From 650b5aae88099f533fa26ac096273da7c1f0cb4f Mon Sep 17 00:00:00 2001
From: sphere <spherallic@gmail.com>
Date: Sun, 24 Oct 2021 22:33:25 +0200
Subject: [PATCH] Visual Mode: correct-enough slope skewing on FOF sides, with
 thanks to Monster Iestyn!

---
 Source/Core/Windows/AboutForm.Designer.cs     |  2 +-
 .../VisualModes/VisualMiddle3D.cs             | 49 +++++--------------
 2 files changed, 12 insertions(+), 39 deletions(-)

diff --git a/Source/Core/Windows/AboutForm.Designer.cs b/Source/Core/Windows/AboutForm.Designer.cs
index da4e577..e5aac4b 100644
--- a/Source/Core/Windows/AboutForm.Designer.cs
+++ b/Source/Core/Windows/AboutForm.Designer.cs
@@ -197,7 +197,7 @@ namespace CodeImp.DoomBuilder.Windows
 			this.label2.Size = new System.Drawing.Size(262, 65);
 			this.label2.TabIndex = 16;
 			this.label2.Text = "developed by: \r\nMascaraSnake, toaster, sphere\r\n\r\n" +
-	"With contributions from:\r\nJustburner, boris, ZZYZX";
+	"With contributions from:\r\nJustburner, Monster Iestyn, boris, ZZYZX";
 			// 
 			// version
 			// 
diff --git a/Source/Plugins/BuilderModes/VisualModes/VisualMiddle3D.cs b/Source/Plugins/BuilderModes/VisualModes/VisualMiddle3D.cs
index 8175bc0..ffd963f 100644
--- a/Source/Plugins/BuilderModes/VisualModes/VisualMiddle3D.cs
+++ b/Source/Plugins/BuilderModes/VisualModes/VisualMiddle3D.cs
@@ -167,44 +167,17 @@ namespace CodeImp.DoomBuilder.BuilderModes
 
 			float topheight = skew ? extrafloor.Ceiling.plane.GetZ(vl) : sourcetopheight;
 			float bottomheight = skew ? extrafloor.Floor.plane.GetZ(vl) : sourcebottomheight;
-			float floorbias = (topheight == bottomheight) ? 1.0f : 0.0f;
+			float topheight2 = skew ? extrafloor.Ceiling.plane.GetZ(vr) : sourcetopheight;
+			float bottomheight2 = skew ? extrafloor.Floor.plane.GetZ(vr) : sourcebottomheight;
+			//float floorbias = (topheight == bottomheight) ? 1.0f : 0.0f;
+			//float floorbias2 = (topheight2 == bottomheight2) ? 1.0f : 0.0f;
 
 			tlt.x = tlb.x = 0;
 			trt.x = trb.x = Sidedef.Line.Length;
-			tlt.y = trt.y = 0;
-			tlb.y = trb.y = (topheight - bottomheight) + floorbias;
-
-			float topheight2 = skew ? topheight : sourcetopheight;
-			float bottomheight2 = skew ? bottomheight : sourcebottomheight;
-
-			// Correct to account for slopes
-			if (General.Map.SRB2)
-			{
-				float slant;
-				float texturevpeg;
-
-				if (!skew)
-				{
-					slant = 0;
-					texturevpeg = 0;
-				}
-				else if (!IsLowerUnpegged())
-				{
-					slant = extrafloor.Floor.plane.GetZ(vr) - extrafloor.Floor.plane.GetZ(vl);
-					texturevpeg = (sourcetopheight - sourcebottomheight) % Math.Abs(tsz.y);
-				}
-				else
-				{
-					slant = extrafloor.Ceiling.plane.GetZ(vr) - extrafloor.Ceiling.plane.GetZ(vl);
-					texturevpeg = 0;
-				}
-
-				topheight2 = topheight + slant;
-				bottomheight2 = bottomheight + slant;
-
-				tlt.y = trt.y = texturevpeg;
-				tlb.y = trb.y = texturevpeg + (topheight - bottomheight) + floorbias;
-			}
+			tlt.y = IsLowerUnpegged() ? 0 : -(topheight - bottomheight);
+			trt.y = IsLowerUnpegged() ? 0 : -(topheight2 - bottomheight2);
+			tlb.y = !IsLowerUnpegged() ? 0 : (topheight - bottomheight);
+			trb.y = !IsLowerUnpegged() ? 0 : (topheight2 - bottomheight2);
 
 			// Apply texture offset
 			tlt += tof;
@@ -219,10 +192,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			trt /= tsz;
 
 			// Geometry coordinates
-			vlt = new Vector3D(vl.x, vl.y, topheight + floorbias);
-			vlb = new Vector3D(vl.x, vl.y, bottomheight + floorbias);
+			vlt = new Vector3D(vl.x, vl.y, topheight);
+			vlb = new Vector3D(vl.x, vl.y, bottomheight);
 			vrb = new Vector3D(vr.x, vr.y, bottomheight2);
-			vrt = new Vector3D(vr.x, vr.y, topheight2 + floorbias);
+			vrt = new Vector3D(vr.x, vr.y, topheight2);
 
 			TexturePlane tp = new TexturePlane();
 			tp.tlt = IsLowerUnpegged() ? tlb : tlt;