From 00c8c6e3b224152693ea784c353cc1619625bc33 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Thu, 16 Aug 2018 00:08:19 +0200
Subject: [PATCH] - generate vertices for skybox sectors in the processing
 pass.

Aside from the sprites this was the only other remaining use of FQuadDrawer.
---
 src/gl/scene/gl_flats.cpp             | 23 ++++-------------------
 src/hwrenderer/scene/hw_drawstructs.h |  2 +-
 src/hwrenderer/scene/hw_flats.cpp     | 12 +++++++-----
 3 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index b75944a47..5499f1357 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -201,24 +201,6 @@ void FDrawInfo::ClearFloodStencil(int vindex)
 	gl_RenderState.SetEffect(EFF_NONE);
 }
 
-//==========================================================================
-//
-//
-//
-//==========================================================================
-
-void FDrawInfo::DrawSkyboxSector(GLFlat *flat, int pass)
-{
-	FQuadDrawer qd;
-	flat->CreateSkyboxVertices(qd.Pointer());
-	gl_RenderState.ApplyLightIndex(flat->dynlightindex);
-	qd.Render(GL_TRIANGLE_FAN);
-
-	flatvertices += 4;
-	flatprimitives++;
-}
-
-
 //==========================================================================
 //
 //
@@ -248,7 +230,10 @@ void FDrawInfo::DrawFlat(GLFlat *flat, int pass, bool trans)	// trans only has m
 		else
 		{
 			gl_RenderState.SetMaterial(flat->gltexture, CLAMP_XY, 0, -1, false);
-			DrawSkyboxSector(flat, pass);
+			gl_RenderState.ApplyLightIndex(flat->dynlightindex);
+			glDrawArrays(GL_TRIANGLE_FAN, flat->iboindex, 4);
+			flatvertices += 4;
+			flatprimitives++;
 		}
 		gl_RenderState.SetObjectColor(0xffffffff);
 		break;
diff --git a/src/hwrenderer/scene/hw_drawstructs.h b/src/hwrenderer/scene/hw_drawstructs.h
index c84f8c179..069a5b1cd 100644
--- a/src/hwrenderer/scene/hw_drawstructs.h
+++ b/src/hwrenderer/scene/hw_drawstructs.h
@@ -295,7 +295,6 @@ class GLFlat
 {
 public:
 	sector_t * sector;
-	float dz; // z offset for rendering hacks
 	float z; // the z position of the flat (only valid for non-sloped planes)
 	FMaterial *gltexture;
 
@@ -351,6 +350,7 @@ public:
 	uint8_t foglevel;
 	uint8_t hw_styleflags;
 	bool fullbright;
+	bool polyoffset;
 	PalEntry ThingColor;	// thing's own color
 	FColormap Colormap;
 	FSpriteModelFrame * modelframe;
diff --git a/src/hwrenderer/scene/hw_flats.cpp b/src/hwrenderer/scene/hw_flats.cpp
index e63f3e74c..6c28d5636 100644
--- a/src/hwrenderer/scene/hw_flats.cpp
+++ b/src/hwrenderer/scene/hw_flats.cpp
@@ -118,7 +118,6 @@ void GLFlat::CreateSkyboxVertices(FFlatVertex *vert)
 		if (y > maxy) maxy = y;
 	}
 
-	float z = plane.plane.ZatPoint(0., 0.) + dz;
 	static float uvals[] = { 0, 0, 1, 1 };
 	static float vvals[] = { 1, 0, 0, 1 };
 	int rot = -xs_FloorToInt(plane.Angle / 90.f);
@@ -231,11 +230,14 @@ void GLFlat::Process(HWDrawInfo *di, sector_t * model, int whichplane, bool fog)
 		lightlevel = abs(lightlevel);
 	}
 
-	// get height from vplane
-	if (whichplane == sector_t::floor && sector->transdoor) dz = -1;
-	else dz = 0;
-
 	z = plane.plane.ZatPoint(0.f, 0.f);
+	if (sector->special == GLSector_Skybox)
+	{
+		auto vert = di->AllocVertices(4);
+		CreateSkyboxVertices(vert.first);
+		iboindex = vert.second;
+	}
+
 	
 	PutFlat(di, fog);
 	rendered_flats++;