UPBGE: Avoid redundant state call to GL_CULL_FACE.

The function SetCullFace now use a state from RAS_Rasterizer to skip
unecessary opengl calls. Also the rendering of plane to screen is now
using the function SetFrontFace instead disabling and renabling the
face culling.

source/gameengine/Ketsji/KX_WorldInfo.cpp

@@ -215,14 +215,13 @@ void KX_WorldInfo::RenderBackground(RAS_Rasterizer *rasty)
 			GPU_material_bind(gpumat, m_scene->lay, 1.0f, false, rasty->GetViewMatrix().Data(),
 			                  rasty->GetViewInvMatrix().Data(), texcofac, false);
 
-			rasty->Disable(RAS_Rasterizer::RAS_CULL_FACE);
+			rasty->SetFrontFace(true);
 			rasty->Enable(RAS_Rasterizer::RAS_DEPTH_TEST);
 			rasty->SetDepthFunc(RAS_Rasterizer::RAS_ALWAYS);
 
 			rasty->DrawOverlayPlane();
 
 			rasty->SetDepthFunc(RAS_Rasterizer::RAS_LEQUAL);
-			rasty->Enable(RAS_Rasterizer::RAS_CULL_FACE);
 
 			GPU_material_unbind(gpumat);
 		}

source/gameengine/Rasterizer/RAS_2DFilterManager.cpp

@@ -88,7 +88,6 @@ RAS_OffScreen *RAS_2DFilterManager::RenderFilters(RAS_Rasterizer *rasty, RAS_ICa
 		return inputofs;
 	}
 
-	rasty->Disable(RAS_Rasterizer::RAS_CULL_FACE);
 	rasty->Disable(RAS_Rasterizer::RAS_DEPTH_TEST);
 	rasty->SetDepthMask(RAS_Rasterizer::RAS_DEPTHMASK_DISABLED);
 	rasty->Disable(RAS_Rasterizer::RAS_BLEND);
@@ -147,7 +146,6 @@ RAS_OffScreen *RAS_2DFilterManager::RenderFilters(RAS_Rasterizer *rasty, RAS_ICa
 
 	rasty->Enable(RAS_Rasterizer::RAS_DEPTH_TEST);
 	rasty->SetDepthMask(RAS_Rasterizer::RAS_DEPTHMASK_ENABLED);
-	rasty->Enable(RAS_Rasterizer::RAS_CULL_FACE);
 
 	return targetofs;
 }

source/gameengine/Rasterizer/RAS_Rasterizer.cpp

@@ -221,7 +221,8 @@ RAS_Rasterizer::RAS_Rasterizer()
 
 	InitOverrideShadersInterface();
 
-	m_state.frontFace = true;
+	m_state.frontFace = -1;
+	m_state.cullFace = -1;
 	m_state.polyOffset[0] = -1.0f;
 	m_state.polyOffset[1] = -1.0f;
 }
@@ -283,7 +284,7 @@ void RAS_Rasterizer::Init()
 
 void RAS_Rasterizer::Exit()
 {
-	Enable(RAS_CULL_FACE);
+	SetCullFace(true);
 	Enable(RAS_DEPTH_TEST);
 
 	SetClearDepth(1.0f);
@@ -313,7 +314,7 @@ void RAS_Rasterizer::BeginFrame(double time)
 	m_state.polyOffset[0] = -1.0f;
 	m_state.polyOffset[1] = -1.0f;
 
-	Enable(RAS_CULL_FACE);
+	SetCullFace(true);
 	Enable(RAS_DEPTH_TEST);
 
 	Disable(RAS_BLEND);
@@ -444,14 +445,13 @@ void RAS_Rasterizer::DrawOffScreen(RAS_ICanvas *canvas, RAS_OffScreen *offScreen
 	SetViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
 	SetScissor(viewport[0], viewport[1], viewport[2], viewport[3]);
 
-	Disable(RAS_CULL_FACE);
+	SetFrontFace(true);
 	SetDepthFunc(RAS_ALWAYS);
 
 	RAS_OffScreen::RestoreScreen();
 	DrawOffScreen(offScreen, nullptr);
 
 	SetDepthFunc(RAS_LEQUAL);
-	Enable(RAS_CULL_FACE);
 }
 
 void RAS_Rasterizer::DrawStereoOffScreen(RAS_ICanvas *canvas, RAS_OffScreen *leftOffScreen, RAS_OffScreen *rightOffScreen,
@@ -471,7 +471,7 @@ void RAS_Rasterizer::DrawStereoOffScreen(RAS_ICanvas *canvas, RAS_OffScreen *lef
 	SetViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
 	SetScissor(viewport[0], viewport[1], viewport[2], viewport[3]);
 
-	Disable(RAS_CULL_FACE);
+	SetFrontFace(true);
 	SetDepthFunc(RAS_ALWAYS);
 
 	RAS_OffScreen::RestoreScreen();
@@ -517,7 +517,6 @@ void RAS_Rasterizer::DrawStereoOffScreen(RAS_ICanvas *canvas, RAS_OffScreen *lef
 	}
 
 	SetDepthFunc(RAS_LEQUAL);
-	Enable(RAS_CULL_FACE);
 }
 
 RAS_Rect RAS_Rasterizer::GetRenderArea(RAS_ICanvas *canvas, StereoMode stereoMode, StereoEye eye)
@@ -863,6 +862,11 @@ bool RAS_Rasterizer::GetCameraOrtho()
 
 void RAS_Rasterizer::SetCullFace(bool enable)
 {
+	if (enable == m_state.cullFace) {
+		return;
+	}
+	m_state.cullFace = enable;
+
 	if (enable) {
 		Enable(RAS_CULL_FACE);
 	}
@@ -1386,7 +1390,7 @@ void RAS_Rasterizer::DisableForText()
 	SetAlphaBlend(GPU_BLEND_ALPHA);
 	SetLines(false); /* needed for texture fonts otherwise they render as wireframe */
 
-	Enable(RAS_CULL_FACE);
+	SetCullFace(true);
 
 	DisableLights();
 

source/gameengine/Rasterizer/RAS_Rasterizer.h

@@ -319,7 +319,8 @@ class RAS_Rasterizer : public mt::SimdClassAllocator
 
 	/// States to reduce OpenGL calls.
 	struct {
-		bool frontFace;
+		char frontFace;
+		char cullFace;
 		float polyOffset[2];
 	} m_state;