From 6b92b95068b871d06a9bd8846278764894b677ba Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Mon, 18 Jun 2018 18:41:59 +0200
Subject: [PATCH] - moved vertex creation for skybox sector to backend
 independent code.

---
 src/gl/renderer/gl_quaddrawer.h       |  4 +++
 src/gl/scene/gl_flats.cpp             | 36 ++-------------------
 src/hwrenderer/scene/hw_drawstructs.h |  1 +
 src/hwrenderer/scene/hw_flats.cpp     | 45 ++++++++++++++++++++++++++-
 4 files changed, 51 insertions(+), 35 deletions(-)

diff --git a/src/gl/renderer/gl_quaddrawer.h b/src/gl/renderer/gl_quaddrawer.h
index b9db606847..c4776ecae0 100644
--- a/src/gl/renderer/gl_quaddrawer.h
+++ b/src/gl/renderer/gl_quaddrawer.h
@@ -23,6 +23,10 @@ public:
 			p = GLRenderer->mVBO->Alloc(4, &ndx);
 		}
 	}
+	FFlatVertex *Pointer()
+	{
+		return p;
+	}
 	void Set(int ndx, float x, float y, float z, float s, float t)
 	{
 		p[ndx].Set(x, y, z, s, t);
diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index 4e32ec299d..6438593f75 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -279,46 +279,14 @@ void FDrawInfo::DrawSubsectors(GLFlat *flat, int pass, bool processlights, bool
 
 //==========================================================================
 //
-// special handling for skyboxes which need texture clamping.
-// This will find the bounding rectangle of the sector and just
-// draw one single polygon filling that rectangle with a clamped
-// texture.
+//
 //
 //==========================================================================
 
 void FDrawInfo::DrawSkyboxSector(GLFlat *flat, int pass, bool processlights)
 {
-
-	float minx = FLT_MAX, miny = FLT_MAX;
-	float maxx = -FLT_MAX, maxy = -FLT_MAX;
-
-	for (auto ln : flat->sector->Lines)
-	{
-		float x = ln->v1->fX();
-		float y = ln->v1->fY();
-		if (x < minx) minx = x;
-		if (y < miny) miny = y;
-		if (x > maxx) maxx = x;
-		if (y > maxy) maxy = y;
-		x = ln->v2->fX();
-		y = ln->v2->fY();
-		if (x < minx) minx = x;
-		if (y < miny) miny = y;
-		if (x > maxx) maxx = x;
-		if (y > maxy) maxy = y;
-	}
-
-	float z = flat->plane.plane.ZatPoint(0., 0.) + flat->dz;
-	static float uvals[] = { 0, 0, 1, 1 };
-	static float vvals[] = { 1, 0, 0, 1 };
-	int rot = -xs_FloorToInt(flat->plane.Angle / 90.f);
-
 	FQuadDrawer qd;
-
-	qd.Set(0, minx, z, miny, uvals[rot & 3], vvals[rot & 3]);
-	qd.Set(1, minx, z, maxy, uvals[(rot + 1) & 3], vvals[(rot + 1) & 3]);
-	qd.Set(2, maxx, z, maxy, uvals[(rot + 2) & 3], vvals[(rot + 2) & 3]);
-	qd.Set(3, maxx, z, miny, uvals[(rot + 3) & 3], vvals[(rot + 3) & 3]);
+	flat->CreateSkyboxVertices(qd.Pointer());
 	qd.Render(GL_TRIANGLE_FAN);
 
 	flatvertices += 4;
diff --git a/src/hwrenderer/scene/hw_drawstructs.h b/src/hwrenderer/scene/hw_drawstructs.h
index 8dcc4632aa..56e744b006 100644
--- a/src/hwrenderer/scene/hw_drawstructs.h
+++ b/src/hwrenderer/scene/hw_drawstructs.h
@@ -314,6 +314,7 @@ public:
 
 	int dynlightindex;
 
+	void CreateSkyboxVertices(FFlatVertex *buffer);
 	bool SetupLights(int pass, FLightNode *head, FDynLightData &lightdata, int portalgroup);
 	bool SetupSubsectorLights(int pass, subsector_t * sub, FDynLightData &lightdata);
 	bool SetupSectorLights(int pass, sector_t * sec, FDynLightData &lightdata);
diff --git a/src/hwrenderer/scene/hw_flats.cpp b/src/hwrenderer/scene/hw_flats.cpp
index 25574fbd3d..adcedbd1df 100644
--- a/src/hwrenderer/scene/hw_flats.cpp
+++ b/src/hwrenderer/scene/hw_flats.cpp
@@ -41,6 +41,7 @@
 #include "hwrenderer/utility/hw_lighting.h"
 #include "hwrenderer/textures/hw_material.h"
 #include "hwrenderer/scene/hw_drawinfo.h"
+#include "hwrenderer/data/flatvertices.h"
 #include "hw_drawstructs.h"
 
 #ifdef _DEBUG
@@ -86,9 +87,51 @@ bool hw_SetPlaneTextureRotation(const GLSectorPlane * secplane, FMaterial * glte
 	return false;
 }
 
+
 //==========================================================================
 //
-// Flats 
+// special handling for skyboxes which need texture clamping.
+// This will find the bounding rectangle of the sector and just
+// draw one single polygon filling that rectangle with a clamped
+// texture.
+//
+//==========================================================================
+
+void GLFlat::CreateSkyboxVertices(FFlatVertex *vert)
+{
+	float minx = FLT_MAX, miny = FLT_MAX;
+	float maxx = -FLT_MAX, maxy = -FLT_MAX;
+
+	for (auto ln : sector->Lines)
+	{
+		float x = ln->v1->fX();
+		float y = ln->v1->fY();
+		if (x < minx) minx = x;
+		if (y < miny) miny = y;
+		if (x > maxx) maxx = x;
+		if (y > maxy) maxy = y;
+		x = ln->v2->fX();
+		y = ln->v2->fY();
+		if (x < minx) minx = x;
+		if (y < miny) miny = y;
+		if (x > maxx) maxx = x;
+		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);
+
+	vert[0].Set(minx, z, miny, uvals[rot & 3], vvals[rot & 3]);
+	vert[1].Set(minx, z, maxy, uvals[(rot + 1) & 3], vvals[(rot + 1) & 3]);
+	vert[2].Set(maxx, z, maxy, uvals[(rot + 2) & 3], vvals[(rot + 2) & 3]);
+	vert[3].Set(maxx, z, miny, uvals[(rot + 3) & 3], vvals[(rot + 3) & 3]);
+}
+
+//==========================================================================
+//
+//
 //
 //==========================================================================