From 1345c8e7b43f4828b39da5555c7c43be40f85359 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sun, 29 Apr 2018 19:28:13 +0200
Subject: [PATCH] - fixed: NewDecal should not be called unless it is
 guaranteed that the decal will be rendered.

This left partially initialized items in the render list.
---
 src/hwrenderer/scene/hw_decal.cpp | 58 ++++++++++++++++---------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/src/hwrenderer/scene/hw_decal.cpp b/src/hwrenderer/scene/hw_decal.cpp
index 3dd2972c8f..423d112764 100644
--- a/src/hwrenderer/scene/hw_decal.cpp
+++ b/src/hwrenderer/scene/hw_decal.cpp
@@ -112,34 +112,9 @@ void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 				zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
 			}
 	}
+	FMaterial *tex = FMaterial::ValidateTexture(texture, true);
 
-	GLDecal &gldecal = *di->AddDecal(type == RENDERWALL_MIRRORSURFACE);
-	gldecal.gltexture = FMaterial::ValidateTexture(texture, true);
-	gldecal.wall = this;
-	gldecal.decal = decal;
-	
-	if (decal->RenderFlags & RF_FULLBRIGHT)
-	{
-		gldecal.light = 255;
-		gldecal.rel = 0;
-	}
-	else
-	{
-		gldecal.light = lightlevel;
-		gldecal.rel = rellight + getExtraLight();
-	}
-	
-	gldecal.colormap = Colormap;
-	
-	if (level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING)
-	{
-		gldecal.colormap.Decolorize();
-	}
-	
-	gldecal.a = decal->Alpha;
-	
 	// now clip the decal to the actual polygon
-	FMaterial *tex = gldecal.gltexture;
 
 	float decalwidth = tex->TextureWidth()  * decal->ScaleX;
 	float decalheight = tex->TextureHeight() * decal->ScaleY;
@@ -178,13 +153,15 @@ void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 		right = decalpixpos + decalwidth;
 		righttex = decalwidth;
 	}
-	if (right <= left) return;	// nothing to draw
+	if (right <= left) 
+		return;	// nothing to draw
 	
+
 	// one texture unit on the wall as vector
 	float vx = (glseg.x2 - glseg.x1) / linelength;
 	float vy = (glseg.y2 - glseg.y1) / linelength;
 	
-	DecalVertex *dv = gldecal.dv;
+	DecalVertex dv[4];
 	dv[1].x = dv[0].x = glseg.x1 + vx * left;
 	dv[1].y = dv[0].y = glseg.y1 + vy * left;
 	
@@ -251,7 +228,32 @@ void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 		for (i = 0; i < 4; i++) dv[i].v = vb - dv[i].v;
 	}
 
+	GLDecal &gldecal = *di->AddDecal(type == RENDERWALL_MIRRORSURFACE);
+	gldecal.gltexture = tex;
+	gldecal.wall = this;
+	gldecal.decal = decal;
+
+	if (decal->RenderFlags & RF_FULLBRIGHT)
+	{
+		gldecal.light = 255;
+		gldecal.rel = 0;
+	}
+	else
+	{
+		gldecal.light = lightlevel;
+		gldecal.rel = rellight + getExtraLight();
+	}
+
+	gldecal.colormap = Colormap;
+
+	if (level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING)
+	{
+		gldecal.colormap.Decolorize();
+	}
+
+	gldecal.a = decal->Alpha;
 	gldecal.zcenter = zpos - decalheight * 0.5f;
+	memcpy(gldecal.dv, dv, sizeof(dv));
 	
 	auto verts = di->AllocVertices(4);
 	gldecal.vertindex = verts.second;