mustTell) chan[i].readPos=stream.tell();
     }
 
@@ -597,6 +621,20 @@ bool DivCSPlayer::tick() {
     }
   }
 
+  // cycle over access times in order to ensure deltas are always higher than 256
+  // (and prevent spurious highlights)
+  for (int i=0; i<16; i++) {
+    short delta=(((short)(curTick&0xffff))-(short)bAccessTS[deltaCyclePos]);
+    if (delta>256) {
+      bAccessTS[deltaCyclePos]=curTick-512;
+    }
+    if (++deltaCyclePos>=bLen) {
+      deltaCyclePos=0;
+    }
+  }
+
+  curTick++;
+
   return ticked;
 }
 
@@ -622,7 +660,9 @@ bool DivCSPlayer::init() {
     chan[i].readPos=chan[i].startPos;
   }
 
+  fastDelaysOff=stream.tell();
   stream.read(fastDelays,16);
+  fastCmdsOff=stream.tell();
   stream.read(fastCmds,16);
 
   // initialize state
@@ -636,6 +676,11 @@ bool DivCSPlayer::init() {
   }
 
   arpSpeed=1;
+  bAccessTS=new unsigned short[bLen];
+  // this value ensures all deltas are higher than 256
+  memset(bAccessTS,0xc0,bLen*sizeof(unsigned short));
+  curTick=0;
+  deltaCyclePos=0;
 
   return true;
 }
diff --git a/src/engine/cmdStream.h b/src/engine/cmdStream.h
index 72f458067..f879240f1 100644
--- a/src/engine/cmdStream.h
+++ b/src/engine/cmdStream.h
@@ -77,6 +77,7 @@ struct DivCSChannelState {
 class DivCSPlayer {
   DivEngine* e;
   unsigned char* b;
+  unsigned short* bAccessTS;
   size_t bLen;
   SafeReader stream;
   DivCSChannelState chan[DIV_MAX_CHANS];
@@ -84,21 +85,25 @@ class DivCSPlayer {
   unsigned char fastCmds[16];
   unsigned char arpSpeed;
   unsigned int fileChans;
+  unsigned int curTick, fastDelaysOff, fastCmdsOff, deltaCyclePos;
 
   short vibTable[64];
   public:
     unsigned char* getData();
+    unsigned short* getDataAccess();
     size_t getDataLen();
     DivCSChannelState* getChanState(int ch);
     unsigned int getFileChans();
     unsigned char* getFastDelays();
     unsigned char* getFastCmds();
+    unsigned int getCurTick();
     void cleanup();
     bool tick();
     bool init();
     DivCSPlayer(DivEngine* en, unsigned char* buf, size_t len):
       e(en),
       b(buf),
+      bAccessTS(NULL),
       bLen(len),
       stream(buf,len) {}
 };
diff --git a/src/gui/csPlayer.cpp b/src/gui/csPlayer.cpp
index 82127561a..78328d1db 100644
--- a/src/gui/csPlayer.cpp
+++ b/src/gui/csPlayer.cpp
@@ -478,22 +478,12 @@ void FurnaceGUI::drawCSPlayer() {
 
             // content
             unsigned char* buf=cs->getData();
+            unsigned short* accessTS=cs->getDataAccess();
+            unsigned int csTick=cs->getCurTick();
+            const float fadeTime=64.0f;
             size_t bufSize=cs->getDataLen();
             csClipper.Begin((bufSize+15)>>4,ImGui::GetTextLineHeightWithSpacing());
             while (csClipper.Step()) {
-              //std::vector<int> highlightsUnsorted;
-              std::vector<int> highlights;
-              int nextHighlight=-1;
-              int highlightPos=0;
-
-              for (int i=0; i<chans; i++) {
-                DivCSChannelState* state=cs->getChanState(i);
-                if ((int)state->readPos>=(csClipper.DisplayStart<<4) && (int)state->readPos<=(csClipper.DisplayEnd<<4)) {
-                  highlights.push_back(state->readPos);
-                }
-              }
-              if (!highlights.empty()) nextHighlight=highlights[0];
-
               for (int i=csClipper.DisplayStart; i<csClipper.DisplayEnd; i++) {
                 ImGui::TableNextRow();
                 ImGui::TableNextColumn();
@@ -504,14 +494,9 @@ void FurnaceGUI::drawCSPlayer() {
                   int pos=(i<<4)|j;
                   ImGui::TableNextColumn();
                   if (pos>=(int)bufSize) continue;
-                  if (pos==nextHighlight) {
-                    ImGui::TableSetBgColor(ImGuiTableBgTarget_CellBg,ImGui::GetColorU32(ImGuiCol_HeaderActive));
-                    highlightPos++;
-                    if (highlightPos>=(int)highlights.size()) {
-                      nextHighlight=-1;
-                    } else {
-                      nextHighlight=highlights[highlightPos];
-                    }
+                  float cellAlpha=(float)(fadeTime-(((short)(csTick&0xffff))-(short)accessTS[pos]))/fadeTime;
+                  if (cellAlpha>0.0f) {
+                    ImGui::TableSetBgColor(ImGuiTableBgTarget_CellBg,ImGui::GetColorU32(ImGuiCol_HeaderActive,cellAlpha));
                   }
                   ImGui::Text("%.2X",buf[pos]);
                 }