Added _ScaledScreenParams shader property to access camera size scaled by render scale.

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightConstantBuffer.cs

         public static int _AdditionalLightDistanceAttenuation;
         public static int _AdditionalLightSpotDir;
         public static int _AdditionalLightSpotAttenuation;
+
+        public static int _ScaledScreenParams;
     }
 
     public static class ShadowConstantBuffer

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightPipeline.cs

             PerCameraBuffer._AdditionalLightDistanceAttenuation = Shader.PropertyToID("_AdditionalLightDistanceAttenuation");
             PerCameraBuffer._AdditionalLightSpotDir = Shader.PropertyToID("_AdditionalLightSpotDir");
             PerCameraBuffer._AdditionalLightSpotAttenuation = Shader.PropertyToID("_AdditionalLightSpotAttenuation");
+            PerCameraBuffer._ScaledScreenParams = Shader.PropertyToID("_ScaledScreenParams");
 
             ShadowConstantBuffer._WorldToShadow = Shader.PropertyToID("_WorldToShadow");
             ShadowConstantBuffer._ShadowData = Shader.PropertyToID("_ShadowData");
             Array.Sort(cameras, m_CameraComparer);
             foreach (Camera camera in cameras)
             {
-                RenderPipeline.BeginCameraRendering(camera);
-
                 bool sceneViewCamera = m_CurrCamera.cameraType == CameraType.SceneView;
                 bool stereoEnabled = IsStereoEnabled(m_CurrCamera);
 
+
+                SetupPerCameraShaderConstants();
+                RenderPipeline.BeginCameraRendering(m_CurrCamera);
 
                 var cmd = CommandBufferPool.Get("");
                 cmd.BeginSample("LightweightPipeline.Render");
             else
                 baseDesc = new RenderTextureDescriptor(m_CurrCamera.pixelWidth, m_CurrCamera.pixelHeight);
 
-            float renderScale = GetRenderScale();
-            baseDesc.width = (int)((float)baseDesc.width * renderScale);
-            baseDesc.height = (int)((float)baseDesc.height * renderScale);
+            baseDesc.width = (int)GetScaledCameraWidth(m_CurrCamera);
+            baseDesc.height = (int)GetScaledCameraHeight(m_CurrCamera);
 
             if (m_RequireDepthTexture)
             {
             Shader.SetGlobalVector(PerFrameBuffer._SubtractiveShadowColor, CoreUtils.ConvertSRGBToActiveColorSpace(RenderSettings.subtractiveShadowColor));
         }
 
+        private void SetupPerCameraShaderConstants()
+        {
+            float cameraWidth = GetScaledCameraWidth(m_CurrCamera);
+            float cameraHeight = GetScaledCameraHeight(m_CurrCamera);
+            Shader.SetGlobalVector(PerCameraBuffer._ScaledScreenParams, new Vector4(cameraWidth, cameraHeight, 1.0f + 1.0f / cameraWidth, 1.0f + 1.0f / cameraHeight));
+        }
+
         private void SetupShaderLightConstants(CommandBuffer cmd, List<VisibleLight> lights, ref LightData lightData)
         {
             // Main light has an optimized shader path for main light. This will benefit games that only care about a single light.
         private float GetRenderScale()
         {
             return m_RenderScale;
+        }
+
+        private float GetScaledCameraWidth(Camera camera)
+        {
+            return (float) camera.pixelWidth * GetRenderScale();
+        }
+
+        private float GetScaledCameraHeight(Camera camera)
+        {
+            return (float) camera.pixelHeight * GetRenderScale();
         }
 
         private RendererConfiguration GetRendererSettings(ref LightData lightData)

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/Core.hlsl

     #define UNITY_Z_0_FAR_FROM_CLIPSPACE(coord) (coord)
 #endif
 
+float4 GetScaledScreenParams()
+{
+    return _ScaledScreenParams;
+}
+
 void AlphaDiscard(half alpha, half cutoff, half offset = 0.0h)
 {
 #ifdef _ALPHATEST_ON

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/Input.hlsl

 half4 _AdditionalLightDistanceAttenuation[MAX_VISIBLE_LIGHTS];
 half4 _AdditionalLightSpotDir[MAX_VISIBLE_LIGHTS];
 half4 _AdditionalLightSpotAttenuation[MAX_VISIBLE_LIGHTS];
+
+float4 _ScaledScreenParams;
 CBUFFER_END
 
 #define UNITY_MATRIX_M     unity_ObjectToWorld