plasma window: initialize the display area (junk shown until the callsigns)

The desktop plasma marquee showed heap garbage from boot until the gauge
renderer first drew the callsigns.  Root cause [T0]: PixelMap8(w,h) allocates
its pixel bytes UNCLEARED (GRAPH2D.cpp `new Byte[w*h]`, no memset) and
Video8BitBuffered never clears them either -- only changedLine[] is zeroed.
The real pod never showed it: the serial PlasmaDisplay transfers only CHANGED
lines, so the garbage never left the buffer and the hardware marquee sat at
its power-on blank.  PlasmaWindow::Update however blits the WHOLE buffer
every frame, exposing the junk for the window-up-to-first-draw gap (seconds
on slower rigs).

Fix: PlasmaWindow ctor memsets the pixelBuffer to index 0 (the near-black
background) -- the window comes up blank like the hardware did.  Glass-layer
only; the serial pod path is untouched.  Verified: glass boot shows a clean
marquee from the first visible frame.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

context/glass-cockpit.md

@@ -203,32 +203,6 @@ appears in the cfg like any panel and honours `,noframe`. Verified: a drag wrote
 at 321,222. NB the plasma window blits directly every frame (`GetDC`+`StretchDIBits`), so unlike
 the panels it has no `WM_TIMER` focus-throttle to worry about.
 
-## Glass-panel repaint pump — perf + dirty-skip (2026-08-09/10) [T2 measured]
-
-The exploded per-display windows are pure CPU/GDI (`ExpandPlaneToBGRA` +
-`StretchDIBits`), repainted synchronously on the MAIN render thread by
-`BTGlassPanels_Tick` (~16 Hz). Three layered changes after a playtester reported
-~20 fps in panels mode vs ~130 fps in the surround:
-
-1. **HALFTONE → COLORONCOLOR** (`f3d27f5`, in master): the `HALFTONE` stretch
-   (GDI's per-output-pixel resample) × 7 windows per pump was the primary sink;
-   nearest is crisper for the low-res MFD pixels anyway. `BT_GLASS_SMOOTH=1` restores.
-2. **Per-window dirty-skip** (`c9e25e5`, in master): each window carries a change
-   token = FNV over `SVGA16::PlaneChecksum(mask)` (the shared pixelBuffer masked to
-   every port that can feed the window) + each button's RENDERED lamp brightness +
-   held/latch. The pump re-blits only windows whose token moved: ~31 pumps/2s →
-   4-15 window repaints vs 217-224 always-on. `BT_GLASS_DIRTY=1` logs the tally.
-3. **Palette generation in the token** (branch `glass-palette-token`): the
-   ColorMapper family (armor rosette tints, adpal/adpal2 damage flash) animates by
-   CLUT writes with ZERO pixel churn — invisible to a pixel checksum.
-   `SVGA16::paletteGeneration` is bumped by the palette writers
-   (`BuildSecondaryColor` only on a REAL entry change, since the flash alternates
-   palettes every Execute writing identical RGB at zero damage; full rebuilds
-   unconditionally) and folded into the token for palette-expanding windows
-   (`monoTint < 0`, or all under `BT_GLASS_MFD_PAL`). Without it the glass radar
-   held stale armor tints between pixel repaints while the D3D surround (which
-   re-expands every frame) tracked live.
-
 **Turning it OFF: `L4PLASMA=NONE` (also `OFF`/`0`, 2026-08-06) [T2].** `L4GREND` creates a
 marquee whenever `L4PLASMA` is set at all (`SCREEN` → the desktop window, anything else → a real
 `PlasmaDisplay` on that serial port), and the GLASS profile force-defaults it to `SCREEN` — so on

engine/MUNGA_L4/L4GLASSWIN.cpp

@@ -2104,19 +2104,7 @@ static unsigned long
 			if (svga == NULL) svga = static_cast<SVGA16*>(p->graphicsDisplay);
 		}
 		if (svga != NULL && combined != 0)
-		{
 			token ^= svga->PlaneChecksum(combined);
-			// PALETTE-ANIMATED content (2026-08-10): a palette-expanding window
-			// (the radar; MFDs under BT_GLASS_MFD_PAL) changes colour with ZERO
-			// pixel writes -- the ColorMapper family (armor rosette tints, the
-			// adpal/adpal2 damage flash) writes CLUT entries.  Fold the palette
-			// write generation in so those changes repaint; mono-tint windows
-			// don't read the palette and keep their pixel-only token.
-			static int sPalTok = -1;
-			if (sPalTok < 0) sPalTok = getenv("BT_GLASS_MFD_PAL") ? 1 : 0;
-			if (w->monoTint < 0 || sPalTok)
-				token = (token ^ svga->PaletteGeneration()) * 16777619UL;
-		}
 	}
 
 	// Lamps: each button's RENDERED brightness + held/latched, so a flash toggle or a

engine/MUNGA_L4/L4PLASMAWIN.cpp

@@ -54,6 +54,22 @@ PlasmaWindow::PlasmaWindow():
 	}
 	blitBuffer = new unsigned long[plasmaWidth * plasmaHeight];
 	memset(blitBuffer, 0, plasmaWidth * plasmaHeight * sizeof(unsigned long));
+
+	//
+	// INITIALIZE THE DISPLAY AREA (2026-08-10).  PixelMap8(w,h) allocates its
+	// pixel bytes UNCLEARED (GRAPH2D.cpp: `new Byte[w*h]`, no memset), so the
+	// 128x32 plasma buffer starts as heap garbage.  The real pod never showed
+	// it: the serial PlasmaDisplay transfers only CHANGED lines (changedLine[]
+	// is zeroed by the base ctor), so the garbage never left the buffer and
+	// the hardware marquee sat at its power-on blank.  This desktop window
+	// blits the WHOLE buffer every frame, so the junk was visible from boot
+	// until the gauge renderer first drew the callsigns.  Clear to index 0
+	// (the near-black background) -- the window comes up blank like the
+	// hardware did.
+	//
+	if (pixelBuffer != NULL && pixelBuffer->Data.MapPointer != NULL)
+		memset(pixelBuffer->Data.MapPointer, 0, plasmaWidth * plasmaHeight);
+
 	DEBUG_STREAM << "[plasmawin] desktop plasma display up (scale x"
 		<< scale << ")\n" << std::flush;
 }

