checkpoint(render): preserve pre-overhaul investigation state

src/AcDream.App/Rendering/PortalDepthMaskRenderer.cs

@@ -8,13 +8,12 @@ namespace AcDream.App.Rendering;
 /// writes — the port of <c>D3DPolyRender::DrawPortalPolyInternal</c>
 /// (Ghidra 0x0059bc90, pc:424490).
 ///
-/// <para><b>Wired by T1 (BR-3, `579c8b0`):</b> seal on interior roots, punch
-/// on outdoor / look-in roots, via <c>RetailPViewPassExecutor.DrawPortalDepthWrite</c>
-/// (the <c>DrawExitPortalMasks</c> slice callback) — safe alongside the
-/// dynamics-drawn-LAST frame order (the first BR-2 attempt punched after
-/// dynamics and erased the player; reverted 88be519). #117 (2026-06-11)
-/// added the two-pass stencil depth gate on the punch side — see
-/// <see cref="DrawDepthFan"/>.</para>
+/// <para>Campaign FW's ordered frame walk restores the positional discipline
+/// on which this primitive depends: farther landscape/static content is
+/// submitted before a building punch, the punch precedes that building's
+/// look-in cells, and nearer content repaints afterward. Consequently both
+/// sides now use retail's one-pass depth operation directly; the former
+/// stencil mark/bias approximation from #117 is intentionally gone.</para>
 ///
 /// <para>Retail projects a portal polygon, software-clips it against the
 /// installed portal view (<c>polyClipFinish</c>), and draws the survivor as a
@@ -78,49 +77,6 @@ public sealed partial class PortalDepthMaskRenderer : IDisposable
     }
 
     /// <summary>
-    /// #117 (2026-06-11): the mark-pass depth bias, in NDC, toward the
-    /// viewer. Retail's punch is DEPTHTEST_ALWAYS and is safe only because
-    /// retail's outdoor pass is painter's-ordered far→near (anything nearer
-    /// redraws AFTER the punch and re-covers it). Our z-buffered MDI frame
-    /// has no such order, so an unconditional far-Z punch erased the depth
-    /// of NEARER occluders (terrain hills, closer buildings) at aperture
-    /// pixels — doors/interiors painted through them (the T5 #117 report).
-    /// The z-buffer-correct equivalent: punch ONLY where the aperture
-    /// polygon itself wins a depth test at its true depth (two-pass
-    /// stencil below). The bias keeps the #108 case covered — terrain
-    /// hugging the door plane (centimeters in front of the aperture) must
-    /// still be punched; a hill or another house meters nearer must not.
-    /// </summary>
-    private const float PunchMarkDepthBias = 0.0005f;
-
-    /// <summary>
-    /// #129 (2026-06-12): NDC depth is non-linear — a constant NDC bias b
-    /// spans ≈ b·d²/near meters of eye depth at eye distance d. With
-    /// znear = 0.1, the 0.0005 constant alone spanned 0.125 m at 5 m but
-    /// ~190 m at a landblock away: every hill/house in front of a distant
-    /// aperture passed the mark and got far-Z punched — door-shaped leaks
-    /// through occluders. Fix: cap the bias's EYE-SPACE span at
-    /// <see cref="PunchMarkBiasEyeCapMeters"/>. Below the ~10 m crossover
-    /// (sqrt(cap·near/0.0005)) the constant-NDC term is smaller and wins —
-    /// bit-identical to the T5-validated close-range behavior (#108 grass
-    /// coverage untouched); beyond it the punch can never reach an occluder
-    /// more than the cap in front of the aperture plane.
-    /// </summary>
-    public const float PunchMarkBiasEyeCapMeters = 0.5f;
-
-    /// <summary>Retail <c>Render::znear</c> = 0.1 (decomp :342173, re-landed
-    /// d4b5c71). The cap conversion below assumes the production camera near
-    /// plane; the small f/(f−n) factor (~1.00002 at far 5000) is ignored.</summary>
-    public const float CameraNearPlaneMeters = 0.1f;
-
-    /// <summary>CPU mirror of the vertex-shader mark-bias expression (keep in
-    /// sync with <c>VertSrc</c>): the NDC bias applied at eye depth
-    /// <paramref name="eyeDepthMeters"/>.</summary>
-    public static float MarkBiasNdc(float eyeDepthMeters) =>
-        MathF.Min(PunchMarkDepthBias,
-            PunchMarkBiasEyeCapMeters * CameraNearPlaneMeters
-            / MathF.Max(eyeDepthMeters * eyeDepthMeters, 1e-6f));
-
     /// <summary>
     /// Draw one portal polygon as an invisible depth write, clipped to the
     /// slice's clip-space half-planes. <paramref name="forceFarZ"/> selects
@@ -130,13 +86,9 @@ public sealed partial class PortalDepthMaskRenderer : IDisposable
     /// depth ALWAYS + true projected depth. It runs immediately after the
     /// gated full depth clear, so there is no nearer content to stomp.</para>
     ///
-    /// <para><b>Punch</b> (outdoor root / look-in): two passes (#117).
-    /// Pass A marks stencil where the aperture fan passes a LEQUAL depth
-    /// test at its (biased) true depth — i.e. where the aperture is
-    /// actually visible against everything drawn so far. Pass B writes the
-    /// far-Z punch with depth ALWAYS but stencil-gated to the marked
-    /// pixels, and zeroes the stencil as it goes (self-cleaning). This is
-    /// the z-buffered equivalent of retail's painter's-order safety.</para>
+    /// <para><b>Punch</b> (outdoor root / look-in): one pass, retail-verbatim
+    /// — depth ALWAYS + far-Z. The ordered frame walk, not a visibility test
+    /// at the aperture plane, supplies retail's painter-order safety.</para>
     /// </summary>
     public void DrawDepthFan(
         ReadOnlySpan<Vector3> worldVerts,