Enable stereo RenderTexture paths

HDCamera manages the main descriptor, so make sure we create it correctly.
The pyramids need a bit of tweaking as well.

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Camera/HDCamera.cs

             Reset();
         }
 
-        public void Update(PostProcessLayer postProcessLayer)
+        public void Update(PostProcessLayer postProcessLayer, bool stereoEnabled)
         {
             // If TAA is enabled projMatrix will hold a jittered projection matrix. The original,
             // non-jittered projection matrix can be accessed via nonJitteredProjMatrix.
             m_LastFrameActive = Time.frameCount;
 
             RenderTextureDescriptor tempDesc;
-            if (false) // pass in FrameSettings.enablestereo
+            if (stereoEnabled)
             {
                 screenSize = new Vector4(XRSettings.eyeTextureWidth, XRSettings.eyeTextureHeight, 1.0f / XRSettings.eyeTextureWidth, 1.0f / XRSettings.eyeTextureHeight);
                 tempDesc = XRSettings.eyeTextureDesc;
         }
 
         // Grab the HDCamera tied to a given Camera and update it.
-        public static HDCamera Get(Camera camera, PostProcessLayer postProcessLayer)
+        public static HDCamera Get(Camera camera, PostProcessLayer postProcessLayer, bool stereoEnabled)
         {
             HDCamera hdcam;
 
                 s_Cameras.Add(camera, hdcam);
             }
 
-            hdcam.Update(postProcessLayer);
+            hdcam.Update(postProcessLayer, stereoEnabled);
             return hdcam;
         }
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipeline.cs

                     }
 
                     var postProcessLayer = camera.GetComponent<PostProcessLayer>();
-                    var hdCamera = HDCamera.Get(camera, postProcessLayer);
+                    var hdCamera = HDCamera.Get(camera, postProcessLayer, m_FrameSettings.enableStereo);
 
                     Resize(hdCamera);
 
                     }
                     ConfigureForShadowMask(enableBakeShadowMask, cmd);
 
-	                InitAndClearBuffer(hdCamera, enableBakeShadowMask, cmd);
+	                InitAndClearBuffer(hdCamera, enableBakeShadowMask, cmd, m_FrameSettings.enableStereo);
 
                     RenderDepthPrepass(m_CullResults, hdCamera, renderContext, cmd);
 
             }
         }
 
-        void InitAndClearBuffer(HDCamera hdCamera, bool enableBakeShadowMask, CommandBuffer cmd)
+        void InitAndClearBuffer(HDCamera hdCamera, bool enableBakeShadowMask, CommandBuffer cmd, bool stereoEnabled)
         {
             using (new ProfilingSample(cmd, "InitAndClearBuffer", GetSampler(CustomSamplerId.InitAndClearBuffer)))
             {
 
 
                     // Color and depth pyramids
-                    m_GaussianPyramidColorBufferDesc = BuildPyramidDescriptor(hdCamera, PyramidType.Color);
+                    m_GaussianPyramidColorBufferDesc = BuildPyramidDescriptor(hdCamera, PyramidType.Color, stereoEnabled);
-                    m_DepthPyramidBufferDesc = BuildPyramidDescriptor(hdCamera, PyramidType.Depth);
+                    m_DepthPyramidBufferDesc = BuildPyramidDescriptor(hdCamera, PyramidType.Depth, stereoEnabled);
 
                     cmd.ReleaseTemporaryRT(m_DepthPyramidBuffer);
                     cmd.GetTemporaryRT(m_DepthPyramidBuffer, m_DepthPyramidBufferDesc, FilterMode.Trilinear);
             Depth = 1
         }
 
-        static RenderTextureDescriptor BuildPyramidDescriptor(HDCamera hdCamera, PyramidType pyramidType )
+        static RenderTextureDescriptor BuildPyramidDescriptor(HDCamera hdCamera, PyramidType pyramidType, bool stereoEnabled)
         {
             var desc = hdCamera.renderTextureDesc;
             desc.colorFormat = (pyramidType == PyramidType.Color) ? RenderTextureFormat.ARGBHalf : RenderTextureFormat.RFloat;
 
             var pyramidSize = CalculatePyramidSize((int)hdCamera.screenSize.x, (int)hdCamera.screenSize.y);
+
-            // Gotta plug-in proper stereo bits from frame settings?
-            if (false /*hdCamera.stereoEnabled*/ && (desc.dimension != TextureDimension.Tex2DArray))
+            if (stereoEnabled && (desc.dimension != TextureDimension.Tex2DArray))
                 widthModifier = 2; // double-wide
 
             desc.width = pyramidSize * widthModifier;