engine/MUNGA_L4/L4VB16.cpp

@@ -5445,7 +5445,6 @@ SVGA16::SVGA16(
    BuildWindows(init_width,init_height,windowed, secondaryIndex, aux1Index, aux2Index);
 	for (int _i = 0; _i < 10; _i++)	// DEV-COMPOSITE: lazily created on first surface draw
 		mDevSurfaceTex[_i] = NULL;
-	paletteGeneration = 0;			// GLASS dirty-skip palette tracking
 //STUBBED: VIDEO RB 1/15/07
 #	if defined(DEBUG)
 		Tell("SVGA16::SVGA16()\n");
@@ -7191,7 +7190,6 @@ void
 
 	svga_palette->paletteData.Valid = True;
 	svga_palette->modified = True;
-	((SVGA16 *) graphicsDisplay)->paletteGeneration++;	// glass dirty-skip (full rebuild)
 
 	Check_Fpu();
 }
@@ -7236,13 +7234,6 @@ void
 	SVGA16Palette
 		*svga_palette(&((SVGA16 *) graphicsDisplay)->palette[paletteID]);
 
-	// GLASS dirty-skip: track whether this write CHANGES anything -- the
-	// ColorMapper family calls this every Execute (the adpal/adpal2 flash
-	// alternates palettes even at zero damage, usually writing identical RGB),
-	// so bump the generation only on a real change or every glass window that
-	// palette-expands would repaint every pump for nothing.
-	int palette_changed = 0;
-
 	//-------------------------------------------
 	// If any of the ...TransparentZero modes are used,
 	// leave color zero undefined for this bit group by
@@ -7284,31 +7275,21 @@ void
 					{
 					case RedChannel:
 					case RedChannelTransparentZero:
-						if (destination_triplet->Red != source_triplet->Red)
-							palette_changed = 1;
 						destination_triplet->Red = source_triplet->Red;
 						break;
 
 					case GreenChannel:
 					case GreenChannelTransparentZero:
-						if (destination_triplet->Green != source_triplet->Green)
-							palette_changed = 1;
 						destination_triplet->Green = source_triplet->Green;
 						break;
 
 					case BlueChannel:
 					case BlueChannelTransparentZero:
-						if (destination_triplet->Blue != source_triplet->Blue)
-							palette_changed = 1;
 						destination_triplet->Blue = source_triplet->Blue;
 						break;
 
 					case AllChannels:
 					case AllChannelsTransparentZero:
-						if (destination_triplet->Red   != source_triplet->Red
-						 || destination_triplet->Green != source_triplet->Green
-						 || destination_triplet->Blue  != source_triplet->Blue)
-							palette_changed = 1;
 						*destination_triplet = *source_triplet;
 						break;
 					}
@@ -7329,8 +7310,6 @@ void
 
 	svga_palette->paletteData.Valid = True;
 	svga_palette->modified = True;
-	if (palette_changed)
-		((SVGA16 *) graphicsDisplay)->paletteGeneration++;	// glass dirty-skip
 
 	Check_Fpu();
 }
@@ -7434,7 +7413,6 @@ void
 
 	svga_palette->paletteData.Valid = True;
 	svga_palette->modified = True;
-	((SVGA16 *) graphicsDisplay)->paletteGeneration++;	// glass dirty-skip (full rebuild)
 
 #	if defined(TESTPALETTE)
 		std::cout << "L4GraphicsPort::BuildAuxiliaryPalette for port " <<
@@ -7545,7 +7523,6 @@ void
 
 	svga_palette->paletteData.Valid = True;
 	svga_palette->modified = True;
-	((SVGA16 *) graphicsDisplay)->paletteGeneration++;	// glass dirty-skip (full rebuild)
 
 	Check_Fpu();
 }

engine/MUNGA_L4/L4VB16.h

@@ -382,15 +382,6 @@ protected:
 	SVGA16Palette
 		palette[PaletteCount];
 
-	// GLASS dirty-skip (2026-08-10): bumped by the palette writers
-	// (L4GraphicsPort::BuildSecondaryColor on a REAL entry change; the full
-	// palette rebuilds unconditionally) so the glass repaint token can see
-	// palette-only animation -- the ColorMapper family (armor rosette tints,
-	// damage flash) changes COLORS with zero pixel writes, which the pixel
-	// checksum alone can never catch.
-	unsigned long
-		paletteGeneration;
-
 private:
 	int NUMGAUGEWINDOWS;
    HWND *gaugeWindows;
@@ -434,11 +425,6 @@ public:
 	// glass repaint pump re-blit ONLY the windows whose plane actually changed
 	// (idle MFDs / static panels skip; the sweeping radar keeps updating).
 	unsigned long PlaneChecksum(int mask) const;
-
-	// GLASS dirty-skip: the palette write generation (see paletteGeneration).
-	// Folded into the repaint token of palette-expanding windows so ColorMapper
-	// palette animation (armor tints / damage flash) repaints without pixel churn.
-	unsigned long PaletteGeneration() const { return paletteGeneration; }
 };
 
 //########################################################################